comparison third_party/sqlite3/sqlite3.h @ 173:827c6ac504cd hg-web

Merged in default here.
author MrJuneJune <me@mrjunejune.com>
date Mon, 19 Jan 2026 18:59:10 -0800
parents 589bab390fb4
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1 /*
2 ** 2001-09-15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
17 **
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
23 **
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
27 **
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
32 */
33 #ifndef SQLITE3_H
34 #define SQLITE3_H
35 #include <stdarg.h> /* Needed for the definition of va_list */
36
37 /*
38 ** Make sure we can call this stuff from C++.
39 */
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43
44
45 /*
46 ** Facilitate override of interface linkage and calling conventions.
47 ** Be aware that these macros may not be used within this particular
48 ** translation of the amalgamation and its associated header file.
49 **
50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51 ** compiler that the target identifier should have external linkage.
52 **
53 ** The SQLITE_CDECL macro is used to set the calling convention for
54 ** public functions that accept a variable number of arguments.
55 **
56 ** The SQLITE_APICALL macro is used to set the calling convention for
57 ** public functions that accept a fixed number of arguments.
58 **
59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60 **
61 ** The SQLITE_CALLBACK macro is used to set the calling convention for
62 ** function pointers.
63 **
64 ** The SQLITE_SYSAPI macro is used to set the calling convention for
65 ** functions provided by the operating system.
66 **
67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68 ** SQLITE_SYSAPI macros are used only when building for environments
69 ** that require non-default calling conventions.
70 */
71 #ifndef SQLITE_EXTERN
72 # define SQLITE_EXTERN extern
73 #endif
74 #ifndef SQLITE_API
75 # define SQLITE_API
76 #endif
77 #ifndef SQLITE_CDECL
78 # define SQLITE_CDECL
79 #endif
80 #ifndef SQLITE_APICALL
81 # define SQLITE_APICALL
82 #endif
83 #ifndef SQLITE_STDCALL
84 # define SQLITE_STDCALL SQLITE_APICALL
85 #endif
86 #ifndef SQLITE_CALLBACK
87 # define SQLITE_CALLBACK
88 #endif
89 #ifndef SQLITE_SYSAPI
90 # define SQLITE_SYSAPI
91 #endif
92
93 /*
94 ** These no-op macros are used in front of interfaces to mark those
95 ** interfaces as either deprecated or experimental. New applications
96 ** should not use deprecated interfaces - they are supported for backwards
97 ** compatibility only. Application writers should be aware that
98 ** experimental interfaces are subject to change in point releases.
99 **
100 ** These macros used to resolve to various kinds of compiler magic that
101 ** would generate warning messages when they were used. But that
102 ** compiler magic ended up generating such a flurry of bug reports
103 ** that we have taken it all out and gone back to using simple
104 ** noop macros.
105 */
106 #define SQLITE_DEPRECATED
107 #define SQLITE_EXPERIMENTAL
108
109 /*
110 ** Ensure these symbols were not defined by some previous header file.
111 */
112 #ifdef SQLITE_VERSION
113 # undef SQLITE_VERSION
114 #endif
115 #ifdef SQLITE_VERSION_NUMBER
116 # undef SQLITE_VERSION_NUMBER
117 #endif
118
119 /*
120 ** CAPI3REF: Compile-Time Library Version Numbers
121 **
122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123 ** evaluates to a string literal that is the SQLite version in the
124 ** format "X.Y.Z" where X is the major version number (always 3 for
125 ** SQLite3) and Y is the minor version number and Z is the release number.)^
126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128 ** numbers used in [SQLITE_VERSION].)^
129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130 ** be larger than the release from which it is derived. Either Y will
131 ** be held constant and Z will be incremented or else Y will be incremented
132 ** and Z will be reset to zero.
133 **
134 ** Since [version 3.6.18] ([dateof:3.6.18]),
135 ** SQLite source code has been stored in the
136 ** <a href="http://fossil-scm.org/">Fossil configuration management
137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138 ** a string which identifies a particular check-in of SQLite
139 ** within its configuration management system. ^The SQLITE_SOURCE_ID
140 ** string contains the date and time of the check-in (UTC) and a SHA1
141 ** or SHA3-256 hash of the entire source tree. If the source code has
142 ** been edited in any way since it was last checked in, then the last
143 ** four hexadecimal digits of the hash may be modified.
144 **
145 ** See also: [sqlite3_libversion()],
146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147 ** [sqlite_version()] and [sqlite_source_id()].
148 */
149 #define SQLITE_VERSION "3.51.2"
150 #define SQLITE_VERSION_NUMBER 3051002
151 #define SQLITE_SOURCE_ID "2026-01-09 17:27:48 b270f8339eb13b504d0b2ba154ebca966b7dde08e40c3ed7d559749818cb2075"
152 #define SQLITE_SCM_BRANCH "branch-3.51"
153 #define SQLITE_SCM_TAGS "release version-3.51.2"
154 #define SQLITE_SCM_DATETIME "2026-01-09T17:27:48.405Z"
155
156 /*
157 ** CAPI3REF: Run-Time Library Version Numbers
158 ** KEYWORDS: sqlite3_version sqlite3_sourceid
159 **
160 ** These interfaces provide the same information as the [SQLITE_VERSION],
161 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
162 ** but are associated with the library instead of the header file. ^(Cautious
163 ** programmers might include assert() statements in their application to
164 ** verify that values returned by these interfaces match the macros in
165 ** the header, and thus ensure that the application is
166 ** compiled with matching library and header files.
167 **
168 ** <blockquote><pre>
169 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
170 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
171 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
172 ** </pre></blockquote>)^
173 **
174 ** ^The sqlite3_version[] string constant contains the text of the
175 ** [SQLITE_VERSION] macro. ^The sqlite3_libversion() function returns a
176 ** pointer to the sqlite3_version[] string constant. The sqlite3_libversion()
177 ** function is provided for use in DLLs since DLL users usually do not have
178 ** direct access to string constants within the DLL. ^The
179 ** sqlite3_libversion_number() function returns an integer equal to
180 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
181 ** a pointer to a string constant whose value is the same as the
182 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
183 ** using an edited copy of [the amalgamation], then the last four characters
184 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
185 **
186 ** See also: [sqlite_version()] and [sqlite_source_id()].
187 */
188 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
189 SQLITE_API const char *sqlite3_libversion(void);
190 SQLITE_API const char *sqlite3_sourceid(void);
191 SQLITE_API int sqlite3_libversion_number(void);
192
193 /*
194 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
195 **
196 ** ^The sqlite3_compileoption_used() function returns 0 or 1
197 ** indicating whether the specified option was defined at
198 ** compile time. ^The SQLITE_ prefix may be omitted from the
199 ** option name passed to sqlite3_compileoption_used().
200 **
201 ** ^The sqlite3_compileoption_get() function allows iterating
202 ** over the list of options that were defined at compile time by
203 ** returning the N-th compile time option string. ^If N is out of range,
204 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
205 ** prefix is omitted from any strings returned by
206 ** sqlite3_compileoption_get().
207 **
208 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
209 ** and sqlite3_compileoption_get() may be omitted by specifying the
210 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
211 **
212 ** See also: SQL functions [sqlite_compileoption_used()] and
213 ** [sqlite_compileoption_get()] and the [compile_options pragma].
214 */
215 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
216 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
217 SQLITE_API const char *sqlite3_compileoption_get(int N);
218 #else
219 # define sqlite3_compileoption_used(X) 0
220 # define sqlite3_compileoption_get(X) ((void*)0)
221 #endif
222
223 /*
224 ** CAPI3REF: Test To See If The Library Is Threadsafe
225 **
226 ** ^The sqlite3_threadsafe() function returns zero if and only if
227 ** SQLite was compiled with mutexing code omitted due to the
228 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
229 **
230 ** SQLite can be compiled with or without mutexes. When
231 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
232 ** are enabled and SQLite is threadsafe. When the
233 ** [SQLITE_THREADSAFE] macro is 0,
234 ** the mutexes are omitted. Without the mutexes, it is not safe
235 ** to use SQLite concurrently from more than one thread.
236 **
237 ** Enabling mutexes incurs a measurable performance penalty.
238 ** So if speed is of utmost importance, it makes sense to disable
239 ** the mutexes. But for maximum safety, mutexes should be enabled.
240 ** ^The default behavior is for mutexes to be enabled.
241 **
242 ** This interface can be used by an application to make sure that the
243 ** version of SQLite that it is linking against was compiled with
244 ** the desired setting of the [SQLITE_THREADSAFE] macro.
245 **
246 ** This interface only reports on the compile-time mutex setting
247 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
248 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
249 ** can be fully or partially disabled using a call to [sqlite3_config()]
250 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
251 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
252 ** sqlite3_threadsafe() function shows only the compile-time setting of
253 ** thread safety, not any run-time changes to that setting made by
254 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
255 ** is unchanged by calls to sqlite3_config().)^
256 **
257 ** See the [threading mode] documentation for additional information.
258 */
259 SQLITE_API int sqlite3_threadsafe(void);
260
261 /*
262 ** CAPI3REF: Database Connection Handle
263 ** KEYWORDS: {database connection} {database connections}
264 **
265 ** Each open SQLite database is represented by a pointer to an instance of
266 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
267 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
268 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
269 ** and [sqlite3_close_v2()] are its destructors. There are many other
270 ** interfaces (such as
271 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
272 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
273 ** sqlite3 object.
274 */
275 typedef struct sqlite3 sqlite3;
276
277 /*
278 ** CAPI3REF: 64-Bit Integer Types
279 ** KEYWORDS: sqlite_int64 sqlite_uint64
280 **
281 ** Because there is no cross-platform way to specify 64-bit integer types
282 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
283 **
284 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
285 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
286 ** compatibility only.
287 **
288 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
289 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
290 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
291 ** between 0 and +18446744073709551615 inclusive.
292 */
293 #ifdef SQLITE_INT64_TYPE
294 typedef SQLITE_INT64_TYPE sqlite_int64;
295 # ifdef SQLITE_UINT64_TYPE
296 typedef SQLITE_UINT64_TYPE sqlite_uint64;
297 # else
298 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
299 # endif
300 #elif defined(_MSC_VER) || defined(__BORLANDC__)
301 typedef __int64 sqlite_int64;
302 typedef unsigned __int64 sqlite_uint64;
303 #else
304 typedef long long int sqlite_int64;
305 typedef unsigned long long int sqlite_uint64;
306 #endif
307 typedef sqlite_int64 sqlite3_int64;
308 typedef sqlite_uint64 sqlite3_uint64;
309
310 /*
311 ** If compiling for a processor that lacks floating point support,
312 ** substitute integer for floating-point.
313 */
314 #ifdef SQLITE_OMIT_FLOATING_POINT
315 # define double sqlite3_int64
316 #endif
317
318 /*
319 ** CAPI3REF: Closing A Database Connection
320 ** DESTRUCTOR: sqlite3
321 **
322 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
323 ** for the [sqlite3] object.
324 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
325 ** the [sqlite3] object is successfully destroyed and all associated
326 ** resources are deallocated.
327 **
328 ** Ideally, applications should [sqlite3_finalize | finalize] all
329 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
330 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
331 ** with the [sqlite3] object prior to attempting to close the object.
332 ** ^If the database connection is associated with unfinalized prepared
333 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
334 ** sqlite3_close() will leave the database connection open and return
335 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
336 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
337 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
338 ** connection immediately, it marks the database connection as an unusable
339 ** "zombie" and makes arrangements to automatically deallocate the database
340 ** connection after all prepared statements are finalized, all BLOB handles
341 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
342 ** is intended for use with host languages that are garbage collected, and
343 ** where the order in which destructors are called is arbitrary.
344 **
345 ** ^If an [sqlite3] object is destroyed while a transaction is open,
346 ** the transaction is automatically rolled back.
347 **
348 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
349 ** must be either a NULL
350 ** pointer or an [sqlite3] object pointer obtained
351 ** from [sqlite3_open()], [sqlite3_open16()], or
352 ** [sqlite3_open_v2()], and not previously closed.
353 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
354 ** argument is a harmless no-op.
355 */
356 SQLITE_API int sqlite3_close(sqlite3*);
357 SQLITE_API int sqlite3_close_v2(sqlite3*);
358
359 /*
360 ** The type for a callback function.
361 ** This is legacy and deprecated. It is included for historical
362 ** compatibility and is not documented.
363 */
364 typedef int (*sqlite3_callback)(void*,int,char**, char**);
365
366 /*
367 ** CAPI3REF: One-Step Query Execution Interface
368 ** METHOD: sqlite3
369 **
370 ** The sqlite3_exec() interface is a convenience wrapper around
371 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
372 ** that allows an application to run multiple statements of SQL
373 ** without having to use a lot of C code.
374 **
375 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
376 ** semicolon-separated SQL statements passed into its 2nd argument,
377 ** in the context of the [database connection] passed in as its 1st
378 ** argument. ^If the callback function of the 3rd argument to
379 ** sqlite3_exec() is not NULL, then it is invoked for each result row
380 ** coming out of the evaluated SQL statements. ^The 4th argument to
381 ** sqlite3_exec() is relayed through to the 1st argument of each
382 ** callback invocation. ^If the callback pointer to sqlite3_exec()
383 ** is NULL, then no callback is ever invoked and result rows are
384 ** ignored.
385 **
386 ** ^If an error occurs while evaluating the SQL statements passed into
387 ** sqlite3_exec(), then execution of the current statement stops and
388 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
389 ** is not NULL then any error message is written into memory obtained
390 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
391 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
392 ** on error message strings returned through the 5th parameter of
393 ** sqlite3_exec() after the error message string is no longer needed.
394 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
395 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
396 ** NULL before returning.
397 **
398 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
399 ** routine returns SQLITE_ABORT without invoking the callback again and
400 ** without running any subsequent SQL statements.
401 **
402 ** ^The 2nd argument to the sqlite3_exec() callback function is the
403 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
404 ** callback is an array of pointers to strings obtained as if from
405 ** [sqlite3_column_text()], one for each column. ^If an element of a
406 ** result row is NULL then the corresponding string pointer for the
407 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
408 ** sqlite3_exec() callback is an array of pointers to strings where each
409 ** entry represents the name of a corresponding result column as obtained
410 ** from [sqlite3_column_name()].
411 **
412 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
413 ** to an empty string, or a pointer that contains only whitespace and/or
414 ** SQL comments, then no SQL statements are evaluated and the database
415 ** is not changed.
416 **
417 ** Restrictions:
418 **
419 ** <ul>
420 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
421 ** is a valid and open [database connection].
422 ** <li> The application must not close the [database connection] specified by
423 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
424 ** <li> The application must not modify the SQL statement text passed into
425 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
426 ** <li> The application must not dereference the arrays or string pointers
427 ** passed as the 3rd and 4th callback parameters after it returns.
428 ** </ul>
429 */
430 SQLITE_API int sqlite3_exec(
431 sqlite3*, /* An open database */
432 const char *sql, /* SQL to be evaluated */
433 int (*callback)(void*,int,char**,char**), /* Callback function */
434 void *, /* 1st argument to callback */
435 char **errmsg /* Error msg written here */
436 );
437
438 /*
439 ** CAPI3REF: Result Codes
440 ** KEYWORDS: {result code definitions}
441 **
442 ** Many SQLite functions return an integer result code from the set shown
443 ** here in order to indicate success or failure.
444 **
445 ** New error codes may be added in future versions of SQLite.
446 **
447 ** See also: [extended result code definitions]
448 */
449 #define SQLITE_OK 0 /* Successful result */
450 /* beginning-of-error-codes */
451 #define SQLITE_ERROR 1 /* Generic error */
452 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
453 #define SQLITE_PERM 3 /* Access permission denied */
454 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
455 #define SQLITE_BUSY 5 /* The database file is locked */
456 #define SQLITE_LOCKED 6 /* A table in the database is locked */
457 #define SQLITE_NOMEM 7 /* A malloc() failed */
458 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
459 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
460 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
461 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
462 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
463 #define SQLITE_FULL 13 /* Insertion failed because database is full */
464 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
465 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
466 #define SQLITE_EMPTY 16 /* Internal use only */
467 #define SQLITE_SCHEMA 17 /* The database schema changed */
468 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
469 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
470 #define SQLITE_MISMATCH 20 /* Data type mismatch */
471 #define SQLITE_MISUSE 21 /* Library used incorrectly */
472 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
473 #define SQLITE_AUTH 23 /* Authorization denied */
474 #define SQLITE_FORMAT 24 /* Not used */
475 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
476 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
477 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
478 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
479 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
480 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
481 /* end-of-error-codes */
482
483 /*
484 ** CAPI3REF: Extended Result Codes
485 ** KEYWORDS: {extended result code definitions}
486 **
487 ** In its default configuration, SQLite API routines return one of 30 integer
488 ** [result codes]. However, experience has shown that many of
489 ** these result codes are too coarse-grained. They do not provide as
490 ** much information about problems as programmers might like. In an effort to
491 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
492 ** and later) include
493 ** support for additional result codes that provide more detailed information
494 ** about errors. These [extended result codes] are enabled or disabled
495 ** on a per database connection basis using the
496 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
497 ** the most recent error can be obtained using
498 ** [sqlite3_extended_errcode()].
499 */
500 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
501 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
502 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
503 #define SQLITE_ERROR_RESERVESIZE (SQLITE_ERROR | (4<<8))
504 #define SQLITE_ERROR_KEY (SQLITE_ERROR | (5<<8))
505 #define SQLITE_ERROR_UNABLE (SQLITE_ERROR | (6<<8))
506 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
507 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
508 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
509 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
510 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
511 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
512 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
513 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
514 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
515 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
516 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
517 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
518 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
519 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
520 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
521 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
522 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
523 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
524 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
525 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
526 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
527 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
528 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
529 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
530 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
531 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
532 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
533 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
534 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
535 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
536 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
537 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
538 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
539 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
540 #define SQLITE_IOERR_BADKEY (SQLITE_IOERR | (35<<8))
541 #define SQLITE_IOERR_CODEC (SQLITE_IOERR | (36<<8))
542 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
543 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
544 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
545 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
546 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
547 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
548 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
549 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
550 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
551 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
552 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
553 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
554 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
555 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
556 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
557 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
558 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
559 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
560 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
561 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
562 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
563 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
564 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
565 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
566 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
567 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
568 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
569 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
570 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
571 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
572 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
573 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
574 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
575 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
576 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
577 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
578 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
579 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
580 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
581 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
582
583 /*
584 ** CAPI3REF: Flags For File Open Operations
585 **
586 ** These bit values are intended for use in the
587 ** 3rd parameter to the [sqlite3_open_v2()] interface and
588 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
589 **
590 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
591 ** used as the third argument to the [sqlite3_open_v2()] interface.
592 ** The other flags have historically been ignored by sqlite3_open_v2(),
593 ** though future versions of SQLite might change so that an error is
594 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
595 ** Applications should not depend on the historical behavior.
596 **
597 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
598 ** [sqlite3_open_v2()] does *not* cause the underlying database file
599 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
600 ** [sqlite3_open_v2()] has historically been a no-op and might become an
601 ** error in future versions of SQLite.
602 */
603 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
604 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
605 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
606 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
607 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
608 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
609 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
610 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
611 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
612 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
613 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
614 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
615 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
616 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
617 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
618 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
619 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
620 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
621 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
622 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
623 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
624 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
625
626 /* Reserved: 0x00F00000 */
627 /* Legacy compatibility: */
628 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
629
630
631 /*
632 ** CAPI3REF: Device Characteristics
633 **
634 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
635 ** object returns an integer which is a vector of these
636 ** bit values expressing I/O characteristics of the mass storage
637 ** device that holds the file that the [sqlite3_io_methods]
638 ** refers to.
639 **
640 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
641 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
642 ** mean that writes of blocks that are nnn bytes in size and
643 ** are aligned to an address which is an integer multiple of
644 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
645 ** that when data is appended to a file, the data is appended
646 ** first then the size of the file is extended, never the other
647 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
648 ** information is written to disk in the same order as calls
649 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
650 ** after reboot following a crash or power loss, the only bytes in a
651 ** file that were written at the application level might have changed
652 ** and that adjacent bytes, even bytes within the same sector are
653 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
654 ** flag indicates that a file cannot be deleted when open. The
655 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
656 ** read-only media and cannot be changed even by processes with
657 ** elevated privileges.
658 **
659 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
660 ** filesystem supports doing multiple write operations atomically when those
661 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
662 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
663 **
664 ** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
665 ** from the database file in amounts that are not a multiple of the
666 ** page size and that do not begin at a page boundary. Without this
667 ** property, SQLite is careful to only do full-page reads and write
668 ** on aligned pages, with the one exception that it will do a sub-page
669 ** read of the first page to access the database header.
670 */
671 #define SQLITE_IOCAP_ATOMIC 0x00000001
672 #define SQLITE_IOCAP_ATOMIC512 0x00000002
673 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
674 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
675 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
676 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
677 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
678 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
679 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
680 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
681 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
682 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
683 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
684 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
685 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
686 #define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
687
688 /*
689 ** CAPI3REF: File Locking Levels
690 **
691 ** SQLite uses one of these integer values as the second
692 ** argument to calls it makes to the xLock() and xUnlock() methods
693 ** of an [sqlite3_io_methods] object. These values are ordered from
694 ** least restrictive to most restrictive.
695 **
696 ** The argument to xLock() is always SHARED or higher. The argument to
697 ** xUnlock is either SHARED or NONE.
698 */
699 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
700 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
701 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
702 #define SQLITE_LOCK_PENDING 3 /* xLock() only */
703 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
704
705 /*
706 ** CAPI3REF: Synchronization Type Flags
707 **
708 ** When SQLite invokes the xSync() method of an
709 ** [sqlite3_io_methods] object it uses a combination of
710 ** these integer values as the second argument.
711 **
712 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
713 ** sync operation only needs to flush data to mass storage. Inode
714 ** information need not be flushed. If the lower four bits of the flag
715 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
716 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
717 ** to use Mac OS X style fullsync instead of fsync().
718 **
719 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
720 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
721 ** settings. The [synchronous pragma] determines when calls to the
722 ** xSync VFS method occur and applies uniformly across all platforms.
723 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
724 ** energetic or rigorous or forceful the sync operations are and
725 ** only make a difference on Mac OSX for the default SQLite code.
726 ** (Third-party VFS implementations might also make the distinction
727 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
728 ** operating systems natively supported by SQLite, only Mac OSX
729 ** cares about the difference.)
730 */
731 #define SQLITE_SYNC_NORMAL 0x00002
732 #define SQLITE_SYNC_FULL 0x00003
733 #define SQLITE_SYNC_DATAONLY 0x00010
734
735 /*
736 ** CAPI3REF: OS Interface Open File Handle
737 **
738 ** An [sqlite3_file] object represents an open file in the
739 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
740 ** implementations will
741 ** want to subclass this object by appending additional fields
742 ** for their own use. The pMethods entry is a pointer to an
743 ** [sqlite3_io_methods] object that defines methods for performing
744 ** I/O operations on the open file.
745 */
746 typedef struct sqlite3_file sqlite3_file;
747 struct sqlite3_file {
748 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
749 };
750
751 /*
752 ** CAPI3REF: OS Interface File Virtual Methods Object
753 **
754 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
755 ** [sqlite3_file] object (or, more commonly, a subclass of the
756 ** [sqlite3_file] object) with a pointer to an instance of this object.
757 ** This object defines the methods used to perform various operations
758 ** against the open file represented by the [sqlite3_file] object.
759 **
760 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
761 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
762 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
763 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
764 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
765 ** to NULL.
766 **
767 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
768 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
769 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
770 ** flag may be ORed in to indicate that only the data of the file
771 ** and not its inode needs to be synced.
772 **
773 ** The integer values to xLock() and xUnlock() are one of
774 ** <ul>
775 ** <li> [SQLITE_LOCK_NONE],
776 ** <li> [SQLITE_LOCK_SHARED],
777 ** <li> [SQLITE_LOCK_RESERVED],
778 ** <li> [SQLITE_LOCK_PENDING], or
779 ** <li> [SQLITE_LOCK_EXCLUSIVE].
780 ** </ul>
781 ** xLock() upgrades the database file lock. In other words, xLock() moves the
782 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
783 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
784 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
785 ** requested lock, then the call to xLock() is a no-op.
786 ** xUnlock() downgrades the database file lock to either SHARED or NONE.
787 ** If the lock is already at or below the requested lock state, then the call
788 ** to xUnlock() is a no-op.
789 ** The xCheckReservedLock() method checks whether any database connection,
790 ** either in this process or in some other process, is holding a RESERVED,
791 ** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
792 ** pointer parameter, true if such a lock exists and false otherwise.
793 **
794 ** The xFileControl() method is a generic interface that allows custom
795 ** VFS implementations to directly control an open file using the
796 ** [sqlite3_file_control()] interface. The second "op" argument is an
797 ** integer opcode. The third argument is a generic pointer intended to
798 ** point to a structure that may contain arguments or space in which to
799 ** write return values. Potential uses for xFileControl() might be
800 ** functions to enable blocking locks with timeouts, to change the
801 ** locking strategy (for example to use dot-file locks), to inquire
802 ** about the status of a lock, or to break stale locks. The SQLite
803 ** core reserves all opcodes less than 100 for its own use.
804 ** A [file control opcodes | list of opcodes] less than 100 is available.
805 ** Applications that define a custom xFileControl method should use opcodes
806 ** greater than 100 to avoid conflicts. VFS implementations should
807 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
808 ** recognize.
809 **
810 ** The xSectorSize() method returns the sector size of the
811 ** device that underlies the file. The sector size is the
812 ** minimum write that can be performed without disturbing
813 ** other bytes in the file. The xDeviceCharacteristics()
814 ** method returns a bit vector describing behaviors of the
815 ** underlying device:
816 **
817 ** <ul>
818 ** <li> [SQLITE_IOCAP_ATOMIC]
819 ** <li> [SQLITE_IOCAP_ATOMIC512]
820 ** <li> [SQLITE_IOCAP_ATOMIC1K]
821 ** <li> [SQLITE_IOCAP_ATOMIC2K]
822 ** <li> [SQLITE_IOCAP_ATOMIC4K]
823 ** <li> [SQLITE_IOCAP_ATOMIC8K]
824 ** <li> [SQLITE_IOCAP_ATOMIC16K]
825 ** <li> [SQLITE_IOCAP_ATOMIC32K]
826 ** <li> [SQLITE_IOCAP_ATOMIC64K]
827 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
828 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
829 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
830 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
831 ** <li> [SQLITE_IOCAP_IMMUTABLE]
832 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
833 ** <li> [SQLITE_IOCAP_SUBPAGE_READ]
834 ** </ul>
835 **
836 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
837 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
838 ** mean that writes of blocks that are nnn bytes in size and
839 ** are aligned to an address which is an integer multiple of
840 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
841 ** that when data is appended to a file, the data is appended
842 ** first then the size of the file is extended, never the other
843 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
844 ** information is written to disk in the same order as calls
845 ** to xWrite().
846 **
847 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
848 ** in the unread portions of the buffer with zeros. A VFS that
849 ** fails to zero-fill short reads might seem to work. However,
850 ** failure to zero-fill short reads will eventually lead to
851 ** database corruption.
852 */
853 typedef struct sqlite3_io_methods sqlite3_io_methods;
854 struct sqlite3_io_methods {
855 int iVersion;
856 int (*xClose)(sqlite3_file*);
857 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
858 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
859 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
860 int (*xSync)(sqlite3_file*, int flags);
861 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
862 int (*xLock)(sqlite3_file*, int);
863 int (*xUnlock)(sqlite3_file*, int);
864 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
865 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
866 int (*xSectorSize)(sqlite3_file*);
867 int (*xDeviceCharacteristics)(sqlite3_file*);
868 /* Methods above are valid for version 1 */
869 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
870 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
871 void (*xShmBarrier)(sqlite3_file*);
872 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
873 /* Methods above are valid for version 2 */
874 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
875 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
876 /* Methods above are valid for version 3 */
877 /* Additional methods may be added in future releases */
878 };
879
880 /*
881 ** CAPI3REF: Standard File Control Opcodes
882 ** KEYWORDS: {file control opcodes} {file control opcode}
883 **
884 ** These integer constants are opcodes for the xFileControl method
885 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
886 ** interface.
887 **
888 ** <ul>
889 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
890 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
891 ** opcode causes the xFileControl method to write the current state of
892 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
893 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
894 ** into an integer that the pArg argument points to.
895 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
896 **
897 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
898 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
899 ** layer a hint of how large the database file will grow to be during the
900 ** current transaction. This hint is not guaranteed to be accurate but it
901 ** is often close. The underlying VFS might choose to preallocate database
902 ** file space based on this hint in order to help writes to the database
903 ** file run faster.
904 **
905 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
906 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
907 ** implements [sqlite3_deserialize()] to set an upper bound on the size
908 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
909 ** If the integer pointed to is negative, then it is filled in with the
910 ** current limit. Otherwise the limit is set to the larger of the value
911 ** of the integer pointed to and the current database size. The integer
912 ** pointed to is set to the new limit.
913 **
914 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
915 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
916 ** extends and truncates the database file in chunks of a size specified
917 ** by the user. The fourth argument to [sqlite3_file_control()] should
918 ** point to an integer (type int) containing the new chunk-size to use
919 ** for the nominated database. Allocating database file space in large
920 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
921 ** improve performance on some systems.
922 **
923 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
924 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
925 ** to the [sqlite3_file] object associated with a particular database
926 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
927 **
928 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
929 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
930 ** to the [sqlite3_file] object associated with the journal file (either
931 ** the [rollback journal] or the [write-ahead log]) for a particular database
932 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
933 **
934 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
935 ** The SQLITE_FCNTL_SYNC_OMITTED file-control is no longer used.
936 **
937 ** <li>[[SQLITE_FCNTL_SYNC]]
938 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
939 ** sent to the VFS immediately before the xSync method is invoked on a
940 ** database file descriptor. Or, if the xSync method is not invoked
941 ** because the user has configured SQLite with
942 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
943 ** of the xSync method. In most cases, the pointer argument passed with
944 ** this file-control is NULL. However, if the database file is being synced
945 ** as part of a multi-database commit, the argument points to a nul-terminated
946 ** string containing the transactions super-journal file name. VFSes that
947 ** do not need this signal should silently ignore this opcode. Applications
948 ** should not call [sqlite3_file_control()] with this opcode as doing so may
949 ** disrupt the operation of the specialized VFSes that do require it.
950 **
951 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
952 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
953 ** and sent to the VFS after a transaction has been committed immediately
954 ** but before the database is unlocked. VFSes that do not need this signal
955 ** should silently ignore this opcode. Applications should not call
956 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
957 ** operation of the specialized VFSes that do require it.
958 **
959 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
960 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
961 ** retry counts and intervals for certain disk I/O operations for the
962 ** windows [VFS] in order to provide robustness in the presence of
963 ** anti-virus programs. By default, the windows VFS will retry file read,
964 ** file write, and file delete operations up to 10 times, with a delay
965 ** of 25 milliseconds before the first retry and with the delay increasing
966 ** by an additional 25 milliseconds with each subsequent retry. This
967 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
968 ** to be adjusted. The values are changed for all database connections
969 ** within the same process. The argument is a pointer to an array of two
970 ** integers where the first integer is the new retry count and the second
971 ** integer is the delay. If either integer is negative, then the setting
972 ** is not changed but instead the prior value of that setting is written
973 ** into the array entry, allowing the current retry settings to be
974 ** interrogated. The zDbName parameter is ignored.
975 **
976 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
977 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
978 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
979 ** write ahead log ([WAL file]) and shared memory
980 ** files used for transaction control
981 ** are automatically deleted when the latest connection to the database
982 ** closes. Setting persistent WAL mode causes those files to persist after
983 ** close. Persisting the files is useful when other processes that do not
984 ** have write permission on the directory containing the database file want
985 ** to read the database file, as the WAL and shared memory files must exist
986 ** in order for the database to be readable. The fourth parameter to
987 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
988 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
989 ** WAL mode. If the integer is -1, then it is overwritten with the current
990 ** WAL persistence setting.
991 **
992 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
993 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
994 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
995 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
996 ** xDeviceCharacteristics methods. The fourth parameter to
997 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
998 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
999 ** mode. If the integer is -1, then it is overwritten with the current
1000 ** zero-damage mode setting.
1001 **
1002 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
1003 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
1004 ** a write transaction to indicate that, unless it is rolled back for some
1005 ** reason, the entire database file will be overwritten by the current
1006 ** transaction. This is used by VACUUM operations.
1007 **
1008 ** <li>[[SQLITE_FCNTL_VFSNAME]]
1009 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1010 ** all [VFSes] in the VFS stack. The names of all VFS shims and the
1011 ** final bottom-level VFS are written into memory obtained from
1012 ** [sqlite3_malloc()] and the result is stored in the char* variable
1013 ** that the fourth parameter of [sqlite3_file_control()] points to.
1014 ** The caller is responsible for freeing the memory when done. As with
1015 ** all file-control actions, there is no guarantee that this will actually
1016 ** do anything. Callers should initialize the char* variable to a NULL
1017 ** pointer in case this file-control is not implemented. This file-control
1018 ** is intended for diagnostic use only.
1019 **
1020 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1021 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1022 ** [VFSes] currently in use. ^(The argument X in
1023 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1024 ** of type "[sqlite3_vfs] **". This opcode will set *X
1025 ** to a pointer to the top-level VFS.)^
1026 ** ^When there are multiple VFS shims in the stack, this opcode finds the
1027 ** upper-most shim only.
1028 **
1029 ** <li>[[SQLITE_FCNTL_PRAGMA]]
1030 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1031 ** file control is sent to the open [sqlite3_file] object corresponding
1032 ** to the database file to which the pragma statement refers. ^The argument
1033 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1034 ** pointers to strings (char**) in which the second element of the array
1035 ** is the name of the pragma and the third element is the argument to the
1036 ** pragma or NULL if the pragma has no argument. ^The handler for an
1037 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1038 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1039 ** or the equivalent and that string will become the result of the pragma or
1040 ** the error message if the pragma fails. ^If the
1041 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1042 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1043 ** file control returns [SQLITE_OK], then the parser assumes that the
1044 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1045 ** prepared statement if result string is NULL, or that returns a copy
1046 ** of the result string if the string is non-NULL.
1047 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1048 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1049 ** that the VFS encountered an error while handling the [PRAGMA] and the
1050 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1051 ** file control occurs at the beginning of pragma statement analysis and so
1052 ** it is able to override built-in [PRAGMA] statements.
1053 **
1054 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1055 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1056 ** file-control may be invoked by SQLite on the database file handle
1057 ** shortly after it is opened in order to provide a custom VFS with access
1058 ** to the connection's busy-handler callback. The argument is of type (void**)
1059 ** - an array of two (void *) values. The first (void *) actually points
1060 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1061 ** busy-handler, this function should be invoked with the second (void *) in
1062 ** the array as the only argument. If it returns non-zero, then the operation
1063 ** should be retried. If it returns zero, the custom VFS should abandon the
1064 ** current operation.
1065 **
1066 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1067 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1068 ** to have SQLite generate a
1069 ** temporary filename using the same algorithm that is followed to generate
1070 ** temporary filenames for TEMP tables and other internal uses. The
1071 ** argument should be a char** which will be filled with the filename
1072 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1073 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1074 **
1075 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1076 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1077 ** maximum number of bytes that will be used for memory-mapped I/O.
1078 ** The argument is a pointer to a value of type sqlite3_int64 that
1079 ** is an advisory maximum number of bytes in the file to memory map. The
1080 ** pointer is overwritten with the old value. The limit is not changed if
1081 ** the value originally pointed to is negative, and so the current limit
1082 ** can be queried by passing in a pointer to a negative number. This
1083 ** file-control is used internally to implement [PRAGMA mmap_size].
1084 **
1085 ** <li>[[SQLITE_FCNTL_TRACE]]
1086 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1087 ** to the VFS about what the higher layers of the SQLite stack are doing.
1088 ** This file control is used by some VFS activity tracing [shims].
1089 ** The argument is a zero-terminated string. Higher layers in the
1090 ** SQLite stack may generate instances of this file control if
1091 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1092 **
1093 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1094 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1095 ** pointer to an integer and it writes a boolean into that integer depending
1096 ** on whether or not the file has been renamed, moved, or deleted since it
1097 ** was first opened.
1098 **
1099 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1100 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1101 ** underlying native file handle associated with a file handle. This file
1102 ** control interprets its argument as a pointer to a native file handle and
1103 ** writes the resulting value there.
1104 **
1105 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1106 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1107 ** opcode causes the xFileControl method to swap the file handle with the one
1108 ** pointed to by the pArg argument. This capability is used during testing
1109 ** and only needs to be supported when SQLITE_TEST is defined.
1110 **
1111 ** <li>[[SQLITE_FCNTL_NULL_IO]]
1112 ** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1113 ** or file handle for the [sqlite3_file] object such that it will no longer
1114 ** read or write to the database file.
1115 **
1116 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1117 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1118 ** be advantageous to block on the next WAL lock if the lock is not immediately
1119 ** available. The WAL subsystem issues this signal during rare
1120 ** circumstances in order to fix a problem with priority inversion.
1121 ** Applications should <em>not</em> use this file-control.
1122 **
1123 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1124 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1125 ** VFS should return SQLITE_NOTFOUND for this opcode.
1126 **
1127 ** <li>[[SQLITE_FCNTL_RBU]]
1128 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1129 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1130 ** this opcode.
1131 **
1132 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1133 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1134 ** the file descriptor is placed in "batch write mode", which
1135 ** means all subsequent write operations will be deferred and done
1136 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1137 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1138 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1139 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1140 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1141 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1142 ** except for calls to the xWrite method and the xFileControl method
1143 ** with [SQLITE_FCNTL_SIZE_HINT].
1144 **
1145 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1146 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1147 ** operations since the previous successful call to
1148 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1149 ** This file control returns [SQLITE_OK] if and only if the writes were
1150 ** all performed successfully and have been committed to persistent storage.
1151 ** ^Regardless of whether or not it is successful, this file control takes
1152 ** the file descriptor out of batch write mode so that all subsequent
1153 ** write operations are independent.
1154 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1155 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1156 **
1157 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1158 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1159 ** operations since the previous successful call to
1160 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1161 ** ^This file control takes the file descriptor out of batch write mode
1162 ** so that all subsequent write operations are independent.
1163 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1164 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1165 **
1166 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1167 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1168 ** to block for up to M milliseconds before failing when attempting to
1169 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1170 ** The parameter is a pointer to a 32-bit signed integer that contains
1171 ** the value that M is to be set to. Before returning, the 32-bit signed
1172 ** integer is overwritten with the previous value of M.
1173 **
1174 ** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1175 ** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1176 ** VFS to block when taking a SHARED lock to connect to a wal mode database.
1177 ** This is used to implement the functionality associated with
1178 ** SQLITE_SETLK_BLOCK_ON_CONNECT.
1179 **
1180 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1181 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1182 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1183 ** The "data version" for the pager is written into the pointer. The
1184 ** "data version" changes whenever any change occurs to the corresponding
1185 ** database file, either through SQL statements on the same database
1186 ** connection or through transactions committed by separate database
1187 ** connections possibly in other processes. The [sqlite3_total_changes()]
1188 ** interface can be used to find if any database on the connection has changed,
1189 ** but that interface responds to changes on TEMP as well as MAIN and does
1190 ** not provide a mechanism to detect changes to MAIN only. Also, the
1191 ** [sqlite3_total_changes()] interface responds to internal changes only and
1192 ** omits changes made by other database connections. The
1193 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1194 ** a single attached database that occur due to other database connections,
1195 ** but omits changes implemented by the database connection on which it is
1196 ** called. This file control is the only mechanism to detect changes that
1197 ** happen either internally or externally and that are associated with
1198 ** a particular attached database.
1199 **
1200 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1201 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1202 ** in wal mode before the client starts to copy pages from the wal
1203 ** file to the database file.
1204 **
1205 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1206 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1207 ** in wal mode after the client has finished copying pages from the wal
1208 ** file to the database file, but before the *-shm file is updated to
1209 ** record the fact that the pages have been checkpointed.
1210 **
1211 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1212 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1213 ** whether or not there is a database client in another process with a wal-mode
1214 ** transaction open on the database or not. It is only available on unix. The
1215 ** (void*) argument passed with this file-control should be a pointer to a
1216 ** value of type (int). The integer value is set to 1 if the database is a wal
1217 ** mode database and there exists at least one client in another process that
1218 ** currently has an SQL transaction open on the database. It is set to 0 if
1219 ** the database is not a wal-mode db, or if there is no such connection in any
1220 ** other process. This opcode cannot be used to detect transactions opened
1221 ** by clients within the current process, only within other processes.
1222 **
1223 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1224 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1225 ** [checksum VFS shim] only.
1226 **
1227 ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1228 ** If there is currently no transaction open on the database, and the
1229 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1230 ** purges the contents of the in-memory page cache. If there is an open
1231 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1232 **
1233 ** <li>[[SQLITE_FCNTL_FILESTAT]]
1234 ** The [SQLITE_FCNTL_FILESTAT] opcode returns low-level diagnostic information
1235 ** about the [sqlite3_file] objects used access the database and journal files
1236 ** for the given schema. The fourth parameter to [sqlite3_file_control()]
1237 ** should be an initialized [sqlite3_str] pointer. JSON text describing
1238 ** various aspects of the sqlite3_file object is appended to the sqlite3_str.
1239 ** The SQLITE_FCNTL_FILESTAT opcode is usually a no-op, unless compile-time
1240 ** options are used to enable it.
1241 ** </ul>
1242 */
1243 #define SQLITE_FCNTL_LOCKSTATE 1
1244 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1245 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1246 #define SQLITE_FCNTL_LAST_ERRNO 4
1247 #define SQLITE_FCNTL_SIZE_HINT 5
1248 #define SQLITE_FCNTL_CHUNK_SIZE 6
1249 #define SQLITE_FCNTL_FILE_POINTER 7
1250 #define SQLITE_FCNTL_SYNC_OMITTED 8
1251 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1252 #define SQLITE_FCNTL_PERSIST_WAL 10
1253 #define SQLITE_FCNTL_OVERWRITE 11
1254 #define SQLITE_FCNTL_VFSNAME 12
1255 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1256 #define SQLITE_FCNTL_PRAGMA 14
1257 #define SQLITE_FCNTL_BUSYHANDLER 15
1258 #define SQLITE_FCNTL_TEMPFILENAME 16
1259 #define SQLITE_FCNTL_MMAP_SIZE 18
1260 #define SQLITE_FCNTL_TRACE 19
1261 #define SQLITE_FCNTL_HAS_MOVED 20
1262 #define SQLITE_FCNTL_SYNC 21
1263 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1264 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1265 #define SQLITE_FCNTL_WAL_BLOCK 24
1266 #define SQLITE_FCNTL_ZIPVFS 25
1267 #define SQLITE_FCNTL_RBU 26
1268 #define SQLITE_FCNTL_VFS_POINTER 27
1269 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1270 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1271 #define SQLITE_FCNTL_PDB 30
1272 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1273 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1274 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1275 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1276 #define SQLITE_FCNTL_DATA_VERSION 35
1277 #define SQLITE_FCNTL_SIZE_LIMIT 36
1278 #define SQLITE_FCNTL_CKPT_DONE 37
1279 #define SQLITE_FCNTL_RESERVE_BYTES 38
1280 #define SQLITE_FCNTL_CKPT_START 39
1281 #define SQLITE_FCNTL_EXTERNAL_READER 40
1282 #define SQLITE_FCNTL_CKSM_FILE 41
1283 #define SQLITE_FCNTL_RESET_CACHE 42
1284 #define SQLITE_FCNTL_NULL_IO 43
1285 #define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1286 #define SQLITE_FCNTL_FILESTAT 45
1287
1288 /* deprecated names */
1289 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1290 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1291 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1292
1293
1294 /*
1295 ** CAPI3REF: Mutex Handle
1296 **
1297 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1298 ** abstract type for a mutex object. The SQLite core never looks
1299 ** at the internal representation of an [sqlite3_mutex]. It only
1300 ** deals with pointers to the [sqlite3_mutex] object.
1301 **
1302 ** Mutexes are created using [sqlite3_mutex_alloc()].
1303 */
1304 typedef struct sqlite3_mutex sqlite3_mutex;
1305
1306 /*
1307 ** CAPI3REF: Loadable Extension Thunk
1308 **
1309 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1310 ** the third parameter to entry points of [loadable extensions]. This
1311 ** structure must be typedefed in order to work around compiler warnings
1312 ** on some platforms.
1313 */
1314 typedef struct sqlite3_api_routines sqlite3_api_routines;
1315
1316 /*
1317 ** CAPI3REF: File Name
1318 **
1319 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1320 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1321 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1322 ** may also be passed to special APIs such as:
1323 **
1324 ** <ul>
1325 ** <li> sqlite3_filename_database()
1326 ** <li> sqlite3_filename_journal()
1327 ** <li> sqlite3_filename_wal()
1328 ** <li> sqlite3_uri_parameter()
1329 ** <li> sqlite3_uri_boolean()
1330 ** <li> sqlite3_uri_int64()
1331 ** <li> sqlite3_uri_key()
1332 ** </ul>
1333 */
1334 typedef const char *sqlite3_filename;
1335
1336 /*
1337 ** CAPI3REF: OS Interface Object
1338 **
1339 ** An instance of the sqlite3_vfs object defines the interface between
1340 ** the SQLite core and the underlying operating system. The "vfs"
1341 ** in the name of the object stands for "virtual file system". See
1342 ** the [VFS | VFS documentation] for further information.
1343 **
1344 ** The VFS interface is sometimes extended by adding new methods onto
1345 ** the end. Each time such an extension occurs, the iVersion field
1346 ** is incremented. The iVersion value started out as 1 in
1347 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1348 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1349 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1350 ** may be appended to the sqlite3_vfs object and the iVersion value
1351 ** may increase again in future versions of SQLite.
1352 ** Note that due to an oversight, the structure
1353 ** of the sqlite3_vfs object changed in the transition from
1354 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1355 ** and yet the iVersion field was not increased.
1356 **
1357 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1358 ** structure used by this VFS. mxPathname is the maximum length of
1359 ** a pathname in this VFS.
1360 **
1361 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1362 ** the pNext pointer. The [sqlite3_vfs_register()]
1363 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1364 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1365 ** searches the list. Neither the application code nor the VFS
1366 ** implementation should use the pNext pointer.
1367 **
1368 ** The pNext field is the only field in the sqlite3_vfs
1369 ** structure that SQLite will ever modify. SQLite will only access
1370 ** or modify this field while holding a particular static mutex.
1371 ** The application should never modify anything within the sqlite3_vfs
1372 ** object once the object has been registered.
1373 **
1374 ** The zName field holds the name of the VFS module. The name must
1375 ** be unique across all VFS modules.
1376 **
1377 ** [[sqlite3_vfs.xOpen]]
1378 ** ^SQLite guarantees that the zFilename parameter to xOpen
1379 ** is either a NULL pointer or string obtained
1380 ** from xFullPathname() with an optional suffix added.
1381 ** ^If a suffix is added to the zFilename parameter, it will
1382 ** consist of a single "-" character followed by no more than
1383 ** 11 alphanumeric and/or "-" characters.
1384 ** ^SQLite further guarantees that
1385 ** the string will be valid and unchanged until xClose() is
1386 ** called. Because of the previous sentence,
1387 ** the [sqlite3_file] can safely store a pointer to the
1388 ** filename if it needs to remember the filename for some reason.
1389 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1390 ** must invent its own temporary name for the file. ^Whenever the
1391 ** xFilename parameter is NULL it will also be the case that the
1392 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1393 **
1394 ** The flags argument to xOpen() includes all bits set in
1395 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1396 ** or [sqlite3_open16()] is used, then flags includes at least
1397 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1398 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1399 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1400 **
1401 ** ^(SQLite will also add one of the following flags to the xOpen()
1402 ** call, depending on the object being opened:
1403 **
1404 ** <ul>
1405 ** <li> [SQLITE_OPEN_MAIN_DB]
1406 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1407 ** <li> [SQLITE_OPEN_TEMP_DB]
1408 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1409 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1410 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1411 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1412 ** <li> [SQLITE_OPEN_WAL]
1413 ** </ul>)^
1414 **
1415 ** The file I/O implementation can use the object type flags to
1416 ** change the way it deals with files. For example, an application
1417 ** that does not care about crash recovery or rollback might make
1418 ** the open of a journal file a no-op. Writes to this journal would
1419 ** also be no-ops, and any attempt to read the journal would return
1420 ** SQLITE_IOERR. Or the implementation might recognize that a database
1421 ** file will be doing page-aligned sector reads and writes in a random
1422 ** order and set up its I/O subsystem accordingly.
1423 **
1424 ** SQLite might also add one of the following flags to the xOpen method:
1425 **
1426 ** <ul>
1427 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1428 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1429 ** </ul>
1430 **
1431 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1432 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1433 ** will be set for TEMP databases and their journals, transient
1434 ** databases, and subjournals.
1435 **
1436 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1437 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1438 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1439 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1440 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1441 ** be created, and that it is an error if it already exists.
1442 ** It is <i>not</i> used to indicate the file should be opened
1443 ** for exclusive access.
1444 **
1445 ** ^At least szOsFile bytes of memory are allocated by SQLite
1446 ** to hold the [sqlite3_file] structure passed as the third
1447 ** argument to xOpen. The xOpen method does not have to
1448 ** allocate the structure; it should just fill it in. Note that
1449 ** the xOpen method must set the sqlite3_file.pMethods to either
1450 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1451 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1452 ** element will be valid after xOpen returns regardless of the success
1453 ** or failure of the xOpen call.
1454 **
1455 ** [[sqlite3_vfs.xAccess]]
1456 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1457 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1458 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1459 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1460 ** flag is never actually used and is not implemented in the built-in
1461 ** VFSes of SQLite. The file is named by the second argument and can be a
1462 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1463 ** non-zero error code if there is an I/O error or if the name of
1464 ** the file given in the second argument is illegal. If SQLITE_OK
1465 ** is returned, then non-zero or zero is written into *pResOut to indicate
1466 ** whether or not the file is accessible.
1467 **
1468 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1469 ** output buffer xFullPathname. The exact size of the output buffer
1470 ** is also passed as a parameter to both methods. If the output buffer
1471 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1472 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1473 ** to prevent this by setting mxPathname to a sufficiently large value.
1474 **
1475 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1476 ** interfaces are not strictly a part of the filesystem, but they are
1477 ** included in the VFS structure for completeness.
1478 ** The xRandomness() function attempts to return nBytes bytes
1479 ** of good-quality randomness into zOut. The return value is
1480 ** the actual number of bytes of randomness obtained.
1481 ** The xSleep() method causes the calling thread to sleep for at
1482 ** least the number of microseconds given. ^The xCurrentTime()
1483 ** method returns a Julian Day Number for the current date and time as
1484 ** a floating point value.
1485 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1486 ** Day Number multiplied by 86400000 (the number of milliseconds in
1487 ** a 24-hour day).
1488 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1489 ** date and time if that method is available (if iVersion is 2 or
1490 ** greater and the function pointer is not NULL) and will fall back
1491 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1492 **
1493 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1494 ** are not used by the SQLite core. These optional interfaces are provided
1495 ** by some VFSes to facilitate testing of the VFS code. By overriding
1496 ** system calls with functions under its control, a test program can
1497 ** simulate faults and error conditions that would otherwise be difficult
1498 ** or impossible to induce. The set of system calls that can be overridden
1499 ** varies from one VFS to another, and from one version of the same VFS to the
1500 ** next. Applications that use these interfaces must be prepared for any
1501 ** or all of these interfaces to be NULL or for their behavior to change
1502 ** from one release to the next. Applications must not attempt to access
1503 ** any of these methods if the iVersion of the VFS is less than 3.
1504 */
1505 typedef struct sqlite3_vfs sqlite3_vfs;
1506 typedef void (*sqlite3_syscall_ptr)(void);
1507 struct sqlite3_vfs {
1508 int iVersion; /* Structure version number (currently 3) */
1509 int szOsFile; /* Size of subclassed sqlite3_file */
1510 int mxPathname; /* Maximum file pathname length */
1511 sqlite3_vfs *pNext; /* Next registered VFS */
1512 const char *zName; /* Name of this virtual file system */
1513 void *pAppData; /* Pointer to application-specific data */
1514 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1515 int flags, int *pOutFlags);
1516 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1517 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1518 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1519 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1520 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1521 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1522 void (*xDlClose)(sqlite3_vfs*, void*);
1523 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1524 int (*xSleep)(sqlite3_vfs*, int microseconds);
1525 int (*xCurrentTime)(sqlite3_vfs*, double*);
1526 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1527 /*
1528 ** The methods above are in version 1 of the sqlite_vfs object
1529 ** definition. Those that follow are added in version 2 or later
1530 */
1531 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1532 /*
1533 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1534 ** Those below are for version 3 and greater.
1535 */
1536 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1537 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1538 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1539 /*
1540 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1541 ** New fields may be appended in future versions. The iVersion
1542 ** value will increment whenever this happens.
1543 */
1544 };
1545
1546 /*
1547 ** CAPI3REF: Flags for the xAccess VFS method
1548 **
1549 ** These integer constants can be used as the third parameter to
1550 ** the xAccess method of an [sqlite3_vfs] object. They determine
1551 ** what kind of permissions the xAccess method is looking for.
1552 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1553 ** simply checks whether the file exists.
1554 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1555 ** checks whether the named directory is both readable and writable
1556 ** (in other words, if files can be added, removed, and renamed within
1557 ** the directory).
1558 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1559 ** [temp_store_directory pragma], though this could change in a future
1560 ** release of SQLite.
1561 ** With SQLITE_ACCESS_READ, the xAccess method
1562 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1563 ** currently unused, though it might be used in a future release of
1564 ** SQLite.
1565 */
1566 #define SQLITE_ACCESS_EXISTS 0
1567 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1568 #define SQLITE_ACCESS_READ 2 /* Unused */
1569
1570 /*
1571 ** CAPI3REF: Flags for the xShmLock VFS method
1572 **
1573 ** These integer constants define the various locking operations
1574 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1575 ** following are the only legal combinations of flags to the
1576 ** xShmLock method:
1577 **
1578 ** <ul>
1579 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1580 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1581 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1582 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1583 ** </ul>
1584 **
1585 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1586 ** was given on the corresponding lock.
1587 **
1588 ** The xShmLock method can transition between unlocked and SHARED or
1589 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1590 ** and EXCLUSIVE.
1591 */
1592 #define SQLITE_SHM_UNLOCK 1
1593 #define SQLITE_SHM_LOCK 2
1594 #define SQLITE_SHM_SHARED 4
1595 #define SQLITE_SHM_EXCLUSIVE 8
1596
1597 /*
1598 ** CAPI3REF: Maximum xShmLock index
1599 **
1600 ** The xShmLock method on [sqlite3_io_methods] may use values
1601 ** between 0 and this upper bound as its "offset" argument.
1602 ** The SQLite core will never attempt to acquire or release a
1603 ** lock outside of this range
1604 */
1605 #define SQLITE_SHM_NLOCK 8
1606
1607
1608 /*
1609 ** CAPI3REF: Initialize The SQLite Library
1610 **
1611 ** ^The sqlite3_initialize() routine initializes the
1612 ** SQLite library. ^The sqlite3_shutdown() routine
1613 ** deallocates any resources that were allocated by sqlite3_initialize().
1614 ** These routines are designed to aid in process initialization and
1615 ** shutdown on embedded systems. Workstation applications using
1616 ** SQLite normally do not need to invoke either of these routines.
1617 **
1618 ** A call to sqlite3_initialize() is an "effective" call if it is
1619 ** the first time sqlite3_initialize() is invoked during the lifetime of
1620 ** the process, or if it is the first time sqlite3_initialize() is invoked
1621 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1622 ** of sqlite3_initialize() does any initialization. All other calls
1623 ** are harmless no-ops.)^
1624 **
1625 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1626 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1627 ** an effective call to sqlite3_shutdown() does any deinitialization.
1628 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1629 **
1630 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1631 ** is not. The sqlite3_shutdown() interface must only be called from a
1632 ** single thread. All open [database connections] must be closed and all
1633 ** other SQLite resources must be deallocated prior to invoking
1634 ** sqlite3_shutdown().
1635 **
1636 ** Among other things, ^sqlite3_initialize() will invoke
1637 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1638 ** will invoke sqlite3_os_end().
1639 **
1640 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1641 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1642 ** the library (perhaps it is unable to allocate a needed resource such
1643 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1644 **
1645 ** ^The sqlite3_initialize() routine is called internally by many other
1646 ** SQLite interfaces so that an application usually does not need to
1647 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1648 ** calls sqlite3_initialize() so the SQLite library will be automatically
1649 ** initialized when [sqlite3_open()] is called if it has not been initialized
1650 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1651 ** compile-time option, then the automatic calls to sqlite3_initialize()
1652 ** are omitted and the application must call sqlite3_initialize() directly
1653 ** prior to using any other SQLite interface. For maximum portability,
1654 ** it is recommended that applications always invoke sqlite3_initialize()
1655 ** directly prior to using any other SQLite interface. Future releases
1656 ** of SQLite may require this. In other words, the behavior exhibited
1657 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1658 ** default behavior in some future release of SQLite.
1659 **
1660 ** The sqlite3_os_init() routine does operating-system specific
1661 ** initialization of the SQLite library. The sqlite3_os_end()
1662 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1663 ** performed by these routines include allocation or deallocation
1664 ** of static resources, initialization of global variables,
1665 ** setting up a default [sqlite3_vfs] module, or setting up
1666 ** a default configuration using [sqlite3_config()].
1667 **
1668 ** The application should never invoke either sqlite3_os_init()
1669 ** or sqlite3_os_end() directly. The application should only invoke
1670 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1671 ** interface is called automatically by sqlite3_initialize() and
1672 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1673 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1674 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1675 ** When [custom builds | built for other platforms]
1676 ** (using the [SQLITE_OS_OTHER=1] compile-time
1677 ** option) the application must supply a suitable implementation for
1678 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1679 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1680 ** must return [SQLITE_OK] on success and some other [error code] upon
1681 ** failure.
1682 */
1683 SQLITE_API int sqlite3_initialize(void);
1684 SQLITE_API int sqlite3_shutdown(void);
1685 SQLITE_API int sqlite3_os_init(void);
1686 SQLITE_API int sqlite3_os_end(void);
1687
1688 /*
1689 ** CAPI3REF: Configuring The SQLite Library
1690 **
1691 ** The sqlite3_config() interface is used to make global configuration
1692 ** changes to SQLite in order to tune SQLite to the specific needs of
1693 ** the application. The default configuration is recommended for most
1694 ** applications and so this routine is usually not necessary. It is
1695 ** provided to support rare applications with unusual needs.
1696 **
1697 ** <b>The sqlite3_config() interface is not threadsafe. The application
1698 ** must ensure that no other SQLite interfaces are invoked by other
1699 ** threads while sqlite3_config() is running.</b>
1700 **
1701 ** The first argument to sqlite3_config() is an integer
1702 ** [configuration option] that determines
1703 ** what property of SQLite is to be configured. Subsequent arguments
1704 ** vary depending on the [configuration option]
1705 ** in the first argument.
1706 **
1707 ** For most configuration options, the sqlite3_config() interface
1708 ** may only be invoked prior to library initialization using
1709 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1710 ** The exceptional configuration options that may be invoked at any time
1711 ** are called "anytime configuration options".
1712 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1713 ** [sqlite3_shutdown()] with a first argument that is not an anytime
1714 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1715 ** Note, however, that ^sqlite3_config() can be called as part of the
1716 ** implementation of an application-defined [sqlite3_os_init()].
1717 **
1718 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1719 ** ^If the option is unknown or SQLite is unable to set the option
1720 ** then this routine returns a non-zero [error code].
1721 */
1722 SQLITE_API int sqlite3_config(int, ...);
1723
1724 /*
1725 ** CAPI3REF: Configure database connections
1726 ** METHOD: sqlite3
1727 **
1728 ** The sqlite3_db_config() interface is used to make configuration
1729 ** changes to a [database connection]. The interface is similar to
1730 ** [sqlite3_config()] except that the changes apply to a single
1731 ** [database connection] (specified in the first argument).
1732 **
1733 ** The second argument to sqlite3_db_config(D,V,...) is the
1734 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1735 ** that indicates what aspect of the [database connection] is being configured.
1736 ** Subsequent arguments vary depending on the configuration verb.
1737 **
1738 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1739 ** the call is considered successful.
1740 */
1741 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1742
1743 /*
1744 ** CAPI3REF: Memory Allocation Routines
1745 **
1746 ** An instance of this object defines the interface between SQLite
1747 ** and low-level memory allocation routines.
1748 **
1749 ** This object is used in only one place in the SQLite interface.
1750 ** A pointer to an instance of this object is the argument to
1751 ** [sqlite3_config()] when the configuration option is
1752 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1753 ** By creating an instance of this object
1754 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1755 ** during configuration, an application can specify an alternative
1756 ** memory allocation subsystem for SQLite to use for all of its
1757 ** dynamic memory needs.
1758 **
1759 ** Note that SQLite comes with several [built-in memory allocators]
1760 ** that are perfectly adequate for the overwhelming majority of applications
1761 ** and that this object is only useful to a tiny minority of applications
1762 ** with specialized memory allocation requirements. This object is
1763 ** also used during testing of SQLite in order to specify an alternative
1764 ** memory allocator that simulates memory out-of-memory conditions in
1765 ** order to verify that SQLite recovers gracefully from such
1766 ** conditions.
1767 **
1768 ** The xMalloc, xRealloc, and xFree methods must work like the
1769 ** malloc(), realloc() and free() functions from the standard C library.
1770 ** ^SQLite guarantees that the second argument to
1771 ** xRealloc is always a value returned by a prior call to xRoundup.
1772 **
1773 ** xSize should return the allocated size of a memory allocation
1774 ** previously obtained from xMalloc or xRealloc. The allocated size
1775 ** is always at least as big as the requested size but may be larger.
1776 **
1777 ** The xRoundup method returns what would be the allocated size of
1778 ** a memory allocation given a particular requested size. Most memory
1779 ** allocators round up memory allocations at least to the next multiple
1780 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1781 ** Every memory allocation request coming in through [sqlite3_malloc()]
1782 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1783 ** that causes the corresponding memory allocation to fail.
1784 **
1785 ** The xInit method initializes the memory allocator. For example,
1786 ** it might allocate any required mutexes or initialize internal data
1787 ** structures. The xShutdown method is invoked (indirectly) by
1788 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1789 ** by xInit. The pAppData pointer is used as the only parameter to
1790 ** xInit and xShutdown.
1791 **
1792 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1793 ** the xInit method, so the xInit method need not be threadsafe. The
1794 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1795 ** not need to be threadsafe either. For all other methods, SQLite
1796 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1797 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1798 ** it is by default) and so the methods are automatically serialized.
1799 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1800 ** methods must be threadsafe or else make their own arrangements for
1801 ** serialization.
1802 **
1803 ** SQLite will never invoke xInit() more than once without an intervening
1804 ** call to xShutdown().
1805 */
1806 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1807 struct sqlite3_mem_methods {
1808 void *(*xMalloc)(int); /* Memory allocation function */
1809 void (*xFree)(void*); /* Free a prior allocation */
1810 void *(*xRealloc)(void*,int); /* Resize an allocation */
1811 int (*xSize)(void*); /* Return the size of an allocation */
1812 int (*xRoundup)(int); /* Round up request size to allocation size */
1813 int (*xInit)(void*); /* Initialize the memory allocator */
1814 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1815 void *pAppData; /* Argument to xInit() and xShutdown() */
1816 };
1817
1818 /*
1819 ** CAPI3REF: Configuration Options
1820 ** KEYWORDS: {configuration option}
1821 **
1822 ** These constants are the available integer configuration options that
1823 ** can be passed as the first argument to the [sqlite3_config()] interface.
1824 **
1825 ** Most of the configuration options for sqlite3_config()
1826 ** will only work if invoked prior to [sqlite3_initialize()] or after
1827 ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1828 ** "anytime configuration options".
1829 ** ^Calling [sqlite3_config()] with a first argument that is not an
1830 ** anytime configuration option in between calls to [sqlite3_initialize()] and
1831 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1832 **
1833 ** The set of anytime configuration options can change (by insertions
1834 ** and/or deletions) from one release of SQLite to the next.
1835 ** As of SQLite version 3.42.0, the complete set of anytime configuration
1836 ** options is:
1837 ** <ul>
1838 ** <li> SQLITE_CONFIG_LOG
1839 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1840 ** </ul>
1841 **
1842 ** New configuration options may be added in future releases of SQLite.
1843 ** Existing configuration options might be discontinued. Applications
1844 ** should check the return code from [sqlite3_config()] to make sure that
1845 ** the call worked. The [sqlite3_config()] interface will return a
1846 ** non-zero [error code] if a discontinued or unsupported configuration option
1847 ** is invoked.
1848 **
1849 ** <dl>
1850 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1851 ** <dd>There are no arguments to this option. ^This option sets the
1852 ** [threading mode] to Single-thread. In other words, it disables
1853 ** all mutexing and puts SQLite into a mode where it can only be used
1854 ** by a single thread. ^If SQLite is compiled with
1855 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1856 ** it is not possible to change the [threading mode] from its default
1857 ** value of Single-thread and so [sqlite3_config()] will return
1858 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1859 ** configuration option.</dd>
1860 **
1861 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1862 ** <dd>There are no arguments to this option. ^This option sets the
1863 ** [threading mode] to Multi-thread. In other words, it disables
1864 ** mutexing on [database connection] and [prepared statement] objects.
1865 ** The application is responsible for serializing access to
1866 ** [database connections] and [prepared statements]. But other mutexes
1867 ** are enabled so that SQLite will be safe to use in a multi-threaded
1868 ** environment as long as no two threads attempt to use the same
1869 ** [database connection] at the same time. ^If SQLite is compiled with
1870 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1871 ** it is not possible to set the Multi-thread [threading mode] and
1872 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1873 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1874 **
1875 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1876 ** <dd>There are no arguments to this option. ^This option sets the
1877 ** [threading mode] to Serialized. In other words, this option enables
1878 ** all mutexes including the recursive
1879 ** mutexes on [database connection] and [prepared statement] objects.
1880 ** In this mode (which is the default when SQLite is compiled with
1881 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1882 ** to [database connections] and [prepared statements] so that the
1883 ** application is free to use the same [database connection] or the
1884 ** same [prepared statement] in different threads at the same time.
1885 ** ^If SQLite is compiled with
1886 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1887 ** it is not possible to set the Serialized [threading mode] and
1888 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1889 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1890 **
1891 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1892 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1893 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1894 ** The argument specifies
1895 ** alternative low-level memory allocation routines to be used in place of
1896 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1897 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1898 ** before the [sqlite3_config()] call returns.</dd>
1899 **
1900 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1901 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1902 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1903 ** The [sqlite3_mem_methods]
1904 ** structure is filled with the currently defined memory allocation routines.)^
1905 ** This option can be used to overload the default memory allocation
1906 ** routines with a wrapper that simulates memory allocation failure or
1907 ** tracks memory usage, for example. </dd>
1908 **
1909 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1910 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes a single argument of
1911 ** type int, interpreted as a boolean, which if true provides a hint to
1912 ** SQLite that it should avoid large memory allocations if possible.
1913 ** SQLite will run faster if it is free to make large memory allocations,
1914 ** but some applications might prefer to run slower in exchange for
1915 ** guarantees about memory fragmentation that are possible if large
1916 ** allocations are avoided. This hint is normally off.
1917 ** </dd>
1918 **
1919 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1920 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes a single argument of type int,
1921 ** interpreted as a boolean, which enables or disables the collection of
1922 ** memory allocation statistics. ^(When memory allocation statistics are
1923 ** disabled, the following SQLite interfaces become non-operational:
1924 ** <ul>
1925 ** <li> [sqlite3_hard_heap_limit64()]
1926 ** <li> [sqlite3_memory_used()]
1927 ** <li> [sqlite3_memory_highwater()]
1928 ** <li> [sqlite3_soft_heap_limit64()]
1929 ** <li> [sqlite3_status64()]
1930 ** </ul>)^
1931 ** ^Memory allocation statistics are enabled by default unless SQLite is
1932 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1933 ** allocation statistics are disabled by default.
1934 ** </dd>
1935 **
1936 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1937 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1938 ** </dd>
1939 **
1940 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1941 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1942 ** that SQLite can use for the database page cache with the default page
1943 ** cache implementation.
1944 ** This configuration option is a no-op if an application-defined page
1945 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1946 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1947 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1948 ** and the number of cache lines (N).
1949 ** The sz argument should be the size of the largest database page
1950 ** (a power of two between 512 and 65536) plus some extra bytes for each
1951 ** page header. ^The number of extra bytes needed by the page header
1952 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1953 ** ^It is harmless, apart from the wasted memory,
1954 ** for the sz parameter to be larger than necessary. The pMem
1955 ** argument must be either a NULL pointer or a pointer to an 8-byte
1956 ** aligned block of memory of at least sz*N bytes, otherwise
1957 ** subsequent behavior is undefined.
1958 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1959 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1960 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1961 ** is exhausted.
1962 ** ^If pMem is NULL and N is non-zero, then each database connection
1963 ** does an initial bulk allocation for page cache memory
1964 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1965 ** of -1024*N bytes if N is negative. ^If additional
1966 ** page cache memory is needed beyond what is provided by the initial
1967 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1968 ** additional cache line. </dd>
1969 **
1970 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1971 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1972 ** that SQLite will use for all of its dynamic memory allocation needs
1973 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1974 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1975 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1976 ** [SQLITE_ERROR] if invoked otherwise.
1977 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1978 ** An 8-byte aligned pointer to the memory,
1979 ** the number of bytes in the memory buffer, and the minimum allocation size.
1980 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1981 ** to using its default memory allocator (the system malloc() implementation),
1982 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1983 ** memory pointer is not NULL then the alternative memory
1984 ** allocator is engaged to handle all of SQLites memory allocation needs.
1985 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1986 ** boundary or subsequent behavior of SQLite will be undefined.
1987 ** The minimum allocation size is capped at 2**12. Reasonable values
1988 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1989 **
1990 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1991 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1992 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1993 ** The argument specifies alternative low-level mutex routines to be used
1994 ** in place of the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1995 ** the content of the [sqlite3_mutex_methods] structure before the call to
1996 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1997 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1998 ** the entire mutexing subsystem is omitted from the build and hence calls to
1999 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
2000 ** return [SQLITE_ERROR].</dd>
2001 **
2002 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
2003 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
2004 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
2005 ** [sqlite3_mutex_methods]
2006 ** structure is filled with the currently defined mutex routines.)^
2007 ** This option can be used to overload the default mutex allocation
2008 ** routines with a wrapper used to track mutex usage for performance
2009 ** profiling or testing, for example. ^If SQLite is compiled with
2010 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
2011 ** the entire mutexing subsystem is omitted from the build and hence calls to
2012 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
2013 ** return [SQLITE_ERROR].</dd>
2014 **
2015 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
2016 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
2017 ** the default size of [lookaside memory] on each [database connection].
2018 ** The first argument is the
2019 ** size of each lookaside buffer slot ("sz") and the second is the number of
2020 ** slots allocated to each database connection ("cnt").)^
2021 ** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2022 ** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2023 ** be used to change the lookaside configuration on individual connections.)^
2024 ** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2025 ** default lookaside configuration at compile-time.
2026 ** </dd>
2027 **
2028 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2029 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2030 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2031 ** the interface to a custom page cache implementation.)^
2032 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2033 **
2034 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2035 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2036 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies off
2037 ** the current page cache implementation into that object.)^ </dd>
2038 **
2039 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2040 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2041 ** global [error log].
2042 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2043 ** function with a call signature of void(*)(void*,int,const char*),
2044 ** and a pointer to void. ^If the function pointer is not NULL, it is
2045 ** invoked by [sqlite3_log()] to process each logging event. ^If the
2046 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2047 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2048 ** passed through as the first parameter to the application-defined logger
2049 ** function whenever that function is invoked. ^The second parameter to
2050 ** the logger function is a copy of the first parameter to the corresponding
2051 ** [sqlite3_log()] call and is intended to be a [result code] or an
2052 ** [extended result code]. ^The third parameter passed to the logger is
2053 ** a log message after formatting via [sqlite3_snprintf()].
2054 ** The SQLite logging interface is not reentrant; the logger function
2055 ** supplied by the application must not invoke any SQLite interface.
2056 ** In a multi-threaded application, the application-defined logger
2057 ** function must be threadsafe. </dd>
2058 **
2059 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2060 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2061 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2062 ** then URI handling is globally disabled.)^ ^If URI handling is globally
2063 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2064 ** [sqlite3_open16()] or
2065 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2066 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2067 ** connection is opened. ^If it is globally disabled, filenames are
2068 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2069 ** database connection is opened. ^(By default, URI handling is globally
2070 ** disabled. The default value may be changed by compiling with the
2071 ** [SQLITE_USE_URI] symbol defined.)^
2072 **
2073 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2074 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2075 ** argument which is interpreted as a boolean in order to enable or disable
2076 ** the use of covering indices for full table scans in the query optimizer.
2077 ** ^The default setting is determined
2078 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2079 ** if that compile-time option is omitted.
2080 ** The ability to disable the use of covering indices for full table scans
2081 ** is because some incorrectly coded legacy applications might malfunction
2082 ** when the optimization is enabled. Providing the ability to
2083 ** disable the optimization allows the older, buggy application code to work
2084 ** without change even with newer versions of SQLite.
2085 **
2086 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2087 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2088 ** <dd> These options are obsolete and should not be used by new code.
2089 ** They are retained for backwards compatibility but are now no-ops.
2090 ** </dd>
2091 **
2092 ** [[SQLITE_CONFIG_SQLLOG]]
2093 ** <dt>SQLITE_CONFIG_SQLLOG
2094 ** <dd>This option is only available if sqlite is compiled with the
2095 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2096 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2097 ** The second should be of type (void*). The callback is invoked by the library
2098 ** in three separate circumstances, identified by the value passed as the
2099 ** fourth parameter. If the fourth parameter is 0, then the database connection
2100 ** passed as the second argument has just been opened. The third argument
2101 ** points to a buffer containing the name of the main database file. If the
2102 ** fourth parameter is 1, then the SQL statement that the third parameter
2103 ** points to has just been executed. Or, if the fourth parameter is 2, then
2104 ** the connection being passed as the second parameter is being closed. The
2105 ** third parameter is passed NULL In this case. An example of using this
2106 ** configuration option can be seen in the "test_sqllog.c" source file in
2107 ** the canonical SQLite source tree.</dd>
2108 **
2109 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2110 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2111 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2112 ** that are the default mmap size limit (the default setting for
2113 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2114 ** ^The default setting can be overridden by each database connection using
2115 ** either the [PRAGMA mmap_size] command, or by using the
2116 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2117 ** will be silently truncated if necessary so that it does not exceed the
2118 ** compile-time maximum mmap size set by the
2119 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2120 ** ^If either argument to this option is negative, then that argument is
2121 ** changed to its compile-time default.
2122 **
2123 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2124 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2125 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2126 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2127 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2128 ** that specifies the maximum size of the created heap.
2129 **
2130 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2131 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2132 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2133 ** is a pointer to an integer and writes into that integer the number of extra
2134 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2135 ** The amount of extra space required can change depending on the compiler,
2136 ** target platform, and SQLite version.
2137 **
2138 ** [[SQLITE_CONFIG_PMASZ]]
2139 ** <dt>SQLITE_CONFIG_PMASZ
2140 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2141 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2142 ** sorter to that integer. The default minimum PMA Size is set by the
2143 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2144 ** to help with sort operations when multithreaded sorting
2145 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2146 ** to be sorted exceeds the page size times the minimum of the
2147 ** [PRAGMA cache_size] setting and this value.
2148 **
2149 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2150 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2151 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2152 ** becomes the [statement journal] spill-to-disk threshold.
2153 ** [Statement journals] are held in memory until their size (in bytes)
2154 ** exceeds this threshold, at which point they are written to disk.
2155 ** Or if the threshold is -1, statement journals are always held
2156 ** exclusively in memory.
2157 ** Since many statement journals never become large, setting the spill
2158 ** threshold to a value such as 64KiB can greatly reduce the amount of
2159 ** I/O required to support statement rollback.
2160 ** The default value for this setting is controlled by the
2161 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2162 **
2163 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2164 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2165 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2166 ** of type (int) - the new value of the sorter-reference size threshold.
2167 ** Usually, when SQLite uses an external sort to order records according
2168 ** to an ORDER BY clause, all fields required by the caller are present in the
2169 ** sorted records. However, if SQLite determines based on the declared type
2170 ** of a table column that its values are likely to be very large - larger
2171 ** than the configured sorter-reference size threshold - then a reference
2172 ** is stored in each sorted record and the required column values loaded
2173 ** from the database as records are returned in sorted order. The default
2174 ** value for this option is to never use this optimization. Specifying a
2175 ** negative value for this option restores the default behavior.
2176 ** This option is only available if SQLite is compiled with the
2177 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2178 **
2179 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2180 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2181 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2182 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2183 ** database created using [sqlite3_deserialize()]. This default maximum
2184 ** size can be adjusted up or down for individual databases using the
2185 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2186 ** configuration setting is never used, then the default maximum is determined
2187 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2188 ** compile-time option is not set, then the default maximum is 1073741824.
2189 **
2190 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2191 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2192 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2193 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2194 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2195 ** defaults to on. This configuration option queries the current setting or
2196 ** changes the setting to off or on. The argument is a pointer to an integer.
2197 ** If that integer initially holds a value of 1, then the ability for VIEWs to
2198 ** have ROWIDs is activated. If the integer initially holds zero, then the
2199 ** ability is deactivated. Any other initial value for the integer leaves the
2200 ** setting unchanged. After changes, if any, the integer is written with
2201 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2202 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2203 ** recommended case) then the integer is always filled with zero, regardless
2204 ** if its initial value.
2205 ** </dl>
2206 */
2207 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2208 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2209 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2210 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2211 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2212 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2213 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2214 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2215 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2216 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2217 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2218 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2219 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2220 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2221 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2222 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2223 #define SQLITE_CONFIG_URI 17 /* int */
2224 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2225 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2226 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2227 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2228 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2229 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2230 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2231 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2232 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2233 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2234 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2235 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2236 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2237
2238 /*
2239 ** CAPI3REF: Database Connection Configuration Options
2240 **
2241 ** These constants are the available integer configuration options that
2242 ** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2243 **
2244 ** The [sqlite3_db_config()] interface is a var-args function. It takes a
2245 ** variable number of parameters, though always at least two. The number of
2246 ** parameters passed into sqlite3_db_config() depends on which of these
2247 ** constants is given as the second parameter. This documentation page
2248 ** refers to parameters beyond the second as "arguments". Thus, when this
2249 ** page says "the N-th argument" it means "the N-th parameter past the
2250 ** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2251 **
2252 ** New configuration options may be added in future releases of SQLite.
2253 ** Existing configuration options might be discontinued. Applications
2254 ** should check the return code from [sqlite3_db_config()] to make sure that
2255 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2256 ** non-zero [error code] if a discontinued or unsupported configuration option
2257 ** is invoked.
2258 **
2259 ** <dl>
2260 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2261 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2262 ** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2263 ** configuration of the [lookaside memory allocator] within a database
2264 ** connection.
2265 ** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2266 ** in the [DBCONFIG arguments|usual format].
2267 ** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2268 ** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2269 ** should have a total of five parameters.
2270 ** <ol>
2271 ** <li><p>The first argument ("buf") is a
2272 ** pointer to a memory buffer to use for lookaside memory.
2273 ** The first argument may be NULL in which case SQLite will allocate the
2274 ** lookaside buffer itself using [sqlite3_malloc()].
2275 ** <li><P>The second argument ("sz") is the
2276 ** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2277 ** is less than 8. The "sz" argument should be a multiple of 8 less than
2278 ** 65536. If "sz" does not meet this constraint, it is reduced in size until
2279 ** it does.
2280 ** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2281 ** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2282 ** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2283 ** parameter is usually chosen so that the product of "sz" and "cnt" is less
2284 ** than 1,000,000.
2285 ** </ol>
2286 ** <p>If the "buf" argument is not NULL, then it must
2287 ** point to a memory buffer with a size that is greater than
2288 ** or equal to the product of "sz" and "cnt".
2289 ** The buffer must be aligned to an 8-byte boundary.
2290 ** The lookaside memory
2291 ** configuration for a database connection can only be changed when that
2292 ** connection is not currently using lookaside memory, or in other words
2293 ** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2294 ** Any attempt to change the lookaside memory configuration when lookaside
2295 ** memory is in use leaves the configuration unchanged and returns
2296 ** [SQLITE_BUSY].
2297 ** If the "buf" argument is NULL and an attempt
2298 ** to allocate memory based on "sz" and "cnt" fails, then
2299 ** lookaside is silently disabled.
2300 ** <p>
2301 ** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2302 ** default lookaside configuration at initialization. The
2303 ** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2304 ** configuration at compile-time. Typical values for lookaside are 1200 for
2305 ** "sz" and 40 to 100 for "cnt".
2306 ** </dd>
2307 **
2308 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2309 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2310 ** <dd> ^This option is used to enable or disable the enforcement of
2311 ** [foreign key constraints]. This is the same setting that is
2312 ** enabled or disabled by the [PRAGMA foreign_keys] statement.
2313 ** The first argument is an integer which is 0 to disable FK enforcement,
2314 ** positive to enable FK enforcement or negative to leave FK enforcement
2315 ** unchanged. The second parameter is a pointer to an integer into which
2316 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2317 ** following this call. The second parameter may be a NULL pointer, in
2318 ** which case the FK enforcement setting is not reported back. </dd>
2319 **
2320 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2321 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2322 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2323 ** There should be two additional arguments.
2324 ** The first argument is an integer which is 0 to disable triggers,
2325 ** positive to enable triggers or negative to leave the setting unchanged.
2326 ** The second parameter is a pointer to an integer into which
2327 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2328 ** following this call. The second parameter may be a NULL pointer, in
2329 ** which case the trigger setting is not reported back.
2330 **
2331 ** <p>Originally this option disabled all triggers. ^(However, since
2332 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2333 ** this option is off. So, in other words, this option now only disables
2334 ** triggers in the main database schema or in the schemas of [ATTACH]-ed
2335 ** databases.)^ </dd>
2336 **
2337 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2338 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2339 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2340 ** There must be two additional arguments.
2341 ** The first argument is an integer which is 0 to disable views,
2342 ** positive to enable views or negative to leave the setting unchanged.
2343 ** The second parameter is a pointer to an integer into which
2344 ** is written 0 or 1 to indicate whether views are disabled or enabled
2345 ** following this call. The second parameter may be a NULL pointer, in
2346 ** which case the view setting is not reported back.
2347 **
2348 ** <p>Originally this option disabled all views. ^(However, since
2349 ** SQLite version 3.35.0, TEMP views are still allowed even if
2350 ** this option is off. So, in other words, this option now only disables
2351 ** views in the main database schema or in the schemas of ATTACH-ed
2352 ** databases.)^ </dd>
2353 **
2354 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2355 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2356 ** <dd> ^This option is used to enable or disable using the
2357 ** [fts3_tokenizer()] function - part of the [FTS3] full-text search engine
2358 ** extension - without using bound parameters as the parameters. Doing so
2359 ** is disabled by default. There must be two additional arguments. The first
2360 ** argument is an integer. If it is passed 0, then using fts3_tokenizer()
2361 ** without bound parameters is disabled. If it is passed a positive value,
2362 ** then calling fts3_tokenizer without bound parameters is enabled. If it
2363 ** is passed a negative value, this setting is not modified - this can be
2364 ** used to query for the current setting. The second parameter is a pointer
2365 ** to an integer into which is written 0 or 1 to indicate the current value
2366 ** of this setting (after it is modified, if applicable). The second
2367 ** parameter may be a NULL pointer, in which case the value of the setting
2368 ** is not reported back. Refer to [FTS3] documentation for further details.
2369 ** </dd>
2370 **
2371 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2372 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2373 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2374 ** interface independently of the [load_extension()] SQL function.
2375 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2376 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2377 ** There must be two additional arguments.
2378 ** When the first argument to this interface is 1, then only the C-API is
2379 ** enabled and the SQL function remains disabled. If the first argument to
2380 ** this interface is 0, then both the C-API and the SQL function are disabled.
2381 ** If the first argument is -1, then no changes are made to the state of either
2382 ** the C-API or the SQL function.
2383 ** The second parameter is a pointer to an integer into which
2384 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2385 ** is disabled or enabled following this call. The second parameter may
2386 ** be a NULL pointer, in which case the new setting is not reported back.
2387 ** </dd>
2388 **
2389 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2390 ** <dd> ^This option is used to change the name of the "main" database
2391 ** schema. This option does not follow the
2392 ** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2393 ** This option takes exactly one additional argument so that the
2394 ** [sqlite3_db_config()] call has a total of three parameters. The
2395 ** extra argument must be a pointer to a constant UTF8 string which
2396 ** will become the new schema name in place of "main". ^SQLite does
2397 ** not make a copy of the new main schema name string, so the application
2398 ** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2399 ** is unchanged until after the database connection closes.
2400 ** </dd>
2401 **
2402 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2403 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2404 ** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2405 ** database handle, SQLite checks if if there are other connections to the
2406 ** same database, and if there are no other database connection (if the
2407 ** connection being closed is the last open connection to the database),
2408 ** then SQLite performs a [checkpoint] before closing the connection and
2409 ** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2410 ** be used to override that behavior. The first argument passed to this
2411 ** operation (the third parameter to [sqlite3_db_config()]) is an integer
2412 ** which is positive to disable checkpoints-on-close, or zero (the default)
2413 ** to enable them, and negative to leave the setting unchanged.
2414 ** The second argument (the fourth parameter) is a pointer to an integer
2415 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2416 ** have been disabled - 0 if they are not disabled, 1 if they are.
2417 ** </dd>
2418 **
2419 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2420 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2421 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2422 ** a single SQL query statement will always use the same algorithm regardless
2423 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2424 ** that look at the values of bound parameters, which can make some queries
2425 ** slower. But the QPSG has the advantage of more predictable behavior. With
2426 ** the QPSG active, SQLite will always use the same query plan in the field as
2427 ** was used during testing in the lab.
2428 ** The first argument to this setting is an integer which is 0 to disable
2429 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2430 ** unchanged. The second parameter is a pointer to an integer into which
2431 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2432 ** following this call.
2433 ** </dd>
2434 **
2435 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2436 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2437 ** include output for any operations performed by trigger programs. This
2438 ** option is used to set or clear (the default) a flag that governs this
2439 ** behavior. The first parameter passed to this operation is an integer -
2440 ** positive to enable output for trigger programs, or zero to disable it,
2441 ** or negative to leave the setting unchanged.
2442 ** The second parameter is a pointer to an integer into which is written
2443 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2444 ** it is not disabled, 1 if it is.
2445 ** </dd>
2446 **
2447 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2448 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2449 ** [VACUUM] in order to reset a database back to an empty database
2450 ** with no schema and no content. The following process works even for
2451 ** a badly corrupted database file:
2452 ** <ol>
2453 ** <li> If the database connection is newly opened, make sure it has read the
2454 ** database schema by preparing then discarding some query against the
2455 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2456 ** errors. This step is only necessary if the application desires to keep
2457 ** the database in WAL mode after the reset if it was in WAL mode before
2458 ** the reset.
2459 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2460 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2461 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2462 ** </ol>
2463 ** Because resetting a database is destructive and irreversible, the
2464 ** process requires the use of this obscure API and multiple steps to
2465 ** help ensure that it does not happen by accident. Because this
2466 ** feature must be capable of resetting corrupt databases, and
2467 ** shutting down virtual tables may require access to that corrupt
2468 ** storage, the library must abandon any installed virtual tables
2469 ** without calling their xDestroy() methods.
2470 **
2471 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2472 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2473 ** "defensive" flag for a database connection. When the defensive
2474 ** flag is enabled, language features that allow ordinary SQL to
2475 ** deliberately corrupt the database file are disabled. The disabled
2476 ** features include but are not limited to the following:
2477 ** <ul>
2478 ** <li> The [PRAGMA writable_schema=ON] statement.
2479 ** <li> The [PRAGMA journal_mode=OFF] statement.
2480 ** <li> The [PRAGMA schema_version=N] statement.
2481 ** <li> Writes to the [sqlite_dbpage] virtual table.
2482 ** <li> Direct writes to [shadow tables].
2483 ** </ul>
2484 ** </dd>
2485 **
2486 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2487 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2488 ** "writable_schema" flag. This has the same effect and is logically equivalent
2489 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2490 ** The first argument to this setting is an integer which is 0 to disable
2491 ** the writable_schema, positive to enable writable_schema, or negative to
2492 ** leave the setting unchanged. The second parameter is a pointer to an
2493 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2494 ** is enabled or disabled following this call.
2495 ** </dd>
2496 **
2497 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2498 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2499 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2500 ** the legacy behavior of the [ALTER TABLE RENAME] command such that it
2501 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2502 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2503 ** additional information. This feature can also be turned on and off
2504 ** using the [PRAGMA legacy_alter_table] statement.
2505 ** </dd>
2506 **
2507 ** [[SQLITE_DBCONFIG_DQS_DML]]
2508 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2509 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2510 ** the legacy [double-quoted string literal] misfeature for DML statements
2511 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2512 ** default value of this setting is determined by the [-DSQLITE_DQS]
2513 ** compile-time option.
2514 ** </dd>
2515 **
2516 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2517 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2518 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2519 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2520 ** such as CREATE TABLE and CREATE INDEX. The
2521 ** default value of this setting is determined by the [-DSQLITE_DQS]
2522 ** compile-time option.
2523 ** </dd>
2524 **
2525 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2526 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2527 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2528 ** assume that database schemas are untainted by malicious content.
2529 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2530 ** takes additional defensive steps to protect the application from harm
2531 ** including:
2532 ** <ul>
2533 ** <li> Prohibit the use of SQL functions inside triggers, views,
2534 ** CHECK constraints, DEFAULT clauses, expression indexes,
2535 ** partial indexes, or generated columns
2536 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2537 ** <li> Prohibit the use of virtual tables inside of triggers or views
2538 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2539 ** </ul>
2540 ** This setting defaults to "on" for legacy compatibility, however
2541 ** all applications are advised to turn it off if possible. This setting
2542 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2543 ** </dd>
2544 **
2545 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2546 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2547 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2548 ** the legacy file format flag. When activated, this flag causes all newly
2549 ** created database files to have a schema format version number (the 4-byte
2550 ** integer found at offset 44 into the database header) of 1. This in turn
2551 ** means that the resulting database file will be readable and writable by
2552 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2553 ** newly created databases are generally not understandable by SQLite versions
2554 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2555 ** is now scarcely any need to generate database files that are compatible
2556 ** all the way back to version 3.0.0, and so this setting is of little
2557 ** practical use, but is provided so that SQLite can continue to claim the
2558 ** ability to generate new database files that are compatible with version
2559 ** 3.0.0.
2560 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2561 ** the [VACUUM] command will fail with an obscure error when attempting to
2562 ** process a table with generated columns and a descending index. This is
2563 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2564 ** either generated columns or descending indexes.
2565 ** </dd>
2566 **
2567 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2568 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2569 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2570 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2571 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2572 ** statistics. For statistics to be collected, the flag must be set on
2573 ** the database handle both when the SQL statement is prepared and when it
2574 ** is stepped. The flag is set (collection of statistics is enabled)
2575 ** by default. <p>This option takes two arguments: an integer and a pointer to
2576 ** an integer. The first argument is 1, 0, or -1 to enable, disable, or
2577 ** leave unchanged the statement scanstatus option. If the second argument
2578 ** is not NULL, then the value of the statement scanstatus setting after
2579 ** processing the first argument is written into the integer that the second
2580 ** argument points to.
2581 ** </dd>
2582 **
2583 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2584 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2585 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2586 ** in which tables and indexes are scanned so that the scans start at the end
2587 ** and work toward the beginning rather than starting at the beginning and
2588 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2589 ** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2590 ** two arguments which are an integer and a pointer to an integer. The first
2591 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2592 ** reverse scan order flag, respectively. If the second argument is not NULL,
2593 ** then 0 or 1 is written into the integer that the second argument points to
2594 ** depending on if the reverse scan order flag is set after processing the
2595 ** first argument.
2596 ** </dd>
2597 **
2598 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2599 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2600 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2601 ** the ability of the [ATTACH DATABASE] SQL command to create a new database
2602 ** file if the database filed named in the ATTACH command does not already
2603 ** exist. This ability of ATTACH to create a new database is enabled by
2604 ** default. Applications can disable or reenable the ability for ATTACH to
2605 ** create new database files using this DBCONFIG option.<p>
2606 ** This option takes two arguments which are an integer and a pointer
2607 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2608 ** leave unchanged the attach-create flag, respectively. If the second
2609 ** argument is not NULL, then 0 or 1 is written into the integer that the
2610 ** second argument points to depending on if the attach-create flag is set
2611 ** after processing the first argument.
2612 ** </dd>
2613 **
2614 ** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2615 ** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2616 ** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2617 ** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2618 ** This capability is enabled by default. Applications can disable or
2619 ** reenable this capability using the current DBCONFIG option. If
2620 ** this capability is disabled, the [ATTACH] command will still work,
2621 ** but the database will be opened read-only. If this option is disabled,
2622 ** then the ability to create a new database using [ATTACH] is also disabled,
2623 ** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2624 ** option.<p>
2625 ** This option takes two arguments which are an integer and a pointer
2626 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2627 ** leave unchanged the ability to ATTACH another database for writing,
2628 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2629 ** into the integer to which the second argument points, depending on whether
2630 ** the ability to ATTACH a read/write database is enabled or disabled
2631 ** after processing the first argument.
2632 ** </dd>
2633 **
2634 ** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2635 ** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2636 ** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2637 ** ability to include comments in SQL text. Comments are enabled by default.
2638 ** An application can disable or reenable comments in SQL text using this
2639 ** DBCONFIG option.<p>
2640 ** This option takes two arguments which are an integer and a pointer
2641 ** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2642 ** leave unchanged the ability to use comments in SQL text,
2643 ** respectively. If the second argument is not NULL, then 0 or 1 is written
2644 ** into the integer that the second argument points to depending on if
2645 ** comments are allowed in SQL text after processing the first argument.
2646 ** </dd>
2647 **
2648 ** </dl>
2649 **
2650 ** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2651 **
2652 ** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2653 ** overall call to [sqlite3_db_config()] has a total of four parameters.
2654 ** The first argument (the third parameter to sqlite3_db_config()) is an integer.
2655 ** The second argument is a pointer to an integer. If the first argument is 1,
2656 ** then the option becomes enabled. If the first integer argument is 0, then the
2657 ** option is disabled. If the first argument is -1, then the option setting
2658 ** is unchanged. The second argument, the pointer to an integer, may be NULL.
2659 ** If the second argument is not NULL, then a value of 0 or 1 is written into
2660 ** the integer to which the second argument points, depending on whether the
2661 ** setting is disabled or enabled after applying any changes specified by
2662 ** the first argument.
2663 **
2664 ** <p>While most SQLITE_DBCONFIG options use the argument format
2665 ** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2666 ** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2667 ** documentation of those exceptional options for details.
2668 */
2669 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2670 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2671 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2672 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2673 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2674 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2675 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2676 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2677 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2678 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2679 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2680 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2681 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2682 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2683 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2684 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2685 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2686 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2687 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2688 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2689 #define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2690 #define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2691 #define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2692 #define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2693
2694 /*
2695 ** CAPI3REF: Enable Or Disable Extended Result Codes
2696 ** METHOD: sqlite3
2697 **
2698 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2699 ** [extended result codes] feature of SQLite. ^The extended result
2700 ** codes are disabled by default for historical compatibility.
2701 */
2702 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2703
2704 /*
2705 ** CAPI3REF: Last Insert Rowid
2706 ** METHOD: sqlite3
2707 **
2708 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2709 ** has a unique 64-bit signed
2710 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2711 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2712 ** names are not also used by explicitly declared columns. ^If
2713 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2714 ** is another alias for the rowid.
2715 **
2716 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2717 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2718 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2719 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2720 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2721 ** zero.
2722 **
2723 ** As well as being set automatically as rows are inserted into database
2724 ** tables, the value returned by this function may be set explicitly by
2725 ** [sqlite3_set_last_insert_rowid()]
2726 **
2727 ** Some virtual table implementations may INSERT rows into rowid tables as
2728 ** part of committing a transaction (e.g. to flush data accumulated in memory
2729 ** to disk). In this case subsequent calls to this function return the rowid
2730 ** associated with these internal INSERT operations, which leads to
2731 ** unintuitive results. Virtual table implementations that do write to rowid
2732 ** tables in this way can avoid this problem by restoring the original
2733 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2734 ** control to the user.
2735 **
2736 ** ^(If an [INSERT] occurs within a trigger then this routine will
2737 ** return the [rowid] of the inserted row as long as the trigger is
2738 ** running. Once the trigger program ends, the value returned
2739 ** by this routine reverts to what it was before the trigger was fired.)^
2740 **
2741 ** ^An [INSERT] that fails due to a constraint violation is not a
2742 ** successful [INSERT] and does not change the value returned by this
2743 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2744 ** and INSERT OR ABORT make no changes to the return value of this
2745 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2746 ** encounters a constraint violation, it does not fail. The
2747 ** INSERT continues to completion after deleting rows that caused
2748 ** the constraint problem so INSERT OR REPLACE will always change
2749 ** the return value of this interface.)^
2750 **
2751 ** ^For the purposes of this routine, an [INSERT] is considered to
2752 ** be successful even if it is subsequently rolled back.
2753 **
2754 ** This function is accessible to SQL statements via the
2755 ** [last_insert_rowid() SQL function].
2756 **
2757 ** If a separate thread performs a new [INSERT] on the same
2758 ** database connection while the [sqlite3_last_insert_rowid()]
2759 ** function is running and thus changes the last insert [rowid],
2760 ** then the value returned by [sqlite3_last_insert_rowid()] is
2761 ** unpredictable and might not equal either the old or the new
2762 ** last insert [rowid].
2763 */
2764 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2765
2766 /*
2767 ** CAPI3REF: Set the Last Insert Rowid value.
2768 ** METHOD: sqlite3
2769 **
2770 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2771 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2772 ** without inserting a row into the database.
2773 */
2774 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2775
2776 /*
2777 ** CAPI3REF: Count The Number Of Rows Modified
2778 ** METHOD: sqlite3
2779 **
2780 ** ^These functions return the number of rows modified, inserted or
2781 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2782 ** statement on the database connection specified by the only parameter.
2783 ** The two functions are identical except for the type of the return value
2784 ** and that if the number of rows modified by the most recent INSERT, UPDATE,
2785 ** or DELETE is greater than the maximum value supported by type "int", then
2786 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2787 ** type of SQL statement does not modify the value returned by these functions.
2788 ** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2789 ** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2790 ** added to the new table by the CREATE TABLE AS SELECT statement are not
2791 ** counted.
2792 **
2793 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2794 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2795 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2796 **
2797 ** Changes to a view that are intercepted by
2798 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2799 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2800 ** DELETE statement run on a view is always zero. Only changes made to real
2801 ** tables are counted.
2802 **
2803 ** Things are more complicated if the sqlite3_changes() function is
2804 ** executed while a trigger program is running. This may happen if the
2805 ** program uses the [changes() SQL function], or if some other callback
2806 ** function invokes sqlite3_changes() directly. Essentially:
2807 **
2808 ** <ul>
2809 ** <li> ^(Before entering a trigger program the value returned by
2810 ** sqlite3_changes() function is saved. After the trigger program
2811 ** has finished, the original value is restored.)^
2812 **
2813 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2814 ** statement sets the value returned by sqlite3_changes()
2815 ** upon completion as normal. Of course, this value will not include
2816 ** any changes performed by sub-triggers, as the sqlite3_changes()
2817 ** value will be saved and restored after each sub-trigger has run.)^
2818 ** </ul>
2819 **
2820 ** ^This means that if the changes() SQL function (or similar) is used
2821 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2822 ** returns the value as set when the calling statement began executing.
2823 ** ^If it is used by the second or subsequent such statement within a trigger
2824 ** program, the value returned reflects the number of rows modified by the
2825 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2826 **
2827 ** If a separate thread makes changes on the same database connection
2828 ** while [sqlite3_changes()] is running then the value returned
2829 ** is unpredictable and not meaningful.
2830 **
2831 ** See also:
2832 ** <ul>
2833 ** <li> the [sqlite3_total_changes()] interface
2834 ** <li> the [count_changes pragma]
2835 ** <li> the [changes() SQL function]
2836 ** <li> the [data_version pragma]
2837 ** </ul>
2838 */
2839 SQLITE_API int sqlite3_changes(sqlite3*);
2840 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2841
2842 /*
2843 ** CAPI3REF: Total Number Of Rows Modified
2844 ** METHOD: sqlite3
2845 **
2846 ** ^These functions return the total number of rows inserted, modified or
2847 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2848 ** since the database connection was opened, including those executed as
2849 ** part of trigger programs. The two functions are identical except for the
2850 ** type of the return value and that if the number of rows modified by the
2851 ** connection exceeds the maximum value supported by type "int", then
2852 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2853 ** any other type of SQL statement does not affect the value returned by
2854 ** sqlite3_total_changes().
2855 **
2856 ** ^Changes made as part of [foreign key actions] are included in the
2857 ** count, but those made as part of REPLACE constraint resolution are
2858 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2859 ** are not counted.
2860 **
2861 ** The [sqlite3_total_changes(D)] interface only reports the number
2862 ** of rows that changed due to SQL statement run against database
2863 ** connection D. Any changes by other database connections are ignored.
2864 ** To detect changes against a database file from other database
2865 ** connections use the [PRAGMA data_version] command or the
2866 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2867 **
2868 ** If a separate thread makes changes on the same database connection
2869 ** while [sqlite3_total_changes()] is running then the value
2870 ** returned is unpredictable and not meaningful.
2871 **
2872 ** See also:
2873 ** <ul>
2874 ** <li> the [sqlite3_changes()] interface
2875 ** <li> the [count_changes pragma]
2876 ** <li> the [changes() SQL function]
2877 ** <li> the [data_version pragma]
2878 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2879 ** </ul>
2880 */
2881 SQLITE_API int sqlite3_total_changes(sqlite3*);
2882 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2883
2884 /*
2885 ** CAPI3REF: Interrupt A Long-Running Query
2886 ** METHOD: sqlite3
2887 **
2888 ** ^This function causes any pending database operation to abort and
2889 ** return at its earliest opportunity. This routine is typically
2890 ** called in response to a user action such as pressing "Cancel"
2891 ** or Ctrl-C where the user wants a long query operation to halt
2892 ** immediately.
2893 **
2894 ** ^It is safe to call this routine from a thread different from the
2895 ** thread that is currently running the database operation. But it
2896 ** is not safe to call this routine with a [database connection] that
2897 ** is closed or might close before sqlite3_interrupt() returns.
2898 **
2899 ** ^If an SQL operation is very nearly finished at the time when
2900 ** sqlite3_interrupt() is called, then it might not have an opportunity
2901 ** to be interrupted and might continue to completion.
2902 **
2903 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2904 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2905 ** that is inside an explicit transaction, then the entire transaction
2906 ** will be rolled back automatically.
2907 **
2908 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2909 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2910 ** that are started after the sqlite3_interrupt() call and before the
2911 ** running statement count reaches zero are interrupted as if they had been
2912 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2913 ** that are started after the running statement count reaches zero are
2914 ** not effected by the sqlite3_interrupt().
2915 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2916 ** SQL statements is a no-op and has no effect on SQL statements
2917 ** that are started after the sqlite3_interrupt() call returns.
2918 **
2919 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2920 ** or not an interrupt is currently in effect for [database connection] D.
2921 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2922 */
2923 SQLITE_API void sqlite3_interrupt(sqlite3*);
2924 SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2925
2926 /*
2927 ** CAPI3REF: Determine If An SQL Statement Is Complete
2928 **
2929 ** These routines are useful during command-line input to determine if the
2930 ** currently entered text seems to form a complete SQL statement or
2931 ** if additional input is needed before sending the text into
2932 ** SQLite for parsing. ^These routines return 1 if the input string
2933 ** appears to be a complete SQL statement. ^A statement is judged to be
2934 ** complete if it ends with a semicolon token and is not a prefix of a
2935 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2936 ** string literals or quoted identifier names or comments are not
2937 ** independent tokens (they are part of the token in which they are
2938 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2939 ** and comments that follow the final semicolon are ignored.
2940 **
2941 ** ^These routines return 0 if the statement is incomplete. ^If a
2942 ** memory allocation fails, then SQLITE_NOMEM is returned.
2943 **
2944 ** ^These routines do not parse the SQL statements and thus
2945 ** will not detect syntactically incorrect SQL.
2946 **
2947 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2948 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2949 ** automatically by sqlite3_complete16(). If that initialization fails,
2950 ** then the return value from sqlite3_complete16() will be non-zero
2951 ** regardless of whether or not the input SQL is complete.)^
2952 **
2953 ** The input to [sqlite3_complete()] must be a zero-terminated
2954 ** UTF-8 string.
2955 **
2956 ** The input to [sqlite3_complete16()] must be a zero-terminated
2957 ** UTF-16 string in native byte order.
2958 */
2959 SQLITE_API int sqlite3_complete(const char *sql);
2960 SQLITE_API int sqlite3_complete16(const void *sql);
2961
2962 /*
2963 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2964 ** KEYWORDS: {busy-handler callback} {busy handler}
2965 ** METHOD: sqlite3
2966 **
2967 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2968 ** that might be invoked with argument P whenever
2969 ** an attempt is made to access a database table associated with
2970 ** [database connection] D when another thread
2971 ** or process has the table locked.
2972 ** The sqlite3_busy_handler() interface is used to implement
2973 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2974 **
2975 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2976 ** is returned immediately upon encountering the lock. ^If the busy callback
2977 ** is not NULL, then the callback might be invoked with two arguments.
2978 **
2979 ** ^The first argument to the busy handler is a copy of the void* pointer which
2980 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2981 ** the busy handler callback is the number of times that the busy handler has
2982 ** been invoked previously for the same locking event. ^If the
2983 ** busy callback returns 0, then no additional attempts are made to
2984 ** access the database and [SQLITE_BUSY] is returned
2985 ** to the application.
2986 ** ^If the callback returns non-zero, then another attempt
2987 ** is made to access the database and the cycle repeats.
2988 **
2989 ** The presence of a busy handler does not guarantee that it will be invoked
2990 ** when there is lock contention. ^If SQLite determines that invoking the busy
2991 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2992 ** to the application instead of invoking the
2993 ** busy handler.
2994 ** Consider a scenario where one process is holding a read lock that
2995 ** it is trying to promote to a reserved lock and
2996 ** a second process is holding a reserved lock that it is trying
2997 ** to promote to an exclusive lock. The first process cannot proceed
2998 ** because it is blocked by the second and the second process cannot
2999 ** proceed because it is blocked by the first. If both processes
3000 ** invoke the busy handlers, neither will make any progress. Therefore,
3001 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
3002 ** will induce the first process to release its read lock and allow
3003 ** the second process to proceed.
3004 **
3005 ** ^The default busy callback is NULL.
3006 **
3007 ** ^(There can only be a single busy handler defined for each
3008 ** [database connection]. Setting a new busy handler clears any
3009 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
3010 ** or evaluating [PRAGMA busy_timeout=N] will change the
3011 ** busy handler and thus clear any previously set busy handler.
3012 **
3013 ** The busy callback should not take any actions which modify the
3014 ** database connection that invoked the busy handler. In other words,
3015 ** the busy handler is not reentrant. Any such actions
3016 ** result in undefined behavior.
3017 **
3018 ** A busy handler must not close the database connection
3019 ** or [prepared statement] that invoked the busy handler.
3020 */
3021 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3022
3023 /*
3024 ** CAPI3REF: Set A Busy Timeout
3025 ** METHOD: sqlite3
3026 **
3027 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3028 ** for a specified amount of time when a table is locked. ^The handler
3029 ** will sleep multiple times until at least "ms" milliseconds of sleeping
3030 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
3031 ** the handler returns 0 which causes [sqlite3_step()] to return
3032 ** [SQLITE_BUSY].
3033 **
3034 ** ^Calling this routine with an argument less than or equal to zero
3035 ** turns off all busy handlers.
3036 **
3037 ** ^(There can only be a single busy handler for a particular
3038 ** [database connection] at any given moment. If another busy handler
3039 ** was defined (using [sqlite3_busy_handler()]) prior to calling
3040 ** this routine, that other busy handler is cleared.)^
3041 **
3042 ** See also: [PRAGMA busy_timeout]
3043 */
3044 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3045
3046 /*
3047 ** CAPI3REF: Set the Setlk Timeout
3048 ** METHOD: sqlite3
3049 **
3050 ** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3051 ** the VFS supports blocking locks, it sets the timeout in ms used by
3052 ** eligible locks taken on wal mode databases by the specified database
3053 ** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3054 ** not support blocking locks, this function is a no-op.
3055 **
3056 ** Passing 0 to this function disables blocking locks altogether. Passing
3057 ** -1 to this function requests that the VFS blocks for a long time -
3058 ** indefinitely if possible. The results of passing any other negative value
3059 ** are undefined.
3060 **
3061 ** Internally, each SQLite database handle stores two timeout values - the
3062 ** busy-timeout (used for rollback mode databases, or if the VFS does not
3063 ** support blocking locks) and the setlk-timeout (used for blocking locks
3064 ** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3065 ** values, this function sets only the setlk-timeout value. Therefore,
3066 ** to configure separate busy-timeout and setlk-timeout values for a single
3067 ** database handle, call sqlite3_busy_timeout() followed by this function.
3068 **
3069 ** Whenever the number of connections to a wal mode database falls from
3070 ** 1 to 0, the last connection takes an exclusive lock on the database,
3071 ** then checkpoints and deletes the wal file. While it is doing this, any
3072 ** new connection that tries to read from the database fails with an
3073 ** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3074 ** passed to this API, the new connection blocks until the exclusive lock
3075 ** has been released.
3076 */
3077 SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3078
3079 /*
3080 ** CAPI3REF: Flags for sqlite3_setlk_timeout()
3081 */
3082 #define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3083
3084 /*
3085 ** CAPI3REF: Convenience Routines For Running Queries
3086 ** METHOD: sqlite3
3087 **
3088 ** This is a legacy interface that is preserved for backwards compatibility.
3089 ** Use of this interface is not recommended.
3090 **
3091 ** Definition: A <b>result table</b> is a memory data structure created by the
3092 ** [sqlite3_get_table()] interface. A result table records the
3093 ** complete query results from one or more queries.
3094 **
3095 ** The table conceptually has a number of rows and columns. But
3096 ** these numbers are not part of the result table itself. These
3097 ** numbers are obtained separately. Let N be the number of rows
3098 ** and M be the number of columns.
3099 **
3100 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
3101 ** There are (N+1)*M elements in the array. The first M pointers point
3102 ** to zero-terminated strings that contain the names of the columns.
3103 ** The remaining entries all point to query results. NULL values result
3104 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
3105 ** string representation as returned by [sqlite3_column_text()].
3106 **
3107 ** A result table might consist of one or more memory allocations.
3108 ** It is not safe to pass a result table directly to [sqlite3_free()].
3109 ** A result table should be deallocated using [sqlite3_free_table()].
3110 **
3111 ** ^(As an example of the result table format, suppose a query result
3112 ** is as follows:
3113 **
3114 ** <blockquote><pre>
3115 ** Name | Age
3116 ** -----------------------
3117 ** Alice | 43
3118 ** Bob | 28
3119 ** Cindy | 21
3120 ** </pre></blockquote>
3121 **
3122 ** There are two columns (M==2) and three rows (N==3). Thus the
3123 ** result table has 8 entries. Suppose the result table is stored
3124 ** in an array named azResult. Then azResult holds this content:
3125 **
3126 ** <blockquote><pre>
3127 ** azResult&#91;0] = "Name";
3128 ** azResult&#91;1] = "Age";
3129 ** azResult&#91;2] = "Alice";
3130 ** azResult&#91;3] = "43";
3131 ** azResult&#91;4] = "Bob";
3132 ** azResult&#91;5] = "28";
3133 ** azResult&#91;6] = "Cindy";
3134 ** azResult&#91;7] = "21";
3135 ** </pre></blockquote>)^
3136 **
3137 ** ^The sqlite3_get_table() function evaluates one or more
3138 ** semicolon-separated SQL statements in the zero-terminated UTF-8
3139 ** string of its 2nd parameter and returns a result table to the
3140 ** pointer given in its 3rd parameter.
3141 **
3142 ** After the application has finished with the result from sqlite3_get_table(),
3143 ** it must pass the result table pointer to sqlite3_free_table() in order to
3144 ** release the memory that was malloced. Because of the way the
3145 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3146 ** function must not try to call [sqlite3_free()] directly. Only
3147 ** [sqlite3_free_table()] is able to release the memory properly and safely.
3148 **
3149 ** The sqlite3_get_table() interface is implemented as a wrapper around
3150 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3151 ** to any internal data structures of SQLite. It uses only the public
3152 ** interface defined here. As a consequence, errors that occur in the
3153 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
3154 ** reflected in subsequent calls to [sqlite3_errcode()] or
3155 ** [sqlite3_errmsg()].
3156 */
3157 SQLITE_API int sqlite3_get_table(
3158 sqlite3 *db, /* An open database */
3159 const char *zSql, /* SQL to be evaluated */
3160 char ***pazResult, /* Results of the query */
3161 int *pnRow, /* Number of result rows written here */
3162 int *pnColumn, /* Number of result columns written here */
3163 char **pzErrmsg /* Error msg written here */
3164 );
3165 SQLITE_API void sqlite3_free_table(char **result);
3166
3167 /*
3168 ** CAPI3REF: Formatted String Printing Functions
3169 **
3170 ** These routines are work-alikes of the "printf()" family of functions
3171 ** from the standard C library.
3172 ** These routines understand most of the common formatting options from
3173 ** the standard library printf()
3174 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3175 ** See the [built-in printf()] documentation for details.
3176 **
3177 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3178 ** results into memory obtained from [sqlite3_malloc64()].
3179 ** The strings returned by these two routines should be
3180 ** released by [sqlite3_free()]. ^Both routines return a
3181 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3182 ** memory to hold the resulting string.
3183 **
3184 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3185 ** the standard C library. The result is written into the
3186 ** buffer supplied as the second parameter whose size is given by
3187 ** the first parameter. Note that the order of the
3188 ** first two parameters is reversed from snprintf().)^ This is an
3189 ** historical accident that cannot be fixed without breaking
3190 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
3191 ** returns a pointer to its buffer instead of the number of
3192 ** characters actually written into the buffer.)^ We admit that
3193 ** the number of characters written would be a more useful return
3194 ** value but we cannot change the implementation of sqlite3_snprintf()
3195 ** now without breaking compatibility.
3196 **
3197 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3198 ** guarantees that the buffer is always zero-terminated. ^The first
3199 ** parameter "n" is the total size of the buffer, including space for
3200 ** the zero terminator. So the longest string that can be completely
3201 ** written will be n-1 characters.
3202 **
3203 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3204 **
3205 ** See also: [built-in printf()], [printf() SQL function]
3206 */
3207 SQLITE_API char *sqlite3_mprintf(const char*,...);
3208 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3209 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3210 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3211
3212 /*
3213 ** CAPI3REF: Memory Allocation Subsystem
3214 **
3215 ** The SQLite core uses these three routines for all of its own
3216 ** internal memory allocation needs. "Core" in the previous sentence
3217 ** does not include operating-system specific [VFS] implementation. The
3218 ** Windows VFS uses native malloc() and free() for some operations.
3219 **
3220 ** ^The sqlite3_malloc() routine returns a pointer to a block
3221 ** of memory at least N bytes in length, where N is the parameter.
3222 ** ^If sqlite3_malloc() is unable to obtain sufficient free
3223 ** memory, it returns a NULL pointer. ^If the parameter N to
3224 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3225 ** a NULL pointer.
3226 **
3227 ** ^The sqlite3_malloc64(N) routine works just like
3228 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3229 ** of a signed 32-bit integer.
3230 **
3231 ** ^Calling sqlite3_free() with a pointer previously returned
3232 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3233 ** that it might be reused. ^The sqlite3_free() routine is
3234 ** a no-op if it is called with a NULL pointer. Passing a NULL pointer
3235 ** to sqlite3_free() is harmless. After being freed, memory
3236 ** should neither be read nor written. Even reading previously freed
3237 ** memory might result in a segmentation fault or other severe error.
3238 ** Memory corruption, a segmentation fault, or other severe error
3239 ** might result if sqlite3_free() is called with a non-NULL pointer that
3240 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3241 **
3242 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3243 ** prior memory allocation X to be at least N bytes.
3244 ** ^If the X parameter to sqlite3_realloc(X,N)
3245 ** is a NULL pointer then its behavior is identical to calling
3246 ** sqlite3_malloc(N).
3247 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3248 ** negative then the behavior is exactly the same as calling
3249 ** sqlite3_free(X).
3250 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3251 ** of at least N bytes in size or NULL if insufficient memory is available.
3252 ** ^If M is the size of the prior allocation, then min(N,M) bytes of the
3253 ** prior allocation are copied into the beginning of the buffer returned
3254 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3255 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3256 ** prior allocation is not freed.
3257 **
3258 ** ^The sqlite3_realloc64(X,N) interface works the same as
3259 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3260 ** of a 32-bit signed integer.
3261 **
3262 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3263 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3264 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3265 ** ^The value returned by sqlite3_msize(X) might be larger than the number
3266 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3267 ** sqlite3_msize(X) returns zero. If X points to something that is not
3268 ** the beginning of memory allocation, or if it points to a formerly
3269 ** valid memory allocation that has now been freed, then the behavior
3270 ** of sqlite3_msize(X) is undefined and possibly harmful.
3271 **
3272 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3273 ** sqlite3_malloc64(), and sqlite3_realloc64()
3274 ** is always aligned to at least an 8 byte boundary, or to a
3275 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3276 ** option is used.
3277 **
3278 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3279 ** must be either NULL or else pointers obtained from a prior
3280 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3281 ** not yet been released.
3282 **
3283 ** The application must not read or write any part of
3284 ** a block of memory after it has been released using
3285 ** [sqlite3_free()] or [sqlite3_realloc()].
3286 */
3287 SQLITE_API void *sqlite3_malloc(int);
3288 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3289 SQLITE_API void *sqlite3_realloc(void*, int);
3290 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3291 SQLITE_API void sqlite3_free(void*);
3292 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3293
3294 /*
3295 ** CAPI3REF: Memory Allocator Statistics
3296 **
3297 ** SQLite provides these two interfaces for reporting on the status
3298 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3299 ** routines, which form the built-in memory allocation subsystem.
3300 **
3301 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3302 ** of memory currently outstanding (malloced but not freed).
3303 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3304 ** value of [sqlite3_memory_used()] since the high-water mark
3305 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3306 ** [sqlite3_memory_highwater()] include any overhead
3307 ** added by SQLite in its implementation of [sqlite3_malloc()],
3308 ** but not overhead added by any underlying system library
3309 ** routines that [sqlite3_malloc()] may call.
3310 **
3311 ** ^The memory high-water mark is reset to the current value of
3312 ** [sqlite3_memory_used()] if and only if the parameter to
3313 ** [sqlite3_memory_highwater()] is true. ^The value returned
3314 ** by [sqlite3_memory_highwater(1)] is the high-water mark
3315 ** prior to the reset.
3316 */
3317 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3318 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3319
3320 /*
3321 ** CAPI3REF: Pseudo-Random Number Generator
3322 **
3323 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3324 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3325 ** already uses the largest possible [ROWID]. The PRNG is also used for
3326 ** the built-in random() and randomblob() SQL functions. This interface allows
3327 ** applications to access the same PRNG for other purposes.
3328 **
3329 ** ^A call to this routine stores N bytes of randomness into buffer P.
3330 ** ^The P parameter can be a NULL pointer.
3331 **
3332 ** ^If this routine has not been previously called or if the previous
3333 ** call had N less than one or a NULL pointer for P, then the PRNG is
3334 ** seeded using randomness obtained from the xRandomness method of
3335 ** the default [sqlite3_vfs] object.
3336 ** ^If the previous call to this routine had an N of 1 or more and a
3337 ** non-NULL P then the pseudo-randomness is generated
3338 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3339 ** method.
3340 */
3341 SQLITE_API void sqlite3_randomness(int N, void *P);
3342
3343 /*
3344 ** CAPI3REF: Compile-Time Authorization Callbacks
3345 ** METHOD: sqlite3
3346 ** KEYWORDS: {authorizer callback}
3347 **
3348 ** ^This routine registers an authorizer callback with a particular
3349 ** [database connection], supplied in the first argument.
3350 ** ^The authorizer callback is invoked as SQL statements are being compiled
3351 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3352 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3353 ** and [sqlite3_prepare16_v3()]. ^At various
3354 ** points during the compilation process, as logic is being created
3355 ** to perform various actions, the authorizer callback is invoked to
3356 ** see if those actions are allowed. ^The authorizer callback should
3357 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3358 ** specific action but allow the SQL statement to continue to be
3359 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3360 ** rejected with an error. ^If the authorizer callback returns
3361 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3362 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3363 ** the authorizer will fail with an error message.
3364 **
3365 ** When the callback returns [SQLITE_OK], that means the operation
3366 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3367 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3368 ** authorizer will fail with an error message explaining that
3369 ** access is denied.
3370 **
3371 ** ^The first parameter to the authorizer callback is a copy of the third
3372 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3373 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3374 ** the particular action to be authorized. ^The third through sixth parameters
3375 ** to the callback are either NULL pointers or zero-terminated strings
3376 ** that contain additional details about the action to be authorized.
3377 ** Applications must always be prepared to encounter a NULL pointer in any
3378 ** of the third through the sixth parameters of the authorization callback.
3379 **
3380 ** ^If the action code is [SQLITE_READ]
3381 ** and the callback returns [SQLITE_IGNORE] then the
3382 ** [prepared statement] statement is constructed to substitute
3383 ** a NULL value in place of the table column that would have
3384 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3385 ** return can be used to deny an untrusted user access to individual
3386 ** columns of a table.
3387 ** ^When a table is referenced by a [SELECT] but no column values are
3388 ** extracted from that table (for example in a query like
3389 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3390 ** is invoked once for that table with a column name that is an empty string.
3391 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3392 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3393 ** [truncate optimization] is disabled and all rows are deleted individually.
3394 **
3395 ** An authorizer is used when [sqlite3_prepare | preparing]
3396 ** SQL statements from an untrusted source, to ensure that the SQL statements
3397 ** do not try to access data they are not allowed to see, or that they do not
3398 ** try to execute malicious statements that damage the database. For
3399 ** example, an application may allow a user to enter arbitrary
3400 ** SQL queries for evaluation by a database. But the application does
3401 ** not want the user to be able to make arbitrary changes to the
3402 ** database. An authorizer could then be put in place while the
3403 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3404 ** disallows everything except [SELECT] statements.
3405 **
3406 ** Applications that need to process SQL from untrusted sources
3407 ** might also consider lowering resource limits using [sqlite3_limit()]
3408 ** and limiting database size using the [max_page_count] [PRAGMA]
3409 ** in addition to using an authorizer.
3410 **
3411 ** ^(Only a single authorizer can be in place on a database connection
3412 ** at a time. Each call to sqlite3_set_authorizer overrides the
3413 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3414 ** The authorizer is disabled by default.
3415 **
3416 ** The authorizer callback must not do anything that will modify
3417 ** the database connection that invoked the authorizer callback.
3418 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3419 ** database connections for the meaning of "modify" in this paragraph.
3420 **
3421 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3422 ** statement might be re-prepared during [sqlite3_step()] due to a
3423 ** schema change. Hence, the application should ensure that the
3424 ** correct authorizer callback remains in place during the [sqlite3_step()].
3425 **
3426 ** ^Note that the authorizer callback is invoked only during
3427 ** [sqlite3_prepare()] or its variants. Authorization is not
3428 ** performed during statement evaluation in [sqlite3_step()], unless
3429 ** as stated in the previous paragraph, sqlite3_step() invokes
3430 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3431 */
3432 SQLITE_API int sqlite3_set_authorizer(
3433 sqlite3*,
3434 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3435 void *pUserData
3436 );
3437
3438 /*
3439 ** CAPI3REF: Authorizer Return Codes
3440 **
3441 ** The [sqlite3_set_authorizer | authorizer callback function] must
3442 ** return either [SQLITE_OK] or one of these two constants in order
3443 ** to signal SQLite whether or not the action is permitted. See the
3444 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3445 ** information.
3446 **
3447 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3448 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3449 */
3450 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3451 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3452
3453 /*
3454 ** CAPI3REF: Authorizer Action Codes
3455 **
3456 ** The [sqlite3_set_authorizer()] interface registers a callback function
3457 ** that is invoked to authorize certain SQL statement actions. The
3458 ** second parameter to the callback is an integer code that specifies
3459 ** what action is being authorized. These are the integer action codes that
3460 ** the authorizer callback may be passed.
3461 **
3462 ** These action code values signify what kind of operation is to be
3463 ** authorized. The 3rd and 4th parameters to the authorization
3464 ** callback function will be parameters or NULL depending on which of these
3465 ** codes is used as the second parameter. ^(The 5th parameter to the
3466 ** authorizer callback is the name of the database ("main", "temp",
3467 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3468 ** is the name of the inner-most trigger or view that is responsible for
3469 ** the access attempt or NULL if this access attempt is directly from
3470 ** top-level SQL code.
3471 */
3472 /******************************************* 3rd ************ 4th ***********/
3473 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3474 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3475 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3476 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3477 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3478 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3479 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3480 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3481 #define SQLITE_DELETE 9 /* Table Name NULL */
3482 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3483 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3484 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3485 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3486 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3487 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3488 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3489 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3490 #define SQLITE_INSERT 18 /* Table Name NULL */
3491 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3492 #define SQLITE_READ 20 /* Table Name Column Name */
3493 #define SQLITE_SELECT 21 /* NULL NULL */
3494 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3495 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3496 #define SQLITE_ATTACH 24 /* Filename NULL */
3497 #define SQLITE_DETACH 25 /* Database Name NULL */
3498 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3499 #define SQLITE_REINDEX 27 /* Index Name NULL */
3500 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3501 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3502 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3503 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3504 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3505 #define SQLITE_COPY 0 /* No longer used */
3506 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3507
3508 /*
3509 ** CAPI3REF: Deprecated Tracing And Profiling Functions
3510 ** DEPRECATED
3511 **
3512 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3513 ** instead of the routines described here.
3514 **
3515 ** These routines register callback functions that can be used for
3516 ** tracing and profiling the execution of SQL statements.
3517 **
3518 ** ^The callback function registered by sqlite3_trace() is invoked at
3519 ** various times when an SQL statement is being run by [sqlite3_step()].
3520 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3521 ** SQL statement text as the statement first begins executing.
3522 ** ^(Additional sqlite3_trace() callbacks might occur
3523 ** as each triggered subprogram is entered. The callbacks for triggers
3524 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3525 **
3526 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3527 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3528 **
3529 ** ^The callback function registered by sqlite3_profile() is invoked
3530 ** as each SQL statement finishes. ^The profile callback contains
3531 ** the original statement text and an estimate of wall-clock time
3532 ** of how long that statement took to run. ^The profile callback
3533 ** time is in units of nanoseconds, however the current implementation
3534 ** is only capable of millisecond resolution so the six least significant
3535 ** digits in the time are meaningless. Future versions of SQLite
3536 ** might provide greater resolution on the profiler callback. Invoking
3537 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3538 ** profile callback.
3539 */
3540 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3541 void(*xTrace)(void*,const char*), void*);
3542 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3543 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3544
3545 /*
3546 ** CAPI3REF: SQL Trace Event Codes
3547 ** KEYWORDS: SQLITE_TRACE
3548 **
3549 ** These constants identify classes of events that can be monitored
3550 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3551 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3552 ** the following constants. ^The first argument to the trace callback
3553 ** is one of the following constants.
3554 **
3555 ** New tracing constants may be added in future releases.
3556 **
3557 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3558 ** ^The T argument is one of the integer type codes above.
3559 ** ^The C argument is a copy of the context pointer passed in as the
3560 ** fourth argument to [sqlite3_trace_v2()].
3561 ** The P and X arguments are pointers whose meanings depend on T.
3562 **
3563 ** <dl>
3564 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3565 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3566 ** first begins running and possibly at other times during the
3567 ** execution of the prepared statement, such as at the start of each
3568 ** trigger subprogram. ^The P argument is a pointer to the
3569 ** [prepared statement]. ^The X argument is a pointer to a string which
3570 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3571 ** that indicates the invocation of a trigger. ^The callback can compute
3572 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3573 ** interface by using the X argument when X begins with "--" and invoking
3574 ** [sqlite3_expanded_sql(P)] otherwise.
3575 **
3576 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3577 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3578 ** information as is provided by the [sqlite3_profile()] callback.
3579 ** ^The P argument is a pointer to the [prepared statement] and the
3580 ** X argument points to a 64-bit integer which is approximately
3581 ** the number of nanoseconds that the prepared statement took to run.
3582 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3583 **
3584 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3585 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3586 ** statement generates a single row of result.
3587 ** ^The P argument is a pointer to the [prepared statement] and the
3588 ** X argument is unused.
3589 **
3590 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3591 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3592 ** connection closes.
3593 ** ^The P argument is a pointer to the [database connection] object
3594 ** and the X argument is unused.
3595 ** </dl>
3596 */
3597 #define SQLITE_TRACE_STMT 0x01
3598 #define SQLITE_TRACE_PROFILE 0x02
3599 #define SQLITE_TRACE_ROW 0x04
3600 #define SQLITE_TRACE_CLOSE 0x08
3601
3602 /*
3603 ** CAPI3REF: SQL Trace Hook
3604 ** METHOD: sqlite3
3605 **
3606 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3607 ** function X against [database connection] D, using property mask M
3608 ** and context pointer P. ^If the X callback is
3609 ** NULL or if the M mask is zero, then tracing is disabled. The
3610 ** M argument should be the bitwise OR-ed combination of
3611 ** zero or more [SQLITE_TRACE] constants.
3612 **
3613 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3614 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3615 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3616 ** database connection may have at most one trace callback.
3617 **
3618 ** ^The X callback is invoked whenever any of the events identified by
3619 ** mask M occur. ^The integer return value from the callback is currently
3620 ** ignored, though this may change in future releases. Callback
3621 ** implementations should return zero to ensure future compatibility.
3622 **
3623 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3624 ** ^The T argument is one of the [SQLITE_TRACE]
3625 ** constants to indicate why the callback was invoked.
3626 ** ^The C argument is a copy of the context pointer.
3627 ** The P and X arguments are pointers whose meanings depend on T.
3628 **
3629 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3630 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3631 ** are deprecated.
3632 */
3633 SQLITE_API int sqlite3_trace_v2(
3634 sqlite3*,
3635 unsigned uMask,
3636 int(*xCallback)(unsigned,void*,void*,void*),
3637 void *pCtx
3638 );
3639
3640 /*
3641 ** CAPI3REF: Query Progress Callbacks
3642 ** METHOD: sqlite3
3643 **
3644 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3645 ** function X to be invoked periodically during long running calls to
3646 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3647 ** database connection D. An example use for this
3648 ** interface is to keep a GUI updated during a large query.
3649 **
3650 ** ^The parameter P is passed through as the only parameter to the
3651 ** callback function X. ^The parameter N is the approximate number of
3652 ** [virtual machine instructions] that are evaluated between successive
3653 ** invocations of the callback X. ^If N is less than one then the progress
3654 ** handler is disabled.
3655 **
3656 ** ^Only a single progress handler may be defined at one time per
3657 ** [database connection]; setting a new progress handler cancels the
3658 ** old one. ^Setting parameter X to NULL disables the progress handler.
3659 ** ^The progress handler is also disabled by setting N to a value less
3660 ** than 1.
3661 **
3662 ** ^If the progress callback returns non-zero, the operation is
3663 ** interrupted. This feature can be used to implement a
3664 ** "Cancel" button on a GUI progress dialog box.
3665 **
3666 ** The progress handler callback must not do anything that will modify
3667 ** the database connection that invoked the progress handler.
3668 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3669 ** database connections for the meaning of "modify" in this paragraph.
3670 **
3671 ** The progress handler callback would originally only be invoked from the
3672 ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3673 ** and similar because those routines might force a reparse of the schema
3674 ** which involves running the bytecode engine. However, beginning with
3675 ** SQLite version 3.41.0, the progress handler callback might also be
3676 ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3677 ** code for complex queries.
3678 */
3679 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3680
3681 /*
3682 ** CAPI3REF: Opening A New Database Connection
3683 ** CONSTRUCTOR: sqlite3
3684 **
3685 ** ^These routines open an SQLite database file as specified by the
3686 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3687 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3688 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3689 ** returned in *ppDb, even if an error occurs. The only exception is that
3690 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3691 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3692 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3693 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3694 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3695 ** an English language description of the error following a failure of any
3696 ** of the sqlite3_open() routines.
3697 **
3698 ** ^The default encoding will be UTF-8 for databases created using
3699 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3700 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3701 **
3702 ** Whether or not an error occurs when it is opened, resources
3703 ** associated with the [database connection] handle should be released by
3704 ** passing it to [sqlite3_close()] when it is no longer required.
3705 **
3706 ** The sqlite3_open_v2() interface works like sqlite3_open()
3707 ** except that it accepts two additional parameters for additional control
3708 ** over the new database connection. ^(The flags parameter to
3709 ** sqlite3_open_v2() must include, at a minimum, one of the following
3710 ** three flag combinations:)^
3711 **
3712 ** <dl>
3713 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3714 ** <dd>The database is opened in read-only mode. If the database does
3715 ** not already exist, an error is returned.</dd>)^
3716 **
3717 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3718 ** <dd>The database is opened for reading and writing if possible, or
3719 ** reading only if the file is write protected by the operating
3720 ** system. In either case the database must already exist, otherwise
3721 ** an error is returned. For historical reasons, if opening in
3722 ** read-write mode fails due to OS-level permissions, an attempt is
3723 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3724 ** used to determine whether the database is actually
3725 ** read-write.</dd>)^
3726 **
3727 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3728 ** <dd>The database is opened for reading and writing, and is created if
3729 ** it does not already exist. This is the behavior that is always used for
3730 ** sqlite3_open() and sqlite3_open16().</dd>)^
3731 ** </dl>
3732 **
3733 ** In addition to the required flags, the following optional flags are
3734 ** also supported:
3735 **
3736 ** <dl>
3737 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3738 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3739 **
3740 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3741 ** <dd>The database will be opened as an in-memory database. The database
3742 ** is named by the "filename" argument for the purposes of cache-sharing,
3743 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3744 ** </dd>)^
3745 **
3746 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3747 ** <dd>The new database connection will use the "multi-thread"
3748 ** [threading mode].)^ This means that separate threads are allowed
3749 ** to use SQLite at the same time, as long as each thread is using
3750 ** a different [database connection].
3751 **
3752 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3753 ** <dd>The new database connection will use the "serialized"
3754 ** [threading mode].)^ This means the multiple threads can safely
3755 ** attempt to use the same database connection at the same time.
3756 ** (Mutexes will block any actual concurrency, but in this mode
3757 ** there is no harm in trying.)
3758 **
3759 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3760 ** <dd>The database is opened with [shared cache] enabled, overriding
3761 ** the default shared cache setting provided by
3762 ** [sqlite3_enable_shared_cache()].)^
3763 ** The [use of shared cache mode is discouraged] and hence shared cache
3764 ** capabilities may be omitted from many builds of SQLite. In such cases,
3765 ** this option is a no-op.
3766 **
3767 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3768 ** <dd>The database is opened with [shared cache] disabled, overriding
3769 ** the default shared cache setting provided by
3770 ** [sqlite3_enable_shared_cache()].)^
3771 **
3772 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3773 ** <dd>The database connection comes up in "extended result code mode".
3774 ** In other words, the database behaves as if
3775 ** [sqlite3_extended_result_codes(db,1)] were called on the database
3776 ** connection as soon as the connection is created. In addition to setting
3777 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3778 ** to return an extended result code.</dd>
3779 **
3780 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3781 ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3782 ** </dl>)^
3783 **
3784 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3785 ** required combinations shown above optionally combined with other
3786 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3787 ** then the behavior is undefined. Historic versions of SQLite
3788 ** have silently ignored surplus bits in the flags parameter to
3789 ** sqlite3_open_v2(), however that behavior might not be carried through
3790 ** into future versions of SQLite and so applications should not rely
3791 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3792 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3793 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3794 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3795 ** by sqlite3_open_v2().
3796 **
3797 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3798 ** [sqlite3_vfs] object that defines the operating system interface that
3799 ** the new database connection should use. ^If the fourth parameter is
3800 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3801 **
3802 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3803 ** is created for the connection. ^This in-memory database will vanish when
3804 ** the database connection is closed. Future versions of SQLite might
3805 ** make use of additional special filenames that begin with the ":" character.
3806 ** It is recommended that when a database filename actually does begin with
3807 ** a ":" character you should prefix the filename with a pathname such as
3808 ** "./" to avoid ambiguity.
3809 **
3810 ** ^If the filename is an empty string, then a private, temporary
3811 ** on-disk database will be created. ^This private database will be
3812 ** automatically deleted as soon as the database connection is closed.
3813 **
3814 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3815 **
3816 ** ^If [URI filename] interpretation is enabled, and the filename argument
3817 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3818 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3819 ** set in the third argument to sqlite3_open_v2(), or if it has
3820 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3821 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3822 ** URI filename interpretation is turned off
3823 ** by default, but future releases of SQLite might enable URI filename
3824 ** interpretation by default. See "[URI filenames]" for additional
3825 ** information.
3826 **
3827 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3828 ** authority, then it must be either an empty string or the string
3829 ** "localhost". ^If the authority is not an empty string or "localhost", an
3830 ** error is returned to the caller. ^The fragment component of a URI, if
3831 ** present, is ignored.
3832 **
3833 ** ^SQLite uses the path component of the URI as the name of the disk file
3834 ** which contains the database. ^If the path begins with a '/' character,
3835 ** then it is interpreted as an absolute path. ^If the path does not begin
3836 ** with a '/' (meaning that the authority section is omitted from the URI)
3837 ** then the path is interpreted as a relative path.
3838 ** ^(On windows, the first component of an absolute path
3839 ** is a drive specification (e.g. "C:").)^
3840 **
3841 ** [[core URI query parameters]]
3842 ** The query component of a URI may contain parameters that are interpreted
3843 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3844 ** SQLite and its built-in [VFSes] interpret the
3845 ** following query parameters:
3846 **
3847 ** <ul>
3848 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3849 ** a VFS object that provides the operating system interface that should
3850 ** be used to access the database file on disk. ^If this option is set to
3851 ** an empty string the default VFS object is used. ^Specifying an unknown
3852 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3853 ** present, then the VFS specified by the option takes precedence over
3854 ** the value passed as the fourth parameter to sqlite3_open_v2().
3855 **
3856 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3857 ** "rwc", or "memory". Attempting to set it to any other value is
3858 ** an error)^.
3859 ** ^If "ro" is specified, then the database is opened for read-only
3860 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3861 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3862 ** "rw", then the database is opened for read-write (but not create)
3863 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3864 ** been set. ^Value "rwc" is equivalent to setting both
3865 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3866 ** set to "memory" then a pure [in-memory database] that never reads
3867 ** or writes from disk is used. ^It is an error to specify a value for
3868 ** the mode parameter that is less restrictive than that specified by
3869 ** the flags passed in the third parameter to sqlite3_open_v2().
3870 **
3871 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3872 ** "private". ^Setting it to "shared" is equivalent to setting the
3873 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3874 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3875 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3876 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3877 ** a URI filename, its value overrides any behavior requested by setting
3878 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3879 **
3880 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3881 ** [powersafe overwrite] property does or does not apply to the
3882 ** storage media on which the database file resides.
3883 **
3884 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3885 ** which if set disables file locking in rollback journal modes. This
3886 ** is useful for accessing a database on a filesystem that does not
3887 ** support locking. Caution: Database corruption might result if two
3888 ** or more processes write to the same database and any one of those
3889 ** processes uses nolock=1.
3890 **
3891 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3892 ** parameter that indicates that the database file is stored on
3893 ** read-only media. ^When immutable is set, SQLite assumes that the
3894 ** database file cannot be changed, even by a process with higher
3895 ** privilege, and so the database is opened read-only and all locking
3896 ** and change detection is disabled. Caution: Setting the immutable
3897 ** property on a database file that does in fact change can result
3898 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3899 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3900 **
3901 ** </ul>
3902 **
3903 ** ^Specifying an unknown parameter in the query component of a URI is not an
3904 ** error. Future versions of SQLite might understand additional query
3905 ** parameters. See "[query parameters with special meaning to SQLite]" for
3906 ** additional information.
3907 **
3908 ** [[URI filename examples]] <h3>URI filename examples</h3>
3909 **
3910 ** <table border="1" align=center cellpadding=5>
3911 ** <tr><th> URI filenames <th> Results
3912 ** <tr><td> file:data.db <td>
3913 ** Open the file "data.db" in the current directory.
3914 ** <tr><td> file:/home/fred/data.db<br>
3915 ** file:///home/fred/data.db <br>
3916 ** file://localhost/home/fred/data.db <br> <td>
3917 ** Open the database file "/home/fred/data.db".
3918 ** <tr><td> file://darkstar/home/fred/data.db <td>
3919 ** An error. "darkstar" is not a recognized authority.
3920 ** <tr><td style="white-space:nowrap">
3921 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3922 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3923 ** C:. Note that the %20 escaping in this example is not strictly
3924 ** necessary - space characters can be used literally
3925 ** in URI filenames.
3926 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3927 ** Open file "data.db" in the current directory for read-only access.
3928 ** Regardless of whether or not shared-cache mode is enabled by
3929 ** default, use a private cache.
3930 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3931 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3932 ** that uses dot-files in place of posix advisory locking.
3933 ** <tr><td> file:data.db?mode=readonly <td>
3934 ** An error. "readonly" is not a valid option for the "mode" parameter.
3935 ** Use "ro" instead: "file:data.db?mode=ro".
3936 ** </table>
3937 **
3938 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3939 ** query components of a URI. A hexadecimal escape sequence consists of a
3940 ** percent sign - "%" - followed by exactly two hexadecimal digits
3941 ** specifying an octet value. ^Before the path or query components of a
3942 ** URI filename are interpreted, they are encoded using UTF-8 and all
3943 ** hexadecimal escape sequences replaced by a single byte containing the
3944 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3945 ** the results are undefined.
3946 **
3947 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3948 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3949 ** codepage is currently defined. Filenames containing international
3950 ** characters must be converted to UTF-8 prior to passing them into
3951 ** sqlite3_open() or sqlite3_open_v2().
3952 **
3953 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3954 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3955 ** features that require the use of temporary files may fail.
3956 **
3957 ** See also: [sqlite3_temp_directory]
3958 */
3959 SQLITE_API int sqlite3_open(
3960 const char *filename, /* Database filename (UTF-8) */
3961 sqlite3 **ppDb /* OUT: SQLite db handle */
3962 );
3963 SQLITE_API int sqlite3_open16(
3964 const void *filename, /* Database filename (UTF-16) */
3965 sqlite3 **ppDb /* OUT: SQLite db handle */
3966 );
3967 SQLITE_API int sqlite3_open_v2(
3968 const char *filename, /* Database filename (UTF-8) */
3969 sqlite3 **ppDb, /* OUT: SQLite db handle */
3970 int flags, /* Flags */
3971 const char *zVfs /* Name of VFS module to use */
3972 );
3973
3974 /*
3975 ** CAPI3REF: Obtain Values For URI Parameters
3976 **
3977 ** These are utility routines, useful to [VFS|custom VFS implementations],
3978 ** that check if a database file was a URI that contained a specific query
3979 ** parameter, and if so obtains the value of that query parameter.
3980 **
3981 ** The first parameter to these interfaces (hereafter referred to
3982 ** as F) must be one of:
3983 ** <ul>
3984 ** <li> A database filename pointer created by the SQLite core and
3985 ** passed into the xOpen() method of a VFS implementation, or
3986 ** <li> A filename obtained from [sqlite3_db_filename()], or
3987 ** <li> A new filename constructed using [sqlite3_create_filename()].
3988 ** </ul>
3989 ** If the F parameter is not one of the above, then the behavior is
3990 ** undefined and probably undesirable. Older versions of SQLite were
3991 ** more tolerant of invalid F parameters than newer versions.
3992 **
3993 ** If F is a suitable filename (as described in the previous paragraph)
3994 ** and if P is the name of the query parameter, then
3995 ** sqlite3_uri_parameter(F,P) returns the value of the P
3996 ** parameter if it exists or a NULL pointer if P does not appear as a
3997 ** query parameter on F. If P is a query parameter of F and it
3998 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3999 ** a pointer to an empty string.
4000 **
4001 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
4002 ** parameter and returns true (1) or false (0) according to the value
4003 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
4004 ** value of query parameter P is one of "yes", "true", or "on" in any
4005 ** case or if the value begins with a non-zero number. The
4006 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
4007 ** query parameter P is one of "no", "false", or "off" in any case or
4008 ** if the value begins with a numeric zero. If P is not a query
4009 ** parameter on F or if the value of P does not match any of the
4010 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
4011 **
4012 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
4013 ** 64-bit signed integer and returns that integer, or D if P does not
4014 ** exist. If the value of P is something other than an integer, then
4015 ** zero is returned.
4016 **
4017 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
4018 ** the value) of the N-th query parameter for filename F, or a NULL
4019 ** pointer if N is less than zero or greater than the number of query
4020 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4021 ** the name of the first query parameter, 1 for the second parameter, and
4022 ** so forth.
4023 **
4024 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4025 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4026 ** is not a database file pathname pointer that the SQLite core passed
4027 ** into the xOpen VFS method, then the behavior of this routine is undefined
4028 ** and probably undesirable.
4029 **
4030 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4031 ** parameter can also be the name of a rollback journal file or WAL file
4032 ** in addition to the main database file. Prior to version 3.31.0, these
4033 ** routines would only work if F was the name of the main database file.
4034 ** When the F parameter is the name of the rollback journal or WAL file,
4035 ** it has access to all the same query parameters as were found on the
4036 ** main database file.
4037 **
4038 ** See the [URI filename] documentation for additional information.
4039 */
4040 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4041 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4042 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4043 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4044
4045 /*
4046 ** CAPI3REF: Translate filenames
4047 **
4048 ** These routines are available to [VFS|custom VFS implementations] for
4049 ** translating filenames between the main database file, the journal file,
4050 ** and the WAL file.
4051 **
4052 ** If F is the name of an sqlite database file, journal file, or WAL file
4053 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4054 ** returns the name of the corresponding database file.
4055 **
4056 ** If F is the name of an sqlite database file, journal file, or WAL file
4057 ** passed by the SQLite core into the VFS, or if F is a database filename
4058 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4059 ** returns the name of the corresponding rollback journal file.
4060 **
4061 ** If F is the name of an sqlite database file, journal file, or WAL file
4062 ** that was passed by the SQLite core into the VFS, or if F is a database
4063 ** filename obtained from [sqlite3_db_filename()], then
4064 ** sqlite3_filename_wal(F) returns the name of the corresponding
4065 ** WAL file.
4066 **
4067 ** In all of the above, if F is not the name of a database, journal or WAL
4068 ** filename passed into the VFS from the SQLite core and F is not the
4069 ** return value from [sqlite3_db_filename()], then the result is
4070 ** undefined and is likely a memory access violation.
4071 */
4072 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4073 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4074 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4075
4076 /*
4077 ** CAPI3REF: Database File Corresponding To A Journal
4078 **
4079 ** ^If X is the name of a rollback or WAL-mode journal file that is
4080 ** passed into the xOpen method of [sqlite3_vfs], then
4081 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4082 ** object that represents the main database file.
4083 **
4084 ** This routine is intended for use in custom [VFS] implementations
4085 ** only. It is not a general-purpose interface.
4086 ** The argument sqlite3_file_object(X) must be a filename pointer that
4087 ** has been passed into [sqlite3_vfs].xOpen method where the
4088 ** flags parameter to xOpen contains one of the bits
4089 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4090 ** of this routine results in undefined and probably undesirable
4091 ** behavior.
4092 */
4093 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4094
4095 /*
4096 ** CAPI3REF: Create and Destroy VFS Filenames
4097 **
4098 ** These interfaces are provided for use by [VFS shim] implementations and
4099 ** are not useful outside of that context.
4100 **
4101 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4102 ** database filename D with corresponding journal file J and WAL file W and
4103 ** an array P of N URI Key/Value pairs. The result from
4104 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4105 ** is safe to pass to routines like:
4106 ** <ul>
4107 ** <li> [sqlite3_uri_parameter()],
4108 ** <li> [sqlite3_uri_boolean()],
4109 ** <li> [sqlite3_uri_int64()],
4110 ** <li> [sqlite3_uri_key()],
4111 ** <li> [sqlite3_filename_database()],
4112 ** <li> [sqlite3_filename_journal()], or
4113 ** <li> [sqlite3_filename_wal()].
4114 ** </ul>
4115 ** If a memory allocation error occurs, sqlite3_create_filename() might
4116 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4117 ** must be released by a corresponding call to sqlite3_free_filename(Y).
4118 **
4119 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4120 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4121 ** to a key and value for a query parameter. The P parameter may be a NULL
4122 ** pointer if N is zero. None of the 2*N pointers in the P array may be
4123 ** NULL pointers and key pointers should not be empty strings.
4124 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4125 ** be NULL pointers, though they can be empty strings.
4126 **
4127 ** The sqlite3_free_filename(Y) routine releases a memory allocation
4128 ** previously obtained from sqlite3_create_filename(). Invoking
4129 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4130 **
4131 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
4132 ** than a NULL pointer or a pointer previously acquired from
4133 ** sqlite3_create_filename(), then bad things such as heap
4134 ** corruption or segfaults may occur. The value Y should not be
4135 ** used again after sqlite3_free_filename(Y) has been called. This means
4136 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4137 ** then the corresponding [sqlite3_module.xClose() method should also be
4138 ** invoked prior to calling sqlite3_free_filename(Y).
4139 */
4140 SQLITE_API sqlite3_filename sqlite3_create_filename(
4141 const char *zDatabase,
4142 const char *zJournal,
4143 const char *zWal,
4144 int nParam,
4145 const char **azParam
4146 );
4147 SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4148
4149 /*
4150 ** CAPI3REF: Error Codes And Messages
4151 ** METHOD: sqlite3
4152 **
4153 ** ^If the most recent sqlite3_* API call associated with
4154 ** [database connection] D failed, then the sqlite3_errcode(D) interface
4155 ** returns the numeric [result code] or [extended result code] for that
4156 ** API call.
4157 ** ^The sqlite3_extended_errcode()
4158 ** interface is the same except that it always returns the
4159 ** [extended result code] even when extended result codes are
4160 ** disabled.
4161 **
4162 ** The values returned by sqlite3_errcode() and/or
4163 ** sqlite3_extended_errcode() might change with each API call.
4164 ** Except, there are some interfaces that are guaranteed to never
4165 ** change the value of the error code. The error-code preserving
4166 ** interfaces include the following:
4167 **
4168 ** <ul>
4169 ** <li> sqlite3_errcode()
4170 ** <li> sqlite3_extended_errcode()
4171 ** <li> sqlite3_errmsg()
4172 ** <li> sqlite3_errmsg16()
4173 ** <li> sqlite3_error_offset()
4174 ** </ul>
4175 **
4176 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4177 ** text that describes the error, as either UTF-8 or UTF-16 respectively,
4178 ** or NULL if no error message is available.
4179 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4180 ** ^(Memory to hold the error message string is managed internally.
4181 ** The application does not need to worry about freeing the result.
4182 ** However, the error string might be overwritten or deallocated by
4183 ** subsequent calls to other SQLite interface functions.)^
4184 **
4185 ** ^The sqlite3_errstr(E) interface returns the English-language text
4186 ** that describes the [result code] E, as UTF-8, or NULL if E is not a
4187 ** result code for which a text error message is available.
4188 ** ^(Memory to hold the error message string is managed internally
4189 ** and must not be freed by the application)^.
4190 **
4191 ** ^If the most recent error references a specific token in the input
4192 ** SQL, the sqlite3_error_offset() interface returns the byte offset
4193 ** of the start of that token. ^The byte offset returned by
4194 ** sqlite3_error_offset() assumes that the input SQL is UTF-8.
4195 ** ^If the most recent error does not reference a specific token in the input
4196 ** SQL, then the sqlite3_error_offset() function returns -1.
4197 **
4198 ** When the serialized [threading mode] is in use, it might be the
4199 ** case that a second error occurs on a separate thread in between
4200 ** the time of the first error and the call to these interfaces.
4201 ** When that happens, the second error will be reported since these
4202 ** interfaces always report the most recent result. To avoid
4203 ** this, each thread can obtain exclusive use of the [database connection] D
4204 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4205 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4206 ** all calls to the interfaces listed here are completed.
4207 **
4208 ** If an interface fails with SQLITE_MISUSE, that means the interface
4209 ** was invoked incorrectly by the application. In that case, the
4210 ** error code and message may or may not be set.
4211 */
4212 SQLITE_API int sqlite3_errcode(sqlite3 *db);
4213 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4214 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4215 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4216 SQLITE_API const char *sqlite3_errstr(int);
4217 SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4218
4219 /*
4220 ** CAPI3REF: Set Error Codes And Message
4221 ** METHOD: sqlite3
4222 **
4223 ** Set the error code of the database handle passed as the first argument
4224 ** to errcode, and the error message to a copy of nul-terminated string
4225 ** zErrMsg. If zErrMsg is passed NULL, then the error message is set to
4226 ** the default message associated with the supplied error code. Subsequent
4227 ** calls to [sqlite3_errcode()] and [sqlite3_errmsg()] and similar will
4228 ** return the values set by this routine in place of what was previously
4229 ** set by SQLite itself.
4230 **
4231 ** This function returns SQLITE_OK if the error code and error message are
4232 ** successfully set, SQLITE_NOMEM if an OOM occurs, and SQLITE_MISUSE if
4233 ** the database handle is NULL or invalid.
4234 **
4235 ** The error code and message set by this routine remains in effect until
4236 ** they are changed, either by another call to this routine or until they are
4237 ** changed to by SQLite itself to reflect the result of some subsquent
4238 ** API call.
4239 **
4240 ** This function is intended for use by SQLite extensions or wrappers. The
4241 ** idea is that an extension or wrapper can use this routine to set error
4242 ** messages and error codes and thus behave more like a core SQLite
4243 ** feature from the point of view of an application.
4244 */
4245 SQLITE_API int sqlite3_set_errmsg(sqlite3 *db, int errcode, const char *zErrMsg);
4246
4247 /*
4248 ** CAPI3REF: Prepared Statement Object
4249 ** KEYWORDS: {prepared statement} {prepared statements}
4250 **
4251 ** An instance of this object represents a single SQL statement that
4252 ** has been compiled into binary form and is ready to be evaluated.
4253 **
4254 ** Think of each SQL statement as a separate computer program. The
4255 ** original SQL text is source code. A prepared statement object
4256 ** is the compiled object code. All SQL must be converted into a
4257 ** prepared statement before it can be run.
4258 **
4259 ** The life-cycle of a prepared statement object usually goes like this:
4260 **
4261 ** <ol>
4262 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4263 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4264 ** interfaces.
4265 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4266 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4267 ** to step 2. Do this zero or more times.
4268 ** <li> Destroy the object using [sqlite3_finalize()].
4269 ** </ol>
4270 */
4271 typedef struct sqlite3_stmt sqlite3_stmt;
4272
4273 /*
4274 ** CAPI3REF: Run-time Limits
4275 ** METHOD: sqlite3
4276 **
4277 ** ^(This interface allows the size of various constructs to be limited
4278 ** on a connection by connection basis. The first parameter is the
4279 ** [database connection] whose limit is to be set or queried. The
4280 ** second parameter is one of the [limit categories] that define a
4281 ** class of constructs to be size limited. The third parameter is the
4282 ** new limit for that construct.)^
4283 **
4284 ** ^If the new limit is a negative number, the limit is unchanged.
4285 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4286 ** [limits | hard upper bound]
4287 ** set at compile-time by a C preprocessor macro called
4288 ** [limits | SQLITE_MAX_<i>NAME</i>].
4289 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4290 ** ^Attempts to increase a limit above its hard upper bound are
4291 ** silently truncated to the hard upper bound.
4292 **
4293 ** ^Regardless of whether or not the limit was changed, the
4294 ** [sqlite3_limit()] interface returns the prior value of the limit.
4295 ** ^Hence, to find the current value of a limit without changing it,
4296 ** simply invoke this interface with the third parameter set to -1.
4297 **
4298 ** Run-time limits are intended for use in applications that manage
4299 ** both their own internal database and also databases that are controlled
4300 ** by untrusted external sources. An example application might be a
4301 ** web browser that has its own databases for storing history and
4302 ** separate databases controlled by JavaScript applications downloaded
4303 ** off the Internet. The internal databases can be given the
4304 ** large, default limits. Databases managed by external sources can
4305 ** be given much smaller limits designed to prevent a denial of service
4306 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4307 ** interface to further control untrusted SQL. The size of the database
4308 ** created by an untrusted script can be contained using the
4309 ** [max_page_count] [PRAGMA].
4310 **
4311 ** New run-time limit categories may be added in future releases.
4312 */
4313 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4314
4315 /*
4316 ** CAPI3REF: Run-Time Limit Categories
4317 ** KEYWORDS: {limit category} {*limit categories}
4318 **
4319 ** These constants define various performance limits
4320 ** that can be lowered at run-time using [sqlite3_limit()].
4321 ** A concise description of these limits follows, and additional information
4322 ** is available at [limits | Limits in SQLite].
4323 **
4324 ** <dl>
4325 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4326 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4327 **
4328 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4329 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4330 **
4331 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4332 ** <dd>The maximum number of columns in a table definition or in the
4333 ** result set of a [SELECT] or the maximum number of columns in an index
4334 ** or in an ORDER BY or GROUP BY clause.</dd>)^
4335 **
4336 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4337 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4338 **
4339 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4340 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4341 **
4342 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4343 ** <dd>The maximum number of instructions in a virtual machine program
4344 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4345 ** the equivalent tries to allocate space for more than this many opcodes
4346 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4347 **
4348 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4349 ** <dd>The maximum number of arguments on a function.</dd>)^
4350 **
4351 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4352 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4353 **
4354 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4355 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4356 ** <dd>The maximum length of the pattern argument to the [LIKE] or
4357 ** [GLOB] operators.</dd>)^
4358 **
4359 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4360 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4361 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4362 **
4363 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4364 ** <dd>The maximum depth of recursion for triggers.</dd>)^
4365 **
4366 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4367 ** <dd>The maximum number of auxiliary worker threads that a single
4368 ** [prepared statement] may start.</dd>)^
4369 ** </dl>
4370 */
4371 #define SQLITE_LIMIT_LENGTH 0
4372 #define SQLITE_LIMIT_SQL_LENGTH 1
4373 #define SQLITE_LIMIT_COLUMN 2
4374 #define SQLITE_LIMIT_EXPR_DEPTH 3
4375 #define SQLITE_LIMIT_COMPOUND_SELECT 4
4376 #define SQLITE_LIMIT_VDBE_OP 5
4377 #define SQLITE_LIMIT_FUNCTION_ARG 6
4378 #define SQLITE_LIMIT_ATTACHED 7
4379 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4380 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4381 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4382 #define SQLITE_LIMIT_WORKER_THREADS 11
4383
4384 /*
4385 ** CAPI3REF: Prepare Flags
4386 **
4387 ** These constants define various flags that can be passed into the
4388 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4389 ** [sqlite3_prepare16_v3()] interfaces.
4390 **
4391 ** New flags may be added in future releases of SQLite.
4392 **
4393 ** <dl>
4394 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4395 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4396 ** that the prepared statement will be retained for a long time and
4397 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4398 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4399 ** be used just once or at most a few times and then destroyed using
4400 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4401 ** on this hint by avoiding the use of [lookaside memory] so as not to
4402 ** deplete the limited store of lookaside memory. Future versions of
4403 ** SQLite may act on this hint differently.
4404 **
4405 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4406 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4407 ** to be required for any prepared statement that wanted to use the
4408 ** [sqlite3_normalized_sql()] interface. However, the
4409 ** [sqlite3_normalized_sql()] interface is now available to all
4410 ** prepared statements, regardless of whether or not they use this
4411 ** flag.
4412 **
4413 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4414 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4415 ** to return an error (error code SQLITE_ERROR) if the statement uses
4416 ** any virtual tables.
4417 **
4418 ** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4419 ** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4420 ** errors from being sent to the error log defined by
4421 ** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4422 ** compiles to see if some SQL syntax is well-formed, without generating
4423 ** messages on the global error log when it is not. If the test compile
4424 ** fails, the sqlite3_prepare_v3() call returns the same error indications
4425 ** with or without this flag; it just omits the call to [sqlite3_log()] that
4426 ** logs the error.
4427 ** </dl>
4428 */
4429 #define SQLITE_PREPARE_PERSISTENT 0x01
4430 #define SQLITE_PREPARE_NORMALIZE 0x02
4431 #define SQLITE_PREPARE_NO_VTAB 0x04
4432 #define SQLITE_PREPARE_DONT_LOG 0x10
4433
4434 /*
4435 ** CAPI3REF: Compiling An SQL Statement
4436 ** KEYWORDS: {SQL statement compiler}
4437 ** METHOD: sqlite3
4438 ** CONSTRUCTOR: sqlite3_stmt
4439 **
4440 ** To execute an SQL statement, it must first be compiled into a byte-code
4441 ** program using one of these routines. Or, in other words, these routines
4442 ** are constructors for the [prepared statement] object.
4443 **
4444 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4445 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4446 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4447 ** for special purposes.
4448 **
4449 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4450 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4451 ** as a convenience. The UTF-16 interfaces work by converting the
4452 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4453 **
4454 ** The first argument, "db", is a [database connection] obtained from a
4455 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4456 ** [sqlite3_open16()]. The database connection must not have been closed.
4457 **
4458 ** The second argument, "zSql", is the statement to be compiled, encoded
4459 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4460 ** and sqlite3_prepare_v3()
4461 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4462 ** and sqlite3_prepare16_v3() use UTF-16.
4463 **
4464 ** ^If the nByte argument is negative, then zSql is read up to the
4465 ** first zero terminator. ^If nByte is positive, then it is the maximum
4466 ** number of bytes read from zSql. When nByte is positive, zSql is read
4467 ** up to the first zero terminator or until the nByte bytes have been read,
4468 ** whichever comes first. ^If nByte is zero, then no prepared
4469 ** statement is generated.
4470 ** If the caller knows that the supplied string is nul-terminated, then
4471 ** there is a small performance advantage to passing an nByte parameter that
4472 ** is the number of bytes in the input string <i>including</i>
4473 ** the nul-terminator.
4474 ** Note that nByte measures the length of the input in bytes, not
4475 ** characters, even for the UTF-16 interfaces.
4476 **
4477 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4478 ** past the end of the first SQL statement in zSql. These routines only
4479 ** compile the first statement in zSql, so *pzTail is left pointing to
4480 ** what remains uncompiled.
4481 **
4482 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4483 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4484 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4485 ** string or a comment) then *ppStmt is set to NULL.
4486 ** The calling procedure is responsible for deleting the compiled
4487 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4488 ** ppStmt may not be NULL.
4489 **
4490 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4491 ** otherwise an [error code] is returned.
4492 **
4493 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4494 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4495 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4496 ** are retained for backwards compatibility, but their use is discouraged.
4497 ** ^In the "vX" interfaces, the prepared statement
4498 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4499 ** original SQL text. This causes the [sqlite3_step()] interface to
4500 ** behave differently in three ways:
4501 **
4502 ** <ol>
4503 ** <li>
4504 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4505 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4506 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4507 ** retries will occur before sqlite3_step() gives up and returns an error.
4508 ** </li>
4509 **
4510 ** <li>
4511 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4512 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4513 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4514 ** and the application would have to make a second call to [sqlite3_reset()]
4515 ** in order to find the underlying cause of the problem. With the "v2" prepare
4516 ** interfaces, the underlying reason for the error is returned immediately.
4517 ** </li>
4518 **
4519 ** <li>
4520 ** ^If the specific value bound to a [parameter | host parameter] in the
4521 ** WHERE clause might influence the choice of query plan for a statement,
4522 ** then the statement will be automatically recompiled, as if there had been
4523 ** a schema change, on the first [sqlite3_step()] call following any change
4524 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4525 ** ^The specific value of a WHERE-clause [parameter] might influence the
4526 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4527 ** or [GLOB] operator or if the parameter is compared to an indexed column
4528 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4529 ** </li>
4530 ** </ol>
4531 **
4532 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4533 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4534 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4535 ** sqlite3_prepare_v2() interface works exactly the same as
4536 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4537 */
4538 SQLITE_API int sqlite3_prepare(
4539 sqlite3 *db, /* Database handle */
4540 const char *zSql, /* SQL statement, UTF-8 encoded */
4541 int nByte, /* Maximum length of zSql in bytes. */
4542 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4543 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4544 );
4545 SQLITE_API int sqlite3_prepare_v2(
4546 sqlite3 *db, /* Database handle */
4547 const char *zSql, /* SQL statement, UTF-8 encoded */
4548 int nByte, /* Maximum length of zSql in bytes. */
4549 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4550 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4551 );
4552 SQLITE_API int sqlite3_prepare_v3(
4553 sqlite3 *db, /* Database handle */
4554 const char *zSql, /* SQL statement, UTF-8 encoded */
4555 int nByte, /* Maximum length of zSql in bytes. */
4556 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4557 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4558 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4559 );
4560 SQLITE_API int sqlite3_prepare16(
4561 sqlite3 *db, /* Database handle */
4562 const void *zSql, /* SQL statement, UTF-16 encoded */
4563 int nByte, /* Maximum length of zSql in bytes. */
4564 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4565 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4566 );
4567 SQLITE_API int sqlite3_prepare16_v2(
4568 sqlite3 *db, /* Database handle */
4569 const void *zSql, /* SQL statement, UTF-16 encoded */
4570 int nByte, /* Maximum length of zSql in bytes. */
4571 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4572 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4573 );
4574 SQLITE_API int sqlite3_prepare16_v3(
4575 sqlite3 *db, /* Database handle */
4576 const void *zSql, /* SQL statement, UTF-16 encoded */
4577 int nByte, /* Maximum length of zSql in bytes. */
4578 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4579 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4580 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4581 );
4582
4583 /*
4584 ** CAPI3REF: Retrieving Statement SQL
4585 ** METHOD: sqlite3_stmt
4586 **
4587 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4588 ** SQL text used to create [prepared statement] P if P was
4589 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4590 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4591 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4592 ** string containing the SQL text of prepared statement P with
4593 ** [bound parameters] expanded.
4594 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4595 ** string containing the normalized SQL text of prepared statement P. The
4596 ** semantics used to normalize a SQL statement are unspecified and subject
4597 ** to change. At a minimum, literal values will be replaced with suitable
4598 ** placeholders.
4599 **
4600 ** ^(For example, if a prepared statement is created using the SQL
4601 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4602 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4603 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4604 ** will return "SELECT 2345,NULL".)^
4605 **
4606 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4607 ** is available to hold the result, or if the result would exceed the
4608 ** maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4609 **
4610 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4611 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4612 ** option causes sqlite3_expanded_sql() to always return NULL.
4613 **
4614 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4615 ** are managed by SQLite and are automatically freed when the prepared
4616 ** statement is finalized.
4617 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4618 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4619 ** by passing it to [sqlite3_free()].
4620 **
4621 ** ^The sqlite3_normalized_sql() interface is only available if
4622 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4623 */
4624 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4625 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4626 #ifdef SQLITE_ENABLE_NORMALIZE
4627 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4628 #endif
4629
4630 /*
4631 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4632 ** METHOD: sqlite3_stmt
4633 **
4634 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4635 ** and only if the [prepared statement] X makes no direct changes to
4636 ** the content of the database file.
4637 **
4638 ** Note that [application-defined SQL functions] or
4639 ** [virtual tables] might change the database indirectly as a side effect.
4640 ** ^(For example, if an application defines a function "eval()" that
4641 ** calls [sqlite3_exec()], then the following SQL statement would
4642 ** change the database file through side-effects:
4643 **
4644 ** <blockquote><pre>
4645 ** SELECT eval('DELETE FROM t1') FROM t2;
4646 ** </pre></blockquote>
4647 **
4648 ** But because the [SELECT] statement does not change the database file
4649 ** directly, sqlite3_stmt_readonly() would still return true.)^
4650 **
4651 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4652 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4653 ** since the statements themselves do not actually modify the database but
4654 ** rather they control the timing of when other statements modify the
4655 ** database. ^The [ATTACH] and [DETACH] statements also cause
4656 ** sqlite3_stmt_readonly() to return true since, while those statements
4657 ** change the configuration of a database connection, they do not make
4658 ** changes to the content of the database files on disk.
4659 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4660 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4661 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4662 ** sqlite3_stmt_readonly() returns false for those commands.
4663 **
4664 ** ^This routine returns false if there is any possibility that the
4665 ** statement might change the database file. ^A false return does
4666 ** not guarantee that the statement will change the database file.
4667 ** ^For example, an UPDATE statement might have a WHERE clause that
4668 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4669 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4670 ** read-only no-op if the table already exists, but
4671 ** sqlite3_stmt_readonly() still returns false for such a statement.
4672 **
4673 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4674 ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4675 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4676 */
4677 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4678
4679 /*
4680 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4681 ** METHOD: sqlite3_stmt
4682 **
4683 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4684 ** prepared statement S is an EXPLAIN statement, or 2 if the
4685 ** statement S is an EXPLAIN QUERY PLAN.
4686 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4687 ** an ordinary statement or a NULL pointer.
4688 */
4689 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4690
4691 /*
4692 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4693 ** METHOD: sqlite3_stmt
4694 **
4695 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4696 ** setting for [prepared statement] S. If E is zero, then S becomes
4697 ** a normal prepared statement. If E is 1, then S behaves as if
4698 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4699 ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4700 **
4701 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4702 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4703 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4704 **
4705 ** Because of the potential need to reprepare, a call to
4706 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4707 ** reprepared because it was created using [sqlite3_prepare()] instead of
4708 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4709 ** hence has no saved SQL text with which to reprepare.
4710 **
4711 ** Changing the explain setting for a prepared statement does not change
4712 ** the original SQL text for the statement. Hence, if the SQL text originally
4713 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4714 ** is called to convert the statement into an ordinary statement, the EXPLAIN
4715 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4716 ** output, even though the statement now acts like a normal SQL statement.
4717 **
4718 ** This routine returns SQLITE_OK if the explain mode is successfully
4719 ** changed, or an error code if the explain mode could not be changed.
4720 ** The explain mode cannot be changed while a statement is active.
4721 ** Hence, it is good practice to call [sqlite3_reset(S)]
4722 ** immediately prior to calling sqlite3_stmt_explain(S,E).
4723 */
4724 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4725
4726 /*
4727 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4728 ** METHOD: sqlite3_stmt
4729 **
4730 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4731 ** [prepared statement] S has been stepped at least once using
4732 ** [sqlite3_step(S)] but has neither run to completion (returned
4733 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4734 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4735 ** interface returns false if S is a NULL pointer. If S is not a
4736 ** NULL pointer and is not a pointer to a valid [prepared statement]
4737 ** object, then the behavior is undefined and probably undesirable.
4738 **
4739 ** This interface can be used in combination [sqlite3_next_stmt()]
4740 ** to locate all prepared statements associated with a database
4741 ** connection that are in need of being reset. This can be used,
4742 ** for example, in diagnostic routines to search for prepared
4743 ** statements that are holding a transaction open.
4744 */
4745 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4746
4747 /*
4748 ** CAPI3REF: Dynamically Typed Value Object
4749 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4750 **
4751 ** SQLite uses the sqlite3_value object to represent all values
4752 ** that can be stored in a database table. SQLite uses dynamic typing
4753 ** for the values it stores. ^Values stored in sqlite3_value objects
4754 ** can be integers, floating point values, strings, BLOBs, or NULL.
4755 **
4756 ** An sqlite3_value object may be either "protected" or "unprotected".
4757 ** Some interfaces require a protected sqlite3_value. Other interfaces
4758 ** will accept either a protected or an unprotected sqlite3_value.
4759 ** Every interface that accepts sqlite3_value arguments specifies
4760 ** whether or not it requires a protected sqlite3_value. The
4761 ** [sqlite3_value_dup()] interface can be used to construct a new
4762 ** protected sqlite3_value from an unprotected sqlite3_value.
4763 **
4764 ** The terms "protected" and "unprotected" refer to whether or not
4765 ** a mutex is held. An internal mutex is held for a protected
4766 ** sqlite3_value object but no mutex is held for an unprotected
4767 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4768 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4769 ** or if SQLite is run in one of reduced mutex modes
4770 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4771 ** then there is no distinction between protected and unprotected
4772 ** sqlite3_value objects and they can be used interchangeably. However,
4773 ** for maximum code portability it is recommended that applications
4774 ** still make the distinction between protected and unprotected
4775 ** sqlite3_value objects even when not strictly required.
4776 **
4777 ** ^The sqlite3_value objects that are passed as parameters into the
4778 ** implementation of [application-defined SQL functions] are protected.
4779 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4780 ** are protected.
4781 ** ^The sqlite3_value object returned by
4782 ** [sqlite3_column_value()] is unprotected.
4783 ** Unprotected sqlite3_value objects may only be used as arguments
4784 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4785 ** [sqlite3_value_dup()].
4786 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4787 ** interfaces require protected sqlite3_value objects.
4788 */
4789 typedef struct sqlite3_value sqlite3_value;
4790
4791 /*
4792 ** CAPI3REF: SQL Function Context Object
4793 **
4794 ** The context in which an SQL function executes is stored in an
4795 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4796 ** is always the first parameter to [application-defined SQL functions].
4797 ** The application-defined SQL function implementation will pass this
4798 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4799 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4800 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4801 ** and/or [sqlite3_set_auxdata()].
4802 */
4803 typedef struct sqlite3_context sqlite3_context;
4804
4805 /*
4806 ** CAPI3REF: Binding Values To Prepared Statements
4807 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4808 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4809 ** METHOD: sqlite3_stmt
4810 **
4811 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4812 ** literals may be replaced by a [parameter] that matches one of the following
4813 ** templates:
4814 **
4815 ** <ul>
4816 ** <li> ?
4817 ** <li> ?NNN
4818 ** <li> :VVV
4819 ** <li> @VVV
4820 ** <li> $VVV
4821 ** </ul>
4822 **
4823 ** In the templates above, NNN represents an integer literal,
4824 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4825 ** parameters (also called "host parameter names" or "SQL parameters")
4826 ** can be set using the sqlite3_bind_*() routines defined here.
4827 **
4828 ** ^The first argument to the sqlite3_bind_*() routines is always
4829 ** a pointer to the [sqlite3_stmt] object returned from
4830 ** [sqlite3_prepare_v2()] or its variants.
4831 **
4832 ** ^The second argument is the index of the SQL parameter to be set.
4833 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4834 ** SQL parameter is used more than once, second and subsequent
4835 ** occurrences have the same index as the first occurrence.
4836 ** ^The index for named parameters can be looked up using the
4837 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4838 ** for "?NNN" parameters is the value of NNN.
4839 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4840 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4841 **
4842 ** ^The third argument is the value to bind to the parameter.
4843 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4844 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4845 ** is ignored and the end result is the same as sqlite3_bind_null().
4846 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4847 ** it should be a pointer to well-formed UTF8 text.
4848 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4849 ** it should be a pointer to well-formed UTF16 text.
4850 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4851 ** it should be a pointer to a well-formed unicode string that is
4852 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4853 ** otherwise.
4854 **
4855 ** [[byte-order determination rules]] ^The byte-order of
4856 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4857 ** found in the first character, which is removed, or in the absence of a BOM
4858 ** the byte order is the native byte order of the host
4859 ** machine for sqlite3_bind_text16() or the byte order specified in
4860 ** the 6th parameter for sqlite3_bind_text64().)^
4861 ** ^If UTF16 input text contains invalid unicode
4862 ** characters, then SQLite might change those invalid characters
4863 ** into the unicode replacement character: U+FFFD.
4864 **
4865 ** ^(In those routines that have a fourth argument, its value is the
4866 ** number of bytes in the parameter. To be clear: the value is the
4867 ** number of <u>bytes</u> in the value, not the number of characters.)^
4868 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4869 ** is negative, then the length of the string is
4870 ** the number of bytes up to the first zero terminator.
4871 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4872 ** the behavior is undefined.
4873 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4874 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4875 ** that parameter must be the byte offset
4876 ** where the NUL terminator would occur assuming the string were NUL
4877 ** terminated. If any NUL characters occur at byte offsets less than
4878 ** the value of the fourth parameter then the resulting string value will
4879 ** contain embedded NULs. The result of expressions involving strings
4880 ** with embedded NULs is undefined.
4881 **
4882 ** ^The fifth argument to the BLOB and string binding interfaces controls
4883 ** or indicates the lifetime of the object referenced by the third parameter.
4884 ** These three options exist:
4885 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4886 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4887 ** if the call to the bind API fails, except the destructor is not called if
4888 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4889 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4890 ** the application remains responsible for disposing of the object. ^In this
4891 ** case, the object and the provided pointer to it must remain valid until
4892 ** either the prepared statement is finalized or the same SQL parameter is
4893 ** bound to something else, whichever occurs sooner.
4894 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4895 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4896 ** object and pointer to it must remain valid until then. ^SQLite will then
4897 ** manage the lifetime of its private copy.
4898 **
4899 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4900 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4901 ** to specify the encoding of the text in the third parameter. If
4902 ** the sixth argument to sqlite3_bind_text64() is not one of the
4903 ** allowed values shown above, or if the text encoding is different
4904 ** from the encoding specified by the sixth parameter, then the behavior
4905 ** is undefined.
4906 **
4907 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4908 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4909 ** (just an integer to hold its size) while it is being processed.
4910 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4911 ** content is later written using
4912 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4913 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4914 **
4915 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4916 ** [prepared statement] S to have an SQL value of NULL, but to also be
4917 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4918 ** a pointer to a destructor function for P. ^SQLite will invoke the
4919 ** destructor D with a single argument of P when it is finished using
4920 ** P, even if the call to sqlite3_bind_pointer() fails. Due to a
4921 ** historical design quirk, results are undefined if D is
4922 ** SQLITE_TRANSIENT. The T parameter should be a static string,
4923 ** preferably a string literal. The sqlite3_bind_pointer() routine is
4924 ** part of the [pointer passing interface] added for SQLite 3.20.0.
4925 **
4926 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4927 ** for the [prepared statement] or with a prepared statement for which
4928 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4929 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4930 ** routine is passed a [prepared statement] that has been finalized, the
4931 ** result is undefined and probably harmful.
4932 **
4933 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4934 ** ^Unbound parameters are interpreted as NULL.
4935 **
4936 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4937 ** [error code] if anything goes wrong.
4938 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4939 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4940 ** [SQLITE_MAX_LENGTH].
4941 ** ^[SQLITE_RANGE] is returned if the parameter
4942 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4943 **
4944 ** See also: [sqlite3_bind_parameter_count()],
4945 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4946 */
4947 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4948 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4949 void(*)(void*));
4950 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4951 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4952 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4953 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4954 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4955 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4956 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4957 void(*)(void*), unsigned char encoding);
4958 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4959 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4960 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4961 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4962
4963 /*
4964 ** CAPI3REF: Number Of SQL Parameters
4965 ** METHOD: sqlite3_stmt
4966 **
4967 ** ^This routine can be used to find the number of [SQL parameters]
4968 ** in a [prepared statement]. SQL parameters are tokens of the
4969 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4970 ** placeholders for values that are [sqlite3_bind_blob | bound]
4971 ** to the parameters at a later time.
4972 **
4973 ** ^(This routine actually returns the index of the largest (rightmost)
4974 ** parameter. For all forms except ?NNN, this will correspond to the
4975 ** number of unique parameters. If parameters of the ?NNN form are used,
4976 ** there may be gaps in the list.)^
4977 **
4978 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4979 ** [sqlite3_bind_parameter_name()], and
4980 ** [sqlite3_bind_parameter_index()].
4981 */
4982 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4983
4984 /*
4985 ** CAPI3REF: Name Of A Host Parameter
4986 ** METHOD: sqlite3_stmt
4987 **
4988 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4989 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4990 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4991 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4992 ** respectively.
4993 ** In other words, the initial ":" or "$" or "@" or "?"
4994 ** is included as part of the name.)^
4995 ** ^Parameters of the form "?" without a following integer have no name
4996 ** and are referred to as "nameless" or "anonymous parameters".
4997 **
4998 ** ^The first host parameter has an index of 1, not 0.
4999 **
5000 ** ^If the value N is out of range or if the N-th parameter is
5001 ** nameless, then NULL is returned. ^The returned string is
5002 ** always in UTF-8 encoding even if the named parameter was
5003 ** originally specified as UTF-16 in [sqlite3_prepare16()],
5004 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
5005 **
5006 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
5007 ** [sqlite3_bind_parameter_count()], and
5008 ** [sqlite3_bind_parameter_index()].
5009 */
5010 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
5011
5012 /*
5013 ** CAPI3REF: Index Of A Parameter With A Given Name
5014 ** METHOD: sqlite3_stmt
5015 **
5016 ** ^Return the index of an SQL parameter given its name. ^The
5017 ** index value returned is suitable for use as the second
5018 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
5019 ** is returned if no matching parameter is found. ^The parameter
5020 ** name must be given in UTF-8 even if the original statement
5021 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
5022 ** [sqlite3_prepare16_v3()].
5023 **
5024 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
5025 ** [sqlite3_bind_parameter_count()], and
5026 ** [sqlite3_bind_parameter_name()].
5027 */
5028 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
5029
5030 /*
5031 ** CAPI3REF: Reset All Bindings On A Prepared Statement
5032 ** METHOD: sqlite3_stmt
5033 **
5034 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
5035 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
5036 ** ^Use this routine to reset all host parameters to NULL.
5037 */
5038 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
5039
5040 /*
5041 ** CAPI3REF: Number Of Columns In A Result Set
5042 ** METHOD: sqlite3_stmt
5043 **
5044 ** ^Return the number of columns in the result set returned by the
5045 ** [prepared statement]. ^If this routine returns 0, that means the
5046 ** [prepared statement] returns no data (for example an [UPDATE]).
5047 ** ^However, just because this routine returns a positive number does not
5048 ** mean that one or more rows of data will be returned. ^A SELECT statement
5049 ** will always have a positive sqlite3_column_count() but depending on the
5050 ** WHERE clause constraints and the table content, it might return no rows.
5051 **
5052 ** See also: [sqlite3_data_count()]
5053 */
5054 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5055
5056 /*
5057 ** CAPI3REF: Column Names In A Result Set
5058 ** METHOD: sqlite3_stmt
5059 **
5060 ** ^These routines return the name assigned to a particular column
5061 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5062 ** interface returns a pointer to a zero-terminated UTF-8 string
5063 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
5064 ** UTF-16 string. ^The first parameter is the [prepared statement]
5065 ** that implements the [SELECT] statement. ^The second parameter is the
5066 ** column number. ^The leftmost column is number 0.
5067 **
5068 ** ^The returned string pointer is valid until either the [prepared statement]
5069 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5070 ** reprepared by the first call to [sqlite3_step()] for a particular run
5071 ** or until the next call to
5072 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5073 **
5074 ** ^If sqlite3_malloc() fails during the processing of either routine
5075 ** (for example during a conversion from UTF-8 to UTF-16) then a
5076 ** NULL pointer is returned.
5077 **
5078 ** ^The name of a result column is the value of the "AS" clause for
5079 ** that column, if there is an AS clause. If there is no AS clause
5080 ** then the name of the column is unspecified and may change from
5081 ** one release of SQLite to the next.
5082 */
5083 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5084 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5085
5086 /*
5087 ** CAPI3REF: Source Of Data In A Query Result
5088 ** METHOD: sqlite3_stmt
5089 **
5090 ** ^These routines provide a means to determine the database, table, and
5091 ** table column that is the origin of a particular result column in a
5092 ** [SELECT] statement.
5093 ** ^The name of the database or table or column can be returned as
5094 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5095 ** the database name, the _table_ routines return the table name, and
5096 ** the origin_ routines return the column name.
5097 ** ^The returned string is valid until the [prepared statement] is destroyed
5098 ** using [sqlite3_finalize()] or until the statement is automatically
5099 ** reprepared by the first call to [sqlite3_step()] for a particular run
5100 ** or until the same information is requested
5101 ** again in a different encoding.
5102 **
5103 ** ^The names returned are the original un-aliased names of the
5104 ** database, table, and column.
5105 **
5106 ** ^The first argument to these interfaces is a [prepared statement].
5107 ** ^These functions return information about the Nth result column returned by
5108 ** the statement, where N is the second function argument.
5109 ** ^The left-most column is column 0 for these routines.
5110 **
5111 ** ^If the Nth column returned by the statement is an expression or
5112 ** subquery and is not a column value, then all of these functions return
5113 ** NULL. ^These routines might also return NULL if a memory allocation error
5114 ** occurs. ^Otherwise, they return the name of the attached database, table,
5115 ** or column that query result column was extracted from.
5116 **
5117 ** ^As with all other SQLite APIs, those whose names end with "16" return
5118 ** UTF-16 encoded strings and the other functions return UTF-8.
5119 **
5120 ** ^These APIs are only available if the library was compiled with the
5121 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5122 **
5123 ** If two or more threads call one or more
5124 ** [sqlite3_column_database_name | column metadata interfaces]
5125 ** for the same [prepared statement] and result column
5126 ** at the same time then the results are undefined.
5127 */
5128 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5129 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5130 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5131 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5132 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5133 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5134
5135 /*
5136 ** CAPI3REF: Declared Datatype Of A Query Result
5137 ** METHOD: sqlite3_stmt
5138 **
5139 ** ^(The first parameter is a [prepared statement].
5140 ** If this statement is a [SELECT] statement and the Nth column of the
5141 ** returned result set of that [SELECT] is a table column (not an
5142 ** expression or subquery) then the declared type of the table
5143 ** column is returned.)^ ^If the Nth column of the result set is an
5144 ** expression or subquery, then a NULL pointer is returned.
5145 ** ^The returned string is always UTF-8 encoded.
5146 **
5147 ** ^(For example, given the database schema:
5148 **
5149 ** CREATE TABLE t1(c1 VARIANT);
5150 **
5151 ** and the following statement to be compiled:
5152 **
5153 ** SELECT c1 + 1, c1 FROM t1;
5154 **
5155 ** this routine would return the string "VARIANT" for the second result
5156 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
5157 **
5158 ** ^SQLite uses dynamic run-time typing. ^So just because a column
5159 ** is declared to contain a particular type does not mean that the
5160 ** data stored in that column is of the declared type. SQLite is
5161 ** strongly typed, but the typing is dynamic not static. ^Type
5162 ** is associated with individual values, not with the containers
5163 ** used to hold those values.
5164 */
5165 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5166 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5167
5168 /*
5169 ** CAPI3REF: Evaluate An SQL Statement
5170 ** METHOD: sqlite3_stmt
5171 **
5172 ** After a [prepared statement] has been prepared using any of
5173 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5174 ** or [sqlite3_prepare16_v3()] or one of the legacy
5175 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5176 ** must be called one or more times to evaluate the statement.
5177 **
5178 ** The details of the behavior of the sqlite3_step() interface depend
5179 ** on whether the statement was prepared using the newer "vX" interfaces
5180 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5181 ** [sqlite3_prepare16_v2()] or the older legacy
5182 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5183 ** new "vX" interface is recommended for new applications but the legacy
5184 ** interface will continue to be supported.
5185 **
5186 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5187 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5188 ** ^With the "v2" interface, any of the other [result codes] or
5189 ** [extended result codes] might be returned as well.
5190 **
5191 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5192 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
5193 ** or occurs outside of an explicit transaction, then you can retry the
5194 ** statement. If the statement is not a [COMMIT] and occurs within an
5195 ** explicit transaction then you should rollback the transaction before
5196 ** continuing.
5197 **
5198 ** ^[SQLITE_DONE] means that the statement has finished executing
5199 ** successfully. sqlite3_step() should not be called again on this virtual
5200 ** machine without first calling [sqlite3_reset()] to reset the virtual
5201 ** machine back to its initial state.
5202 **
5203 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5204 ** is returned each time a new row of data is ready for processing by the
5205 ** caller. The values may be accessed using the [column access functions].
5206 ** sqlite3_step() is called again to retrieve the next row of data.
5207 **
5208 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5209 ** violation) has occurred. sqlite3_step() should not be called again on
5210 ** the VM. More information may be found by calling [sqlite3_errmsg()].
5211 ** ^With the legacy interface, a more specific error code (for example,
5212 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5213 ** can be obtained by calling [sqlite3_reset()] on the
5214 ** [prepared statement]. ^In the "v2" interface,
5215 ** the more specific error code is returned directly by sqlite3_step().
5216 **
5217 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5218 ** Perhaps it was called on a [prepared statement] that has
5219 ** already been [sqlite3_finalize | finalized] or on one that had
5220 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5221 ** be the case that the same database connection is being used by two or
5222 ** more threads at the same moment in time.
5223 **
5224 ** For all versions of SQLite up to and including 3.6.23.1, a call to
5225 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
5226 ** other than [SQLITE_ROW] before any subsequent invocation of
5227 ** sqlite3_step(). Failure to reset the prepared statement using
5228 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5229 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5230 ** sqlite3_step() began
5231 ** calling [sqlite3_reset()] automatically in this circumstance rather
5232 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5233 ** break because any application that ever receives an SQLITE_MISUSE error
5234 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5235 ** can be used to restore the legacy behavior.
5236 **
5237 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5238 ** API always returns a generic error code, [SQLITE_ERROR], following any
5239 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5240 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5241 ** specific [error codes] that better describes the error.
5242 ** We admit that this is a goofy design. The problem has been fixed
5243 ** with the "v2" interface. If you prepare all of your SQL statements
5244 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5245 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5246 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5247 ** then the more specific [error codes] are returned directly
5248 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5249 */
5250 SQLITE_API int sqlite3_step(sqlite3_stmt*);
5251
5252 /*
5253 ** CAPI3REF: Number of columns in a result set
5254 ** METHOD: sqlite3_stmt
5255 **
5256 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
5257 ** current row of the result set of [prepared statement] P.
5258 ** ^If prepared statement P does not have results ready to return
5259 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5260 ** interfaces) then sqlite3_data_count(P) returns 0.
5261 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5262 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5263 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5264 ** will return non-zero if previous call to [sqlite3_step](P) returned
5265 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5266 ** where it always returns zero since each step of that multi-step
5267 ** pragma returns 0 columns of data.
5268 **
5269 ** See also: [sqlite3_column_count()]
5270 */
5271 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5272
5273 /*
5274 ** CAPI3REF: Fundamental Datatypes
5275 ** KEYWORDS: SQLITE_TEXT
5276 **
5277 ** ^(Every value in SQLite has one of five fundamental datatypes:
5278 **
5279 ** <ul>
5280 ** <li> 64-bit signed integer
5281 ** <li> 64-bit IEEE floating point number
5282 ** <li> string
5283 ** <li> BLOB
5284 ** <li> NULL
5285 ** </ul>)^
5286 **
5287 ** These constants are codes for each of those types.
5288 **
5289 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5290 ** for a completely different meaning. Software that links against both
5291 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5292 ** SQLITE_TEXT.
5293 */
5294 #define SQLITE_INTEGER 1
5295 #define SQLITE_FLOAT 2
5296 #define SQLITE_BLOB 4
5297 #define SQLITE_NULL 5
5298 #ifdef SQLITE_TEXT
5299 # undef SQLITE_TEXT
5300 #else
5301 # define SQLITE_TEXT 3
5302 #endif
5303 #define SQLITE3_TEXT 3
5304
5305 /*
5306 ** CAPI3REF: Result Values From A Query
5307 ** KEYWORDS: {column access functions}
5308 ** METHOD: sqlite3_stmt
5309 **
5310 ** <b>Summary:</b>
5311 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5312 ** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5313 ** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5314 ** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5315 ** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5316 ** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5317 ** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5318 ** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5319 ** [sqlite3_value|unprotected sqlite3_value] object.
5320 ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5321 ** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5322 ** or a UTF-8 TEXT result in bytes
5323 ** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5324 ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5325 ** TEXT in bytes
5326 ** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5327 ** datatype of the result
5328 ** </table></blockquote>
5329 **
5330 ** <b>Details:</b>
5331 **
5332 ** ^These routines return information about a single column of the current
5333 ** result row of a query. ^In every case the first argument is a pointer
5334 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5335 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5336 ** and the second argument is the index of the column for which information
5337 ** should be returned. ^The leftmost column of the result set has the index 0.
5338 ** ^The number of columns in the result can be determined using
5339 ** [sqlite3_column_count()].
5340 **
5341 ** If the SQL statement does not currently point to a valid row, or if the
5342 ** column index is out of range, the result is undefined.
5343 ** These routines may only be called when the most recent call to
5344 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5345 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5346 ** If any of these routines are called after [sqlite3_reset()] or
5347 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5348 ** something other than [SQLITE_ROW], the results are undefined.
5349 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5350 ** are called from a different thread while any of these routines
5351 ** are pending, then the results are undefined.
5352 **
5353 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5354 ** each return the value of a result column in a specific data format. If
5355 ** the result column is not initially in the requested format (for example,
5356 ** if the query returns an integer but the sqlite3_column_text() interface
5357 ** is used to extract the value) then an automatic type conversion is performed.
5358 **
5359 ** ^The sqlite3_column_type() routine returns the
5360 ** [SQLITE_INTEGER | datatype code] for the initial data type
5361 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5362 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5363 ** The return value of sqlite3_column_type() can be used to decide which
5364 ** of the first six interface should be used to extract the column value.
5365 ** The value returned by sqlite3_column_type() is only meaningful if no
5366 ** automatic type conversions have occurred for the value in question.
5367 ** After a type conversion, the result of calling sqlite3_column_type()
5368 ** is undefined, though harmless. Future
5369 ** versions of SQLite may change the behavior of sqlite3_column_type()
5370 ** following a type conversion.
5371 **
5372 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5373 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
5374 ** of that BLOB or string.
5375 **
5376 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5377 ** routine returns the number of bytes in that BLOB or string.
5378 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5379 ** the string to UTF-8 and then returns the number of bytes.
5380 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
5381 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5382 ** the number of bytes in that string.
5383 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5384 **
5385 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5386 ** routine returns the number of bytes in that BLOB or string.
5387 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5388 ** the string to UTF-16 and then returns the number of bytes.
5389 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5390 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5391 ** the number of bytes in that string.
5392 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5393 **
5394 ** ^The values returned by [sqlite3_column_bytes()] and
5395 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5396 ** of the string. ^For clarity: the values returned by
5397 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5398 ** bytes in the string, not the number of characters.
5399 **
5400 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5401 ** even empty strings, are always zero-terminated. ^The return
5402 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5403 **
5404 ** ^Strings returned by sqlite3_column_text16() always have the endianness
5405 ** which is native to the platform, regardless of the text encoding set
5406 ** for the database.
5407 **
5408 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5409 ** [unprotected sqlite3_value] object. In a multithreaded environment,
5410 ** an unprotected sqlite3_value object may only be used safely with
5411 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
5412 ** If the [unprotected sqlite3_value] object returned by
5413 ** [sqlite3_column_value()] is used in any other way, including calls
5414 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5415 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5416 ** Hence, the sqlite3_column_value() interface
5417 ** is normally only useful within the implementation of
5418 ** [application-defined SQL functions] or [virtual tables], not within
5419 ** top-level application code.
5420 **
5421 ** These routines may attempt to convert the datatype of the result.
5422 ** ^For example, if the internal representation is FLOAT and a text result
5423 ** is requested, [sqlite3_snprintf()] is used internally to perform the
5424 ** conversion automatically. ^(The following table details the conversions
5425 ** that are applied:
5426 **
5427 ** <blockquote>
5428 ** <table border="1">
5429 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5430 **
5431 ** <tr><td> NULL <td> INTEGER <td> Result is 0
5432 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5433 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5434 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5435 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5436 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5437 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5438 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5439 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5440 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5441 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5442 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5443 ** <tr><td> TEXT <td> BLOB <td> No change
5444 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5445 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5446 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5447 ** </table>
5448 ** </blockquote>)^
5449 **
5450 ** Note that when type conversions occur, pointers returned by prior
5451 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5452 ** sqlite3_column_text16() may be invalidated.
5453 ** Type conversions and pointer invalidations might occur
5454 ** in the following cases:
5455 **
5456 ** <ul>
5457 ** <li> The initial content is a BLOB and sqlite3_column_text() or
5458 ** sqlite3_column_text16() is called. A zero-terminator might
5459 ** need to be added to the string.</li>
5460 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5461 ** sqlite3_column_text16() is called. The content must be converted
5462 ** to UTF-16.</li>
5463 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5464 ** sqlite3_column_text() is called. The content must be converted
5465 ** to UTF-8.</li>
5466 ** </ul>
5467 **
5468 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5469 ** not invalidate a prior pointer, though of course the content of the buffer
5470 ** that the prior pointer references will have been modified. Other kinds
5471 ** of conversion are done in place when it is possible, but sometimes they
5472 ** are not possible and in those cases prior pointers are invalidated.
5473 **
5474 ** The safest policy is to invoke these routines
5475 ** in one of the following ways:
5476 **
5477 ** <ul>
5478 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5479 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5480 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5481 ** </ul>
5482 **
5483 ** In other words, you should call sqlite3_column_text(),
5484 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5485 ** into the desired format, then invoke sqlite3_column_bytes() or
5486 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5487 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5488 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5489 ** with calls to sqlite3_column_bytes().
5490 **
5491 ** ^The pointers returned are valid until a type conversion occurs as
5492 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5493 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5494 ** and BLOBs is freed automatically. Do not pass the pointers returned
5495 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5496 ** [sqlite3_free()].
5497 **
5498 ** As long as the input parameters are correct, these routines will only
5499 ** fail if an out-of-memory error occurs during a format conversion.
5500 ** Only the following subset of interfaces are subject to out-of-memory
5501 ** errors:
5502 **
5503 ** <ul>
5504 ** <li> sqlite3_column_blob()
5505 ** <li> sqlite3_column_text()
5506 ** <li> sqlite3_column_text16()
5507 ** <li> sqlite3_column_bytes()
5508 ** <li> sqlite3_column_bytes16()
5509 ** </ul>
5510 **
5511 ** If an out-of-memory error occurs, then the return value from these
5512 ** routines is the same as if the column had contained an SQL NULL value.
5513 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5514 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5515 ** return value is obtained and before any
5516 ** other SQLite interface is called on the same [database connection].
5517 */
5518 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5519 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5520 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5521 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5522 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5523 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5524 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5525 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5526 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5527 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5528
5529 /*
5530 ** CAPI3REF: Destroy A Prepared Statement Object
5531 ** DESTRUCTOR: sqlite3_stmt
5532 **
5533 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5534 ** ^If the most recent evaluation of the statement encountered no errors
5535 ** or if the statement has never been evaluated, then sqlite3_finalize() returns
5536 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5537 ** sqlite3_finalize(S) returns the appropriate [error code] or
5538 ** [extended error code].
5539 **
5540 ** ^The sqlite3_finalize(S) routine can be called at any point during
5541 ** the life cycle of [prepared statement] S:
5542 ** before statement S is ever evaluated, after
5543 ** one or more calls to [sqlite3_reset()], or after any call
5544 ** to [sqlite3_step()] regardless of whether or not the statement has
5545 ** completed execution.
5546 **
5547 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5548 **
5549 ** The application must finalize every [prepared statement] in order to avoid
5550 ** resource leaks. It is a grievous error for the application to try to use
5551 ** a prepared statement after it has been finalized. Any use of a prepared
5552 ** statement after it has been finalized can result in undefined and
5553 ** undesirable behavior such as segfaults and heap corruption.
5554 */
5555 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5556
5557 /*
5558 ** CAPI3REF: Reset A Prepared Statement Object
5559 ** METHOD: sqlite3_stmt
5560 **
5561 ** The sqlite3_reset() function is called to reset a [prepared statement]
5562 ** object back to its initial state, ready to be re-executed.
5563 ** ^Any SQL statement variables that had values bound to them using
5564 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5565 ** Use [sqlite3_clear_bindings()] to reset the bindings.
5566 **
5567 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5568 ** back to the beginning of its program.
5569 **
5570 ** ^The return code from [sqlite3_reset(S)] indicates whether or not
5571 ** the previous evaluation of prepared statement S completed successfully.
5572 ** ^If [sqlite3_step(S)] has never before been called on S or if
5573 ** [sqlite3_step(S)] has not been called since the previous call
5574 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5575 ** [SQLITE_OK].
5576 **
5577 ** ^If the most recent call to [sqlite3_step(S)] for the
5578 ** [prepared statement] S indicated an error, then
5579 ** [sqlite3_reset(S)] returns an appropriate [error code].
5580 ** ^The [sqlite3_reset(S)] interface might also return an [error code]
5581 ** if there were no prior errors but the process of resetting
5582 ** the prepared statement caused a new error. ^For example, if an
5583 ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5584 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5585 ** the overall statement might still fail and the [sqlite3_reset(S)] call
5586 ** might return SQLITE_BUSY if locking constraints prevent the
5587 ** database change from committing. Therefore, it is important that
5588 ** applications check the return code from [sqlite3_reset(S)] even if
5589 ** no prior call to [sqlite3_step(S)] indicated a problem.
5590 **
5591 ** ^The [sqlite3_reset(S)] interface does not change the values
5592 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5593 */
5594 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5595
5596
5597 /*
5598 ** CAPI3REF: Create Or Redefine SQL Functions
5599 ** KEYWORDS: {function creation routines}
5600 ** METHOD: sqlite3
5601 **
5602 ** ^These functions (collectively known as "function creation routines")
5603 ** are used to add SQL functions or aggregates or to redefine the behavior
5604 ** of existing SQL functions or aggregates. The only differences between
5605 ** the three "sqlite3_create_function*" routines are the text encoding
5606 ** expected for the second parameter (the name of the function being
5607 ** created) and the presence or absence of a destructor callback for
5608 ** the application data pointer. Function sqlite3_create_window_function()
5609 ** is similar, but allows the user to supply the extra callback functions
5610 ** needed by [aggregate window functions].
5611 **
5612 ** ^The first parameter is the [database connection] to which the SQL
5613 ** function is to be added. ^If an application uses more than one database
5614 ** connection then application-defined SQL functions must be added
5615 ** to each database connection separately.
5616 **
5617 ** ^The second parameter is the name of the SQL function to be created or
5618 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5619 ** representation, exclusive of the zero-terminator. ^Note that the name
5620 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5621 ** ^Any attempt to create a function with a longer name
5622 ** will result in [SQLITE_MISUSE] being returned.
5623 **
5624 ** ^The third parameter (nArg)
5625 ** is the number of arguments that the SQL function or
5626 ** aggregate takes. ^If this parameter is -1, then the SQL function or
5627 ** aggregate may take any number of arguments between 0 and the limit
5628 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5629 ** parameter is less than -1 or greater than 127 then the behavior is
5630 ** undefined.
5631 **
5632 ** ^The fourth parameter, eTextRep, specifies what
5633 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5634 ** its parameters. The application should set this parameter to
5635 ** [SQLITE_UTF16LE] if the function implementation invokes
5636 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5637 ** implementation invokes [sqlite3_value_text16be()] on an input, or
5638 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5639 ** otherwise. ^The same SQL function may be registered multiple times using
5640 ** different preferred text encodings, with different implementations for
5641 ** each encoding.
5642 ** ^When multiple implementations of the same function are available, SQLite
5643 ** will pick the one that involves the least amount of data conversion.
5644 **
5645 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5646 ** to signal that the function will always return the same result given
5647 ** the same inputs within a single SQL statement. Most SQL functions are
5648 ** deterministic. The built-in [random()] SQL function is an example of a
5649 ** function that is not deterministic. The SQLite query planner is able to
5650 ** perform additional optimizations on deterministic functions, so use
5651 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5652 **
5653 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5654 ** flag, which if present prevents the function from being invoked from
5655 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5656 ** index expressions, or the WHERE clause of partial indexes.
5657 **
5658 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5659 ** all application-defined SQL functions that do not need to be
5660 ** used inside of triggers, views, CHECK constraints, or other elements of
5661 ** the database schema. This flag is especially recommended for SQL
5662 ** functions that have side effects or reveal internal application state.
5663 ** Without this flag, an attacker might be able to modify the schema of
5664 ** a database file to include invocations of the function with parameters
5665 ** chosen by the attacker, which the application will then execute when
5666 ** the database file is opened and read.
5667 **
5668 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5669 ** function can gain access to this pointer using [sqlite3_user_data()].)^
5670 **
5671 ** ^The sixth, seventh and eighth parameters passed to the three
5672 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5673 ** pointers to C-language functions that implement the SQL function or
5674 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5675 ** callback only; NULL pointers must be passed as the xStep and xFinal
5676 ** parameters. ^An aggregate SQL function requires an implementation of xStep
5677 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5678 ** SQL function or aggregate, pass NULL pointers for all three function
5679 ** callbacks.
5680 **
5681 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5682 ** and xInverse) passed to sqlite3_create_window_function are pointers to
5683 ** C-language callbacks that implement the new function. xStep and xFinal
5684 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5685 ** which case a regular aggregate function is created, or must both be
5686 ** non-NULL, in which case the new function may be used as either an aggregate
5687 ** or aggregate window function. More details regarding the implementation
5688 ** of aggregate window functions are
5689 ** [user-defined window functions|available here].
5690 **
5691 ** ^(If the final parameter to sqlite3_create_function_v2() or
5692 ** sqlite3_create_window_function() is not NULL, then it is the destructor for
5693 ** the application data pointer. The destructor is invoked when the function
5694 ** is deleted, either by being overloaded or when the database connection
5695 ** closes.)^ ^The destructor is also invoked if the call to
5696 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5697 ** invoked, it is passed a single argument which is a copy of the application
5698 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5699 **
5700 ** ^It is permitted to register multiple implementations of the same
5701 ** functions with the same name but with either differing numbers of
5702 ** arguments or differing preferred text encodings. ^SQLite will use
5703 ** the implementation that most closely matches the way in which the
5704 ** SQL function is used. ^A function implementation with a non-negative
5705 ** nArg parameter is a better match than a function implementation with
5706 ** a negative nArg. ^A function where the preferred text encoding
5707 ** matches the database encoding is a better
5708 ** match than a function where the encoding is different.
5709 ** ^A function where the encoding difference is between UTF16le and UTF16be
5710 ** is a closer match than a function where the encoding difference is
5711 ** between UTF8 and UTF16.
5712 **
5713 ** ^Built-in functions may be overloaded by new application-defined functions.
5714 **
5715 ** ^An application-defined function is permitted to call other
5716 ** SQLite interfaces. However, such calls must not
5717 ** close the database connection nor finalize or reset the prepared
5718 ** statement in which the function is running.
5719 */
5720 SQLITE_API int sqlite3_create_function(
5721 sqlite3 *db,
5722 const char *zFunctionName,
5723 int nArg,
5724 int eTextRep,
5725 void *pApp,
5726 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5727 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5728 void (*xFinal)(sqlite3_context*)
5729 );
5730 SQLITE_API int sqlite3_create_function16(
5731 sqlite3 *db,
5732 const void *zFunctionName,
5733 int nArg,
5734 int eTextRep,
5735 void *pApp,
5736 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5737 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5738 void (*xFinal)(sqlite3_context*)
5739 );
5740 SQLITE_API int sqlite3_create_function_v2(
5741 sqlite3 *db,
5742 const char *zFunctionName,
5743 int nArg,
5744 int eTextRep,
5745 void *pApp,
5746 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5747 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5748 void (*xFinal)(sqlite3_context*),
5749 void(*xDestroy)(void*)
5750 );
5751 SQLITE_API int sqlite3_create_window_function(
5752 sqlite3 *db,
5753 const char *zFunctionName,
5754 int nArg,
5755 int eTextRep,
5756 void *pApp,
5757 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5758 void (*xFinal)(sqlite3_context*),
5759 void (*xValue)(sqlite3_context*),
5760 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5761 void(*xDestroy)(void*)
5762 );
5763
5764 /*
5765 ** CAPI3REF: Text Encodings
5766 **
5767 ** These constants define integer codes that represent the various
5768 ** text encodings supported by SQLite.
5769 */
5770 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5771 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5772 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5773 #define SQLITE_UTF16 4 /* Use native byte order */
5774 #define SQLITE_ANY 5 /* Deprecated */
5775 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5776
5777 /*
5778 ** CAPI3REF: Function Flags
5779 **
5780 ** These constants may be ORed together with the
5781 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5782 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5783 ** [sqlite3_create_function_v2()].
5784 **
5785 ** <dl>
5786 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5787 ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5788 ** the same output when the input parameters are the same.
5789 ** The [abs|abs() function] is deterministic, for example, but
5790 ** [randomblob|randomblob()] is not. Functions must
5791 ** be deterministic in order to be used in certain contexts such as
5792 ** with the WHERE clause of [partial indexes] or in [generated columns].
5793 ** SQLite might also optimize deterministic functions by factoring them
5794 ** out of inner loops.
5795 ** </dd>
5796 **
5797 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5798 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5799 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5800 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5801 ** [expression indexes], [partial indexes], or [generated columns].
5802 ** <p>
5803 ** The SQLITE_DIRECTONLY flag is recommended for any
5804 ** [application-defined SQL function]
5805 ** that has side-effects or that could potentially leak sensitive information.
5806 ** This will prevent attacks in which an application is tricked
5807 ** into using a database file that has had its schema surreptitiously
5808 ** modified to invoke the application-defined function in ways that are
5809 ** harmful.
5810 ** <p>
5811 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5812 ** [application-defined SQL functions], regardless of whether or not they
5813 ** are security sensitive, as doing so prevents those functions from being used
5814 ** inside of the database schema, and thus ensures that the database
5815 ** can be inspected and modified using generic tools (such as the [CLI])
5816 ** that do not have access to the application-defined functions.
5817 ** </dd>
5818 **
5819 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5820 ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5821 ** to cause problems even if misused. An innocuous function should have
5822 ** no side effects and should not depend on any values other than its
5823 ** input parameters. The [abs|abs() function] is an example of an
5824 ** innocuous function.
5825 ** The [load_extension() SQL function] is not innocuous because of its
5826 ** side effects.
5827 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5828 ** exactly the same. The [random|random() function] is an example of a
5829 ** function that is innocuous but not deterministic.
5830 ** <p>Some heightened security settings
5831 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5832 ** disable the use of SQL functions inside views and triggers and in
5833 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5834 ** [expression indexes], [partial indexes], and [generated columns] unless
5835 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5836 ** are innocuous. Developers are advised to avoid using the
5837 ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5838 ** function has been carefully audited and found to be free of potentially
5839 ** security-adverse side-effects and information-leaks.
5840 ** </dd>
5841 **
5842 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5843 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5844 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5845 ** This flag instructs SQLite to omit some corner-case optimizations that
5846 ** might disrupt the operation of the [sqlite3_value_subtype()] function,
5847 ** causing it to return zero rather than the correct subtype().
5848 ** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5849 ** property. If the SQLITE_SUBTYPE property is omitted, then the return
5850 ** value from [sqlite3_value_subtype()] might sometimes be zero even though
5851 ** a non-zero subtype was specified by the function argument expression.
5852 **
5853 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5854 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5855 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5856 ** result.
5857 ** Every function that invokes [sqlite3_result_subtype()] should have this
5858 ** property. If it does not, then the call to [sqlite3_result_subtype()]
5859 ** might become a no-op if the function is used as a term in an
5860 ** [expression index]. On the other hand, SQL functions that never invoke
5861 ** [sqlite3_result_subtype()] should avoid setting this property, as the
5862 ** purpose of this property is to disable certain optimizations that are
5863 ** incompatible with subtypes.
5864 **
5865 ** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5866 ** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5867 ** that internally orders the values provided to the first argument. The
5868 ** ordered-set aggregate SQL notation with a single ORDER BY term can be
5869 ** used to invoke this function. If the ordered-set aggregate notation is
5870 ** used on a function that lacks this flag, then an error is raised. Note
5871 ** that the ordered-set aggregate syntax is only available if SQLite is
5872 ** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5873 ** </dd>
5874 ** </dl>
5875 */
5876 #define SQLITE_DETERMINISTIC 0x000000800
5877 #define SQLITE_DIRECTONLY 0x000080000
5878 #define SQLITE_SUBTYPE 0x000100000
5879 #define SQLITE_INNOCUOUS 0x000200000
5880 #define SQLITE_RESULT_SUBTYPE 0x001000000
5881 #define SQLITE_SELFORDER1 0x002000000
5882
5883 /*
5884 ** CAPI3REF: Deprecated Functions
5885 ** DEPRECATED
5886 **
5887 ** These functions are [deprecated]. In order to maintain
5888 ** backwards compatibility with older code, these functions continue
5889 ** to be supported. However, new applications should avoid
5890 ** the use of these functions. To encourage programmers to avoid
5891 ** these functions, we will not explain what they do.
5892 */
5893 #ifndef SQLITE_OMIT_DEPRECATED
5894 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5895 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5896 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5897 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5898 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5899 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5900 void*,sqlite3_int64);
5901 #endif
5902
5903 /*
5904 ** CAPI3REF: Obtaining SQL Values
5905 ** METHOD: sqlite3_value
5906 **
5907 ** <b>Summary:</b>
5908 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5909 ** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5910 ** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5911 ** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5912 ** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5913 ** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5914 ** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5915 ** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5916 ** the native byteorder
5917 ** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5918 ** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5919 ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5920 ** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5921 ** or a UTF-8 TEXT in bytes
5922 ** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5923 ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5924 ** TEXT in bytes
5925 ** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5926 ** datatype of the value
5927 ** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5928 ** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5929 ** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5930 ** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5931 ** against a virtual table.
5932 ** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5933 ** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5934 ** </table></blockquote>
5935 **
5936 ** <b>Details:</b>
5937 **
5938 ** These routines extract type, size, and content information from
5939 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5940 ** are used to pass parameter information into the functions that
5941 ** implement [application-defined SQL functions] and [virtual tables].
5942 **
5943 ** These routines work only with [protected sqlite3_value] objects.
5944 ** Any attempt to use these routines on an [unprotected sqlite3_value]
5945 ** is not threadsafe.
5946 **
5947 ** ^These routines work just like the corresponding [column access functions]
5948 ** except that these routines take a single [protected sqlite3_value] object
5949 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5950 **
5951 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5952 ** in the native byte-order of the host machine. ^The
5953 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5954 ** extract UTF-16 strings as big-endian and little-endian respectively.
5955 **
5956 ** ^If [sqlite3_value] object V was initialized
5957 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5958 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5959 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5960 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5961 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5962 **
5963 ** ^(The sqlite3_value_type(V) interface returns the
5964 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5965 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5966 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5967 ** Other interfaces might change the datatype for an sqlite3_value object.
5968 ** For example, if the datatype is initially SQLITE_INTEGER and
5969 ** sqlite3_value_text(V) is called to extract a text value for that
5970 ** integer, then subsequent calls to sqlite3_value_type(V) might return
5971 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5972 ** occurs is undefined and may change from one release of SQLite to the next.
5973 **
5974 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5975 ** numeric affinity to the value. This means that an attempt is
5976 ** made to convert the value to an integer or floating point. If
5977 ** such a conversion is possible without loss of information (in other
5978 ** words, if the value is a string that looks like a number)
5979 ** then the conversion is performed. Otherwise no conversion occurs.
5980 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5981 **
5982 ** ^Within the [xUpdate] method of a [virtual table], the
5983 ** sqlite3_value_nochange(X) interface returns true if and only if
5984 ** the column corresponding to X is unchanged by the UPDATE operation
5985 ** that the xUpdate method call was invoked to implement and if
5986 ** the prior [xColumn] method call that was invoked to extract
5987 ** the value for that column returned without setting a result (probably
5988 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5989 ** was unchanging). ^Within an [xUpdate] method, any value for which
5990 ** sqlite3_value_nochange(X) is true will in all other respects appear
5991 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5992 ** than within an [xUpdate] method call for an UPDATE statement, then
5993 ** the return value is arbitrary and meaningless.
5994 **
5995 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5996 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5997 ** interfaces. ^If X comes from an SQL literal value, or a table column,
5998 ** or an expression, then sqlite3_value_frombind(X) returns zero.
5999 **
6000 ** Please pay particular attention to the fact that the pointer returned
6001 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
6002 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
6003 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
6004 ** or [sqlite3_value_text16()].
6005 **
6006 ** These routines must be called from the same thread as
6007 ** the SQL function that supplied the [sqlite3_value*] parameters.
6008 **
6009 ** As long as the input parameter is correct, these routines can only
6010 ** fail if an out-of-memory error occurs during a format conversion.
6011 ** Only the following subset of interfaces are subject to out-of-memory
6012 ** errors:
6013 **
6014 ** <ul>
6015 ** <li> sqlite3_value_blob()
6016 ** <li> sqlite3_value_text()
6017 ** <li> sqlite3_value_text16()
6018 ** <li> sqlite3_value_text16le()
6019 ** <li> sqlite3_value_text16be()
6020 ** <li> sqlite3_value_bytes()
6021 ** <li> sqlite3_value_bytes16()
6022 ** </ul>
6023 **
6024 ** If an out-of-memory error occurs, then the return value from these
6025 ** routines is the same as if the column had contained an SQL NULL value.
6026 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
6027 ** by invoking the [sqlite3_errcode()] immediately after the suspect
6028 ** return value is obtained and before any
6029 ** other SQLite interface is called on the same [database connection].
6030 */
6031 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
6032 SQLITE_API double sqlite3_value_double(sqlite3_value*);
6033 SQLITE_API int sqlite3_value_int(sqlite3_value*);
6034 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
6035 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
6036 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
6037 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
6038 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
6039 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
6040 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
6041 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
6042 SQLITE_API int sqlite3_value_type(sqlite3_value*);
6043 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
6044 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
6045 SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
6046
6047 /*
6048 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
6049 ** METHOD: sqlite3_value
6050 **
6051 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6052 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6053 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6054 ** returns something other than SQLITE_TEXT, then the return value from
6055 ** sqlite3_value_encoding(X) is meaningless. ^Calls to
6056 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6057 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6058 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6059 ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6060 **
6061 ** This routine is intended for used by applications that test and validate
6062 ** the SQLite implementation. This routine is inquiring about the opaque
6063 ** internal state of an [sqlite3_value] object. Ordinary applications should
6064 ** not need to know what the internal state of an sqlite3_value object is and
6065 ** hence should not need to use this interface.
6066 */
6067 SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6068
6069 /*
6070 ** CAPI3REF: Finding The Subtype Of SQL Values
6071 ** METHOD: sqlite3_value
6072 **
6073 ** The sqlite3_value_subtype(V) function returns the subtype for
6074 ** an [application-defined SQL function] argument V. The subtype
6075 ** information can be used to pass a limited amount of context from
6076 ** one SQL function to another. Use the [sqlite3_result_subtype()]
6077 ** routine to set the subtype for the return value of an SQL function.
6078 **
6079 ** Every [application-defined SQL function] that invokes this interface
6080 ** should include the [SQLITE_SUBTYPE] property in the text
6081 ** encoding argument when the function is [sqlite3_create_function|registered].
6082 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6083 ** might return zero instead of the upstream subtype in some corner cases.
6084 */
6085 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6086
6087 /*
6088 ** CAPI3REF: Copy And Free SQL Values
6089 ** METHOD: sqlite3_value
6090 **
6091 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6092 ** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6093 ** is a [protected sqlite3_value] object even if the input is not.
6094 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6095 ** memory allocation fails. ^If V is a [pointer value], then the result
6096 ** of sqlite3_value_dup(V) is a NULL value.
6097 **
6098 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6099 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6100 ** then sqlite3_value_free(V) is a harmless no-op.
6101 */
6102 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6103 SQLITE_API void sqlite3_value_free(sqlite3_value*);
6104
6105 /*
6106 ** CAPI3REF: Obtain Aggregate Function Context
6107 ** METHOD: sqlite3_context
6108 **
6109 ** Implementations of aggregate SQL functions use this
6110 ** routine to allocate memory for storing their state.
6111 **
6112 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6113 ** for a particular aggregate function, SQLite allocates
6114 ** N bytes of memory, zeroes out that memory, and returns a pointer
6115 ** to the new memory. ^On second and subsequent calls to
6116 ** sqlite3_aggregate_context() for the same aggregate function instance,
6117 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
6118 ** called once for each invocation of the xStep callback and then one
6119 ** last time when the xFinal callback is invoked. ^(When no rows match
6120 ** an aggregate query, the xStep() callback of the aggregate function
6121 ** implementation is never called and xFinal() is called exactly once.
6122 ** In those cases, sqlite3_aggregate_context() might be called for the
6123 ** first time from within xFinal().)^
6124 **
6125 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6126 ** when first called if N is less than or equal to zero or if a memory
6127 ** allocation error occurs.
6128 **
6129 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6130 ** determined by the N parameter on the first successful call. Changing the
6131 ** value of N in any subsequent call to sqlite3_aggregate_context() within
6132 ** the same aggregate function instance will not resize the memory
6133 ** allocation.)^ Within the xFinal callback, it is customary to set
6134 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6135 ** pointless memory allocations occur.
6136 **
6137 ** ^SQLite automatically frees the memory allocated by
6138 ** sqlite3_aggregate_context() when the aggregate query concludes.
6139 **
6140 ** The first parameter must be a copy of the
6141 ** [sqlite3_context | SQL function context] that is the first parameter
6142 ** to the xStep or xFinal callback routine that implements the aggregate
6143 ** function.
6144 **
6145 ** This routine must be called from the same thread in which
6146 ** the aggregate SQL function is running.
6147 */
6148 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6149
6150 /*
6151 ** CAPI3REF: User Data For Functions
6152 ** METHOD: sqlite3_context
6153 **
6154 ** ^The sqlite3_user_data() interface returns a copy of
6155 ** the pointer that was the pUserData parameter (the 5th parameter)
6156 ** of the [sqlite3_create_function()]
6157 ** and [sqlite3_create_function16()] routines that originally
6158 ** registered the application defined function.
6159 **
6160 ** This routine must be called from the same thread in which
6161 ** the application-defined function is running.
6162 */
6163 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6164
6165 /*
6166 ** CAPI3REF: Database Connection For Functions
6167 ** METHOD: sqlite3_context
6168 **
6169 ** ^The sqlite3_context_db_handle() interface returns a copy of
6170 ** the pointer to the [database connection] (the 1st parameter)
6171 ** of the [sqlite3_create_function()]
6172 ** and [sqlite3_create_function16()] routines that originally
6173 ** registered the application defined function.
6174 */
6175 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6176
6177 /*
6178 ** CAPI3REF: Function Auxiliary Data
6179 ** METHOD: sqlite3_context
6180 **
6181 ** These functions may be used by (non-aggregate) SQL functions to
6182 ** associate auxiliary data with argument values. If the same argument
6183 ** value is passed to multiple invocations of the same SQL function during
6184 ** query execution, under some circumstances the associated auxiliary data
6185 ** might be preserved. An example of where this might be useful is in a
6186 ** regular-expression matching function. The compiled version of the regular
6187 ** expression can be stored as auxiliary data associated with the pattern string.
6188 ** Then as long as the pattern string remains the same,
6189 ** the compiled regular expression can be reused on multiple
6190 ** invocations of the same function.
6191 **
6192 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6193 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6194 ** value to the application-defined function. ^N is zero for the left-most
6195 ** function argument. ^If there is no auxiliary data
6196 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6197 ** returns a NULL pointer.
6198 **
6199 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6200 ** N-th argument of the application-defined function. ^Subsequent
6201 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6202 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6203 ** NULL if the auxiliary data has been discarded.
6204 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6205 ** SQLite will invoke the destructor function X with parameter P exactly
6206 ** once, when the auxiliary data is discarded.
6207 ** SQLite is free to discard the auxiliary data at any time, including: <ul>
6208 ** <li> ^(when the corresponding function parameter changes)^, or
6209 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6210 ** SQL statement)^, or
6211 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6212 ** parameter)^, or
6213 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6214 ** allocation error occurs.)^
6215 ** <li> ^(during the original sqlite3_set_auxdata() call if the function
6216 ** is evaluated during query planning instead of during query execution,
6217 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6218 **
6219 ** Note the last two bullets in particular. The destructor X in
6220 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6221 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6222 ** should be called near the end of the function implementation and the
6223 ** function implementation should not make any use of P after
6224 ** sqlite3_set_auxdata() has been called. Furthermore, a call to
6225 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6226 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6227 ** condition occurred during the sqlite3_set_auxdata() call or if the
6228 ** function is being evaluated during query planning rather than during
6229 ** query execution.
6230 **
6231 ** ^(In practice, auxiliary data is preserved between function calls for
6232 ** function parameters that are compile-time constants, including literal
6233 ** values and [parameters] and expressions composed from the same.)^
6234 **
6235 ** The value of the N parameter to these interfaces should be non-negative.
6236 ** Future enhancements may make use of negative N values to define new
6237 ** kinds of function caching behavior.
6238 **
6239 ** These routines must be called from the same thread in which
6240 ** the SQL function is running.
6241 **
6242 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6243 */
6244 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6245 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6246
6247 /*
6248 ** CAPI3REF: Database Connection Client Data
6249 ** METHOD: sqlite3
6250 **
6251 ** These functions are used to associate one or more named pointers
6252 ** with a [database connection].
6253 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6254 ** to be attached to [database connection] D using name N. Subsequent
6255 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6256 ** or a NULL pointer if there were no prior calls to
6257 ** sqlite3_set_clientdata() with the same values of D and N.
6258 ** Names are compared using strcmp() and are thus case sensitive.
6259 ** It returns 0 on success and SQLITE_NOMEM on allocation failure.
6260 **
6261 ** If P and X are both non-NULL, then the destructor X is invoked with
6262 ** argument P on the first of the following occurrences:
6263 ** <ul>
6264 ** <li> An out-of-memory error occurs during the call to
6265 ** sqlite3_set_clientdata() which attempts to register pointer P.
6266 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6267 ** with the same D and N parameters.
6268 ** <li> The database connection closes. SQLite does not make any guarantees
6269 ** about the order in which destructors are called, only that all
6270 ** destructors will be called exactly once at some point during the
6271 ** database connection closing process.
6272 ** </ul>
6273 **
6274 ** SQLite does not do anything with client data other than invoke
6275 ** destructors on the client data at the appropriate time. The intended
6276 ** use for client data is to provide a mechanism for wrapper libraries
6277 ** to store additional information about an SQLite database connection.
6278 **
6279 ** There is no limit (other than available memory) on the number of different
6280 ** client data pointers (with different names) that can be attached to a
6281 ** single database connection. However, the implementation is optimized
6282 ** for the case of having only one or two different client data names.
6283 ** Applications and wrapper libraries are discouraged from using more than
6284 ** one client data name each.
6285 **
6286 ** There is no way to enumerate the client data pointers
6287 ** associated with a database connection. The N parameter can be thought
6288 ** of as a secret key such that only code that knows the secret key is able
6289 ** to access the associated data.
6290 **
6291 ** Security Warning: These interfaces should not be exposed in scripting
6292 ** languages or in other circumstances where it might be possible for an
6293 ** attacker to invoke them. Any agent that can invoke these interfaces
6294 ** can probably also take control of the process.
6295 **
6296 ** Database connection client data is only available for SQLite
6297 ** version 3.44.0 ([dateof:3.44.0]) and later.
6298 **
6299 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6300 */
6301 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6302 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6303
6304 /*
6305 ** CAPI3REF: Constants Defining Special Destructor Behavior
6306 **
6307 ** These are special values for the destructor that is passed in as the
6308 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6309 ** argument is SQLITE_STATIC, it means that the content pointer is constant
6310 ** and will never change. It does not need to be destroyed. ^The
6311 ** SQLITE_TRANSIENT value means that the content will likely change in
6312 ** the near future and that SQLite should make its own private copy of
6313 ** the content before returning.
6314 **
6315 ** The typedef is necessary to work around problems in certain
6316 ** C++ compilers.
6317 */
6318 typedef void (*sqlite3_destructor_type)(void*);
6319 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
6320 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6321
6322 /*
6323 ** CAPI3REF: Setting The Result Of An SQL Function
6324 ** METHOD: sqlite3_context
6325 **
6326 ** These routines are used by the xFunc or xFinal callbacks that
6327 ** implement SQL functions and aggregates. See
6328 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
6329 ** for additional information.
6330 **
6331 ** These functions work very much like the [parameter binding] family of
6332 ** functions used to bind values to host parameters in prepared statements.
6333 ** Refer to the [SQL parameter] documentation for additional information.
6334 **
6335 ** ^The sqlite3_result_blob() interface sets the result from
6336 ** an application-defined function to be the BLOB whose content is pointed
6337 ** to by the second parameter and which is N bytes long where N is the
6338 ** third parameter.
6339 **
6340 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6341 ** interfaces set the result of the application-defined function to be
6342 ** a BLOB containing all zero bytes and N bytes in size.
6343 **
6344 ** ^The sqlite3_result_double() interface sets the result from
6345 ** an application-defined function to be a floating point value specified
6346 ** by its 2nd argument.
6347 **
6348 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6349 ** cause the implemented SQL function to throw an exception.
6350 ** ^SQLite uses the string pointed to by the
6351 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6352 ** as the text of an error message. ^SQLite interprets the error
6353 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
6354 ** interprets the string from sqlite3_result_error16() as UTF-16 using
6355 ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6356 ** ^If the third parameter to sqlite3_result_error()
6357 ** or sqlite3_result_error16() is negative then SQLite takes as the error
6358 ** message all text up through the first zero character.
6359 ** ^If the third parameter to sqlite3_result_error() or
6360 ** sqlite3_result_error16() is non-negative then SQLite takes that many
6361 ** bytes (not characters) from the 2nd parameter as the error message.
6362 ** ^The sqlite3_result_error() and sqlite3_result_error16()
6363 ** routines make a private copy of the error message text before
6364 ** they return. Hence, the calling function can deallocate or
6365 ** modify the text after they return without harm.
6366 ** ^The sqlite3_result_error_code() function changes the error code
6367 ** returned by SQLite as a result of an error in a function. ^By default,
6368 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6369 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6370 **
6371 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6372 ** error indicating that a string or BLOB is too long to represent.
6373 **
6374 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6375 ** error indicating that a memory allocation failed.
6376 **
6377 ** ^The sqlite3_result_int() interface sets the return value
6378 ** of the application-defined function to be the 32-bit signed integer
6379 ** value given in the 2nd argument.
6380 ** ^The sqlite3_result_int64() interface sets the return value
6381 ** of the application-defined function to be the 64-bit signed integer
6382 ** value given in the 2nd argument.
6383 **
6384 ** ^The sqlite3_result_null() interface sets the return value
6385 ** of the application-defined function to be NULL.
6386 **
6387 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
6388 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6389 ** set the return value of the application-defined function to be
6390 ** a text string which is represented as UTF-8, UTF-16 native byte order,
6391 ** UTF-16 little endian, or UTF-16 big endian, respectively.
6392 ** ^The sqlite3_result_text64() interface sets the return value of an
6393 ** application-defined function to be a text string in an encoding
6394 ** specified by the fifth (and last) parameter, which must be one
6395 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6396 ** ^SQLite takes the text result from the application from
6397 ** the 2nd parameter of the sqlite3_result_text* interfaces.
6398 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6399 ** other than sqlite3_result_text64() is negative, then SQLite computes
6400 ** the string length itself by searching the 2nd parameter for the first
6401 ** zero character.
6402 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6403 ** is non-negative, then as many bytes (not characters) of the text
6404 ** pointed to by the 2nd parameter are taken as the application-defined
6405 ** function result. If the 3rd parameter is non-negative, then it
6406 ** must be the byte offset into the string where the NUL terminator would
6407 ** appear if the string were NUL terminated. If any NUL characters occur
6408 ** in the string at a byte offset that is less than the value of the 3rd
6409 ** parameter, then the resulting string will contain embedded NULs and the
6410 ** result of expressions operating on strings with embedded NULs is undefined.
6411 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6412 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6413 ** function as the destructor on the text or BLOB result when it has
6414 ** finished using that result.
6415 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6416 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6417 ** assumes that the text or BLOB result is in constant space and does not
6418 ** copy the content of the parameter nor call a destructor on the content
6419 ** when it has finished using that result.
6420 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6421 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6422 ** then SQLite makes a copy of the result into space obtained
6423 ** from [sqlite3_malloc()] before it returns.
6424 **
6425 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6426 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6427 ** when the encoding is not UTF8, if the input UTF16 begins with a
6428 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6429 ** string and the rest of the string is interpreted according to the
6430 ** byte-order specified by the BOM. ^The byte-order specified by
6431 ** the BOM at the beginning of the text overrides the byte-order
6432 ** specified by the interface procedure. ^So, for example, if
6433 ** sqlite3_result_text16le() is invoked with text that begins
6434 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6435 ** first two bytes of input are skipped and the remaining input
6436 ** is interpreted as UTF16BE text.
6437 **
6438 ** ^For UTF16 input text to the sqlite3_result_text16(),
6439 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6440 ** sqlite3_result_text64() routines, if the text contains invalid
6441 ** UTF16 characters, the invalid characters might be converted
6442 ** into the unicode replacement character, U+FFFD.
6443 **
6444 ** ^The sqlite3_result_value() interface sets the result of
6445 ** the application-defined function to be a copy of the
6446 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6447 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6448 ** so that the [sqlite3_value] specified in the parameter may change or
6449 ** be deallocated after sqlite3_result_value() returns without harm.
6450 ** ^A [protected sqlite3_value] object may always be used where an
6451 ** [unprotected sqlite3_value] object is required, so either
6452 ** kind of [sqlite3_value] object can be used with this interface.
6453 **
6454 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6455 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6456 ** also associates the host-language pointer P or type T with that
6457 ** NULL value such that the pointer can be retrieved within an
6458 ** [application-defined SQL function] using [sqlite3_value_pointer()].
6459 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
6460 ** for the P parameter. ^SQLite invokes D with P as its only argument
6461 ** when SQLite is finished with P. The T parameter should be a static
6462 ** string and preferably a string literal. The sqlite3_result_pointer()
6463 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6464 **
6465 ** If these routines are called from within a different thread
6466 ** than the one containing the application-defined function that received
6467 ** the [sqlite3_context] pointer, the results are undefined.
6468 */
6469 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6470 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6471 sqlite3_uint64,void(*)(void*));
6472 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6473 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6474 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6475 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6476 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6477 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6478 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6479 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6480 SQLITE_API void sqlite3_result_null(sqlite3_context*);
6481 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6482 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6483 void(*)(void*), unsigned char encoding);
6484 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6485 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6486 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6487 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6488 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6489 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6490 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6491
6492
6493 /*
6494 ** CAPI3REF: Setting The Subtype Of An SQL Function
6495 ** METHOD: sqlite3_context
6496 **
6497 ** The sqlite3_result_subtype(C,T) function causes the subtype of
6498 ** the result from the [application-defined SQL function] with
6499 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
6500 ** of the subtype T are preserved in current versions of SQLite;
6501 ** higher order bits are discarded.
6502 ** The number of subtype bytes preserved by SQLite might increase
6503 ** in future releases of SQLite.
6504 **
6505 ** Every [application-defined SQL function] that invokes this interface
6506 ** should include the [SQLITE_RESULT_SUBTYPE] property in its
6507 ** text encoding argument when the SQL function is
6508 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6509 ** property is omitted from the function that invokes sqlite3_result_subtype(),
6510 ** then in some cases the sqlite3_result_subtype() might fail to set
6511 ** the result subtype.
6512 **
6513 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6514 ** SQL function that invokes the sqlite3_result_subtype() interface
6515 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6516 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6517 ** by default.
6518 */
6519 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6520
6521 /*
6522 ** CAPI3REF: Define New Collating Sequences
6523 ** METHOD: sqlite3
6524 **
6525 ** ^These functions add, remove, or modify a [collation] associated
6526 ** with the [database connection] specified as the first argument.
6527 **
6528 ** ^The name of the collation is a UTF-8 string
6529 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6530 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6531 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6532 ** considered to be the same name.
6533 **
6534 ** ^(The third argument (eTextRep) must be one of the constants:
6535 ** <ul>
6536 ** <li> [SQLITE_UTF8],
6537 ** <li> [SQLITE_UTF16LE],
6538 ** <li> [SQLITE_UTF16BE],
6539 ** <li> [SQLITE_UTF16], or
6540 ** <li> [SQLITE_UTF16_ALIGNED].
6541 ** </ul>)^
6542 ** ^The eTextRep argument determines the encoding of strings passed
6543 ** to the collating function callback, xCompare.
6544 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6545 ** force strings to be UTF16 with native byte order.
6546 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6547 ** on an even byte address.
6548 **
6549 ** ^The fourth argument, pArg, is an application data pointer that is passed
6550 ** through as the first argument to the collating function callback.
6551 **
6552 ** ^The fifth argument, xCompare, is a pointer to the collating function.
6553 ** ^Multiple collating functions can be registered using the same name but
6554 ** with different eTextRep parameters and SQLite will use whichever
6555 ** function requires the least amount of data transformation.
6556 ** ^If the xCompare argument is NULL then the collating function is
6557 ** deleted. ^When all collating functions having the same name are deleted,
6558 ** that collation is no longer usable.
6559 **
6560 ** ^The collating function callback is invoked with a copy of the pArg
6561 ** application data pointer and with two strings in the encoding specified
6562 ** by the eTextRep argument. The two integer parameters to the collating
6563 ** function callback are the length of the two strings, in bytes. The collating
6564 ** function must return an integer that is negative, zero, or positive
6565 ** if the first string is less than, equal to, or greater than the second,
6566 ** respectively. A collating function must always return the same answer
6567 ** given the same inputs. If two or more collating functions are registered
6568 ** to the same collation name (using different eTextRep values) then all
6569 ** must give an equivalent answer when invoked with equivalent strings.
6570 ** The collating function must obey the following properties for all
6571 ** strings A, B, and C:
6572 **
6573 ** <ol>
6574 ** <li> If A==B then B==A.
6575 ** <li> If A==B and B==C then A==C.
6576 ** <li> If A&lt;B THEN B&gt;A.
6577 ** <li> If A&lt;B and B&lt;C then A&lt;C.
6578 ** </ol>
6579 **
6580 ** If a collating function fails any of the above constraints and that
6581 ** collating function is registered and used, then the behavior of SQLite
6582 ** is undefined.
6583 **
6584 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6585 ** with the addition that the xDestroy callback is invoked on pArg when
6586 ** the collating function is deleted.
6587 ** ^Collating functions are deleted when they are overridden by later
6588 ** calls to the collation creation functions or when the
6589 ** [database connection] is closed using [sqlite3_close()].
6590 **
6591 ** ^The xDestroy callback is <u>not</u> called if the
6592 ** sqlite3_create_collation_v2() function fails. Applications that invoke
6593 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6594 ** check the return code and dispose of the application data pointer
6595 ** themselves rather than expecting SQLite to deal with it for them.
6596 ** This is different from every other SQLite interface. The inconsistency
6597 ** is unfortunate but cannot be changed without breaking backwards
6598 ** compatibility.
6599 **
6600 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6601 */
6602 SQLITE_API int sqlite3_create_collation(
6603 sqlite3*,
6604 const char *zName,
6605 int eTextRep,
6606 void *pArg,
6607 int(*xCompare)(void*,int,const void*,int,const void*)
6608 );
6609 SQLITE_API int sqlite3_create_collation_v2(
6610 sqlite3*,
6611 const char *zName,
6612 int eTextRep,
6613 void *pArg,
6614 int(*xCompare)(void*,int,const void*,int,const void*),
6615 void(*xDestroy)(void*)
6616 );
6617 SQLITE_API int sqlite3_create_collation16(
6618 sqlite3*,
6619 const void *zName,
6620 int eTextRep,
6621 void *pArg,
6622 int(*xCompare)(void*,int,const void*,int,const void*)
6623 );
6624
6625 /*
6626 ** CAPI3REF: Collation Needed Callbacks
6627 ** METHOD: sqlite3
6628 **
6629 ** ^To avoid having to register all collation sequences before a database
6630 ** can be used, a single callback function may be registered with the
6631 ** [database connection] to be invoked whenever an undefined collation
6632 ** sequence is required.
6633 **
6634 ** ^If the function is registered using the sqlite3_collation_needed() API,
6635 ** then it is passed the names of undefined collation sequences as strings
6636 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6637 ** the names are passed as UTF-16 in machine native byte order.
6638 ** ^A call to either function replaces the existing collation-needed callback.
6639 **
6640 ** ^(When the callback is invoked, the first argument passed is a copy
6641 ** of the second argument to sqlite3_collation_needed() or
6642 ** sqlite3_collation_needed16(). The second argument is the database
6643 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6644 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6645 ** sequence function required. The fourth parameter is the name of the
6646 ** required collation sequence.)^
6647 **
6648 ** The callback function should register the desired collation using
6649 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6650 ** [sqlite3_create_collation_v2()].
6651 */
6652 SQLITE_API int sqlite3_collation_needed(
6653 sqlite3*,
6654 void*,
6655 void(*)(void*,sqlite3*,int eTextRep,const char*)
6656 );
6657 SQLITE_API int sqlite3_collation_needed16(
6658 sqlite3*,
6659 void*,
6660 void(*)(void*,sqlite3*,int eTextRep,const void*)
6661 );
6662
6663 #ifdef SQLITE_ENABLE_CEROD
6664 /*
6665 ** Specify the activation key for a CEROD database. Unless
6666 ** activated, none of the CEROD routines will work.
6667 */
6668 SQLITE_API void sqlite3_activate_cerod(
6669 const char *zPassPhrase /* Activation phrase */
6670 );
6671 #endif
6672
6673 /*
6674 ** CAPI3REF: Suspend Execution For A Short Time
6675 **
6676 ** The sqlite3_sleep() function causes the current thread to suspend execution
6677 ** for at least a number of milliseconds specified in its parameter.
6678 **
6679 ** If the operating system does not support sleep requests with
6680 ** millisecond time resolution, then the time will be rounded up to
6681 ** the nearest second. The number of milliseconds of sleep actually
6682 ** requested from the operating system is returned.
6683 **
6684 ** ^SQLite implements this interface by calling the xSleep()
6685 ** method of the default [sqlite3_vfs] object. If the xSleep() method
6686 ** of the default VFS is not implemented correctly, or not implemented at
6687 ** all, then the behavior of sqlite3_sleep() may deviate from the description
6688 ** in the previous paragraphs.
6689 **
6690 ** If a negative argument is passed to sqlite3_sleep() the results vary by
6691 ** VFS and operating system. Some system treat a negative argument as an
6692 ** instruction to sleep forever. Others understand it to mean do not sleep
6693 ** at all. ^In SQLite version 3.42.0 and later, a negative
6694 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6695 ** down into the xSleep method of the VFS.
6696 */
6697 SQLITE_API int sqlite3_sleep(int);
6698
6699 /*
6700 ** CAPI3REF: Name Of The Folder Holding Temporary Files
6701 **
6702 ** ^(If this global variable is made to point to a string which is
6703 ** the name of a folder (a.k.a. directory), then all temporary files
6704 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6705 ** will be placed in that directory.)^ ^If this variable
6706 ** is a NULL pointer, then SQLite performs a search for an appropriate
6707 ** temporary file directory.
6708 **
6709 ** Applications are strongly discouraged from using this global variable.
6710 ** It is required to set a temporary folder on Windows Runtime (WinRT).
6711 ** But for all other platforms, it is highly recommended that applications
6712 ** neither read nor write this variable. This global variable is a relic
6713 ** that exists for backwards compatibility of legacy applications and should
6714 ** be avoided in new projects.
6715 **
6716 ** It is not safe to read or modify this variable in more than one
6717 ** thread at a time. It is not safe to read or modify this variable
6718 ** if a [database connection] is being used at the same time in a separate
6719 ** thread.
6720 ** It is intended that this variable be set once
6721 ** as part of process initialization and before any SQLite interface
6722 ** routines have been called and that this variable remain unchanged
6723 ** thereafter.
6724 **
6725 ** ^The [temp_store_directory pragma] may modify this variable and cause
6726 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6727 ** the [temp_store_directory pragma] always assumes that any string
6728 ** that this variable points to is held in memory obtained from
6729 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6730 ** using [sqlite3_free].
6731 ** Hence, if this variable is modified directly, either it should be
6732 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6733 ** or else the use of the [temp_store_directory pragma] should be avoided.
6734 ** Except when requested by the [temp_store_directory pragma], SQLite
6735 ** does not free the memory that sqlite3_temp_directory points to. If
6736 ** the application wants that memory to be freed, it must do
6737 ** so itself, taking care to only do so after all [database connection]
6738 ** objects have been destroyed.
6739 **
6740 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6741 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6742 ** features that require the use of temporary files may fail. Here is an
6743 ** example of how to do this using C++ with the Windows Runtime:
6744 **
6745 ** <blockquote><pre>
6746 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6747 ** &nbsp; TemporaryFolder->Path->Data();
6748 ** char zPathBuf&#91;MAX_PATH + 1&#93;;
6749 ** memset(zPathBuf, 0, sizeof(zPathBuf));
6750 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6751 ** &nbsp; NULL, NULL);
6752 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6753 ** </pre></blockquote>
6754 */
6755 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6756
6757 /*
6758 ** CAPI3REF: Name Of The Folder Holding Database Files
6759 **
6760 ** ^(If this global variable is made to point to a string which is
6761 ** the name of a folder (a.k.a. directory), then all database files
6762 ** specified with a relative pathname and created or accessed by
6763 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6764 ** to be relative to that directory.)^ ^If this variable is a NULL
6765 ** pointer, then SQLite assumes that all database files specified
6766 ** with a relative pathname are relative to the current directory
6767 ** for the process. Only the windows VFS makes use of this global
6768 ** variable; it is ignored by the unix VFS.
6769 **
6770 ** Changing the value of this variable while a database connection is
6771 ** open can result in a corrupt database.
6772 **
6773 ** It is not safe to read or modify this variable in more than one
6774 ** thread at a time. It is not safe to read or modify this variable
6775 ** if a [database connection] is being used at the same time in a separate
6776 ** thread.
6777 ** It is intended that this variable be set once
6778 ** as part of process initialization and before any SQLite interface
6779 ** routines have been called and that this variable remain unchanged
6780 ** thereafter.
6781 **
6782 ** ^The [data_store_directory pragma] may modify this variable and cause
6783 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6784 ** the [data_store_directory pragma] always assumes that any string
6785 ** that this variable points to is held in memory obtained from
6786 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6787 ** using [sqlite3_free].
6788 ** Hence, if this variable is modified directly, either it should be
6789 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6790 ** or else the use of the [data_store_directory pragma] should be avoided.
6791 */
6792 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6793
6794 /*
6795 ** CAPI3REF: Win32 Specific Interface
6796 **
6797 ** These interfaces are available only on Windows. The
6798 ** [sqlite3_win32_set_directory] interface is used to set the value associated
6799 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6800 ** zValue, depending on the value of the type parameter. The zValue parameter
6801 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6802 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6803 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6804 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6805 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6806 ** [sqlite3_data_directory] variable is intended to act as a replacement for
6807 ** the current directory on the sub-platforms of Win32 where that concept is
6808 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6809 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6810 ** sqlite3_win32_set_directory interface except the string parameter must be
6811 ** UTF-8 or UTF-16, respectively.
6812 */
6813 SQLITE_API int sqlite3_win32_set_directory(
6814 unsigned long type, /* Identifier for directory being set or reset */
6815 void *zValue /* New value for directory being set or reset */
6816 );
6817 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6818 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6819
6820 /*
6821 ** CAPI3REF: Win32 Directory Types
6822 **
6823 ** These macros are only available on Windows. They define the allowed values
6824 ** for the type argument to the [sqlite3_win32_set_directory] interface.
6825 */
6826 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6827 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6828
6829 /*
6830 ** CAPI3REF: Test For Auto-Commit Mode
6831 ** KEYWORDS: {autocommit mode}
6832 ** METHOD: sqlite3
6833 **
6834 ** ^The sqlite3_get_autocommit() interface returns non-zero or
6835 ** zero if the given database connection is or is not in autocommit mode,
6836 ** respectively. ^Autocommit mode is on by default.
6837 ** ^Autocommit mode is disabled by a [BEGIN] statement.
6838 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6839 **
6840 ** If certain kinds of errors occur on a statement within a multi-statement
6841 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6842 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6843 ** transaction might be rolled back automatically. The only way to
6844 ** find out whether SQLite automatically rolled back the transaction after
6845 ** an error is to use this function.
6846 **
6847 ** If another thread changes the autocommit status of the database
6848 ** connection while this routine is running, then the return value
6849 ** is undefined.
6850 */
6851 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6852
6853 /*
6854 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6855 ** METHOD: sqlite3_stmt
6856 **
6857 ** ^The sqlite3_db_handle interface returns the [database connection] handle
6858 ** to which a [prepared statement] belongs. ^The [database connection]
6859 ** returned by sqlite3_db_handle is the same [database connection]
6860 ** that was the first argument
6861 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6862 ** create the statement in the first place.
6863 */
6864 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6865
6866 /*
6867 ** CAPI3REF: Return The Schema Name For A Database Connection
6868 ** METHOD: sqlite3
6869 **
6870 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6871 ** for the N-th database on database connection D, or a NULL pointer if N is
6872 ** out of range. An N value of 0 means the main database file. An N of 1 is
6873 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6874 ** databases.
6875 **
6876 ** Space to hold the string that is returned by sqlite3_db_name() is managed
6877 ** by SQLite itself. The string might be deallocated by any operation that
6878 ** changes the schema, including [ATTACH] or [DETACH] or calls to
6879 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6880 ** occur on a different thread. Applications that need to
6881 ** remember the string long-term should make their own copy. Applications that
6882 ** are accessing the same database connection simultaneously on multiple
6883 ** threads should mutex-protect calls to this API and should make their own
6884 ** private copy of the result prior to releasing the mutex.
6885 */
6886 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6887
6888 /*
6889 ** CAPI3REF: Return The Filename For A Database Connection
6890 ** METHOD: sqlite3
6891 **
6892 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6893 ** associated with database N of connection D.
6894 ** ^If there is no attached database N on the database
6895 ** connection D, or if database N is a temporary or in-memory database, then
6896 ** this function will return either a NULL pointer or an empty string.
6897 **
6898 ** ^The string value returned by this routine is owned and managed by
6899 ** the database connection. ^The value will be valid until the database N
6900 ** is [DETACH]-ed or until the database connection closes.
6901 **
6902 ** ^The filename returned by this function is the output of the
6903 ** xFullPathname method of the [VFS]. ^In other words, the filename
6904 ** will be an absolute pathname, even if the filename used
6905 ** to open the database originally was a URI or relative pathname.
6906 **
6907 ** If the filename pointer returned by this routine is not NULL, then it
6908 ** can be used as the filename input parameter to these routines:
6909 ** <ul>
6910 ** <li> [sqlite3_uri_parameter()]
6911 ** <li> [sqlite3_uri_boolean()]
6912 ** <li> [sqlite3_uri_int64()]
6913 ** <li> [sqlite3_filename_database()]
6914 ** <li> [sqlite3_filename_journal()]
6915 ** <li> [sqlite3_filename_wal()]
6916 ** </ul>
6917 */
6918 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6919
6920 /*
6921 ** CAPI3REF: Determine if a database is read-only
6922 ** METHOD: sqlite3
6923 **
6924 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6925 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6926 ** the name of a database on connection D.
6927 */
6928 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6929
6930 /*
6931 ** CAPI3REF: Determine the transaction state of a database
6932 ** METHOD: sqlite3
6933 **
6934 ** ^The sqlite3_txn_state(D,S) interface returns the current
6935 ** [transaction state] of schema S in database connection D. ^If S is NULL,
6936 ** then the highest transaction state of any schema on database connection D
6937 ** is returned. Transaction states are (in order of lowest to highest):
6938 ** <ol>
6939 ** <li value="0"> SQLITE_TXN_NONE
6940 ** <li value="1"> SQLITE_TXN_READ
6941 ** <li value="2"> SQLITE_TXN_WRITE
6942 ** </ol>
6943 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6944 ** a valid schema, then -1 is returned.
6945 */
6946 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6947
6948 /*
6949 ** CAPI3REF: Allowed return values from sqlite3_txn_state()
6950 ** KEYWORDS: {transaction state}
6951 **
6952 ** These constants define the current transaction state of a database file.
6953 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6954 ** constants in order to describe the transaction state of schema S
6955 ** in [database connection] D.
6956 **
6957 ** <dl>
6958 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6959 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6960 ** pending.</dd>
6961 **
6962 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6963 ** <dd>The SQLITE_TXN_READ state means that the database is currently
6964 ** in a read transaction. Content has been read from the database file
6965 ** but nothing in the database file has changed. The transaction state
6966 ** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
6967 ** no other conflicting concurrent write transactions. The transaction
6968 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6969 ** [COMMIT].</dd>
6970 **
6971 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6972 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6973 ** in a write transaction. Content has been written to the database file
6974 ** but has not yet committed. The transaction state will change to
6975 ** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6976 */
6977 #define SQLITE_TXN_NONE 0
6978 #define SQLITE_TXN_READ 1
6979 #define SQLITE_TXN_WRITE 2
6980
6981 /*
6982 ** CAPI3REF: Find the next prepared statement
6983 ** METHOD: sqlite3
6984 **
6985 ** ^This interface returns a pointer to the next [prepared statement] after
6986 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6987 ** then this interface returns a pointer to the first prepared statement
6988 ** associated with the database connection pDb. ^If no prepared statement
6989 ** satisfies the conditions of this routine, it returns NULL.
6990 **
6991 ** The [database connection] pointer D in a call to
6992 ** [sqlite3_next_stmt(D,S)] must refer to an open database
6993 ** connection and in particular must not be a NULL pointer.
6994 */
6995 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6996
6997 /*
6998 ** CAPI3REF: Commit And Rollback Notification Callbacks
6999 ** METHOD: sqlite3
7000 **
7001 ** ^The sqlite3_commit_hook() interface registers a callback
7002 ** function to be invoked whenever a transaction is [COMMIT | committed].
7003 ** ^Any callback set by a previous call to sqlite3_commit_hook()
7004 ** for the same database connection is overridden.
7005 ** ^The sqlite3_rollback_hook() interface registers a callback
7006 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
7007 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
7008 ** for the same database connection is overridden.
7009 ** ^The pArg argument is passed through to the callback.
7010 ** ^If the callback on a commit hook function returns non-zero,
7011 ** then the commit is converted into a rollback.
7012 **
7013 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
7014 ** return the P argument from the previous call of the same function
7015 ** on the same [database connection] D, or NULL for
7016 ** the first call for each function on D.
7017 **
7018 ** The commit and rollback hook callbacks are not reentrant.
7019 ** The callback implementation must not do anything that will modify
7020 ** the database connection that invoked the callback. Any actions
7021 ** to modify the database connection must be deferred until after the
7022 ** completion of the [sqlite3_step()] call that triggered the commit
7023 ** or rollback hook in the first place.
7024 ** Note that running any other SQL statements, including SELECT statements,
7025 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
7026 ** the database connections for the meaning of "modify" in this paragraph.
7027 **
7028 ** ^Registering a NULL function disables the callback.
7029 **
7030 ** ^When the commit hook callback routine returns zero, the [COMMIT]
7031 ** operation is allowed to continue normally. ^If the commit hook
7032 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
7033 ** ^The rollback hook is invoked on a rollback that results from a commit
7034 ** hook returning non-zero, just as it would be with any other rollback.
7035 **
7036 ** ^For the purposes of this API, a transaction is said to have been
7037 ** rolled back if an explicit "ROLLBACK" statement is executed, or
7038 ** an error or constraint causes an implicit rollback to occur.
7039 ** ^The rollback callback is not invoked if a transaction is
7040 ** automatically rolled back because the database connection is closed.
7041 **
7042 ** See also the [sqlite3_update_hook()] interface.
7043 */
7044 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
7045 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
7046
7047 /*
7048 ** CAPI3REF: Autovacuum Compaction Amount Callback
7049 ** METHOD: sqlite3
7050 **
7051 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7052 ** function C that is invoked prior to each autovacuum of the database
7053 ** file. ^The callback is passed a copy of the generic data pointer (P),
7054 ** the schema-name of the attached database that is being autovacuumed,
7055 ** the size of the database file in pages, the number of free pages,
7056 ** and the number of bytes per page, respectively. The callback should
7057 ** return the number of free pages that should be removed by the
7058 ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7059 ** ^If the value returned is greater than or equal to the number of
7060 ** free pages, then a complete autovacuum happens.
7061 **
7062 ** <p>^If there are multiple ATTACH-ed database files that are being
7063 ** modified as part of a transaction commit, then the autovacuum pages
7064 ** callback is invoked separately for each file.
7065 **
7066 ** <p><b>The callback is not reentrant.</b> The callback function should
7067 ** not attempt to invoke any other SQLite interface. If it does, bad
7068 ** things may happen, including segmentation faults and corrupt database
7069 ** files. The callback function should be a simple function that
7070 ** does some arithmetic on its input parameters and returns a result.
7071 **
7072 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7073 ** destructor for the P parameter. ^If X is not NULL, then X(P) is
7074 ** invoked whenever the database connection closes or when the callback
7075 ** is overwritten by another invocation of sqlite3_autovacuum_pages().
7076 **
7077 ** <p>^There is only one autovacuum pages callback per database connection.
7078 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7079 ** previous invocations for that database connection. ^If the callback
7080 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7081 ** then the autovacuum steps callback is canceled. The return value
7082 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7083 ** be some other error code if something goes wrong. The current
7084 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7085 ** return codes might be added in future releases.
7086 **
7087 ** <p>If no autovacuum pages callback is specified (the usual case) or
7088 ** a NULL pointer is provided for the callback,
7089 ** then the default behavior is to vacuum all free pages. So, in other
7090 ** words, the default behavior is the same as if the callback function
7091 ** were something like this:
7092 **
7093 ** <blockquote><pre>
7094 ** &nbsp; unsigned int demonstration_autovac_pages_callback(
7095 ** &nbsp; void *pClientData,
7096 ** &nbsp; const char *zSchema,
7097 ** &nbsp; unsigned int nDbPage,
7098 ** &nbsp; unsigned int nFreePage,
7099 ** &nbsp; unsigned int nBytePerPage
7100 ** &nbsp; ){
7101 ** &nbsp; return nFreePage;
7102 ** &nbsp; }
7103 ** </pre></blockquote>
7104 */
7105 SQLITE_API int sqlite3_autovacuum_pages(
7106 sqlite3 *db,
7107 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7108 void*,
7109 void(*)(void*)
7110 );
7111
7112
7113 /*
7114 ** CAPI3REF: Data Change Notification Callbacks
7115 ** METHOD: sqlite3
7116 **
7117 ** ^The sqlite3_update_hook() interface registers a callback function
7118 ** with the [database connection] identified by the first argument
7119 ** to be invoked whenever a row is updated, inserted or deleted in
7120 ** a [rowid table].
7121 ** ^Any callback set by a previous call to this function
7122 ** for the same database connection is overridden.
7123 **
7124 ** ^The second argument is a pointer to the function to invoke when a
7125 ** row is updated, inserted or deleted in a rowid table.
7126 ** ^The update hook is disabled by invoking sqlite3_update_hook()
7127 ** with a NULL pointer as the second parameter.
7128 ** ^The first argument to the callback is a copy of the third argument
7129 ** to sqlite3_update_hook().
7130 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7131 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
7132 ** to be invoked.
7133 ** ^The third and fourth arguments to the callback contain pointers to the
7134 ** database and table name containing the affected row.
7135 ** ^The final callback parameter is the [rowid] of the row.
7136 ** ^In the case of an update, this is the [rowid] after the update takes place.
7137 **
7138 ** ^(The update hook is not invoked when internal system tables are
7139 ** modified (i.e. sqlite_sequence).)^
7140 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7141 **
7142 ** ^In the current implementation, the update hook
7143 ** is not invoked when conflicting rows are deleted because of an
7144 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7145 ** invoked when rows are deleted using the [truncate optimization].
7146 ** The exceptions defined in this paragraph might change in a future
7147 ** release of SQLite.
7148 **
7149 ** Whether the update hook is invoked before or after the
7150 ** corresponding change is currently unspecified and may differ
7151 ** depending on the type of change. Do not rely on the order of the
7152 ** hook call with regards to the final result of the operation which
7153 ** triggers the hook.
7154 **
7155 ** The update hook implementation must not do anything that will modify
7156 ** the database connection that invoked the update hook. Any actions
7157 ** to modify the database connection must be deferred until after the
7158 ** completion of the [sqlite3_step()] call that triggered the update hook.
7159 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7160 ** database connections for the meaning of "modify" in this paragraph.
7161 **
7162 ** ^The sqlite3_update_hook(D,C,P) function
7163 ** returns the P argument from the previous call
7164 ** on the same [database connection] D, or NULL for
7165 ** the first call on D.
7166 **
7167 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7168 ** and [sqlite3_preupdate_hook()] interfaces.
7169 */
7170 SQLITE_API void *sqlite3_update_hook(
7171 sqlite3*,
7172 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7173 void*
7174 );
7175
7176 /*
7177 ** CAPI3REF: Enable Or Disable Shared Pager Cache
7178 **
7179 ** ^(This routine enables or disables the sharing of the database cache
7180 ** and schema data structures between [database connection | connections]
7181 ** to the same database. Sharing is enabled if the argument is true
7182 ** and disabled if the argument is false.)^
7183 **
7184 ** This interface is omitted if SQLite is compiled with
7185 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7186 ** compile-time option is recommended because the
7187 ** [use of shared cache mode is discouraged].
7188 **
7189 ** ^Cache sharing is enabled and disabled for an entire process.
7190 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7191 ** In prior versions of SQLite,
7192 ** sharing was enabled or disabled for each thread separately.
7193 **
7194 ** ^(The cache sharing mode set by this interface effects all subsequent
7195 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7196 ** Existing database connections continue to use the sharing mode
7197 ** that was in effect at the time they were opened.)^
7198 **
7199 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7200 ** successfully. An [error code] is returned otherwise.)^
7201 **
7202 ** ^Shared cache is disabled by default. It is recommended that it stay
7203 ** that way. In other words, do not use this routine. This interface
7204 ** continues to be provided for historical compatibility, but its use is
7205 ** discouraged. Any use of shared cache is discouraged. If shared cache
7206 ** must be used, it is recommended that shared cache only be enabled for
7207 ** individual database connections using the [sqlite3_open_v2()] interface
7208 ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7209 **
7210 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7211 ** and will always return SQLITE_MISUSE. On those systems,
7212 ** shared cache mode should be enabled per-database connection via
7213 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7214 **
7215 ** This interface is threadsafe on processors where writing a
7216 ** 32-bit integer is atomic.
7217 **
7218 ** See Also: [SQLite Shared-Cache Mode]
7219 */
7220 SQLITE_API int sqlite3_enable_shared_cache(int);
7221
7222 /*
7223 ** CAPI3REF: Attempt To Free Heap Memory
7224 **
7225 ** ^The sqlite3_release_memory() interface attempts to free N bytes
7226 ** of heap memory by deallocating non-essential memory allocations
7227 ** held by the database library. Memory used to cache database
7228 ** pages to improve performance is an example of non-essential memory.
7229 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
7230 ** which might be more or less than the amount requested.
7231 ** ^The sqlite3_release_memory() routine is a no-op returning zero
7232 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7233 **
7234 ** See also: [sqlite3_db_release_memory()]
7235 */
7236 SQLITE_API int sqlite3_release_memory(int);
7237
7238 /*
7239 ** CAPI3REF: Free Memory Used By A Database Connection
7240 ** METHOD: sqlite3
7241 **
7242 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7243 ** memory as possible from database connection D. Unlike the
7244 ** [sqlite3_release_memory()] interface, this interface is in effect even
7245 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7246 ** omitted.
7247 **
7248 ** See also: [sqlite3_release_memory()]
7249 */
7250 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7251
7252 /*
7253 ** CAPI3REF: Impose A Limit On Heap Size
7254 **
7255 ** These interfaces impose limits on the amount of heap memory that will be
7256 ** used by all database connections within a single process.
7257 **
7258 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7259 ** soft limit on the amount of heap memory that may be allocated by SQLite.
7260 ** ^SQLite strives to keep heap memory utilization below the soft heap
7261 ** limit by reducing the number of pages held in the page cache
7262 ** as heap memory usages approaches the limit.
7263 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
7264 ** below the limit, it will exceed the limit rather than generate
7265 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7266 ** is advisory only.
7267 **
7268 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7269 ** N bytes on the amount of memory that will be allocated. ^The
7270 ** sqlite3_hard_heap_limit64(N) interface is similar to
7271 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7272 ** when the hard heap limit is reached.
7273 **
7274 ** ^The return value from both sqlite3_soft_heap_limit64() and
7275 ** sqlite3_hard_heap_limit64() is the size of
7276 ** the heap limit prior to the call, or negative in the case of an
7277 ** error. ^If the argument N is negative
7278 ** then no change is made to the heap limit. Hence, the current
7279 ** size of heap limits can be determined by invoking
7280 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7281 **
7282 ** ^Setting the heap limits to zero disables the heap limiter mechanism.
7283 **
7284 ** ^The soft heap limit may not be greater than the hard heap limit.
7285 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7286 ** is invoked with a value of N that is greater than the hard heap limit,
7287 ** the soft heap limit is set to the value of the hard heap limit.
7288 ** ^The soft heap limit is automatically enabled whenever the hard heap
7289 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7290 ** the soft heap limit is outside the range of 1..N, then the soft heap
7291 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7292 ** hard heap limit is enabled makes the soft heap limit equal to the
7293 ** hard heap limit.
7294 **
7295 ** The memory allocation limits can also be adjusted using
7296 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7297 **
7298 ** ^(The heap limits are not enforced in the current implementation
7299 ** if one or more of following conditions are true:
7300 **
7301 ** <ul>
7302 ** <li> The limit value is set to zero.
7303 ** <li> Memory accounting is disabled using a combination of the
7304 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7305 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7306 ** <li> An alternative page cache implementation is specified using
7307 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7308 ** <li> The page cache allocates from its own memory pool supplied
7309 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7310 ** from the heap.
7311 ** </ul>)^
7312 **
7313 ** The circumstances under which SQLite will enforce the heap limits may
7314 ** change in future releases of SQLite.
7315 */
7316 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7317 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7318
7319 /*
7320 ** CAPI3REF: Deprecated Soft Heap Limit Interface
7321 ** DEPRECATED
7322 **
7323 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7324 ** interface. This routine is provided for historical compatibility
7325 ** only. All new applications should use the
7326 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
7327 */
7328 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7329
7330
7331 /*
7332 ** CAPI3REF: Extract Metadata About A Column Of A Table
7333 ** METHOD: sqlite3
7334 **
7335 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7336 ** information about column C of table T in database D
7337 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7338 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
7339 ** the final five arguments with appropriate values if the specified
7340 ** column exists. ^The sqlite3_table_column_metadata() interface returns
7341 ** SQLITE_ERROR if the specified column does not exist.
7342 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7343 ** NULL pointer, then this routine simply checks for the existence of the
7344 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7345 ** does not. If the table name parameter T in a call to
7346 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7347 ** undefined behavior.
7348 **
7349 ** ^The column is identified by the second, third and fourth parameters to
7350 ** this function. ^(The second parameter is either the name of the database
7351 ** (i.e. "main", "temp", or an attached database) containing the specified
7352 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7353 ** for the table using the same algorithm used by the database engine to
7354 ** resolve unqualified table references.
7355 **
7356 ** ^The third and fourth parameters to this function are the table and column
7357 ** name of the desired column, respectively.
7358 **
7359 ** ^Metadata is returned by writing to the memory locations passed as the 5th
7360 ** and subsequent parameters to this function. ^Any of these arguments may be
7361 ** NULL, in which case the corresponding element of metadata is omitted.
7362 **
7363 ** ^(<blockquote>
7364 ** <table border="1">
7365 ** <tr><th> Parameter <th> Output<br>Type <th> Description
7366 **
7367 ** <tr><td> 5th <td> const char* <td> Data type
7368 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7369 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7370 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7371 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7372 ** </table>
7373 ** </blockquote>)^
7374 **
7375 ** ^The memory pointed to by the character pointers returned for the
7376 ** declaration type and collation sequence is valid until the next
7377 ** call to any SQLite API function.
7378 **
7379 ** ^If the specified table is actually a view, an [error code] is returned.
7380 **
7381 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7382 ** is not a [WITHOUT ROWID] table and an
7383 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7384 ** parameters are set for the explicitly declared column. ^(If there is no
7385 ** [INTEGER PRIMARY KEY] column, then the outputs
7386 ** for the [rowid] are set as follows:
7387 **
7388 ** <pre>
7389 ** data type: "INTEGER"
7390 ** collation sequence: "BINARY"
7391 ** not null: 0
7392 ** primary key: 1
7393 ** auto increment: 0
7394 ** </pre>)^
7395 **
7396 ** ^This function causes all database schemas to be read from disk and
7397 ** parsed, if that has not already been done, and returns an error if
7398 ** any errors are encountered while loading the schema.
7399 */
7400 SQLITE_API int sqlite3_table_column_metadata(
7401 sqlite3 *db, /* Connection handle */
7402 const char *zDbName, /* Database name or NULL */
7403 const char *zTableName, /* Table name */
7404 const char *zColumnName, /* Column name */
7405 char const **pzDataType, /* OUTPUT: Declared data type */
7406 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7407 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7408 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7409 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7410 );
7411
7412 /*
7413 ** CAPI3REF: Load An Extension
7414 ** METHOD: sqlite3
7415 **
7416 ** ^This interface loads an SQLite extension library from the named file.
7417 **
7418 ** ^The sqlite3_load_extension() interface attempts to load an
7419 ** [SQLite extension] library contained in the file zFile. If
7420 ** the file cannot be loaded directly, attempts are made to load
7421 ** with various operating-system specific extensions added.
7422 ** So for example, if "samplelib" cannot be loaded, then names like
7423 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7424 ** be tried also.
7425 **
7426 ** ^The entry point is zProc.
7427 ** ^(zProc may be 0, in which case SQLite will try to come up with an
7428 ** entry point name on its own. It first tries "sqlite3_extension_init".
7429 ** If that does not work, it constructs a name "sqlite3_X_init" where
7430 ** X consists of the lower-case equivalent of all ASCII alphabetic
7431 ** characters in the filename from the last "/" to the first following
7432 ** "." and omitting any initial "lib".)^
7433 ** ^The sqlite3_load_extension() interface returns
7434 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7435 ** ^If an error occurs and pzErrMsg is not 0, then the
7436 ** [sqlite3_load_extension()] interface shall attempt to
7437 ** fill *pzErrMsg with error message text stored in memory
7438 ** obtained from [sqlite3_malloc()]. The calling function
7439 ** should free this memory by calling [sqlite3_free()].
7440 **
7441 ** ^Extension loading must be enabled using
7442 ** [sqlite3_enable_load_extension()] or
7443 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7444 ** prior to calling this API,
7445 ** otherwise an error will be returned.
7446 **
7447 ** <b>Security warning:</b> It is recommended that the
7448 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7449 ** interface. The use of the [sqlite3_enable_load_extension()] interface
7450 ** should be avoided. This will keep the SQL function [load_extension()]
7451 ** disabled and prevent SQL injections from giving attackers
7452 ** access to extension loading capabilities.
7453 **
7454 ** See also the [load_extension() SQL function].
7455 */
7456 SQLITE_API int sqlite3_load_extension(
7457 sqlite3 *db, /* Load the extension into this database connection */
7458 const char *zFile, /* Name of the shared library containing extension */
7459 const char *zProc, /* Entry point. Derived from zFile if 0 */
7460 char **pzErrMsg /* Put error message here if not 0 */
7461 );
7462
7463 /*
7464 ** CAPI3REF: Enable Or Disable Extension Loading
7465 ** METHOD: sqlite3
7466 **
7467 ** ^So as not to open security holes in older applications that are
7468 ** unprepared to deal with [extension loading], and as a means of disabling
7469 ** [extension loading] while evaluating user-entered SQL, the following API
7470 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7471 **
7472 ** ^Extension loading is off by default.
7473 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7474 ** to turn extension loading on and call it with onoff==0 to turn
7475 ** it back off again.
7476 **
7477 ** ^This interface enables or disables both the C-API
7478 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
7479 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7480 ** to enable or disable only the C-API.)^
7481 **
7482 ** <b>Security warning:</b> It is recommended that extension loading
7483 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7484 ** rather than this interface, so the [load_extension()] SQL function
7485 ** remains disabled. This will prevent SQL injections from giving attackers
7486 ** access to extension loading capabilities.
7487 */
7488 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7489
7490 /*
7491 ** CAPI3REF: Automatically Load Statically Linked Extensions
7492 **
7493 ** ^This interface causes the xEntryPoint() function to be invoked for
7494 ** each new [database connection] that is created. The idea here is that
7495 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7496 ** that is to be automatically loaded into all new database connections.
7497 **
7498 ** ^(Even though the function prototype shows that xEntryPoint() takes
7499 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
7500 ** arguments and expects an integer result as if the signature of the
7501 ** entry point were as follows:
7502 **
7503 ** <blockquote><pre>
7504 ** &nbsp; int xEntryPoint(
7505 ** &nbsp; sqlite3 *db,
7506 ** &nbsp; const char **pzErrMsg,
7507 ** &nbsp; const struct sqlite3_api_routines *pThunk
7508 ** &nbsp; );
7509 ** </pre></blockquote>)^
7510 **
7511 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7512 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7513 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7514 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7515 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7516 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7517 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7518 **
7519 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7520 ** on the list of automatic extensions is a harmless no-op. ^No entry point
7521 ** will be called more than once for each database connection that is opened.
7522 **
7523 ** See also: [sqlite3_reset_auto_extension()]
7524 ** and [sqlite3_cancel_auto_extension()]
7525 */
7526 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7527
7528 /*
7529 ** CAPI3REF: Cancel Automatic Extension Loading
7530 **
7531 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7532 ** initialization routine X that was registered using a prior call to
7533 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7534 ** routine returns 1 if initialization routine X was successfully
7535 ** unregistered and it returns 0 if X was not on the list of initialization
7536 ** routines.
7537 */
7538 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7539
7540 /*
7541 ** CAPI3REF: Reset Automatic Extension Loading
7542 **
7543 ** ^This interface disables all automatic extensions previously
7544 ** registered using [sqlite3_auto_extension()].
7545 */
7546 SQLITE_API void sqlite3_reset_auto_extension(void);
7547
7548 /*
7549 ** Structures used by the virtual table interface
7550 */
7551 typedef struct sqlite3_vtab sqlite3_vtab;
7552 typedef struct sqlite3_index_info sqlite3_index_info;
7553 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7554 typedef struct sqlite3_module sqlite3_module;
7555
7556 /*
7557 ** CAPI3REF: Virtual Table Object
7558 ** KEYWORDS: sqlite3_module {virtual table module}
7559 **
7560 ** This structure, sometimes called a "virtual table module",
7561 ** defines the implementation of a [virtual table].
7562 ** This structure consists mostly of methods for the module.
7563 **
7564 ** ^A virtual table module is created by filling in a persistent
7565 ** instance of this structure and passing a pointer to that instance
7566 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7567 ** ^The registration remains valid until it is replaced by a different
7568 ** module or until the [database connection] closes. The content
7569 ** of this structure must not change while it is registered with
7570 ** any database connection.
7571 */
7572 struct sqlite3_module {
7573 int iVersion;
7574 int (*xCreate)(sqlite3*, void *pAux,
7575 int argc, const char *const*argv,
7576 sqlite3_vtab **ppVTab, char**);
7577 int (*xConnect)(sqlite3*, void *pAux,
7578 int argc, const char *const*argv,
7579 sqlite3_vtab **ppVTab, char**);
7580 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7581 int (*xDisconnect)(sqlite3_vtab *pVTab);
7582 int (*xDestroy)(sqlite3_vtab *pVTab);
7583 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7584 int (*xClose)(sqlite3_vtab_cursor*);
7585 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7586 int argc, sqlite3_value **argv);
7587 int (*xNext)(sqlite3_vtab_cursor*);
7588 int (*xEof)(sqlite3_vtab_cursor*);
7589 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7590 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7591 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7592 int (*xBegin)(sqlite3_vtab *pVTab);
7593 int (*xSync)(sqlite3_vtab *pVTab);
7594 int (*xCommit)(sqlite3_vtab *pVTab);
7595 int (*xRollback)(sqlite3_vtab *pVTab);
7596 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7597 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7598 void **ppArg);
7599 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7600 /* The methods above are in version 1 of the sqlite_module object. Those
7601 ** below are for version 2 and greater. */
7602 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7603 int (*xRelease)(sqlite3_vtab *pVTab, int);
7604 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7605 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7606 ** Those below are for version 3 and greater. */
7607 int (*xShadowName)(const char*);
7608 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7609 ** Those below are for version 4 and greater. */
7610 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7611 const char *zTabName, int mFlags, char **pzErr);
7612 };
7613
7614 /*
7615 ** CAPI3REF: Virtual Table Indexing Information
7616 ** KEYWORDS: sqlite3_index_info
7617 **
7618 ** The sqlite3_index_info structure and its substructures is used as part
7619 ** of the [virtual table] interface to
7620 ** pass information into and receive the reply from the [xBestIndex]
7621 ** method of a [virtual table module]. The fields under **Inputs** are the
7622 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
7623 ** results into the **Outputs** fields.
7624 **
7625 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
7626 **
7627 ** <blockquote>column OP expr</blockquote>
7628 **
7629 ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7630 ** stored in aConstraint[].op using one of the
7631 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7632 ** ^(The index of the column is stored in
7633 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7634 ** expr on the right-hand side can be evaluated (and thus the constraint
7635 ** is usable) and false if it cannot.)^
7636 **
7637 ** ^The optimizer automatically inverts terms of the form "expr OP column"
7638 ** and makes other simplifications to the WHERE clause in an attempt to
7639 ** get as many WHERE clause terms into the form shown above as possible.
7640 ** ^The aConstraint[] array only reports WHERE clause terms that are
7641 ** relevant to the particular virtual table being queried.
7642 **
7643 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7644 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7645 **
7646 ** The colUsed field indicates which columns of the virtual table may be
7647 ** required by the current scan. Virtual table columns are numbered from
7648 ** zero in the order in which they appear within the CREATE TABLE statement
7649 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7650 ** the corresponding bit is set within the colUsed mask if the column may be
7651 ** required by SQLite. If the table has at least 64 columns and any column
7652 ** to the right of the first 63 is required, then bit 63 of colUsed is also
7653 ** set. In other words, column iCol may be required if the expression
7654 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7655 ** non-zero.
7656 **
7657 ** The [xBestIndex] method must fill aConstraintUsage[] with information
7658 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7659 ** the right-hand side of the corresponding aConstraint[] is evaluated
7660 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7661 ** is true, then the constraint is assumed to be fully handled by the
7662 ** virtual table and might not be checked again by the byte code.)^ ^(The
7663 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7664 ** is left in its default setting of false, the constraint will always be
7665 ** checked separately in byte code. If the omit flag is changed to true, then
7666 ** the constraint may or may not be checked in byte code. In other words,
7667 ** when the omit flag is true there is no guarantee that the constraint will
7668 ** not be checked again using byte code.)^
7669 **
7670 ** ^The idxNum and idxStr values are recorded and passed into the
7671 ** [xFilter] method.
7672 ** ^[sqlite3_free()] is used to free idxStr if and only if
7673 ** needToFreeIdxStr is true.
7674 **
7675 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7676 ** the correct order to satisfy the ORDER BY clause so that no separate
7677 ** sorting step is required.
7678 **
7679 ** ^The estimatedCost value is an estimate of the cost of a particular
7680 ** strategy. A cost of N indicates that the cost of the strategy is similar
7681 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7682 ** indicates that the expense of the operation is similar to that of a
7683 ** binary search on a unique indexed field of an SQLite table with N rows.
7684 **
7685 ** ^The estimatedRows value is an estimate of the number of rows that
7686 ** will be returned by the strategy.
7687 **
7688 ** The xBestIndex method may optionally populate the idxFlags field with a
7689 ** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7690 ** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7691 ** output to show the idxNum as hex instead of as decimal. Another flag is
7692 ** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7693 ** return at most one row.
7694 **
7695 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7696 ** SQLite also assumes that if a call to the xUpdate() method is made as
7697 ** part of the same statement to delete or update a virtual table row and the
7698 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7699 ** any database changes. In other words, if the xUpdate() returns
7700 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7701 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7702 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7703 ** the xUpdate method are automatically rolled back by SQLite.
7704 **
7705 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7706 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7707 ** If a virtual table extension is
7708 ** used with an SQLite version earlier than 3.8.2, the results of attempting
7709 ** to read or write the estimatedRows field are undefined (but are likely
7710 ** to include crashing the application). The estimatedRows field should
7711 ** therefore only be used if [sqlite3_libversion_number()] returns a
7712 ** value greater than or equal to 3008002. Similarly, the idxFlags field
7713 ** was added for [version 3.9.0] ([dateof:3.9.0]).
7714 ** It may therefore only be used if
7715 ** sqlite3_libversion_number() returns a value greater than or equal to
7716 ** 3009000.
7717 */
7718 struct sqlite3_index_info {
7719 /* Inputs */
7720 int nConstraint; /* Number of entries in aConstraint */
7721 struct sqlite3_index_constraint {
7722 int iColumn; /* Column constrained. -1 for ROWID */
7723 unsigned char op; /* Constraint operator */
7724 unsigned char usable; /* True if this constraint is usable */
7725 int iTermOffset; /* Used internally - xBestIndex should ignore */
7726 } *aConstraint; /* Table of WHERE clause constraints */
7727 int nOrderBy; /* Number of terms in the ORDER BY clause */
7728 struct sqlite3_index_orderby {
7729 int iColumn; /* Column number */
7730 unsigned char desc; /* True for DESC. False for ASC. */
7731 } *aOrderBy; /* The ORDER BY clause */
7732 /* Outputs */
7733 struct sqlite3_index_constraint_usage {
7734 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7735 unsigned char omit; /* Do not code a test for this constraint */
7736 } *aConstraintUsage;
7737 int idxNum; /* Number used to identify the index */
7738 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7739 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7740 int orderByConsumed; /* True if output is already ordered */
7741 double estimatedCost; /* Estimated cost of using this index */
7742 /* Fields below are only available in SQLite 3.8.2 and later */
7743 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7744 /* Fields below are only available in SQLite 3.9.0 and later */
7745 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7746 /* Fields below are only available in SQLite 3.10.0 and later */
7747 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7748 };
7749
7750 /*
7751 ** CAPI3REF: Virtual Table Scan Flags
7752 **
7753 ** Virtual table implementations are allowed to set the
7754 ** [sqlite3_index_info].idxFlags field to some combination of
7755 ** these bits.
7756 */
7757 #define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7758 #define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7759 /* in EXPLAIN QUERY PLAN */
7760
7761 /*
7762 ** CAPI3REF: Virtual Table Constraint Operator Codes
7763 **
7764 ** These macros define the allowed values for the
7765 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7766 ** an operator that is part of a constraint term in the WHERE clause of
7767 ** a query that uses a [virtual table].
7768 **
7769 ** ^The left-hand operand of the operator is given by the corresponding
7770 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7771 ** operand is the rowid.
7772 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7773 ** operators have no left-hand operand, and so for those operators the
7774 ** corresponding aConstraint[].iColumn is meaningless and should not be
7775 ** used.
7776 **
7777 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7778 ** value 255 are reserved to represent functions that are overloaded
7779 ** by the [xFindFunction|xFindFunction method] of the virtual table
7780 ** implementation.
7781 **
7782 ** The right-hand operands for each constraint might be accessible using
7783 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7784 ** operand is only available if it appears as a single constant literal
7785 ** in the input SQL. If the right-hand operand is another column or an
7786 ** expression (even a constant expression) or a parameter, then the
7787 ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7788 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7789 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7790 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7791 ** always return SQLITE_NOTFOUND.
7792 **
7793 ** The collating sequence to be used for comparison can be found using
7794 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7795 ** tables, the collating sequence of constraints does not matter (for example
7796 ** because the constraints are numeric) and so the sqlite3_vtab_collation()
7797 ** interface is not commonly needed.
7798 */
7799 #define SQLITE_INDEX_CONSTRAINT_EQ 2
7800 #define SQLITE_INDEX_CONSTRAINT_GT 4
7801 #define SQLITE_INDEX_CONSTRAINT_LE 8
7802 #define SQLITE_INDEX_CONSTRAINT_LT 16
7803 #define SQLITE_INDEX_CONSTRAINT_GE 32
7804 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7805 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7806 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7807 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7808 #define SQLITE_INDEX_CONSTRAINT_NE 68
7809 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7810 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7811 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7812 #define SQLITE_INDEX_CONSTRAINT_IS 72
7813 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7814 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7815 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7816
7817 /*
7818 ** CAPI3REF: Register A Virtual Table Implementation
7819 ** METHOD: sqlite3
7820 **
7821 ** ^These routines are used to register a new [virtual table module] name.
7822 ** ^Module names must be registered before
7823 ** creating a new [virtual table] using the module and before using a
7824 ** preexisting [virtual table] for the module.
7825 **
7826 ** ^The module name is registered on the [database connection] specified
7827 ** by the first parameter. ^The name of the module is given by the
7828 ** second parameter. ^The third parameter is a pointer to
7829 ** the implementation of the [virtual table module]. ^The fourth
7830 ** parameter is an arbitrary client data pointer that is passed through
7831 ** into the [xCreate] and [xConnect] methods of the virtual table module
7832 ** when a new virtual table is being created or reinitialized.
7833 **
7834 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7835 ** is a pointer to a destructor for the pClientData. ^SQLite will
7836 ** invoke the destructor function (if it is not NULL) when SQLite
7837 ** no longer needs the pClientData pointer. ^The destructor will also
7838 ** be invoked if the call to sqlite3_create_module_v2() fails.
7839 ** ^The sqlite3_create_module()
7840 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7841 ** destructor.
7842 **
7843 ** ^If the third parameter (the pointer to the sqlite3_module object) is
7844 ** NULL then no new module is created and any existing modules with the
7845 ** same name are dropped.
7846 **
7847 ** See also: [sqlite3_drop_modules()]
7848 */
7849 SQLITE_API int sqlite3_create_module(
7850 sqlite3 *db, /* SQLite connection to register module with */
7851 const char *zName, /* Name of the module */
7852 const sqlite3_module *p, /* Methods for the module */
7853 void *pClientData /* Client data for xCreate/xConnect */
7854 );
7855 SQLITE_API int sqlite3_create_module_v2(
7856 sqlite3 *db, /* SQLite connection to register module with */
7857 const char *zName, /* Name of the module */
7858 const sqlite3_module *p, /* Methods for the module */
7859 void *pClientData, /* Client data for xCreate/xConnect */
7860 void(*xDestroy)(void*) /* Module destructor function */
7861 );
7862
7863 /*
7864 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7865 ** METHOD: sqlite3
7866 **
7867 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7868 ** table modules from database connection D except those named on list L.
7869 ** The L parameter must be either NULL or a pointer to an array of pointers
7870 ** to strings where the array is terminated by a single NULL pointer.
7871 ** ^If the L parameter is NULL, then all virtual table modules are removed.
7872 **
7873 ** See also: [sqlite3_create_module()]
7874 */
7875 SQLITE_API int sqlite3_drop_modules(
7876 sqlite3 *db, /* Remove modules from this connection */
7877 const char **azKeep /* Except, do not remove the ones named here */
7878 );
7879
7880 /*
7881 ** CAPI3REF: Virtual Table Instance Object
7882 ** KEYWORDS: sqlite3_vtab
7883 **
7884 ** Every [virtual table module] implementation uses a subclass
7885 ** of this object to describe a particular instance
7886 ** of the [virtual table]. Each subclass will
7887 ** be tailored to the specific needs of the module implementation.
7888 ** The purpose of this superclass is to define certain fields that are
7889 ** common to all module implementations.
7890 **
7891 ** ^Virtual tables methods can set an error message by assigning a
7892 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7893 ** take care that any prior string is freed by a call to [sqlite3_free()]
7894 ** prior to assigning a new string to zErrMsg. ^After the error message
7895 ** is delivered up to the client application, the string will be automatically
7896 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7897 */
7898 struct sqlite3_vtab {
7899 const sqlite3_module *pModule; /* The module for this virtual table */
7900 int nRef; /* Number of open cursors */
7901 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7902 /* Virtual table implementations will typically add additional fields */
7903 };
7904
7905 /*
7906 ** CAPI3REF: Virtual Table Cursor Object
7907 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7908 **
7909 ** Every [virtual table module] implementation uses a subclass of the
7910 ** following structure to describe cursors that point into the
7911 ** [virtual table] and are used
7912 ** to loop through the virtual table. Cursors are created using the
7913 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7914 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7915 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7916 ** of the module. Each module implementation will define
7917 ** the content of a cursor structure to suit its own needs.
7918 **
7919 ** This superclass exists in order to define fields of the cursor that
7920 ** are common to all implementations.
7921 */
7922 struct sqlite3_vtab_cursor {
7923 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7924 /* Virtual table implementations will typically add additional fields */
7925 };
7926
7927 /*
7928 ** CAPI3REF: Declare The Schema Of A Virtual Table
7929 **
7930 ** ^The [xCreate] and [xConnect] methods of a
7931 ** [virtual table module] call this interface
7932 ** to declare the format (the names and datatypes of the columns) of
7933 ** the virtual tables they implement.
7934 */
7935 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7936
7937 /*
7938 ** CAPI3REF: Overload A Function For A Virtual Table
7939 ** METHOD: sqlite3
7940 **
7941 ** ^(Virtual tables can provide alternative implementations of functions
7942 ** using the [xFindFunction] method of the [virtual table module].
7943 ** But global versions of those functions
7944 ** must exist in order to be overloaded.)^
7945 **
7946 ** ^(This API makes sure a global version of a function with a particular
7947 ** name and number of parameters exists. If no such function exists
7948 ** before this API is called, a new function is created.)^ ^The implementation
7949 ** of the new function always causes an exception to be thrown. So
7950 ** the new function is not good for anything by itself. Its only
7951 ** purpose is to be a placeholder function that can be overloaded
7952 ** by a [virtual table].
7953 */
7954 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7955
7956 /*
7957 ** CAPI3REF: A Handle To An Open BLOB
7958 ** KEYWORDS: {BLOB handle} {BLOB handles}
7959 **
7960 ** An instance of this object represents an open BLOB on which
7961 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7962 ** ^Objects of this type are created by [sqlite3_blob_open()]
7963 ** and destroyed by [sqlite3_blob_close()].
7964 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7965 ** can be used to read or write small subsections of the BLOB.
7966 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7967 */
7968 typedef struct sqlite3_blob sqlite3_blob;
7969
7970 /*
7971 ** CAPI3REF: Open A BLOB For Incremental I/O
7972 ** METHOD: sqlite3
7973 ** CONSTRUCTOR: sqlite3_blob
7974 **
7975 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7976 ** in row iRow, column zColumn, table zTable in database zDb;
7977 ** in other words, the same BLOB that would be selected by:
7978 **
7979 ** <pre>
7980 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7981 ** </pre>)^
7982 **
7983 ** ^(Parameter zDb is not the filename that contains the database, but
7984 ** rather the symbolic name of the database. For attached databases, this is
7985 ** the name that appears after the AS keyword in the [ATTACH] statement.
7986 ** For the main database file, the database name is "main". For TEMP
7987 ** tables, the database name is "temp".)^
7988 **
7989 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7990 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7991 ** read-only access.
7992 **
7993 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7994 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7995 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7996 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7997 ** on *ppBlob after this function returns.
7998 **
7999 ** This function fails with SQLITE_ERROR if any of the following are true:
8000 ** <ul>
8001 ** <li> ^(Database zDb does not exist)^,
8002 ** <li> ^(Table zTable does not exist within database zDb)^,
8003 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
8004 ** <li> ^(Column zColumn does not exist)^,
8005 ** <li> ^(Row iRow is not present in the table)^,
8006 ** <li> ^(The specified column of row iRow contains a value that is not
8007 ** a TEXT or BLOB value)^,
8008 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
8009 ** constraint and the blob is being opened for read/write access)^,
8010 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
8011 ** column zColumn is part of a [child key] definition and the blob is
8012 ** being opened for read/write access)^.
8013 ** </ul>
8014 **
8015 ** ^Unless it returns SQLITE_MISUSE, this function sets the
8016 ** [database connection] error code and message accessible via
8017 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8018 **
8019 ** A BLOB referenced by sqlite3_blob_open() may be read using the
8020 ** [sqlite3_blob_read()] interface and modified by using
8021 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
8022 ** different row of the same table using the [sqlite3_blob_reopen()]
8023 ** interface. However, the column, table, or database of a [BLOB handle]
8024 ** cannot be changed after the [BLOB handle] is opened.
8025 **
8026 ** ^(If the row that a BLOB handle points to is modified by an
8027 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
8028 ** then the BLOB handle is marked as "expired".
8029 ** This is true if any column of the row is changed, even a column
8030 ** other than the one the BLOB handle is open on.)^
8031 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
8032 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
8033 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
8034 ** rolled back by the expiration of the BLOB. Such changes will eventually
8035 ** commit if the transaction continues to completion.)^
8036 **
8037 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
8038 ** the opened blob. ^The size of a blob may not be changed by this
8039 ** interface. Use the [UPDATE] SQL command to change the size of a
8040 ** blob.
8041 **
8042 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
8043 ** and the built-in [zeroblob] SQL function may be used to create a
8044 ** zero-filled blob to read or write using the incremental-blob interface.
8045 **
8046 ** To avoid a resource leak, every open [BLOB handle] should eventually
8047 ** be released by a call to [sqlite3_blob_close()].
8048 **
8049 ** See also: [sqlite3_blob_close()],
8050 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8051 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8052 */
8053 SQLITE_API int sqlite3_blob_open(
8054 sqlite3*,
8055 const char *zDb,
8056 const char *zTable,
8057 const char *zColumn,
8058 sqlite3_int64 iRow,
8059 int flags,
8060 sqlite3_blob **ppBlob
8061 );
8062
8063 /*
8064 ** CAPI3REF: Move a BLOB Handle to a New Row
8065 ** METHOD: sqlite3_blob
8066 **
8067 ** ^This function is used to move an existing [BLOB handle] so that it points
8068 ** to a different row of the same database table. ^The new row is identified
8069 ** by the rowid value passed as the second argument. Only the row can be
8070 ** changed. ^The database, table and column on which the blob handle is open
8071 ** remain the same. Moving an existing [BLOB handle] to a new row is
8072 ** faster than closing the existing handle and opening a new one.
8073 **
8074 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8075 ** it must exist and there must be either a blob or text value stored in
8076 ** the nominated column.)^ ^If the new row is not present in the table, or if
8077 ** it does not contain a blob or text value, or if another error occurs, an
8078 ** SQLite error code is returned and the blob handle is considered aborted.
8079 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8080 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8081 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8082 ** always returns zero.
8083 **
8084 ** ^This function sets the database handle error code and message.
8085 */
8086 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8087
8088 /*
8089 ** CAPI3REF: Close A BLOB Handle
8090 ** DESTRUCTOR: sqlite3_blob
8091 **
8092 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8093 ** unconditionally. Even if this routine returns an error code, the
8094 ** handle is still closed.)^
8095 **
8096 ** ^If the blob handle being closed was opened for read-write access, and if
8097 ** the database is in auto-commit mode and there are no other open read-write
8098 ** blob handles or active write statements, the current transaction is
8099 ** committed. ^If an error occurs while committing the transaction, an error
8100 ** code is returned and the transaction rolled back.
8101 **
8102 ** Calling this function with an argument that is not a NULL pointer or an
8103 ** open blob handle results in undefined behavior. ^Calling this routine
8104 ** with a null pointer (such as would be returned by a failed call to
8105 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8106 ** is passed a valid open blob handle, the values returned by the
8107 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8108 */
8109 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8110
8111 /*
8112 ** CAPI3REF: Return The Size Of An Open BLOB
8113 ** METHOD: sqlite3_blob
8114 **
8115 ** ^Returns the size in bytes of the BLOB accessible via the
8116 ** successfully opened [BLOB handle] in its only argument. ^The
8117 ** incremental blob I/O routines can only read or overwrite existing
8118 ** blob content; they cannot change the size of a blob.
8119 **
8120 ** This routine only works on a [BLOB handle] which has been created
8121 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8122 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8123 ** to this routine results in undefined and probably undesirable behavior.
8124 */
8125 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8126
8127 /*
8128 ** CAPI3REF: Read Data From A BLOB Incrementally
8129 ** METHOD: sqlite3_blob
8130 **
8131 ** ^(This function is used to read data from an open [BLOB handle] into a
8132 ** caller-supplied buffer. N bytes of data are copied into buffer Z
8133 ** from the open BLOB, starting at offset iOffset.)^
8134 **
8135 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
8136 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8137 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
8138 ** ^The size of the blob (and hence the maximum value of N+iOffset)
8139 ** can be determined using the [sqlite3_blob_bytes()] interface.
8140 **
8141 ** ^An attempt to read from an expired [BLOB handle] fails with an
8142 ** error code of [SQLITE_ABORT].
8143 **
8144 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8145 ** Otherwise, an [error code] or an [extended error code] is returned.)^
8146 **
8147 ** This routine only works on a [BLOB handle] which has been created
8148 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8149 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8150 ** to this routine results in undefined and probably undesirable behavior.
8151 **
8152 ** See also: [sqlite3_blob_write()].
8153 */
8154 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8155
8156 /*
8157 ** CAPI3REF: Write Data Into A BLOB Incrementally
8158 ** METHOD: sqlite3_blob
8159 **
8160 ** ^(This function is used to write data into an open [BLOB handle] from a
8161 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
8162 ** into the open BLOB, starting at offset iOffset.)^
8163 **
8164 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8165 ** Otherwise, an [error code] or an [extended error code] is returned.)^
8166 ** ^Unless SQLITE_MISUSE is returned, this function sets the
8167 ** [database connection] error code and message accessible via
8168 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8169 **
8170 ** ^If the [BLOB handle] passed as the first argument was not opened for
8171 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8172 ** this function returns [SQLITE_READONLY].
8173 **
8174 ** This function may only modify the contents of the BLOB; it is
8175 ** not possible to increase the size of a BLOB using this API.
8176 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
8177 ** [SQLITE_ERROR] is returned and no data is written. The size of the
8178 ** BLOB (and hence the maximum value of N+iOffset) can be determined
8179 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8180 ** than zero [SQLITE_ERROR] is returned and no data is written.
8181 **
8182 ** ^An attempt to write to an expired [BLOB handle] fails with an
8183 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8184 ** before the [BLOB handle] expired are not rolled back by the
8185 ** expiration of the handle, though of course those changes might
8186 ** have been overwritten by the statement that expired the BLOB handle
8187 ** or by other independent statements.
8188 **
8189 ** This routine only works on a [BLOB handle] which has been created
8190 ** by a prior successful call to [sqlite3_blob_open()] and which has not
8191 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8192 ** to this routine results in undefined and probably undesirable behavior.
8193 **
8194 ** See also: [sqlite3_blob_read()].
8195 */
8196 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8197
8198 /*
8199 ** CAPI3REF: Virtual File System Objects
8200 **
8201 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8202 ** that SQLite uses to interact
8203 ** with the underlying operating system. Most SQLite builds come with a
8204 ** single default VFS that is appropriate for the host computer.
8205 ** New VFSes can be registered and existing VFSes can be unregistered.
8206 ** The following interfaces are provided.
8207 **
8208 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8209 ** ^Names are case sensitive.
8210 ** ^Names are zero-terminated UTF-8 strings.
8211 ** ^If there is no match, a NULL pointer is returned.
8212 ** ^If zVfsName is NULL then the default VFS is returned.
8213 **
8214 ** ^New VFSes are registered with sqlite3_vfs_register().
8215 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8216 ** ^The same VFS can be registered multiple times without injury.
8217 ** ^To make an existing VFS into the default VFS, register it again
8218 ** with the makeDflt flag set. If two different VFSes with the
8219 ** same name are registered, the behavior is undefined. If a
8220 ** VFS is registered with a name that is NULL or an empty string,
8221 ** then the behavior is undefined.
8222 **
8223 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8224 ** ^(If the default VFS is unregistered, another VFS is chosen as
8225 ** the default. The choice for the new VFS is arbitrary.)^
8226 */
8227 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8228 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8229 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8230
8231 /*
8232 ** CAPI3REF: Mutexes
8233 **
8234 ** The SQLite core uses these routines for thread
8235 ** synchronization. Though they are intended for internal
8236 ** use by SQLite, code that links against SQLite is
8237 ** permitted to use any of these routines.
8238 **
8239 ** The SQLite source code contains multiple implementations
8240 ** of these mutex routines. An appropriate implementation
8241 ** is selected automatically at compile-time. The following
8242 ** implementations are available in the SQLite core:
8243 **
8244 ** <ul>
8245 ** <li> SQLITE_MUTEX_PTHREADS
8246 ** <li> SQLITE_MUTEX_W32
8247 ** <li> SQLITE_MUTEX_NOOP
8248 ** </ul>
8249 **
8250 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
8251 ** that does no real locking and is appropriate for use in
8252 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8253 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8254 ** and Windows.
8255 **
8256 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8257 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8258 ** implementation is included with the library. In this case the
8259 ** application must supply a custom mutex implementation using the
8260 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8261 ** before calling sqlite3_initialize() or any other public sqlite3_
8262 ** function that calls sqlite3_initialize().
8263 **
8264 ** ^The sqlite3_mutex_alloc() routine allocates a new
8265 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8266 ** routine returns NULL if it is unable to allocate the requested
8267 ** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8268 ** integer constants:
8269 **
8270 ** <ul>
8271 ** <li> SQLITE_MUTEX_FAST
8272 ** <li> SQLITE_MUTEX_RECURSIVE
8273 ** <li> SQLITE_MUTEX_STATIC_MAIN
8274 ** <li> SQLITE_MUTEX_STATIC_MEM
8275 ** <li> SQLITE_MUTEX_STATIC_OPEN
8276 ** <li> SQLITE_MUTEX_STATIC_PRNG
8277 ** <li> SQLITE_MUTEX_STATIC_LRU
8278 ** <li> SQLITE_MUTEX_STATIC_PMEM
8279 ** <li> SQLITE_MUTEX_STATIC_APP1
8280 ** <li> SQLITE_MUTEX_STATIC_APP2
8281 ** <li> SQLITE_MUTEX_STATIC_APP3
8282 ** <li> SQLITE_MUTEX_STATIC_VFS1
8283 ** <li> SQLITE_MUTEX_STATIC_VFS2
8284 ** <li> SQLITE_MUTEX_STATIC_VFS3
8285 ** </ul>
8286 **
8287 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8288 ** cause sqlite3_mutex_alloc() to create
8289 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8290 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8291 ** The mutex implementation does not need to make a distinction
8292 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8293 ** not want to. SQLite will only request a recursive mutex in
8294 ** cases where it really needs one. If a faster non-recursive mutex
8295 ** implementation is available on the host platform, the mutex subsystem
8296 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
8297 **
8298 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8299 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8300 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
8301 ** used by the current version of SQLite. Future versions of SQLite
8302 ** may add additional static mutexes. Static mutexes are for internal
8303 ** use by SQLite only. Applications that use SQLite mutexes should
8304 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8305 ** SQLITE_MUTEX_RECURSIVE.
8306 **
8307 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8308 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8309 ** returns a different mutex on every call. ^For the static
8310 ** mutex types, the same mutex is returned on every call that has
8311 ** the same type number.
8312 **
8313 ** ^The sqlite3_mutex_free() routine deallocates a previously
8314 ** allocated dynamic mutex. Attempting to deallocate a static
8315 ** mutex results in undefined behavior.
8316 **
8317 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8318 ** to enter a mutex. ^If another thread is already within the mutex,
8319 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8320 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8321 ** upon successful entry. ^(Mutexes created using
8322 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8323 ** In such cases, the
8324 ** mutex must be exited an equal number of times before another thread
8325 ** can enter.)^ If the same thread tries to enter any mutex other
8326 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8327 **
8328 ** ^(Some systems (for example, Windows 95) do not support the operation
8329 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8330 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8331 ** sqlite3_mutex_try() as an optimization, so this is acceptable
8332 ** behavior. The exceptions are unix builds that set the
8333 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8334 ** sqlite3_mutex_try() is required.)^
8335 **
8336 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
8337 ** previously entered by the same thread. The behavior
8338 ** is undefined if the mutex is not currently entered by the
8339 ** calling thread or is not currently allocated.
8340 **
8341 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8342 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8343 ** then any of the four routines behaves as a no-op.
8344 **
8345 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8346 */
8347 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8348 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8349 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8350 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8351 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8352
8353 /*
8354 ** CAPI3REF: Mutex Methods Object
8355 **
8356 ** An instance of this structure defines the low-level routines
8357 ** used to allocate and use mutexes.
8358 **
8359 ** Usually, the default mutex implementations provided by SQLite are
8360 ** sufficient, however the application has the option of substituting a custom
8361 ** implementation for specialized deployments or systems for which SQLite
8362 ** does not provide a suitable implementation. In this case, the application
8363 ** creates and populates an instance of this structure to pass
8364 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8365 ** Additionally, an instance of this structure can be used as an
8366 ** output variable when querying the system for the current mutex
8367 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8368 **
8369 ** ^The xMutexInit method defined by this structure is invoked as
8370 ** part of system initialization by the sqlite3_initialize() function.
8371 ** ^The xMutexInit routine is called by SQLite exactly once for each
8372 ** effective call to [sqlite3_initialize()].
8373 **
8374 ** ^The xMutexEnd method defined by this structure is invoked as
8375 ** part of system shutdown by the sqlite3_shutdown() function. The
8376 ** implementation of this method is expected to release all outstanding
8377 ** resources obtained by the mutex methods implementation, especially
8378 ** those obtained by the xMutexInit method. ^The xMutexEnd()
8379 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8380 **
8381 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8382 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8383 ** xMutexNotheld) implement the following interfaces (respectively):
8384 **
8385 ** <ul>
8386 ** <li> [sqlite3_mutex_alloc()] </li>
8387 ** <li> [sqlite3_mutex_free()] </li>
8388 ** <li> [sqlite3_mutex_enter()] </li>
8389 ** <li> [sqlite3_mutex_try()] </li>
8390 ** <li> [sqlite3_mutex_leave()] </li>
8391 ** <li> [sqlite3_mutex_held()] </li>
8392 ** <li> [sqlite3_mutex_notheld()] </li>
8393 ** </ul>)^
8394 **
8395 ** The only difference is that the public sqlite3_XXX functions enumerated
8396 ** above silently ignore any invocations that pass a NULL pointer instead
8397 ** of a valid mutex handle. The implementations of the methods defined
8398 ** by this structure are not required to handle this case. The results
8399 ** of passing a NULL pointer instead of a valid mutex handle are undefined
8400 ** (i.e. it is acceptable to provide an implementation that segfaults if
8401 ** it is passed a NULL pointer).
8402 **
8403 ** The xMutexInit() method must be threadsafe. It must be harmless to
8404 ** invoke xMutexInit() multiple times within the same process and without
8405 ** intervening calls to xMutexEnd(). Second and subsequent calls to
8406 ** xMutexInit() must be no-ops.
8407 **
8408 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8409 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8410 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8411 ** memory allocation for a fast or recursive mutex.
8412 **
8413 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8414 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8415 ** If xMutexInit fails in any way, it is expected to clean up after itself
8416 ** prior to returning.
8417 */
8418 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8419 struct sqlite3_mutex_methods {
8420 int (*xMutexInit)(void);
8421 int (*xMutexEnd)(void);
8422 sqlite3_mutex *(*xMutexAlloc)(int);
8423 void (*xMutexFree)(sqlite3_mutex *);
8424 void (*xMutexEnter)(sqlite3_mutex *);
8425 int (*xMutexTry)(sqlite3_mutex *);
8426 void (*xMutexLeave)(sqlite3_mutex *);
8427 int (*xMutexHeld)(sqlite3_mutex *);
8428 int (*xMutexNotheld)(sqlite3_mutex *);
8429 };
8430
8431 /*
8432 ** CAPI3REF: Mutex Verification Routines
8433 **
8434 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8435 ** are intended for use inside assert() statements. The SQLite core
8436 ** never uses these routines except inside an assert() and applications
8437 ** are advised to follow the lead of the core. The SQLite core only
8438 ** provides implementations for these routines when it is compiled
8439 ** with the SQLITE_DEBUG flag. External mutex implementations
8440 ** are only required to provide these routines if SQLITE_DEBUG is
8441 ** defined and if NDEBUG is not defined.
8442 **
8443 ** These routines should return true if the mutex in their argument
8444 ** is held or not held, respectively, by the calling thread.
8445 **
8446 ** The implementation is not required to provide versions of these
8447 ** routines that actually work. If the implementation does not provide working
8448 ** versions of these routines, it should at least provide stubs that always
8449 ** return true so that one does not get spurious assertion failures.
8450 **
8451 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
8452 ** the routine should return 1. This seems counter-intuitive since
8453 ** clearly the mutex cannot be held if it does not exist. But
8454 ** the reason the mutex does not exist is because the build is not
8455 ** using mutexes. And we do not want the assert() containing the
8456 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
8457 ** the appropriate thing to do. The sqlite3_mutex_notheld()
8458 ** interface should also return 1 when given a NULL pointer.
8459 */
8460 #ifndef NDEBUG
8461 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8462 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8463 #endif
8464
8465 /*
8466 ** CAPI3REF: Mutex Types
8467 **
8468 ** The [sqlite3_mutex_alloc()] interface takes a single argument
8469 ** which is one of these integer constants.
8470 **
8471 ** The set of static mutexes may change from one SQLite release to the
8472 ** next. Applications that override the built-in mutex logic must be
8473 ** prepared to accommodate additional static mutexes.
8474 */
8475 #define SQLITE_MUTEX_FAST 0
8476 #define SQLITE_MUTEX_RECURSIVE 1
8477 #define SQLITE_MUTEX_STATIC_MAIN 2
8478 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8479 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8480 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8481 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8482 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8483 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8484 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8485 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8486 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8487 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8488 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8489 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8490 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8491
8492 /* Legacy compatibility: */
8493 #define SQLITE_MUTEX_STATIC_MASTER 2
8494
8495
8496 /*
8497 ** CAPI3REF: Retrieve the mutex for a database connection
8498 ** METHOD: sqlite3
8499 **
8500 ** ^This interface returns a pointer to the [sqlite3_mutex] object that
8501 ** serializes access to the [database connection] given in the argument
8502 ** when the [threading mode] is Serialized.
8503 ** ^If the [threading mode] is Single-thread or Multi-thread then this
8504 ** routine returns a NULL pointer.
8505 */
8506 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8507
8508 /*
8509 ** CAPI3REF: Low-Level Control Of Database Files
8510 ** METHOD: sqlite3
8511 ** KEYWORDS: {file control}
8512 **
8513 ** ^The [sqlite3_file_control()] interface makes a direct call to the
8514 ** xFileControl method for the [sqlite3_io_methods] object associated
8515 ** with a particular database identified by the second argument. ^The
8516 ** name of the database is "main" for the main database or "temp" for the
8517 ** TEMP database, or the name that appears after the AS keyword for
8518 ** databases that are added using the [ATTACH] SQL command.
8519 ** ^A NULL pointer can be used in place of "main" to refer to the
8520 ** main database file.
8521 ** ^The third and fourth parameters to this routine
8522 ** are passed directly through to the second and third parameters of
8523 ** the xFileControl method. ^The return value of the xFileControl
8524 ** method becomes the return value of this routine.
8525 **
8526 ** A few opcodes for [sqlite3_file_control()] are handled directly
8527 ** by the SQLite core and never invoke the
8528 ** sqlite3_io_methods.xFileControl method.
8529 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8530 ** a pointer to the underlying [sqlite3_file] object to be written into
8531 ** the space pointed to by the 4th parameter. The
8532 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8533 ** the [sqlite3_file] object associated with the journal file instead of
8534 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8535 ** a pointer to the underlying [sqlite3_vfs] object for the file.
8536 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8537 ** from the pager.
8538 **
8539 ** ^If the second parameter (zDbName) does not match the name of any
8540 ** open database file, then SQLITE_ERROR is returned. ^This error
8541 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
8542 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
8543 ** also return SQLITE_ERROR. There is no way to distinguish between
8544 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8545 ** xFileControl method.
8546 **
8547 ** See also: [file control opcodes]
8548 */
8549 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8550
8551 /*
8552 ** CAPI3REF: Testing Interface
8553 **
8554 ** ^The sqlite3_test_control() interface is used to read out internal
8555 ** state of SQLite and to inject faults into SQLite for testing
8556 ** purposes. ^The first parameter is an operation code that determines
8557 ** the number, meaning, and operation of all subsequent parameters.
8558 **
8559 ** This interface is not for use by applications. It exists solely
8560 ** for verifying the correct operation of the SQLite library. Depending
8561 ** on how the SQLite library is compiled, this interface might not exist.
8562 **
8563 ** The details of the operation codes, their meanings, the parameters
8564 ** they take, and what they do are all subject to change without notice.
8565 ** Unlike most of the SQLite API, this function is not guaranteed to
8566 ** operate consistently from one release to the next.
8567 */
8568 SQLITE_API int sqlite3_test_control(int op, ...);
8569
8570 /*
8571 ** CAPI3REF: Testing Interface Operation Codes
8572 **
8573 ** These constants are the valid operation code parameters used
8574 ** as the first argument to [sqlite3_test_control()].
8575 **
8576 ** These parameters and their meanings are subject to change
8577 ** without notice. These values are for testing purposes only.
8578 ** Applications should not use any of these parameters or the
8579 ** [sqlite3_test_control()] interface.
8580 */
8581 #define SQLITE_TESTCTRL_FIRST 5
8582 #define SQLITE_TESTCTRL_PRNG_SAVE 5
8583 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
8584 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8585 #define SQLITE_TESTCTRL_FK_NO_ACTION 7
8586 #define SQLITE_TESTCTRL_BITVEC_TEST 8
8587 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
8588 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8589 #define SQLITE_TESTCTRL_PENDING_BYTE 11
8590 #define SQLITE_TESTCTRL_ASSERT 12
8591 #define SQLITE_TESTCTRL_ALWAYS 13
8592 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8593 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8594 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8595 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8596 #define SQLITE_TESTCTRL_GETOPT 16
8597 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8598 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8599 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8600 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8601 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8602 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8603 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8604 #define SQLITE_TESTCTRL_BYTEORDER 22
8605 #define SQLITE_TESTCTRL_ISINIT 23
8606 #define SQLITE_TESTCTRL_SORTER_MMAP 24
8607 #define SQLITE_TESTCTRL_IMPOSTER 25
8608 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8609 #define SQLITE_TESTCTRL_RESULT_INTREAL 27
8610 #define SQLITE_TESTCTRL_PRNG_SEED 28
8611 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8612 #define SQLITE_TESTCTRL_SEEK_COUNT 30
8613 #define SQLITE_TESTCTRL_TRACEFLAGS 31
8614 #define SQLITE_TESTCTRL_TUNE 32
8615 #define SQLITE_TESTCTRL_LOGEST 33
8616 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8617 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8618
8619 /*
8620 ** CAPI3REF: SQL Keyword Checking
8621 **
8622 ** These routines provide access to the set of SQL language keywords
8623 ** recognized by SQLite. Applications can use these routines to determine
8624 ** whether or not a specific identifier needs to be escaped (for example,
8625 ** by enclosing in double-quotes) so as not to confuse the parser.
8626 **
8627 ** The sqlite3_keyword_count() interface returns the number of distinct
8628 ** keywords understood by SQLite.
8629 **
8630 ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8631 ** makes *Z point to that keyword expressed as UTF8 and writes the number
8632 ** of bytes in the keyword into *L. The string that *Z points to is not
8633 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8634 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8635 ** or L are NULL or invalid pointers then calls to
8636 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8637 **
8638 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8639 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8640 ** if it is and zero if not.
8641 **
8642 ** The parser used by SQLite is forgiving. It is often possible to use
8643 ** a keyword as an identifier as long as such use does not result in a
8644 ** parsing ambiguity. For example, the statement
8645 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8646 ** creates a new table named "BEGIN" with three columns named
8647 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8648 ** using keywords as identifiers. Common techniques used to avoid keyword
8649 ** name collisions include:
8650 ** <ul>
8651 ** <li> Put all identifier names inside double-quotes. This is the official
8652 ** SQL way to escape identifier names.
8653 ** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8654 ** but it is what SQL Server does and so lots of programmers use this
8655 ** technique.
8656 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8657 ** with "Z".
8658 ** <li> Include a digit somewhere in every identifier name.
8659 ** </ul>
8660 **
8661 ** Note that the number of keywords understood by SQLite can depend on
8662 ** compile-time options. For example, "VACUUM" is not a keyword if
8663 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8664 ** new keywords may be added to future releases of SQLite.
8665 */
8666 SQLITE_API int sqlite3_keyword_count(void);
8667 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8668 SQLITE_API int sqlite3_keyword_check(const char*,int);
8669
8670 /*
8671 ** CAPI3REF: Dynamic String Object
8672 ** KEYWORDS: {dynamic string}
8673 **
8674 ** An instance of the sqlite3_str object contains a dynamically-sized
8675 ** string under construction.
8676 **
8677 ** The lifecycle of an sqlite3_str object is as follows:
8678 ** <ol>
8679 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8680 ** <li> ^Text is appended to the sqlite3_str object using various
8681 ** methods, such as [sqlite3_str_appendf()].
8682 ** <li> ^The sqlite3_str object is destroyed and the string it created
8683 ** is returned using the [sqlite3_str_finish()] interface.
8684 ** </ol>
8685 */
8686 typedef struct sqlite3_str sqlite3_str;
8687
8688 /*
8689 ** CAPI3REF: Create A New Dynamic String Object
8690 ** CONSTRUCTOR: sqlite3_str
8691 **
8692 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8693 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8694 ** [sqlite3_str_new()] must be freed by a subsequent call to
8695 ** [sqlite3_str_finish(X)].
8696 **
8697 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8698 ** valid [sqlite3_str] object, though in the event of an out-of-memory
8699 ** error the returned object might be a special singleton that will
8700 ** silently reject new text, always return SQLITE_NOMEM from
8701 ** [sqlite3_str_errcode()], always return 0 for
8702 ** [sqlite3_str_length()], and always return NULL from
8703 ** [sqlite3_str_finish(X)]. It is always safe to use the value
8704 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8705 ** to any of the other [sqlite3_str] methods.
8706 **
8707 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8708 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8709 ** length of the string contained in the [sqlite3_str] object will be
8710 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8711 ** of [SQLITE_MAX_LENGTH].
8712 */
8713 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8714
8715 /*
8716 ** CAPI3REF: Finalize A Dynamic String
8717 ** DESTRUCTOR: sqlite3_str
8718 **
8719 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8720 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8721 ** that contains the constructed string. The calling application should
8722 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8723 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8724 ** errors were encountered during construction of the string. ^The
8725 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8726 ** string in [sqlite3_str] object X is zero bytes long.
8727 */
8728 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8729
8730 /*
8731 ** CAPI3REF: Add Content To A Dynamic String
8732 ** METHOD: sqlite3_str
8733 **
8734 ** These interfaces add content to an sqlite3_str object previously obtained
8735 ** from [sqlite3_str_new()].
8736 **
8737 ** ^The [sqlite3_str_appendf(X,F,...)] and
8738 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8739 ** functionality of SQLite to append formatted text onto the end of
8740 ** [sqlite3_str] object X.
8741 **
8742 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8743 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8744 ** S must contain at least N non-zero bytes of content. To append a
8745 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8746 ** method instead.
8747 **
8748 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8749 ** zero-terminated string S onto the end of [sqlite3_str] object X.
8750 **
8751 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8752 ** single-byte character C onto the end of [sqlite3_str] object X.
8753 ** ^This method can be used, for example, to add whitespace indentation.
8754 **
8755 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8756 ** inside [sqlite3_str] object X back to zero bytes in length.
8757 **
8758 ** These methods do not return a result code. ^If an error occurs, that fact
8759 ** is recorded in the [sqlite3_str] object and can be recovered by a
8760 ** subsequent call to [sqlite3_str_errcode(X)].
8761 */
8762 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8763 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8764 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8765 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8766 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8767 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8768
8769 /*
8770 ** CAPI3REF: Status Of A Dynamic String
8771 ** METHOD: sqlite3_str
8772 **
8773 ** These interfaces return the current status of an [sqlite3_str] object.
8774 **
8775 ** ^If any prior errors have occurred while constructing the dynamic string
8776 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8777 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8778 ** [SQLITE_NOMEM] following any out-of-memory error, or
8779 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8780 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8781 **
8782 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8783 ** of the dynamic string under construction in [sqlite3_str] object X.
8784 ** ^The length returned by [sqlite3_str_length(X)] does not include the
8785 ** zero-termination byte.
8786 **
8787 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8788 ** content of the dynamic string under construction in X. The value
8789 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8790 ** and might be freed or altered by any subsequent method on the same
8791 ** [sqlite3_str] object. Applications must not use the pointer returned by
8792 ** [sqlite3_str_value(X)] after any subsequent method call on the same
8793 ** object. ^Applications may change the content of the string returned
8794 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8795 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8796 ** write any byte after any subsequent sqlite3_str method call.
8797 */
8798 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8799 SQLITE_API int sqlite3_str_length(sqlite3_str*);
8800 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8801
8802 /*
8803 ** CAPI3REF: SQLite Runtime Status
8804 **
8805 ** ^These interfaces are used to retrieve runtime status information
8806 ** about the performance of SQLite, and optionally to reset various
8807 ** highwater marks. ^The first argument is an integer code for
8808 ** the specific parameter to measure. ^(Recognized integer codes
8809 ** are of the form [status parameters | SQLITE_STATUS_...].)^
8810 ** ^The current value of the parameter is returned into *pCurrent.
8811 ** ^The highest recorded value is returned in *pHighwater. ^If the
8812 ** resetFlag is true, then the highest record value is reset after
8813 ** *pHighwater is written. ^(Some parameters do not record the highest
8814 ** value. For those parameters
8815 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8816 ** ^(Other parameters record only the highwater mark and not the current
8817 ** value. For these latter parameters nothing is written into *pCurrent.)^
8818 **
8819 ** ^The sqlite3_status() and sqlite3_status64() routines return
8820 ** SQLITE_OK on success and a non-zero [error code] on failure.
8821 **
8822 ** If either the current value or the highwater mark is too large to
8823 ** be represented by a 32-bit integer, then the values returned by
8824 ** sqlite3_status() are undefined.
8825 **
8826 ** See also: [sqlite3_db_status()]
8827 */
8828 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8829 SQLITE_API int sqlite3_status64(
8830 int op,
8831 sqlite3_int64 *pCurrent,
8832 sqlite3_int64 *pHighwater,
8833 int resetFlag
8834 );
8835
8836
8837 /*
8838 ** CAPI3REF: Status Parameters
8839 ** KEYWORDS: {status parameters}
8840 **
8841 ** These integer constants designate various run-time status parameters
8842 ** that can be returned by [sqlite3_status()].
8843 **
8844 ** <dl>
8845 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8846 ** <dd>This parameter is the current amount of memory checked out
8847 ** using [sqlite3_malloc()], either directly or indirectly. The
8848 ** figure includes calls made to [sqlite3_malloc()] by the application
8849 ** and internal memory usage by the SQLite library. Auxiliary page-cache
8850 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8851 ** this parameter. The amount returned is the sum of the allocation
8852 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8853 **
8854 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8855 ** <dd>This parameter records the largest memory allocation request
8856 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8857 ** internal equivalents). Only the value returned in the
8858 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8859 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8860 **
8861 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8862 ** <dd>This parameter records the number of separate memory allocations
8863 ** currently checked out.</dd>)^
8864 **
8865 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8866 ** <dd>This parameter returns the number of pages used out of the
8867 ** [pagecache memory allocator] that was configured using
8868 ** [SQLITE_CONFIG_PAGECACHE]. The
8869 ** value returned is in pages, not in bytes.</dd>)^
8870 **
8871 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8872 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8873 ** <dd>This parameter returns the number of bytes of page cache
8874 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8875 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8876 ** returned value includes allocations that overflowed because they
8877 ** were too large (they were larger than the "sz" parameter to
8878 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8879 ** no space was left in the page cache.</dd>)^
8880 **
8881 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8882 ** <dd>This parameter records the largest memory allocation request
8883 ** handed to the [pagecache memory allocator]. Only the value returned in the
8884 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8885 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8886 **
8887 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8888 ** <dd>No longer used.</dd>
8889 **
8890 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8891 ** <dd>No longer used.</dd>
8892 **
8893 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8894 ** <dd>No longer used.</dd>
8895 **
8896 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8897 ** <dd>The *pHighwater parameter records the deepest parser stack.
8898 ** The *pCurrent value is undefined. The *pHighwater value is only
8899 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8900 ** </dl>
8901 **
8902 ** New status parameters may be added from time to time.
8903 */
8904 #define SQLITE_STATUS_MEMORY_USED 0
8905 #define SQLITE_STATUS_PAGECACHE_USED 1
8906 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8907 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8908 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8909 #define SQLITE_STATUS_MALLOC_SIZE 5
8910 #define SQLITE_STATUS_PARSER_STACK 6
8911 #define SQLITE_STATUS_PAGECACHE_SIZE 7
8912 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8913 #define SQLITE_STATUS_MALLOC_COUNT 9
8914
8915 /*
8916 ** CAPI3REF: Database Connection Status
8917 ** METHOD: sqlite3
8918 **
8919 ** ^This interface is used to retrieve runtime status information
8920 ** about a single [database connection]. ^The first argument is the
8921 ** database connection object to be interrogated. ^The second argument
8922 ** is an integer constant, taken from the set of
8923 ** [SQLITE_DBSTATUS options], that
8924 ** determines the parameter to interrogate. The set of
8925 ** [SQLITE_DBSTATUS options] is likely
8926 ** to grow in future releases of SQLite.
8927 **
8928 ** ^The current value of the requested parameter is written into *pCur
8929 ** and the highest instantaneous value is written into *pHiwtr. ^If
8930 ** the resetFlg is true, then the highest instantaneous value is
8931 ** reset back down to the current value.
8932 **
8933 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8934 ** non-zero [error code] on failure.
8935 **
8936 ** ^The sqlite3_db_status64(D,O,C,H,R) routine works exactly the same
8937 ** way as sqlite3_db_status(D,O,C,H,R) routine except that the C and H
8938 ** parameters are pointer to 64-bit integers (type: sqlite3_int64) instead
8939 ** of pointers to 32-bit integers, which allows larger status values
8940 ** to be returned. If a status value exceeds 2,147,483,647 then
8941 ** sqlite3_db_status() will truncate the value whereas sqlite3_db_status64()
8942 ** will return the full value.
8943 **
8944 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8945 */
8946 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8947 SQLITE_API int sqlite3_db_status64(sqlite3*,int,sqlite3_int64*,sqlite3_int64*,int);
8948
8949 /*
8950 ** CAPI3REF: Status Parameters for database connections
8951 ** KEYWORDS: {SQLITE_DBSTATUS options}
8952 **
8953 ** These constants are the available integer "verbs" that can be passed as
8954 ** the second argument to the [sqlite3_db_status()] interface.
8955 **
8956 ** New verbs may be added in future releases of SQLite. Existing verbs
8957 ** might be discontinued. Applications should check the return code from
8958 ** [sqlite3_db_status()] to make sure that the call worked.
8959 ** The [sqlite3_db_status()] interface will return a non-zero error code
8960 ** if a discontinued or unsupported verb is invoked.
8961 **
8962 ** <dl>
8963 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8964 ** <dd>This parameter returns the number of lookaside memory slots currently
8965 ** checked out.</dd>)^
8966 **
8967 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8968 ** <dd>This parameter returns the number of malloc attempts that were
8969 ** satisfied using lookaside memory. Only the high-water value is meaningful;
8970 ** the current value is always zero.</dd>)^
8971 **
8972 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8973 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8974 ** <dd>This parameter returns the number of malloc attempts that might have
8975 ** been satisfied using lookaside memory but failed due to the amount of
8976 ** memory requested being larger than the lookaside slot size.
8977 ** Only the high-water value is meaningful;
8978 ** the current value is always zero.</dd>)^
8979 **
8980 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8981 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8982 ** <dd>This parameter returns the number of malloc attempts that might have
8983 ** been satisfied using lookaside memory but failed due to all lookaside
8984 ** memory already being in use.
8985 ** Only the high-water value is meaningful;
8986 ** the current value is always zero.</dd>)^
8987 **
8988 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8989 ** <dd>This parameter returns the approximate number of bytes of heap
8990 ** memory used by all pager caches associated with the database connection.)^
8991 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8992 ** </dd>
8993 **
8994 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8995 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8996 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8997 ** pager cache is shared between two or more connections the bytes of heap
8998 ** memory used by that pager cache is divided evenly between the attached
8999 ** connections.)^ In other words, if none of the pager caches associated
9000 ** with the database connection are shared, this request returns the same
9001 ** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
9002 ** shared, the value returned by this call will be smaller than that returned
9003 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
9004 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
9005 **
9006 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
9007 ** <dd>This parameter returns the approximate number of bytes of heap
9008 ** memory used to store the schema for all databases associated
9009 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
9010 ** ^The full amount of memory used by the schemas is reported, even if the
9011 ** schema memory is shared with other database connections due to
9012 ** [shared cache mode] being enabled.
9013 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
9014 ** </dd>
9015 **
9016 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
9017 ** <dd>This parameter returns the approximate number of bytes of heap
9018 ** and lookaside memory used by all prepared statements associated with
9019 ** the database connection.)^
9020 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
9021 ** </dd>
9022 **
9023 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
9024 ** <dd>This parameter returns the number of pager cache hits that have
9025 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
9026 ** is always 0.
9027 ** </dd>
9028 **
9029 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
9030 ** <dd>This parameter returns the number of pager cache misses that have
9031 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
9032 ** is always 0.
9033 ** </dd>
9034 **
9035 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
9036 ** <dd>This parameter returns the number of dirty cache entries that have
9037 ** been written to disk. Specifically, the number of pages written to the
9038 ** wal file in wal mode databases, or the number of pages written to the
9039 ** database file in rollback mode databases. Any pages written as part of
9040 ** transaction rollback or database recovery operations are not included.
9041 ** If an IO or other error occurs while writing a page to disk, the effect
9042 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
9043 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
9044 ** <p>
9045 ** ^(There is overlap between the quantities measured by this parameter
9046 ** (SQLITE_DBSTATUS_CACHE_WRITE) and SQLITE_DBSTATUS_TEMPBUF_SPILL.
9047 ** Resetting one will reduce the other.)^
9048 ** </dd>
9049 **
9050 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
9051 ** <dd>This parameter returns the number of dirty cache entries that have
9052 ** been written to disk in the middle of a transaction due to the page
9053 ** cache overflowing. Transactions are more efficient if they are written
9054 ** to disk all at once. When pages spill mid-transaction, that introduces
9055 ** additional overhead. This parameter can be used to help identify
9056 ** inefficiencies that can be resolved by increasing the cache size.
9057 ** </dd>
9058 **
9059 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
9060 ** <dd>This parameter returns zero for the current value if and only if
9061 ** all foreign key constraints (deferred or immediate) have been
9062 ** resolved.)^ ^The highwater mark is always 0.
9063 **
9064 ** [[SQLITE_DBSTATUS_TEMPBUF_SPILL] ^(<dt>SQLITE_DBSTATUS_TEMPBUF_SPILL</dt>
9065 ** <dd>^(This parameter returns the number of bytes written to temporary
9066 ** files on disk that could have been kept in memory had sufficient memory
9067 ** been available. This value includes writes to intermediate tables that
9068 ** are part of complex queries, external sorts that spill to disk, and
9069 ** writes to TEMP tables.)^
9070 ** ^The highwater mark is always 0.
9071 ** <p>
9072 ** ^(There is overlap between the quantities measured by this parameter
9073 ** (SQLITE_DBSTATUS_TEMPBUF_SPILL) and SQLITE_DBSTATUS_CACHE_WRITE.
9074 ** Resetting one will reduce the other.)^
9075 ** </dd>
9076 ** </dl>
9077 */
9078 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9079 #define SQLITE_DBSTATUS_CACHE_USED 1
9080 #define SQLITE_DBSTATUS_SCHEMA_USED 2
9081 #define SQLITE_DBSTATUS_STMT_USED 3
9082 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9083 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9084 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9085 #define SQLITE_DBSTATUS_CACHE_HIT 7
9086 #define SQLITE_DBSTATUS_CACHE_MISS 8
9087 #define SQLITE_DBSTATUS_CACHE_WRITE 9
9088 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
9089 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9090 #define SQLITE_DBSTATUS_CACHE_SPILL 12
9091 #define SQLITE_DBSTATUS_TEMPBUF_SPILL 13
9092 #define SQLITE_DBSTATUS_MAX 13 /* Largest defined DBSTATUS */
9093
9094
9095 /*
9096 ** CAPI3REF: Prepared Statement Status
9097 ** METHOD: sqlite3_stmt
9098 **
9099 ** ^(Each prepared statement maintains various
9100 ** [SQLITE_STMTSTATUS counters] that measure the number
9101 ** of times it has performed specific operations.)^ These counters can
9102 ** be used to monitor the performance characteristics of the prepared
9103 ** statements. For example, if the number of table steps greatly exceeds
9104 ** the number of table searches or result rows, that would tend to indicate
9105 ** that the prepared statement is using a full table scan rather than
9106 ** an index.
9107 **
9108 ** ^(This interface is used to retrieve and reset counter values from
9109 ** a [prepared statement]. The first argument is the prepared statement
9110 ** object to be interrogated. The second argument
9111 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9112 ** to be interrogated.)^
9113 ** ^The current value of the requested counter is returned.
9114 ** ^If the resetFlg is true, then the counter is reset to zero after this
9115 ** interface call returns.
9116 **
9117 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
9118 */
9119 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9120
9121 /*
9122 ** CAPI3REF: Status Parameters for prepared statements
9123 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9124 **
9125 ** These preprocessor macros define integer codes that name counter
9126 ** values associated with the [sqlite3_stmt_status()] interface.
9127 ** The meanings of the various counters are as follows:
9128 **
9129 ** <dl>
9130 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9131 ** <dd>^This is the number of times that SQLite has stepped forward in
9132 ** a table as part of a full table scan. Large numbers for this counter
9133 ** may indicate opportunities for performance improvement through
9134 ** careful use of indices.</dd>
9135 **
9136 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9137 ** <dd>^This is the number of sort operations that have occurred.
9138 ** A non-zero value in this counter may indicate an opportunity to
9139 ** improve performance through careful use of indices.</dd>
9140 **
9141 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9142 ** <dd>^This is the number of rows inserted into transient indices that
9143 ** were created automatically in order to help joins run faster.
9144 ** A non-zero value in this counter may indicate an opportunity to
9145 ** improve performance by adding permanent indices that do not
9146 ** need to be reinitialized each time the statement is run.</dd>
9147 **
9148 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9149 ** <dd>^This is the number of virtual machine operations executed
9150 ** by the prepared statement if that number is less than or equal
9151 ** to 2147483647. The number of virtual machine operations can be
9152 ** used as a proxy for the total work done by the prepared statement.
9153 ** If the number of virtual machine operations exceeds 2147483647
9154 ** then the value returned by this statement status code is undefined.</dd>
9155 **
9156 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9157 ** <dd>^This is the number of times that the prepare statement has been
9158 ** automatically regenerated due to schema changes or changes to
9159 ** [bound parameters] that might affect the query plan.</dd>
9160 **
9161 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9162 ** <dd>^This is the number of times that the prepared statement has
9163 ** been run. A single "run" for the purposes of this counter is one
9164 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9165 ** The counter is incremented on the first [sqlite3_step()] call of each
9166 ** cycle.</dd>
9167 **
9168 ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9169 ** [[SQLITE_STMTSTATUS_FILTER HIT]]
9170 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9171 ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9172 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9173 ** step was bypassed because a Bloom filter returned not-found. The
9174 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9175 ** times that the Bloom filter returned a find, and thus the join step
9176 ** had to be processed as normal.</dd>
9177 **
9178 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9179 ** <dd>^This is the approximate number of bytes of heap memory
9180 ** used to store the prepared statement. ^This value is not actually
9181 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9182 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9183 ** </dd>
9184 ** </dl>
9185 */
9186 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9187 #define SQLITE_STMTSTATUS_SORT 2
9188 #define SQLITE_STMTSTATUS_AUTOINDEX 3
9189 #define SQLITE_STMTSTATUS_VM_STEP 4
9190 #define SQLITE_STMTSTATUS_REPREPARE 5
9191 #define SQLITE_STMTSTATUS_RUN 6
9192 #define SQLITE_STMTSTATUS_FILTER_MISS 7
9193 #define SQLITE_STMTSTATUS_FILTER_HIT 8
9194 #define SQLITE_STMTSTATUS_MEMUSED 99
9195
9196 /*
9197 ** CAPI3REF: Custom Page Cache Object
9198 **
9199 ** The sqlite3_pcache type is opaque. It is implemented by
9200 ** the pluggable module. The SQLite core has no knowledge of
9201 ** its size or internal structure and never deals with the
9202 ** sqlite3_pcache object except by holding and passing pointers
9203 ** to the object.
9204 **
9205 ** See [sqlite3_pcache_methods2] for additional information.
9206 */
9207 typedef struct sqlite3_pcache sqlite3_pcache;
9208
9209 /*
9210 ** CAPI3REF: Custom Page Cache Object
9211 **
9212 ** The sqlite3_pcache_page object represents a single page in the
9213 ** page cache. The page cache will allocate instances of this
9214 ** object. Various methods of the page cache use pointers to instances
9215 ** of this object as parameters or as their return value.
9216 **
9217 ** See [sqlite3_pcache_methods2] for additional information.
9218 */
9219 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9220 struct sqlite3_pcache_page {
9221 void *pBuf; /* The content of the page */
9222 void *pExtra; /* Extra information associated with the page */
9223 };
9224
9225 /*
9226 ** CAPI3REF: Application Defined Page Cache.
9227 ** KEYWORDS: {page cache}
9228 **
9229 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9230 ** register an alternative page cache implementation by passing in an
9231 ** instance of the sqlite3_pcache_methods2 structure.)^
9232 ** In many applications, most of the heap memory allocated by
9233 ** SQLite is used for the page cache.
9234 ** By implementing a
9235 ** custom page cache using this API, an application can better control
9236 ** the amount of memory consumed by SQLite, the way in which
9237 ** that memory is allocated and released, and the policies used to
9238 ** determine exactly which parts of a database file are cached and for
9239 ** how long.
9240 **
9241 ** The alternative page cache mechanism is an
9242 ** extreme measure that is only needed by the most demanding applications.
9243 ** The built-in page cache is recommended for most uses.
9244 **
9245 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9246 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9247 ** the application may discard the parameter after the call to
9248 ** [sqlite3_config()] returns.)^
9249 **
9250 ** [[the xInit() page cache method]]
9251 ** ^(The xInit() method is called once for each effective
9252 ** call to [sqlite3_initialize()])^
9253 ** (usually only once during the lifetime of the process). ^(The xInit()
9254 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9255 ** The intent of the xInit() method is to set up global data structures
9256 ** required by the custom page cache implementation.
9257 ** ^(If the xInit() method is NULL, then the
9258 ** built-in default page cache is used instead of the application defined
9259 ** page cache.)^
9260 **
9261 ** [[the xShutdown() page cache method]]
9262 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
9263 ** It can be used to clean up
9264 ** any outstanding resources before process shutdown, if required.
9265 ** ^The xShutdown() method may be NULL.
9266 **
9267 ** ^SQLite automatically serializes calls to the xInit method,
9268 ** so the xInit method need not be threadsafe. ^The
9269 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
9270 ** not need to be threadsafe either. All other methods must be threadsafe
9271 ** in multithreaded applications.
9272 **
9273 ** ^SQLite will never invoke xInit() more than once without an intervening
9274 ** call to xShutdown().
9275 **
9276 ** [[the xCreate() page cache methods]]
9277 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
9278 ** SQLite will typically create one cache instance for each open database file,
9279 ** though this is not guaranteed. ^The
9280 ** first parameter, szPage, is the size in bytes of the pages that must
9281 ** be allocated by the cache. ^szPage will always be a power of two. ^The
9282 ** second parameter szExtra is a number of bytes of extra storage
9283 ** associated with each page cache entry. ^The szExtra parameter will be
9284 ** a number less than 250. SQLite will use the
9285 ** extra szExtra bytes on each page to store metadata about the underlying
9286 ** database page on disk. The value passed into szExtra depends
9287 ** on the SQLite version, the target platform, and how SQLite was compiled.
9288 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9289 ** created will be used to cache database pages of a file stored on disk, or
9290 ** false if it is used for an in-memory database. The cache implementation
9291 ** does not have to do anything special based upon the value of bPurgeable;
9292 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9293 ** never invoke xUnpin() except to deliberately delete a page.
9294 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9295 ** false will always have the "discard" flag set to true.
9296 ** ^Hence, a cache created with bPurgeable set to false will
9297 ** never contain any unpinned pages.
9298 **
9299 ** [[the xCachesize() page cache method]]
9300 ** ^(The xCachesize() method may be called at any time by SQLite to set the
9301 ** suggested maximum cache-size (number of pages stored) for the cache
9302 ** instance passed as the first argument. This is the value configured using
9303 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9304 ** parameter, the implementation is not required to do anything with this
9305 ** value; it is advisory only.
9306 **
9307 ** [[the xPagecount() page cache methods]]
9308 ** The xPagecount() method must return the number of pages currently
9309 ** stored in the cache, both pinned and unpinned.
9310 **
9311 ** [[the xFetch() page cache methods]]
9312 ** The xFetch() method locates a page in the cache and returns a pointer to
9313 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9314 ** The pBuf element of the returned sqlite3_pcache_page object will be a
9315 ** pointer to a buffer of szPage bytes used to store the content of a
9316 ** single database page. The pExtra element of sqlite3_pcache_page will be
9317 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
9318 ** for each entry in the page cache.
9319 **
9320 ** The page to be fetched is determined by the key. ^The minimum key value
9321 ** is 1. After it has been retrieved using xFetch, the page is considered
9322 ** to be "pinned".
9323 **
9324 ** If the requested page is already in the page cache, then the page cache
9325 ** implementation must return a pointer to the page buffer with its content
9326 ** intact. If the requested page is not already in the cache, then the
9327 ** cache implementation should use the value of the createFlag
9328 ** parameter to help it determine what action to take:
9329 **
9330 ** <table border=1 width=85% align=center>
9331 ** <tr><th> createFlag <th> Behavior when page is not already in cache
9332 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9333 ** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9334 ** Otherwise return NULL.
9335 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9336 ** NULL if allocating a new page is effectively impossible.
9337 ** </table>
9338 **
9339 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9340 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
9341 ** failed.)^ In between the xFetch() calls, SQLite may
9342 ** attempt to unpin one or more cache pages by spilling the content of
9343 ** pinned pages to disk and synching the operating system disk cache.
9344 **
9345 ** [[the xUnpin() page cache method]]
9346 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9347 ** as its second argument. If the third parameter, discard, is non-zero,
9348 ** then the page must be evicted from the cache.
9349 ** ^If the discard parameter is
9350 ** zero, then the page may be discarded or retained at the discretion of the
9351 ** page cache implementation. ^The page cache implementation
9352 ** may choose to evict unpinned pages at any time.
9353 **
9354 ** The cache must not perform any reference counting. A single
9355 ** call to xUnpin() unpins the page regardless of the number of prior calls
9356 ** to xFetch().
9357 **
9358 ** [[the xRekey() page cache methods]]
9359 ** The xRekey() method is used to change the key value associated with the
9360 ** page passed as the second argument. If the cache
9361 ** previously contains an entry associated with newKey, it must be
9362 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9363 ** to be pinned.
9364 **
9365 ** When SQLite calls the xTruncate() method, the cache must discard all
9366 ** existing cache entries with page numbers (keys) greater than or equal
9367 ** to the value of the iLimit parameter passed to xTruncate(). If any
9368 ** of these pages are pinned, they become implicitly unpinned, meaning that
9369 ** they can be safely discarded.
9370 **
9371 ** [[the xDestroy() page cache method]]
9372 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9373 ** All resources associated with the specified cache should be freed. ^After
9374 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9375 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9376 ** functions.
9377 **
9378 ** [[the xShrink() page cache method]]
9379 ** ^SQLite invokes the xShrink() method when it wants the page cache to
9380 ** free up as much of heap memory as possible. The page cache implementation
9381 ** is not obligated to free any memory, but well-behaved implementations should
9382 ** do their best.
9383 */
9384 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9385 struct sqlite3_pcache_methods2 {
9386 int iVersion;
9387 void *pArg;
9388 int (*xInit)(void*);
9389 void (*xShutdown)(void*);
9390 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9391 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9392 int (*xPagecount)(sqlite3_pcache*);
9393 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9394 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9395 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9396 unsigned oldKey, unsigned newKey);
9397 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9398 void (*xDestroy)(sqlite3_pcache*);
9399 void (*xShrink)(sqlite3_pcache*);
9400 };
9401
9402 /*
9403 ** This is the obsolete pcache_methods object that has now been replaced
9404 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9405 ** retained in the header file for backwards compatibility only.
9406 */
9407 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9408 struct sqlite3_pcache_methods {
9409 void *pArg;
9410 int (*xInit)(void*);
9411 void (*xShutdown)(void*);
9412 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9413 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9414 int (*xPagecount)(sqlite3_pcache*);
9415 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9416 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9417 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9418 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9419 void (*xDestroy)(sqlite3_pcache*);
9420 };
9421
9422
9423 /*
9424 ** CAPI3REF: Online Backup Object
9425 **
9426 ** The sqlite3_backup object records state information about an ongoing
9427 ** online backup operation. ^The sqlite3_backup object is created by
9428 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
9429 ** [sqlite3_backup_finish()].
9430 **
9431 ** See Also: [Using the SQLite Online Backup API]
9432 */
9433 typedef struct sqlite3_backup sqlite3_backup;
9434
9435 /*
9436 ** CAPI3REF: Online Backup API.
9437 **
9438 ** The backup API copies the content of one database into another.
9439 ** It is useful either for creating backups of databases or
9440 ** for copying in-memory databases to or from persistent files.
9441 **
9442 ** See Also: [Using the SQLite Online Backup API]
9443 **
9444 ** ^SQLite holds a write transaction open on the destination database file
9445 ** for the duration of the backup operation.
9446 ** ^The source database is read-locked only while it is being read;
9447 ** it is not locked continuously for the entire backup operation.
9448 ** ^Thus, the backup may be performed on a live source database without
9449 ** preventing other database connections from
9450 ** reading or writing to the source database while the backup is underway.
9451 **
9452 ** ^(To perform a backup operation:
9453 ** <ol>
9454 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9455 ** backup,
9456 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9457 ** the data between the two databases, and finally
9458 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9459 ** associated with the backup operation.
9460 ** </ol>)^
9461 ** There should be exactly one call to sqlite3_backup_finish() for each
9462 ** successful call to sqlite3_backup_init().
9463 **
9464 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9465 **
9466 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9467 ** [database connection] associated with the destination database
9468 ** and the database name, respectively.
9469 ** ^The database name is "main" for the main database, "temp" for the
9470 ** temporary database, or the name specified after the AS keyword in
9471 ** an [ATTACH] statement for an attached database.
9472 ** ^The S and M arguments passed to
9473 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9474 ** and database name of the source database, respectively.
9475 ** ^The source and destination [database connections] (parameters S and D)
9476 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9477 ** an error.
9478 **
9479 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9480 ** there is already a read or read-write transaction open on the
9481 ** destination database.
9482 **
9483 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9484 ** returned and an error code and error message are stored in the
9485 ** destination [database connection] D.
9486 ** ^The error code and message for the failed call to sqlite3_backup_init()
9487 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9488 ** [sqlite3_errmsg16()] functions.
9489 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
9490 ** [sqlite3_backup] object.
9491 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9492 ** sqlite3_backup_finish() functions to perform the specified backup
9493 ** operation.
9494 **
9495 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9496 **
9497 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9498 ** the source and destination databases specified by [sqlite3_backup] object B.
9499 ** ^If N is negative, all remaining source pages are copied.
9500 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9501 ** are still more pages to be copied, then the function returns [SQLITE_OK].
9502 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9503 ** from source to destination, then it returns [SQLITE_DONE].
9504 ** ^If an error occurs while running sqlite3_backup_step(B,N),
9505 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
9506 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9507 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9508 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9509 **
9510 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9511 ** <ol>
9512 ** <li> the destination database was opened read-only, or
9513 ** <li> the destination database is using write-ahead-log journaling
9514 ** and the destination and source page sizes differ, or
9515 ** <li> the destination database is an in-memory database and the
9516 ** destination and source page sizes differ.
9517 ** </ol>)^
9518 **
9519 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9520 ** the [sqlite3_busy_handler | busy-handler function]
9521 ** is invoked (if one is specified). ^If the
9522 ** busy-handler returns non-zero before the lock is available, then
9523 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9524 ** sqlite3_backup_step() can be retried later. ^If the source
9525 ** [database connection]
9526 ** is being used to write to the source database when sqlite3_backup_step()
9527 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9528 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
9529 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9530 ** [SQLITE_READONLY] is returned, then
9531 ** there is no point in retrying the call to sqlite3_backup_step(). These
9532 ** errors are considered fatal.)^ The application must accept
9533 ** that the backup operation has failed and pass the backup operation handle
9534 ** to the sqlite3_backup_finish() to release associated resources.
9535 **
9536 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9537 ** on the destination file. ^The exclusive lock is not released until either
9538 ** sqlite3_backup_finish() is called or the backup operation is complete
9539 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9540 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
9541 ** lasts for the duration of the sqlite3_backup_step() call.
9542 ** ^Because the source database is not locked between calls to
9543 ** sqlite3_backup_step(), the source database may be modified mid-way
9544 ** through the backup process. ^If the source database is modified by an
9545 ** external process or via a database connection other than the one being
9546 ** used by the backup operation, then the backup will be automatically
9547 ** restarted by the next call to sqlite3_backup_step(). ^If the source
9548 ** database is modified by using the same database connection as is used
9549 ** by the backup operation, then the backup database is automatically
9550 ** updated at the same time.
9551 **
9552 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9553 **
9554 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9555 ** application wishes to abandon the backup operation, the application
9556 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9557 ** ^The sqlite3_backup_finish() interfaces releases all
9558 ** resources associated with the [sqlite3_backup] object.
9559 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9560 ** active write-transaction on the destination database is rolled back.
9561 ** The [sqlite3_backup] object is invalid
9562 ** and may not be used following a call to sqlite3_backup_finish().
9563 **
9564 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9565 ** sqlite3_backup_step() errors occurred, regardless of whether or not
9566 ** sqlite3_backup_step() completed.
9567 ** ^If an out-of-memory condition or IO error occurred during any prior
9568 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9569 ** sqlite3_backup_finish() returns the corresponding [error code].
9570 **
9571 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9572 ** is not a permanent error and does not affect the return value of
9573 ** sqlite3_backup_finish().
9574 **
9575 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9576 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9577 **
9578 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
9579 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9580 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9581 ** in the source database at the conclusion of the most recent
9582 ** sqlite3_backup_step().
9583 ** ^(The values returned by these functions are only updated by
9584 ** sqlite3_backup_step(). If the source database is modified in a way that
9585 ** changes the size of the source database or the number of pages remaining,
9586 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
9587 ** and sqlite3_backup_remaining() until after the next
9588 ** sqlite3_backup_step().)^
9589 **
9590 ** <b>Concurrent Usage of Database Handles</b>
9591 **
9592 ** ^The source [database connection] may be used by the application for other
9593 ** purposes while a backup operation is underway or being initialized.
9594 ** ^If SQLite is compiled and configured to support threadsafe database
9595 ** connections, then the source database connection may be used concurrently
9596 ** from within other threads.
9597 **
9598 ** However, the application must guarantee that the destination
9599 ** [database connection] is not passed to any other API (by any thread) after
9600 ** sqlite3_backup_init() is called and before the corresponding call to
9601 ** sqlite3_backup_finish(). SQLite does not currently check to see
9602 ** if the application incorrectly accesses the destination [database connection]
9603 ** and so no error code is reported, but the operations may malfunction
9604 ** nevertheless. Use of the destination database connection while a
9605 ** backup is in progress might also cause a mutex deadlock.
9606 **
9607 ** If running in [shared cache mode], the application must
9608 ** guarantee that the shared cache used by the destination database
9609 ** is not accessed while the backup is running. In practice this means
9610 ** that the application must guarantee that the disk file being
9611 ** backed up to is not accessed by any connection within the process,
9612 ** not just the specific connection that was passed to sqlite3_backup_init().
9613 **
9614 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9615 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9616 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9617 ** APIs are not strictly speaking threadsafe. If they are invoked at the
9618 ** same time as another thread is invoking sqlite3_backup_step() it is
9619 ** possible that they return invalid values.
9620 **
9621 ** <b>Alternatives To Using The Backup API</b>
9622 **
9623 ** Other techniques for safely creating a consistent backup of an SQLite
9624 ** database include:
9625 **
9626 ** <ul>
9627 ** <li> The [VACUUM INTO] command.
9628 ** <li> The [sqlite3_rsync] utility program.
9629 ** </ul>
9630 */
9631 SQLITE_API sqlite3_backup *sqlite3_backup_init(
9632 sqlite3 *pDest, /* Destination database handle */
9633 const char *zDestName, /* Destination database name */
9634 sqlite3 *pSource, /* Source database handle */
9635 const char *zSourceName /* Source database name */
9636 );
9637 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9638 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9639 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9640 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9641
9642 /*
9643 ** CAPI3REF: Unlock Notification
9644 ** METHOD: sqlite3
9645 **
9646 ** ^When running in shared-cache mode, a database operation may fail with
9647 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9648 ** individual tables within the shared-cache cannot be obtained. See
9649 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9650 ** ^This API may be used to register a callback that SQLite will invoke
9651 ** when the connection currently holding the required lock relinquishes it.
9652 ** ^This API is only available if the library was compiled with the
9653 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9654 **
9655 ** See Also: [Using the SQLite Unlock Notification Feature].
9656 **
9657 ** ^Shared-cache locks are released when a database connection concludes
9658 ** its current transaction, either by committing it or rolling it back.
9659 **
9660 ** ^When a connection (known as the blocked connection) fails to obtain a
9661 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9662 ** identity of the database connection (the blocking connection) that
9663 ** has locked the required resource is stored internally. ^After an
9664 ** application receives an SQLITE_LOCKED error, it may call the
9665 ** sqlite3_unlock_notify() method with the blocked connection handle as
9666 ** the first argument to register for a callback that will be invoked
9667 ** when the blocking connection's current transaction is concluded. ^The
9668 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9669 ** call that concludes the blocking connection's transaction.
9670 **
9671 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9672 ** there is a chance that the blocking connection will have already
9673 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9674 ** If this happens, then the specified callback is invoked immediately,
9675 ** from within the call to sqlite3_unlock_notify().)^
9676 **
9677 ** ^If the blocked connection is attempting to obtain a write-lock on a
9678 ** shared-cache table, and more than one other connection currently holds
9679 ** a read-lock on the same table, then SQLite arbitrarily selects one of
9680 ** the other connections to use as the blocking connection.
9681 **
9682 ** ^(There may be at most one unlock-notify callback registered by a
9683 ** blocked connection. If sqlite3_unlock_notify() is called when the
9684 ** blocked connection already has a registered unlock-notify callback,
9685 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9686 ** called with a NULL pointer as its second argument, then any existing
9687 ** unlock-notify callback is canceled. ^The blocked connection's
9688 ** unlock-notify callback may also be canceled by closing the blocked
9689 ** connection using [sqlite3_close()].
9690 **
9691 ** The unlock-notify callback is not reentrant. If an application invokes
9692 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
9693 ** crash or deadlock may be the result.
9694 **
9695 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9696 ** returns SQLITE_OK.
9697 **
9698 ** <b>Callback Invocation Details</b>
9699 **
9700 ** When an unlock-notify callback is registered, the application provides a
9701 ** single void* pointer that is passed to the callback when it is invoked.
9702 ** However, the signature of the callback function allows SQLite to pass
9703 ** it an array of void* context pointers. The first argument passed to
9704 ** an unlock-notify callback is a pointer to an array of void* pointers,
9705 ** and the second is the number of entries in the array.
9706 **
9707 ** When a blocking connection's transaction is concluded, there may be
9708 ** more than one blocked connection that has registered for an unlock-notify
9709 ** callback. ^If two or more such blocked connections have specified the
9710 ** same callback function, then instead of invoking the callback function
9711 ** multiple times, it is invoked once with the set of void* context pointers
9712 ** specified by the blocked connections bundled together into an array.
9713 ** This gives the application an opportunity to prioritize any actions
9714 ** related to the set of unblocked database connections.
9715 **
9716 ** <b>Deadlock Detection</b>
9717 **
9718 ** Assuming that after registering for an unlock-notify callback a
9719 ** database waits for the callback to be issued before taking any further
9720 ** action (a reasonable assumption), then using this API may cause the
9721 ** application to deadlock. For example, if connection X is waiting for
9722 ** connection Y's transaction to be concluded, and similarly connection
9723 ** Y is waiting on connection X's transaction, then neither connection
9724 ** will proceed and the system may remain deadlocked indefinitely.
9725 **
9726 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9727 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9728 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9729 ** unlock-notify callback is registered. The system is said to be in
9730 ** a deadlocked state if connection A has registered for an unlock-notify
9731 ** callback on the conclusion of connection B's transaction, and connection
9732 ** B has itself registered for an unlock-notify callback when connection
9733 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9734 ** the system is also considered to be deadlocked if connection B has
9735 ** registered for an unlock-notify callback on the conclusion of connection
9736 ** C's transaction, where connection C is waiting on connection A. ^Any
9737 ** number of levels of indirection are allowed.
9738 **
9739 ** <b>The "DROP TABLE" Exception</b>
9740 **
9741 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9742 ** always appropriate to call sqlite3_unlock_notify(). There is however,
9743 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9744 ** SQLite checks if there are any currently executing SELECT statements
9745 ** that belong to the same connection. If there are, SQLITE_LOCKED is
9746 ** returned. In this case there is no "blocking connection", so invoking
9747 ** sqlite3_unlock_notify() results in the unlock-notify callback being
9748 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9749 ** or "DROP INDEX" query, an infinite loop might be the result.
9750 **
9751 ** One way around this problem is to check the extended error code returned
9752 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9753 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9754 ** the special "DROP TABLE/INDEX" case, the extended error code is just
9755 ** SQLITE_LOCKED.)^
9756 */
9757 SQLITE_API int sqlite3_unlock_notify(
9758 sqlite3 *pBlocked, /* Waiting connection */
9759 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9760 void *pNotifyArg /* Argument to pass to xNotify */
9761 );
9762
9763
9764 /*
9765 ** CAPI3REF: String Comparison
9766 **
9767 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9768 ** and extensions to compare the contents of two buffers containing UTF-8
9769 ** strings in a case-independent fashion, using the same definition of "case
9770 ** independence" that SQLite uses internally when comparing identifiers.
9771 */
9772 SQLITE_API int sqlite3_stricmp(const char *, const char *);
9773 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9774
9775 /*
9776 ** CAPI3REF: String Globbing
9777 *
9778 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9779 ** string X matches the [GLOB] pattern P.
9780 ** ^The definition of [GLOB] pattern matching used in
9781 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9782 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9783 ** is case sensitive.
9784 **
9785 ** Note that this routine returns zero on a match and non-zero if the strings
9786 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9787 **
9788 ** See also: [sqlite3_strlike()].
9789 */
9790 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9791
9792 /*
9793 ** CAPI3REF: String LIKE Matching
9794 *
9795 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9796 ** string X matches the [LIKE] pattern P with escape character E.
9797 ** ^The definition of [LIKE] pattern matching used in
9798 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9799 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9800 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9801 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9802 ** insensitive - equivalent upper and lower case ASCII characters match
9803 ** one another.
9804 **
9805 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9806 ** only ASCII characters are case folded.
9807 **
9808 ** Note that this routine returns zero on a match and non-zero if the strings
9809 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9810 **
9811 ** See also: [sqlite3_strglob()].
9812 */
9813 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9814
9815 /*
9816 ** CAPI3REF: Error Logging Interface
9817 **
9818 ** ^The [sqlite3_log()] interface writes a message into the [error log]
9819 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9820 ** ^If logging is enabled, the zFormat string and subsequent arguments are
9821 ** used with [sqlite3_snprintf()] to generate the final output string.
9822 **
9823 ** The sqlite3_log() interface is intended for use by extensions such as
9824 ** virtual tables, collating functions, and SQL functions. While there is
9825 ** nothing to prevent an application from calling sqlite3_log(), doing so
9826 ** is considered bad form.
9827 **
9828 ** The zFormat string must not be NULL.
9829 **
9830 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9831 ** will not use dynamically allocated memory. The log message is stored in
9832 ** a fixed-length buffer on the stack. If the log message is longer than
9833 ** a few hundred characters, it will be truncated to the length of the
9834 ** buffer.
9835 */
9836 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9837
9838 /*
9839 ** CAPI3REF: Write-Ahead Log Commit Hook
9840 ** METHOD: sqlite3
9841 **
9842 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9843 ** is invoked each time data is committed to a database in wal mode.
9844 **
9845 ** ^(The callback is invoked by SQLite after the commit has taken place and
9846 ** the associated write-lock on the database released)^, so the implementation
9847 ** may read, write or [checkpoint] the database as required.
9848 **
9849 ** ^The first parameter passed to the callback function when it is invoked
9850 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9851 ** registering the callback. ^The second is a copy of the database handle.
9852 ** ^The third parameter is the name of the database that was written to -
9853 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9854 ** is the number of pages currently in the write-ahead log file,
9855 ** including those that were just committed.
9856 **
9857 ** ^The callback function should normally return [SQLITE_OK]. ^If an error
9858 ** code is returned, that error will propagate back up through the
9859 ** SQLite code base to cause the statement that provoked the callback
9860 ** to report an error, though the commit will have still occurred. If the
9861 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9862 ** that does not correspond to any valid SQLite error code, the results
9863 ** are undefined.
9864 **
9865 ** ^A single database handle may have at most a single write-ahead log
9866 ** callback registered at one time. ^Calling [sqlite3_wal_hook()]
9867 ** replaces the default behavior or previously registered write-ahead
9868 ** log callback.
9869 **
9870 ** ^The return value is a copy of the third parameter from the
9871 ** previous call, if any, or 0.
9872 **
9873 ** ^The [sqlite3_wal_autocheckpoint()] interface and the
9874 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and
9875 ** will overwrite any prior [sqlite3_wal_hook()] settings.
9876 **
9877 ** ^If a write-ahead log callback is set using this function then
9878 ** [sqlite3_wal_checkpoint_v2()] or [PRAGMA wal_checkpoint]
9879 ** should be invoked periodically to keep the write-ahead log file
9880 ** from growing without bound.
9881 **
9882 ** ^Passing a NULL pointer for the callback disables automatic
9883 ** checkpointing entirely. To re-enable the default behavior, call
9884 ** sqlite3_wal_autocheckpoint(db,1000) or use [PRAGMA wal_checkpoint].
9885 */
9886 SQLITE_API void *sqlite3_wal_hook(
9887 sqlite3*,
9888 int(*)(void *,sqlite3*,const char*,int),
9889 void*
9890 );
9891
9892 /*
9893 ** CAPI3REF: Configure an auto-checkpoint
9894 ** METHOD: sqlite3
9895 **
9896 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9897 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9898 ** to automatically [checkpoint]
9899 ** after committing a transaction if there are N or
9900 ** more frames in the [write-ahead log] file. ^Passing zero or
9901 ** a negative value as the N parameter disables automatic
9902 ** checkpoints entirely.
9903 **
9904 ** ^The callback registered by this function replaces any existing callback
9905 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9906 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9907 ** configured by this function.
9908 **
9909 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9910 ** from SQL.
9911 **
9912 ** ^Checkpoints initiated by this mechanism are
9913 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9914 **
9915 ** ^Every new [database connection] defaults to having the auto-checkpoint
9916 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9917 ** pages.
9918 **
9919 ** ^The use of this interface is only necessary if the default setting
9920 ** is found to be suboptimal for a particular application.
9921 */
9922 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9923
9924 /*
9925 ** CAPI3REF: Checkpoint a database
9926 ** METHOD: sqlite3
9927 **
9928 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9929 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9930 **
9931 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9932 ** [write-ahead log] for database X on [database connection] D to be
9933 ** transferred into the database file and for the write-ahead log to
9934 ** be reset. See the [checkpointing] documentation for addition
9935 ** information.
9936 **
9937 ** This interface used to be the only way to cause a checkpoint to
9938 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9939 ** interface was added. This interface is retained for backwards
9940 ** compatibility and as a convenience for applications that need to manually
9941 ** start a callback but which do not need the full power (and corresponding
9942 ** complication) of [sqlite3_wal_checkpoint_v2()].
9943 */
9944 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9945
9946 /*
9947 ** CAPI3REF: Checkpoint a database
9948 ** METHOD: sqlite3
9949 **
9950 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9951 ** operation on database X of [database connection] D in mode M. Status
9952 ** information is written back into integers pointed to by L and C.)^
9953 ** ^(The M parameter must be a valid [checkpoint mode]:)^
9954 **
9955 ** <dl>
9956 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9957 ** ^Checkpoint as many frames as possible without waiting for any database
9958 ** readers or writers to finish, then sync the database file if all frames
9959 ** in the log were checkpointed. ^The [busy-handler callback]
9960 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9961 ** ^On the other hand, passive mode might leave the checkpoint unfinished
9962 ** if there are concurrent readers or writers.
9963 **
9964 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9965 ** ^This mode blocks (it invokes the
9966 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9967 ** database writer and all readers are reading from the most recent database
9968 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9969 ** database file. ^This mode blocks new database writers while it is pending,
9970 ** but new database readers are allowed to continue unimpeded.
9971 **
9972 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9973 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9974 ** that after checkpointing the log file it blocks (calls the
9975 ** [busy-handler callback])
9976 ** until all readers are reading from the database file only. ^This ensures
9977 ** that the next writer will restart the log file from the beginning.
9978 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9979 ** database writer attempts while it is pending, but does not impede readers.
9980 **
9981 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9982 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9983 ** addition that it also truncates the log file to zero bytes just prior
9984 ** to a successful return.
9985 **
9986 ** <dt>SQLITE_CHECKPOINT_NOOP<dd>
9987 ** ^This mode always checkpoints zero frames. The only reason to invoke
9988 ** a NOOP checkpoint is to access the values returned by
9989 ** sqlite3_wal_checkpoint_v2() via output parameters *pnLog and *pnCkpt.
9990 ** </dl>
9991 **
9992 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9993 ** the log file or to -1 if the checkpoint could not run because
9994 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9995 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9996 ** log file (including any that were already checkpointed before the function
9997 ** was called) or to -1 if the checkpoint could not run due to an error or
9998 ** because the database is not in WAL mode. ^Note that upon successful
9999 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
10000 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
10001 **
10002 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
10003 ** any other process is running a checkpoint operation at the same time, the
10004 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
10005 ** busy-handler configured, it will not be invoked in this case.
10006 **
10007 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
10008 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
10009 ** obtained immediately, and a busy-handler is configured, it is invoked and
10010 ** the writer lock retried until either the busy-handler returns 0 or the lock
10011 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
10012 ** database readers as described above. ^If the busy-handler returns 0 before
10013 ** the writer lock is obtained or while waiting for database readers, the
10014 ** checkpoint operation proceeds from that point in the same way as
10015 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
10016 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
10017 **
10018 ** ^If parameter zDb is NULL or points to a zero length string, then the
10019 ** specified operation is attempted on all WAL databases [attached] to
10020 ** [database connection] db. In this case the
10021 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
10022 ** an SQLITE_BUSY error is encountered when processing one or more of the
10023 ** attached WAL databases, the operation is still attempted on any remaining
10024 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
10025 ** error occurs while processing an attached database, processing is abandoned
10026 ** and the error code is returned to the caller immediately. ^If no error
10027 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
10028 ** databases, SQLITE_OK is returned.
10029 **
10030 ** ^If database zDb is the name of an attached database that is not in WAL
10031 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
10032 ** zDb is not NULL (or a zero length string) and is not the name of any
10033 ** attached database, SQLITE_ERROR is returned to the caller.
10034 **
10035 ** ^Unless it returns SQLITE_MISUSE,
10036 ** the sqlite3_wal_checkpoint_v2() interface
10037 ** sets the error information that is queried by
10038 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
10039 **
10040 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
10041 ** from SQL.
10042 */
10043 SQLITE_API int sqlite3_wal_checkpoint_v2(
10044 sqlite3 *db, /* Database handle */
10045 const char *zDb, /* Name of attached database (or NULL) */
10046 int eMode, /* SQLITE_CHECKPOINT_* value */
10047 int *pnLog, /* OUT: Size of WAL log in frames */
10048 int *pnCkpt /* OUT: Total number of frames checkpointed */
10049 );
10050
10051 /*
10052 ** CAPI3REF: Checkpoint Mode Values
10053 ** KEYWORDS: {checkpoint mode}
10054 **
10055 ** These constants define all valid values for the "checkpoint mode" passed
10056 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
10057 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
10058 ** meaning of each of these checkpoint modes.
10059 */
10060 #define SQLITE_CHECKPOINT_NOOP -1 /* Do no work at all */
10061 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
10062 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
10063 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
10064 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
10065
10066 /*
10067 ** CAPI3REF: Virtual Table Interface Configuration
10068 **
10069 ** This function may be called by either the [xConnect] or [xCreate] method
10070 ** of a [virtual table] implementation to configure
10071 ** various facets of the virtual table interface.
10072 **
10073 ** If this interface is invoked outside the context of an xConnect or
10074 ** xCreate virtual table method then the behavior is undefined.
10075 **
10076 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
10077 ** [database connection] in which the virtual table is being created and
10078 ** which is passed in as the first argument to the [xConnect] or [xCreate]
10079 ** method that is invoking sqlite3_vtab_config(). The C parameter is one
10080 ** of the [virtual table configuration options]. The presence and meaning
10081 ** of parameters after C depend on which [virtual table configuration option]
10082 ** is used.
10083 */
10084 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
10085
10086 /*
10087 ** CAPI3REF: Virtual Table Configuration Options
10088 ** KEYWORDS: {virtual table configuration options}
10089 ** KEYWORDS: {virtual table configuration option}
10090 **
10091 ** These macros define the various options to the
10092 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
10093 ** can use to customize and optimize their behavior.
10094 **
10095 ** <dl>
10096 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10097 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10098 ** <dd>Calls of the form
10099 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10100 ** where X is an integer. If X is zero, then the [virtual table] whose
10101 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10102 ** support constraints. In this configuration (which is the default) if
10103 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10104 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10105 ** specified as part of the user's SQL statement, regardless of the actual
10106 ** ON CONFLICT mode specified.
10107 **
10108 ** If X is non-zero, then the virtual table implementation guarantees
10109 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10110 ** any modifications to internal or persistent data structures have been made.
10111 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10112 ** is able to roll back a statement or database transaction, and abandon
10113 ** or continue processing the current SQL statement as appropriate.
10114 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10115 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10116 ** had been ABORT.
10117 **
10118 ** Virtual table implementations that are required to handle OR REPLACE
10119 ** must do so within the [xUpdate] method. If a call to the
10120 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10121 ** CONFLICT policy is REPLACE, the virtual table implementation should
10122 ** silently replace the appropriate rows within the xUpdate callback and
10123 ** return SQLITE_OK. Or, if this is not possible, it may return
10124 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10125 ** constraint handling.
10126 ** </dd>
10127 **
10128 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10129 ** <dd>Calls of the form
10130 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10131 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10132 ** prohibits that virtual table from being used from within triggers and
10133 ** views.
10134 ** </dd>
10135 **
10136 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10137 ** <dd>Calls of the form
10138 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10139 ** [xConnect] or [xCreate] methods of a [virtual table] implementation
10140 ** identify that virtual table as being safe to use from within triggers
10141 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10142 ** virtual table can do no serious harm even if it is controlled by a
10143 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10144 ** flag unless absolutely necessary.
10145 ** </dd>
10146 **
10147 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10148 ** <dd>Calls of the form
10149 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10150 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10151 ** instruct the query planner to begin at least a read transaction on
10152 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10153 ** virtual table is used.
10154 ** </dd>
10155 ** </dl>
10156 */
10157 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10158 #define SQLITE_VTAB_INNOCUOUS 2
10159 #define SQLITE_VTAB_DIRECTONLY 3
10160 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10161
10162 /*
10163 ** CAPI3REF: Determine The Virtual Table Conflict Policy
10164 **
10165 ** This function may only be called from within a call to the [xUpdate] method
10166 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10167 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10168 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10169 ** of the SQL statement that triggered the call to the [xUpdate] method of the
10170 ** [virtual table].
10171 */
10172 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10173
10174 /*
10175 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10176 **
10177 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10178 ** method of a [virtual table], then it might return true if the
10179 ** column is being fetched as part of an UPDATE operation during which the
10180 ** column value will not change. The virtual table implementation can use
10181 ** this hint as permission to substitute a return value that is less
10182 ** expensive to compute and that the corresponding
10183 ** [xUpdate] method understands as a "no-change" value.
10184 **
10185 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10186 ** the column is not changed by the UPDATE statement, then the xColumn
10187 ** method can optionally return without setting a result, without calling
10188 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10189 ** In that case, [sqlite3_value_nochange(X)] will return true for the
10190 ** same column in the [xUpdate] method.
10191 **
10192 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10193 ** implementations should continue to give a correct answer even if the
10194 ** sqlite3_vtab_nochange() interface were to always return false. In the
10195 ** current implementation, the sqlite3_vtab_nochange() interface does always
10196 ** returns false for the enhanced [UPDATE FROM] statement.
10197 */
10198 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10199
10200 /*
10201 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10202 ** METHOD: sqlite3_index_info
10203 **
10204 ** This function may only be called from within a call to the [xBestIndex]
10205 ** method of a [virtual table]. This function returns a pointer to a string
10206 ** that is the name of the appropriate collation sequence to use for text
10207 ** comparisons on the constraint identified by its arguments.
10208 **
10209 ** The first argument must be the pointer to the [sqlite3_index_info] object
10210 ** that is the first parameter to the xBestIndex() method. The second argument
10211 ** must be an index into the aConstraint[] array belonging to the
10212 ** sqlite3_index_info structure passed to xBestIndex.
10213 **
10214 ** Important:
10215 ** The first parameter must be the same pointer that is passed into the
10216 ** xBestMethod() method. The first parameter may not be a pointer to a
10217 ** different [sqlite3_index_info] object, even an exact copy.
10218 **
10219 ** The return value is computed as follows:
10220 **
10221 ** <ol>
10222 ** <li><p> If the constraint comes from a WHERE clause expression that contains
10223 ** a [COLLATE operator], then the name of the collation specified by
10224 ** that COLLATE operator is returned.
10225 ** <li><p> If there is no COLLATE operator, but the column that is the subject
10226 ** of the constraint specifies an alternative collating sequence via
10227 ** a [COLLATE clause] on the column definition within the CREATE TABLE
10228 ** statement that was passed into [sqlite3_declare_vtab()], then the
10229 ** name of that alternative collating sequence is returned.
10230 ** <li><p> Otherwise, "BINARY" is returned.
10231 ** </ol>
10232 */
10233 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10234
10235 /*
10236 ** CAPI3REF: Determine if a virtual table query is DISTINCT
10237 ** METHOD: sqlite3_index_info
10238 **
10239 ** This API may only be used from within an [xBestIndex|xBestIndex method]
10240 ** of a [virtual table] implementation. The result of calling this
10241 ** interface from outside of xBestIndex() is undefined and probably harmful.
10242 **
10243 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10244 ** 3. The integer returned by sqlite3_vtab_distinct()
10245 ** gives the virtual table additional information about how the query
10246 ** planner wants the output to be ordered. As long as the virtual table
10247 ** can meet the ordering requirements of the query planner, it may set
10248 ** the "orderByConsumed" flag.
10249 **
10250 ** <ol><li value="0"><p>
10251 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10252 ** that the query planner needs the virtual table to return all rows in the
10253 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10254 ** [sqlite3_index_info] object. This is the default expectation. If the
10255 ** virtual table outputs all rows in sorted order, then it is always safe for
10256 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10257 ** the return value from sqlite3_vtab_distinct().
10258 ** <li value="1"><p>
10259 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10260 ** that the query planner does not need the rows to be returned in sorted order
10261 ** as long as all rows with the same values in all columns identified by the
10262 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10263 ** is doing a GROUP BY.
10264 ** <li value="2"><p>
10265 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10266 ** that the query planner does not need the rows returned in any particular
10267 ** order, as long as rows with the same values in all columns identified
10268 ** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10269 ** contain the same values for all columns identified by "colUsed", all but
10270 ** one such row may optionally be omitted from the result.)^
10271 ** The virtual table is not required to omit rows that are duplicates
10272 ** over the "colUsed" columns, but if the virtual table can do that without
10273 ** too much extra effort, it could potentially help the query to run faster.
10274 ** This mode is used for a DISTINCT query.
10275 ** <li value="3"><p>
10276 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10277 ** virtual table must return rows in the order defined by "aOrderBy" as
10278 ** if the sqlite3_vtab_distinct() interface had returned 0. However if
10279 ** two or more rows in the result have the same values for all columns
10280 ** identified by "colUsed", then all but one such row may optionally be
10281 ** omitted.)^ Like when the return value is 2, the virtual table
10282 ** is not required to omit rows that are duplicates over the "colUsed"
10283 ** columns, but if the virtual table can do that without
10284 ** too much extra effort, it could potentially help the query to run faster.
10285 ** This mode is used for queries
10286 ** that have both DISTINCT and ORDER BY clauses.
10287 ** </ol>
10288 **
10289 ** <p>The following table summarizes the conditions under which the
10290 ** virtual table is allowed to set the "orderByConsumed" flag based on
10291 ** the value returned by sqlite3_vtab_distinct(). This table is a
10292 ** restatement of the previous four paragraphs:
10293 **
10294 ** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10295 ** <tr>
10296 ** <td valign="top">sqlite3_vtab_distinct() return value
10297 ** <td valign="top">Rows are returned in aOrderBy order
10298 ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10299 ** <td valign="top">Duplicates over all colUsed columns may be omitted
10300 ** <tr><td>0<td>yes<td>yes<td>no
10301 ** <tr><td>1<td>no<td>yes<td>no
10302 ** <tr><td>2<td>no<td>yes<td>yes
10303 ** <tr><td>3<td>yes<td>yes<td>yes
10304 ** </table>
10305 **
10306 ** ^For the purposes of comparing virtual table output values to see if the
10307 ** values are the same value for sorting purposes, two NULL values are considered
10308 ** to be the same. In other words, the comparison operator is "IS"
10309 ** (or "IS NOT DISTINCT FROM") and not "==".
10310 **
10311 ** If a virtual table implementation is unable to meet the requirements
10312 ** specified above, then it must not set the "orderByConsumed" flag in the
10313 ** [sqlite3_index_info] object or an incorrect answer may result.
10314 **
10315 ** ^A virtual table implementation is always free to return rows in any order
10316 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10317 ** "orderByConsumed" flag is unset, the query planner will add extra
10318 ** [bytecode] to ensure that the final results returned by the SQL query are
10319 ** ordered correctly. The use of the "orderByConsumed" flag and the
10320 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10321 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10322 ** flag might help queries against a virtual table to run faster. Being
10323 ** overly aggressive and setting the "orderByConsumed" flag when it is not
10324 ** valid to do so, on the other hand, might cause SQLite to return incorrect
10325 ** results.
10326 */
10327 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10328
10329 /*
10330 ** CAPI3REF: Identify and handle IN constraints in xBestIndex
10331 **
10332 ** This interface may only be used from within an
10333 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10334 ** The result of invoking this interface from any other context is
10335 ** undefined and probably harmful.
10336 **
10337 ** ^(A constraint on a virtual table of the form
10338 ** "[IN operator|column IN (...)]" is
10339 ** communicated to the xBestIndex method as a
10340 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10341 ** this constraint, it must set the corresponding
10342 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10343 ** the usual mode of handling IN operators, SQLite generates [bytecode]
10344 ** that invokes the [xFilter|xFilter() method] once for each value
10345 ** on the right-hand side of the IN operator.)^ Thus the virtual table
10346 ** only sees a single value from the right-hand side of the IN operator
10347 ** at a time.
10348 **
10349 ** In some cases, however, it would be advantageous for the virtual
10350 ** table to see all values on the right-hand of the IN operator all at
10351 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10352 **
10353 ** <ol>
10354 ** <li><p>
10355 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10356 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10357 ** is an [IN operator] that can be processed all at once. ^In other words,
10358 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10359 ** by which the virtual table can ask SQLite if all-at-once processing
10360 ** of the IN operator is even possible.
10361 **
10362 ** <li><p>
10363 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10364 ** to SQLite that the virtual table does or does not want to process
10365 ** the IN operator all-at-once, respectively. ^Thus when the third
10366 ** parameter (F) is non-negative, this interface is the mechanism by
10367 ** which the virtual table tells SQLite how it wants to process the
10368 ** IN operator.
10369 ** </ol>
10370 **
10371 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10372 ** within the same xBestIndex method call. ^For any given P,N pair,
10373 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10374 ** within the same xBestIndex call. ^If the interface returns true
10375 ** (non-zero), that means that the constraint is an IN operator
10376 ** that can be processed all-at-once. ^If the constraint is not an IN
10377 ** operator or cannot be processed all-at-once, then the interface returns
10378 ** false.
10379 **
10380 ** ^(All-at-once processing of the IN operator is selected if both of the
10381 ** following conditions are met:
10382 **
10383 ** <ol>
10384 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10385 ** integer. This is how the virtual table tells SQLite that it wants to
10386 ** use the N-th constraint.
10387 **
10388 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10389 ** non-negative had F>=1.
10390 ** </ol>)^
10391 **
10392 ** ^If either or both of the conditions above are false, then SQLite uses
10393 ** the traditional one-at-a-time processing strategy for the IN constraint.
10394 ** ^If both conditions are true, then the argvIndex-th parameter to the
10395 ** xFilter method will be an [sqlite3_value] that appears to be NULL,
10396 ** but which can be passed to [sqlite3_vtab_in_first()] and
10397 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10398 ** of the IN constraint.
10399 */
10400 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10401
10402 /*
10403 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10404 **
10405 ** These interfaces are only useful from within the
10406 ** [xFilter|xFilter() method] of a [virtual table] implementation.
10407 ** The result of invoking these interfaces from any other context
10408 ** is undefined and probably harmful.
10409 **
10410 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10411 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10412 ** xFilter method which invokes these routines, and specifically
10413 ** a parameter that was previously selected for all-at-once IN constraint
10414 ** processing using the [sqlite3_vtab_in()] interface in the
10415 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10416 ** an xFilter argument that was selected for all-at-once IN constraint
10417 ** processing, then these routines return [SQLITE_ERROR].)^
10418 **
10419 ** ^(Use these routines to access all values on the right-hand side
10420 ** of the IN constraint using code like the following:
10421 **
10422 ** <blockquote><pre>
10423 ** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10424 ** &nbsp; rc==SQLITE_OK && pVal;
10425 ** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10426 ** &nbsp; ){
10427 ** &nbsp; // do something with pVal
10428 ** &nbsp; }
10429 ** &nbsp; if( rc!=SQLITE_DONE ){
10430 ** &nbsp; // an error has occurred
10431 ** &nbsp; }
10432 ** </pre></blockquote>)^
10433 **
10434 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10435 ** routines return SQLITE_OK and set *P to point to the first or next value
10436 ** on the RHS of the IN constraint. ^If there are no more values on the
10437 ** right hand side of the IN constraint, then *P is set to NULL and these
10438 ** routines return [SQLITE_DONE]. ^The return value might be
10439 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10440 **
10441 ** The *ppOut values returned by these routines are only valid until the
10442 ** next call to either of these routines or until the end of the xFilter
10443 ** method from which these routines were called. If the virtual table
10444 ** implementation needs to retain the *ppOut values for longer, it must make
10445 ** copies. The *ppOut values are [protected sqlite3_value|protected].
10446 */
10447 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10448 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10449
10450 /*
10451 ** CAPI3REF: Constraint values in xBestIndex()
10452 ** METHOD: sqlite3_index_info
10453 **
10454 ** This API may only be used from within the [xBestIndex|xBestIndex method]
10455 ** of a [virtual table] implementation. The result of calling this interface
10456 ** from outside of an xBestIndex method are undefined and probably harmful.
10457 **
10458 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10459 ** the [xBestIndex] method of a [virtual table] implementation, with P being
10460 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10461 ** J being a 0-based index into P->aConstraint[], then this routine
10462 ** attempts to set *V to the value of the right-hand operand of
10463 ** that constraint if the right-hand operand is known. ^If the
10464 ** right-hand operand is not known, then *V is set to a NULL pointer.
10465 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10466 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10467 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10468 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10469 ** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10470 ** something goes wrong.
10471 **
10472 ** The sqlite3_vtab_rhs_value() interface is usually only successful if
10473 ** the right-hand operand of a constraint is a literal value in the original
10474 ** SQL statement. If the right-hand operand is an expression or a reference
10475 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10476 ** will probably return [SQLITE_NOTFOUND].
10477 **
10478 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10479 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10480 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10481 **
10482 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10483 ** and remains valid for the duration of the xBestIndex method call.
10484 ** ^When xBestIndex returns, the sqlite3_value object returned by
10485 ** sqlite3_vtab_rhs_value() is automatically deallocated.
10486 **
10487 ** The "_rhs_" in the name of this routine is an abbreviation for
10488 ** "Right-Hand Side".
10489 */
10490 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10491
10492 /*
10493 ** CAPI3REF: Conflict resolution modes
10494 ** KEYWORDS: {conflict resolution mode}
10495 **
10496 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
10497 ** inform a [virtual table] implementation of the [ON CONFLICT] mode
10498 ** for the SQL statement being evaluated.
10499 **
10500 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
10501 ** return value from the [sqlite3_set_authorizer()] callback and that
10502 ** [SQLITE_ABORT] is also a [result code].
10503 */
10504 #define SQLITE_ROLLBACK 1
10505 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10506 #define SQLITE_FAIL 3
10507 /* #define SQLITE_ABORT 4 // Also an error code */
10508 #define SQLITE_REPLACE 5
10509
10510 /*
10511 ** CAPI3REF: Prepared Statement Scan Status Opcodes
10512 ** KEYWORDS: {scanstatus options}
10513 **
10514 ** The following constants can be used for the T parameter to the
10515 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10516 ** different metric for sqlite3_stmt_scanstatus() to return.
10517 **
10518 ** When the value returned to V is a string, space to hold that string is
10519 ** managed by the prepared statement S and will be automatically freed when
10520 ** S is finalized.
10521 **
10522 ** Not all values are available for all query elements. When a value is
10523 ** not available, the output variable is set to -1 if the value is numeric,
10524 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10525 **
10526 ** <dl>
10527 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10528 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10529 ** set to the total number of times that the X-th loop has run.</dd>
10530 **
10531 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10532 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10533 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
10534 **
10535 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10536 ** <dd>^The "double" variable pointed to by the V parameter will be set to the
10537 ** query planner's estimate for the average number of rows output from each
10538 ** iteration of the X-th loop. If the query planner's estimate was accurate,
10539 ** then this value will approximate the quotient NVISIT/NLOOP and the
10540 ** product of this value for all prior loops with the same SELECTID will
10541 ** be the NLOOP value for the current loop.</dd>
10542 **
10543 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10544 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10545 ** to a zero-terminated UTF-8 string containing the name of the index or table
10546 ** used for the X-th loop.</dd>
10547 **
10548 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10549 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10550 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10551 ** description for the X-th loop.</dd>
10552 **
10553 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10554 ** <dd>^The "int" variable pointed to by the V parameter will be set to the
10555 ** id for the X-th query plan element. The id value is unique within the
10556 ** statement. The select-id is the same value as is output in the first
10557 ** column of an [EXPLAIN QUERY PLAN] query.</dd>
10558 **
10559 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10560 ** <dd>The "int" variable pointed to by the V parameter will be set to the
10561 ** id of the parent of the current query element, if applicable, or
10562 ** to zero if the query element has no parent. This is the same value as
10563 ** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10564 **
10565 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10566 ** <dd>The sqlite3_int64 output value is set to the number of cycles,
10567 ** according to the processor time-stamp counter, that elapsed while the
10568 ** query element was being processed. This value is not available for
10569 ** all query elements - if it is unavailable the output variable is
10570 ** set to -1.</dd>
10571 ** </dl>
10572 */
10573 #define SQLITE_SCANSTAT_NLOOP 0
10574 #define SQLITE_SCANSTAT_NVISIT 1
10575 #define SQLITE_SCANSTAT_EST 2
10576 #define SQLITE_SCANSTAT_NAME 3
10577 #define SQLITE_SCANSTAT_EXPLAIN 4
10578 #define SQLITE_SCANSTAT_SELECTID 5
10579 #define SQLITE_SCANSTAT_PARENTID 6
10580 #define SQLITE_SCANSTAT_NCYCLE 7
10581
10582 /*
10583 ** CAPI3REF: Prepared Statement Scan Status
10584 ** METHOD: sqlite3_stmt
10585 **
10586 ** These interfaces return information about the predicted and measured
10587 ** performance for pStmt. Advanced applications can use this
10588 ** interface to compare the predicted and the measured performance and
10589 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10590 **
10591 ** Since this interface is expected to be rarely used, it is only
10592 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10593 ** compile-time option.
10594 **
10595 ** The "iScanStatusOp" parameter determines which status information to return.
10596 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10597 ** of this interface is undefined. ^The requested measurement is written into
10598 ** a variable pointed to by the "pOut" parameter.
10599 **
10600 ** The "flags" parameter must be passed a mask of flags. At present only
10601 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10602 ** is specified, then status information is available for all elements
10603 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10604 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10605 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10606 ** the EXPLAIN QUERY PLAN output) are available. Invoking API
10607 ** sqlite3_stmt_scanstatus() is equivalent to calling
10608 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10609 **
10610 ** Parameter "idx" identifies the specific query element to retrieve statistics
10611 ** for. Query elements are numbered starting from zero. A value of -1 may
10612 ** retrieve statistics for the entire query. ^If idx is out of range
10613 ** - less than -1 or greater than or equal to the total number of query
10614 ** elements used to implement the statement - a non-zero value is returned and
10615 ** the variable that pOut points to is unchanged.
10616 **
10617 ** See also: [sqlite3_stmt_scanstatus_reset()]
10618 */
10619 SQLITE_API int sqlite3_stmt_scanstatus(
10620 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10621 int idx, /* Index of loop to report on */
10622 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10623 void *pOut /* Result written here */
10624 );
10625 SQLITE_API int sqlite3_stmt_scanstatus_v2(
10626 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10627 int idx, /* Index of loop to report on */
10628 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10629 int flags, /* Mask of flags defined below */
10630 void *pOut /* Result written here */
10631 );
10632
10633 /*
10634 ** CAPI3REF: Prepared Statement Scan Status
10635 ** KEYWORDS: {scan status flags}
10636 */
10637 #define SQLITE_SCANSTAT_COMPLEX 0x0001
10638
10639 /*
10640 ** CAPI3REF: Zero Scan-Status Counters
10641 ** METHOD: sqlite3_stmt
10642 **
10643 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10644 **
10645 ** This API is only available if the library is built with pre-processor
10646 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10647 */
10648 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10649
10650 /*
10651 ** CAPI3REF: Flush caches to disk mid-transaction
10652 ** METHOD: sqlite3
10653 **
10654 ** ^If a write-transaction is open on [database connection] D when the
10655 ** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10656 ** pages in the pager-cache that are not currently in use are written out
10657 ** to disk. A dirty page may be in use if a database cursor created by an
10658 ** active SQL statement is reading from it, or if it is page 1 of a database
10659 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10660 ** interface flushes caches for all schemas - "main", "temp", and
10661 ** any [attached] databases.
10662 **
10663 ** ^If this function needs to obtain extra database locks before dirty pages
10664 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
10665 ** immediately and there is a busy-handler callback configured, it is invoked
10666 ** in the usual manner. ^If the required lock still cannot be obtained, then
10667 ** the database is skipped and an attempt made to flush any dirty pages
10668 ** belonging to the next (if any) database. ^If any databases are skipped
10669 ** because locks cannot be obtained, but no other error occurs, this
10670 ** function returns SQLITE_BUSY.
10671 **
10672 ** ^If any other error occurs while flushing dirty pages to disk (for
10673 ** example an IO error or out-of-memory condition), then processing is
10674 ** abandoned and an SQLite [error code] is returned to the caller immediately.
10675 **
10676 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10677 **
10678 ** ^This function does not set the database handle error code or message
10679 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10680 */
10681 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10682
10683 /*
10684 ** CAPI3REF: The pre-update hook.
10685 ** METHOD: sqlite3
10686 **
10687 ** ^These interfaces are only available if SQLite is compiled using the
10688 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10689 **
10690 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10691 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10692 ** on a database table.
10693 ** ^At most one preupdate hook may be registered at a time on a single
10694 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10695 ** the previous setting.
10696 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10697 ** with a NULL pointer as the second parameter.
10698 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10699 ** the first parameter to callbacks.
10700 **
10701 ** ^The preupdate hook only fires for changes to real database tables; the
10702 ** preupdate hook is not invoked for changes to [virtual tables] or to
10703 ** system tables like sqlite_sequence or sqlite_stat1.
10704 **
10705 ** ^The second parameter to the preupdate callback is a pointer to
10706 ** the [database connection] that registered the preupdate hook.
10707 ** ^The third parameter to the preupdate callback is one of the constants
10708 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10709 ** kind of update operation that is about to occur.
10710 ** ^(The fourth parameter to the preupdate callback is the name of the
10711 ** database within the database connection that is being modified. This
10712 ** will be "main" for the main database or "temp" for TEMP tables or
10713 ** the name given after the AS keyword in the [ATTACH] statement for attached
10714 ** databases.)^
10715 ** ^The fifth parameter to the preupdate callback is the name of the
10716 ** table that is being modified.
10717 **
10718 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
10719 ** parameter passed to the preupdate callback is the initial [rowid] of the
10720 ** row being modified or deleted. For an INSERT operation on a rowid table,
10721 ** or any operation on a WITHOUT ROWID table, the value of the sixth
10722 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10723 ** seventh parameter is the final rowid value of the row being inserted
10724 ** or updated. The value of the seventh parameter passed to the callback
10725 ** function is not defined for operations on WITHOUT ROWID tables, or for
10726 ** DELETE operations on rowid tables.
10727 **
10728 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10729 ** the previous call on the same [database connection] D, or NULL for
10730 ** the first call on D.
10731 **
10732 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10733 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10734 ** provide additional information about a preupdate event. These routines
10735 ** may only be called from within a preupdate callback. Invoking any of
10736 ** these routines from outside of a preupdate callback or with a
10737 ** [database connection] pointer that is different from the one supplied
10738 ** to the preupdate callback results in undefined and probably undesirable
10739 ** behavior.
10740 **
10741 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10742 ** in the row that is being inserted, updated, or deleted.
10743 **
10744 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10745 ** a [protected sqlite3_value] that contains the value of the Nth column of
10746 ** the table row before it is updated. The N parameter must be between 0
10747 ** and one less than the number of columns or the behavior will be
10748 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10749 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10750 ** behavior is undefined. The [sqlite3_value] that P points to
10751 ** will be destroyed when the preupdate callback returns.
10752 **
10753 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10754 ** a [protected sqlite3_value] that contains the value of the Nth column of
10755 ** the table row after it is updated. The N parameter must be between 0
10756 ** and one less than the number of columns or the behavior will be
10757 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10758 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10759 ** behavior is undefined. The [sqlite3_value] that P points to
10760 ** will be destroyed when the preupdate callback returns.
10761 **
10762 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10763 ** callback was invoked as a result of a direct insert, update, or delete
10764 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
10765 ** triggers; or 2 for changes resulting from triggers called by top-level
10766 ** triggers; and so forth.
10767 **
10768 ** When the [sqlite3_blob_write()] API is used to update a blob column,
10769 ** the pre-update hook is invoked with SQLITE_DELETE, because
10770 ** the new values are not yet available. In this case, when a
10771 ** callback made with op==SQLITE_DELETE is actually a write using the
10772 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10773 ** the index of the column being written. In other cases, where the
10774 ** pre-update hook is being invoked for some other reason, including a
10775 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10776 **
10777 ** See also: [sqlite3_update_hook()]
10778 */
10779 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10780 SQLITE_API void *sqlite3_preupdate_hook(
10781 sqlite3 *db,
10782 void(*xPreUpdate)(
10783 void *pCtx, /* Copy of third arg to preupdate_hook() */
10784 sqlite3 *db, /* Database handle */
10785 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10786 char const *zDb, /* Database name */
10787 char const *zName, /* Table name */
10788 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10789 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10790 ),
10791 void*
10792 );
10793 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10794 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10795 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10796 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10797 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10798 #endif
10799
10800 /*
10801 ** CAPI3REF: Low-level system error code
10802 ** METHOD: sqlite3
10803 **
10804 ** ^Attempt to return the underlying operating system error code or error
10805 ** number that caused the most recent I/O error or failure to open a file.
10806 ** The return value is OS-dependent. For example, on unix systems, after
10807 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10808 ** called to get back the underlying "errno" that caused the problem, such
10809 ** as ENOSPC, EAUTH, EISDIR, and so forth.
10810 */
10811 SQLITE_API int sqlite3_system_errno(sqlite3*);
10812
10813 /*
10814 ** CAPI3REF: Database Snapshot
10815 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
10816 **
10817 ** An instance of the snapshot object records the state of a [WAL mode]
10818 ** database for some specific point in history.
10819 **
10820 ** In [WAL mode], multiple [database connections] that are open on the
10821 ** same database file can each be reading a different historical version
10822 ** of the database file. When a [database connection] begins a read
10823 ** transaction, that connection sees an unchanging copy of the database
10824 ** as it existed for the point in time when the transaction first started.
10825 ** Subsequent changes to the database from other connections are not seen
10826 ** by the reader until a new read transaction is started.
10827 **
10828 ** The sqlite3_snapshot object records state information about an historical
10829 ** version of the database file so that it is possible to later open a new read
10830 ** transaction that sees that historical version of the database rather than
10831 ** the most recent version.
10832 */
10833 typedef struct sqlite3_snapshot {
10834 unsigned char hidden[48];
10835 } sqlite3_snapshot;
10836
10837 /*
10838 ** CAPI3REF: Record A Database Snapshot
10839 ** CONSTRUCTOR: sqlite3_snapshot
10840 **
10841 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10842 ** new [sqlite3_snapshot] object that records the current state of
10843 ** schema S in database connection D. ^On success, the
10844 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10845 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10846 ** If there is not already a read-transaction open on schema S when
10847 ** this function is called, one is opened automatically.
10848 **
10849 ** If a read-transaction is opened by this function, then it is guaranteed
10850 ** that the returned snapshot object may not be invalidated by a database
10851 ** writer or checkpointer until after the read-transaction is closed. This
10852 ** is not guaranteed if a read-transaction is already open when this
10853 ** function is called. In that case, any subsequent write or checkpoint
10854 ** operation on the database may invalidate the returned snapshot handle,
10855 ** even while the read-transaction remains open.
10856 **
10857 ** The following must be true for this function to succeed. If any of
10858 ** the following statements are false when sqlite3_snapshot_get() is
10859 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
10860 ** in this case.
10861 **
10862 ** <ul>
10863 ** <li> The database handle must not be in [autocommit mode].
10864 **
10865 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
10866 **
10867 ** <li> There must not be a write transaction open on schema S of database
10868 ** connection D.
10869 **
10870 ** <li> One or more transactions must have been written to the current wal
10871 ** file since it was created on disk (by any connection). This means
10872 ** that a snapshot cannot be taken on a wal mode database with no wal
10873 ** file immediately after it is first opened. At least one transaction
10874 ** must be written to it first.
10875 ** </ul>
10876 **
10877 ** This function may also return SQLITE_NOMEM. If it is called with the
10878 ** database handle in autocommit mode but fails for some other reason,
10879 ** whether or not a read transaction is opened on schema S is undefined.
10880 **
10881 ** The [sqlite3_snapshot] object returned from a successful call to
10882 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10883 ** to avoid a memory leak.
10884 **
10885 ** The [sqlite3_snapshot_get()] interface is only available when the
10886 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10887 */
10888 SQLITE_API int sqlite3_snapshot_get(
10889 sqlite3 *db,
10890 const char *zSchema,
10891 sqlite3_snapshot **ppSnapshot
10892 );
10893
10894 /*
10895 ** CAPI3REF: Start a read transaction on an historical snapshot
10896 ** METHOD: sqlite3_snapshot
10897 **
10898 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10899 ** transaction or upgrades an existing one for schema S of
10900 ** [database connection] D such that the read transaction refers to
10901 ** historical [snapshot] P, rather than the most recent change to the
10902 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10903 ** on success or an appropriate [error code] if it fails.
10904 **
10905 ** ^In order to succeed, the database connection must not be in
10906 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10907 ** is already a read transaction open on schema S, then the database handle
10908 ** must have no active statements (SELECT statements that have been passed
10909 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10910 ** SQLITE_ERROR is returned if either of these conditions is violated, or
10911 ** if schema S does not exist, or if the snapshot object is invalid.
10912 **
10913 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10914 ** snapshot has been overwritten by a [checkpoint]. In this case
10915 ** SQLITE_ERROR_SNAPSHOT is returned.
10916 **
10917 ** If there is already a read transaction open when this function is
10918 ** invoked, then the same read transaction remains open (on the same
10919 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10920 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
10921 ** SQLITE_IOERR error code - is returned, then the final state of the
10922 ** read transaction is undefined. If SQLITE_OK is returned, then the
10923 ** read transaction is now open on database snapshot P.
10924 **
10925 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10926 ** database connection D does not know that the database file for
10927 ** schema S is in [WAL mode]. A database connection might not know
10928 ** that the database file is in [WAL mode] if there has been no prior
10929 ** I/O on that database connection, or if the database entered [WAL mode]
10930 ** after the most recent I/O on the database connection.)^
10931 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
10932 ** database connection in order to make it ready to use snapshots.)
10933 **
10934 ** The [sqlite3_snapshot_open()] interface is only available when the
10935 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10936 */
10937 SQLITE_API int sqlite3_snapshot_open(
10938 sqlite3 *db,
10939 const char *zSchema,
10940 sqlite3_snapshot *pSnapshot
10941 );
10942
10943 /*
10944 ** CAPI3REF: Destroy a snapshot
10945 ** DESTRUCTOR: sqlite3_snapshot
10946 **
10947 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10948 ** The application must eventually free every [sqlite3_snapshot] object
10949 ** using this routine to avoid a memory leak.
10950 **
10951 ** The [sqlite3_snapshot_free()] interface is only available when the
10952 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10953 */
10954 SQLITE_API void sqlite3_snapshot_free(sqlite3_snapshot*);
10955
10956 /*
10957 ** CAPI3REF: Compare the ages of two snapshot handles.
10958 ** METHOD: sqlite3_snapshot
10959 **
10960 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10961 ** of two valid snapshot handles.
10962 **
10963 ** If the two snapshot handles are not associated with the same database
10964 ** file, the result of the comparison is undefined.
10965 **
10966 ** Additionally, the result of the comparison is only valid if both of the
10967 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10968 ** last time the wal file was deleted. The wal file is deleted when the
10969 ** database is changed back to rollback mode or when the number of database
10970 ** clients drops to zero. If either snapshot handle was obtained before the
10971 ** wal file was last deleted, the value returned by this function
10972 ** is undefined.
10973 **
10974 ** Otherwise, this API returns a negative value if P1 refers to an older
10975 ** snapshot than P2, zero if the two handles refer to the same database
10976 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
10977 **
10978 ** This interface is only available if SQLite is compiled with the
10979 ** [SQLITE_ENABLE_SNAPSHOT] option.
10980 */
10981 SQLITE_API int sqlite3_snapshot_cmp(
10982 sqlite3_snapshot *p1,
10983 sqlite3_snapshot *p2
10984 );
10985
10986 /*
10987 ** CAPI3REF: Recover snapshots from a wal file
10988 ** METHOD: sqlite3_snapshot
10989 **
10990 ** If a [WAL file] remains on disk after all database connections close
10991 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10992 ** or because the last process to have the database opened exited without
10993 ** calling [sqlite3_close()]) and a new connection is subsequently opened
10994 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10995 ** will only be able to open the last transaction added to the WAL file
10996 ** even though the WAL file contains other valid transactions.
10997 **
10998 ** This function attempts to scan the WAL file associated with database zDb
10999 ** of database handle db and make all valid snapshots available to
11000 ** sqlite3_snapshot_open(). It is an error if there is already a read
11001 ** transaction open on the database, or if the database is not a WAL mode
11002 ** database.
11003 **
11004 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
11005 **
11006 ** This interface is only available if SQLite is compiled with the
11007 ** [SQLITE_ENABLE_SNAPSHOT] option.
11008 */
11009 SQLITE_API int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
11010
11011 /*
11012 ** CAPI3REF: Serialize a database
11013 **
11014 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
11015 ** memory that is a serialization of the S database on
11016 ** [database connection] D. If S is a NULL pointer, the main database is used.
11017 ** If P is not a NULL pointer, then the size of the database in bytes
11018 ** is written into *P.
11019 **
11020 ** For an ordinary on-disk database file, the serialization is just a
11021 ** copy of the disk file. For an in-memory database or a "TEMP" database,
11022 ** the serialization is the same sequence of bytes which would be written
11023 ** to disk if that database were backed up to disk.
11024 **
11025 ** The usual case is that sqlite3_serialize() copies the serialization of
11026 ** the database into memory obtained from [sqlite3_malloc64()] and returns
11027 ** a pointer to that memory. The caller is responsible for freeing the
11028 ** returned value to avoid a memory leak. However, if the F argument
11029 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
11030 ** are made, and the sqlite3_serialize() function will return a pointer
11031 ** to the contiguous memory representation of the database that SQLite
11032 ** is currently using for that database, or NULL if no such contiguous
11033 ** memory representation of the database exists. A contiguous memory
11034 ** representation of the database will usually only exist if there has
11035 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
11036 ** values of D and S.
11037 ** The size of the database is written into *P even if the
11038 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
11039 ** of the database exists.
11040 **
11041 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
11042 ** the returned buffer content will remain accessible and unchanged
11043 ** until either the next write operation on the connection or when
11044 ** the connection is closed, and applications must not modify the
11045 ** buffer. If the bit had been clear, the returned buffer will not
11046 ** be accessed by SQLite after the call.
11047 **
11048 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
11049 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
11050 ** allocation error occurs.
11051 **
11052 ** This interface is omitted if SQLite is compiled with the
11053 ** [SQLITE_OMIT_DESERIALIZE] option.
11054 */
11055 SQLITE_API unsigned char *sqlite3_serialize(
11056 sqlite3 *db, /* The database connection */
11057 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
11058 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
11059 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
11060 );
11061
11062 /*
11063 ** CAPI3REF: Flags for sqlite3_serialize
11064 **
11065 ** Zero or more of the following constants can be OR-ed together for
11066 ** the F argument to [sqlite3_serialize(D,S,P,F)].
11067 **
11068 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
11069 ** a pointer to contiguous in-memory database that it is currently using,
11070 ** without making a copy of the database. If SQLite is not currently using
11071 ** a contiguous in-memory database, then this option causes
11072 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
11073 ** using a contiguous in-memory database if it has been initialized by a
11074 ** prior call to [sqlite3_deserialize()].
11075 */
11076 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
11077
11078 /*
11079 ** CAPI3REF: Deserialize a database
11080 **
11081 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
11082 ** [database connection] D to disconnect from database S and then
11083 ** reopen S as an in-memory database based on the serialization
11084 ** contained in P. If S is a NULL pointer, the main database is
11085 ** used. The serialized database P is N bytes in size. M is the size
11086 ** of the buffer P, which might be larger than N. If M is larger than
11087 ** N, and the SQLITE_DESERIALIZE_READONLY bit is not set in F, then
11088 ** SQLite is permitted to add content to the in-memory database as
11089 ** long as the total size does not exceed M bytes.
11090 **
11091 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
11092 ** invoke sqlite3_free() on the serialization buffer when the database
11093 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
11094 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
11095 ** if writes on the database cause it to grow larger than M bytes.
11096 **
11097 ** Applications must not modify the buffer P or invalidate it before
11098 ** the database connection D is closed.
11099 **
11100 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11101 ** database is currently in a read transaction or is involved in a backup
11102 ** operation.
11103 **
11104 ** It is not possible to deserialize into the TEMP database. If the
11105 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11106 ** function returns SQLITE_ERROR.
11107 **
11108 ** The deserialized database should not be in [WAL mode]. If the database
11109 ** is in WAL mode, then any attempt to use the database file will result
11110 ** in an [SQLITE_CANTOPEN] error. The application can set the
11111 ** [file format version numbers] (bytes 18 and 19) of the input database P
11112 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11113 ** database file into rollback mode and work around this limitation.
11114 **
11115 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11116 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11117 ** [sqlite3_free()] is invoked on argument P prior to returning.
11118 **
11119 ** This interface is omitted if SQLite is compiled with the
11120 ** [SQLITE_OMIT_DESERIALIZE] option.
11121 */
11122 SQLITE_API int sqlite3_deserialize(
11123 sqlite3 *db, /* The database connection */
11124 const char *zSchema, /* Which DB to reopen with the deserialization */
11125 unsigned char *pData, /* The serialized database content */
11126 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11127 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11128 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11129 );
11130
11131 /*
11132 ** CAPI3REF: Flags for sqlite3_deserialize()
11133 **
11134 ** The following are allowed values for the 6th argument (the F argument) to
11135 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11136 **
11137 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11138 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11139 ** and that SQLite should take ownership of this memory and automatically
11140 ** free it when it has finished using it. Without this flag, the caller
11141 ** is responsible for freeing any dynamically allocated memory.
11142 **
11143 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11144 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
11145 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11146 ** Without this flag, the deserialized database cannot increase in size beyond
11147 ** the number of bytes specified by the M parameter.
11148 **
11149 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11150 ** should be treated as read-only.
11151 */
11152 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11153 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11154 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11155
11156 /*
11157 ** CAPI3REF: Bind array values to the CARRAY table-valued function
11158 **
11159 ** The sqlite3_carray_bind(S,I,P,N,F,X) interface binds an array value to
11160 ** one of the first argument of the [carray() table-valued function]. The
11161 ** S parameter is a pointer to the [prepared statement] that uses the carray()
11162 ** functions. I is the parameter index to be bound. P is a pointer to the
11163 ** array to be bound, and N is the number of eements in the array. The
11164 ** F argument is one of constants [SQLITE_CARRAY_INT32], [SQLITE_CARRAY_INT64],
11165 ** [SQLITE_CARRAY_DOUBLE], [SQLITE_CARRAY_TEXT], or [SQLITE_CARRAY_BLOB] to
11166 ** indicate the datatype of the array being bound. The X argument is not a
11167 ** NULL pointer, then SQLite will invoke the function X on the P parameter
11168 ** after it has finished using P, even if the call to
11169 ** sqlite3_carray_bind() fails. The special-case finalizer
11170 ** SQLITE_TRANSIENT has no effect here.
11171 */
11172 SQLITE_API int sqlite3_carray_bind(
11173 sqlite3_stmt *pStmt, /* Statement to be bound */
11174 int i, /* Parameter index */
11175 void *aData, /* Pointer to array data */
11176 int nData, /* Number of data elements */
11177 int mFlags, /* CARRAY flags */
11178 void (*xDel)(void*) /* Destructor for aData */
11179 );
11180
11181 /*
11182 ** CAPI3REF: Datatypes for the CARRAY table-valued function
11183 **
11184 ** The fifth argument to the [sqlite3_carray_bind()] interface musts be
11185 ** one of the following constants, to specify the datatype of the array
11186 ** that is being bound into the [carray table-valued function].
11187 */
11188 #define SQLITE_CARRAY_INT32 0 /* Data is 32-bit signed integers */
11189 #define SQLITE_CARRAY_INT64 1 /* Data is 64-bit signed integers */
11190 #define SQLITE_CARRAY_DOUBLE 2 /* Data is doubles */
11191 #define SQLITE_CARRAY_TEXT 3 /* Data is char* */
11192 #define SQLITE_CARRAY_BLOB 4 /* Data is struct iovec */
11193
11194 /*
11195 ** Versions of the above #defines that omit the initial SQLITE_, for
11196 ** legacy compatibility.
11197 */
11198 #define CARRAY_INT32 0 /* Data is 32-bit signed integers */
11199 #define CARRAY_INT64 1 /* Data is 64-bit signed integers */
11200 #define CARRAY_DOUBLE 2 /* Data is doubles */
11201 #define CARRAY_TEXT 3 /* Data is char* */
11202 #define CARRAY_BLOB 4 /* Data is struct iovec */
11203
11204 /*
11205 ** Undo the hack that converts floating point types to integer for
11206 ** builds on processors without floating point support.
11207 */
11208 #ifdef SQLITE_OMIT_FLOATING_POINT
11209 # undef double
11210 #endif
11211
11212 #if defined(__wasi__)
11213 # undef SQLITE_WASI
11214 # define SQLITE_WASI 1
11215 # ifndef SQLITE_OMIT_LOAD_EXTENSION
11216 # define SQLITE_OMIT_LOAD_EXTENSION
11217 # endif
11218 # ifndef SQLITE_THREADSAFE
11219 # define SQLITE_THREADSAFE 0
11220 # endif
11221 #endif
11222
11223 #ifdef __cplusplus
11224 } /* End of the 'extern "C"' block */
11225 #endif
11226 /* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11227
11228 /******** Begin file sqlite3rtree.h *********/
11229 /*
11230 ** 2010 August 30
11231 **
11232 ** The author disclaims copyright to this source code. In place of
11233 ** a legal notice, here is a blessing:
11234 **
11235 ** May you do good and not evil.
11236 ** May you find forgiveness for yourself and forgive others.
11237 ** May you share freely, never taking more than you give.
11238 **
11239 *************************************************************************
11240 */
11241
11242 #ifndef _SQLITE3RTREE_H_
11243 #define _SQLITE3RTREE_H_
11244
11245
11246 #ifdef __cplusplus
11247 extern "C" {
11248 #endif
11249
11250 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11251 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11252
11253 /* The double-precision datatype used by RTree depends on the
11254 ** SQLITE_RTREE_INT_ONLY compile-time option.
11255 */
11256 #ifdef SQLITE_RTREE_INT_ONLY
11257 typedef sqlite3_int64 sqlite3_rtree_dbl;
11258 #else
11259 typedef double sqlite3_rtree_dbl;
11260 #endif
11261
11262 /*
11263 ** Register a geometry callback named zGeom that can be used as part of an
11264 ** R-Tree geometry query as follows:
11265 **
11266 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11267 */
11268 SQLITE_API int sqlite3_rtree_geometry_callback(
11269 sqlite3 *db,
11270 const char *zGeom,
11271 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11272 void *pContext
11273 );
11274
11275
11276 /*
11277 ** A pointer to a structure of the following type is passed as the first
11278 ** argument to callbacks registered using rtree_geometry_callback().
11279 */
11280 struct sqlite3_rtree_geometry {
11281 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11282 int nParam; /* Size of array aParam[] */
11283 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11284 void *pUser; /* Callback implementation user data */
11285 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11286 };
11287
11288 /*
11289 ** Register a 2nd-generation geometry callback named zScore that can be
11290 ** used as part of an R-Tree geometry query as follows:
11291 **
11292 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11293 */
11294 SQLITE_API int sqlite3_rtree_query_callback(
11295 sqlite3 *db,
11296 const char *zQueryFunc,
11297 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11298 void *pContext,
11299 void (*xDestructor)(void*)
11300 );
11301
11302
11303 /*
11304 ** A pointer to a structure of the following type is passed as the
11305 ** argument to scored geometry callback registered using
11306 ** sqlite3_rtree_query_callback().
11307 **
11308 ** Note that the first 5 fields of this structure are identical to
11309 ** sqlite3_rtree_geometry. This structure is a subclass of
11310 ** sqlite3_rtree_geometry.
11311 */
11312 struct sqlite3_rtree_query_info {
11313 void *pContext; /* pContext from when function registered */
11314 int nParam; /* Number of function parameters */
11315 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11316 void *pUser; /* callback can use this, if desired */
11317 void (*xDelUser)(void*); /* function to free pUser */
11318 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11319 unsigned int *anQueue; /* Number of pending entries in the queue */
11320 int nCoord; /* Number of coordinates */
11321 int iLevel; /* Level of current node or entry */
11322 int mxLevel; /* The largest iLevel value in the tree */
11323 sqlite3_int64 iRowid; /* Rowid for current entry */
11324 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11325 int eParentWithin; /* Visibility of parent node */
11326 int eWithin; /* OUT: Visibility */
11327 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11328 /* The following fields are only available in 3.8.11 and later */
11329 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11330 };
11331
11332 /*
11333 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11334 */
11335 #define NOT_WITHIN 0 /* Object completely outside of query region */
11336 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11337 #define FULLY_WITHIN 2 /* Object fully contained within query region */
11338
11339
11340 #ifdef __cplusplus
11341 } /* end of the 'extern "C"' block */
11342 #endif
11343
11344 #endif /* ifndef _SQLITE3RTREE_H_ */
11345
11346 /******** End of sqlite3rtree.h *********/
11347 /******** Begin file sqlite3session.h *********/
11348
11349 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11350 #define __SQLITESESSION_H_ 1
11351
11352 /*
11353 ** Make sure we can call this stuff from C++.
11354 */
11355 #ifdef __cplusplus
11356 extern "C" {
11357 #endif
11358
11359
11360 /*
11361 ** CAPI3REF: Session Object Handle
11362 **
11363 ** An instance of this object is a [session] that can be used to
11364 ** record changes to a database.
11365 */
11366 typedef struct sqlite3_session sqlite3_session;
11367
11368 /*
11369 ** CAPI3REF: Changeset Iterator Handle
11370 **
11371 ** An instance of this object acts as a cursor for iterating
11372 ** over the elements of a [changeset] or [patchset].
11373 */
11374 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11375
11376 /*
11377 ** CAPI3REF: Create A New Session Object
11378 ** CONSTRUCTOR: sqlite3_session
11379 **
11380 ** Create a new session object attached to database handle db. If successful,
11381 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
11382 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11383 ** error code (e.g. SQLITE_NOMEM) is returned.
11384 **
11385 ** It is possible to create multiple session objects attached to a single
11386 ** database handle.
11387 **
11388 ** Session objects created using this function should be deleted using the
11389 ** [sqlite3session_delete()] function before the database handle that they
11390 ** are attached to is itself closed. If the database handle is closed before
11391 ** the session object is deleted, then the results of calling any session
11392 ** module function, including [sqlite3session_delete()] on the session object
11393 ** are undefined.
11394 **
11395 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11396 ** is not possible for an application to register a pre-update hook on a
11397 ** database handle that has one or more session objects attached. Nor is
11398 ** it possible to create a session object attached to a database handle for
11399 ** which a pre-update hook is already defined. The results of attempting
11400 ** either of these things are undefined.
11401 **
11402 ** The session object will be used to create changesets for tables in
11403 ** database zDb, where zDb is either "main", or "temp", or the name of an
11404 ** attached database. It is not an error if database zDb is not attached
11405 ** to the database when the session object is created.
11406 */
11407 SQLITE_API int sqlite3session_create(
11408 sqlite3 *db, /* Database handle */
11409 const char *zDb, /* Name of db (e.g. "main") */
11410 sqlite3_session **ppSession /* OUT: New session object */
11411 );
11412
11413 /*
11414 ** CAPI3REF: Delete A Session Object
11415 ** DESTRUCTOR: sqlite3_session
11416 **
11417 ** Delete a session object previously allocated using
11418 ** [sqlite3session_create()]. Once a session object has been deleted, the
11419 ** results of attempting to use pSession with any other session module
11420 ** function are undefined.
11421 **
11422 ** Session objects must be deleted before the database handle to which they
11423 ** are attached is closed. Refer to the documentation for
11424 ** [sqlite3session_create()] for details.
11425 */
11426 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11427
11428 /*
11429 ** CAPI3REF: Configure a Session Object
11430 ** METHOD: sqlite3_session
11431 **
11432 ** This method is used to configure a session object after it has been
11433 ** created. At present the only valid values for the second parameter are
11434 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11435 **
11436 */
11437 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11438
11439 /*
11440 ** CAPI3REF: Options for sqlite3session_object_config
11441 **
11442 ** The following values may passed as the the 2nd parameter to
11443 ** sqlite3session_object_config().
11444 **
11445 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11446 ** This option is used to set, clear or query the flag that enables
11447 ** the [sqlite3session_changeset_size()] API. Because it imposes some
11448 ** computational overhead, this API is disabled by default. Argument
11449 ** pArg must point to a value of type (int). If the value is initially
11450 ** 0, then the sqlite3session_changeset_size() API is disabled. If it
11451 ** is greater than 0, then the same API is enabled. Or, if the initial
11452 ** value is less than zero, no change is made. In all cases the (int)
11453 ** variable is set to 1 if the sqlite3session_changeset_size() API is
11454 ** enabled following the current call, or 0 otherwise.
11455 **
11456 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11457 ** the first table has been attached to the session object.
11458 **
11459 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11460 ** This option is used to set, clear or query the flag that enables
11461 ** collection of data for tables with no explicit PRIMARY KEY.
11462 **
11463 ** Normally, tables with no explicit PRIMARY KEY are simply ignored
11464 ** by the sessions module. However, if this flag is set, it behaves
11465 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11466 ** as their leftmost columns.
11467 **
11468 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11469 ** the first table has been attached to the session object.
11470 */
11471 #define SQLITE_SESSION_OBJCONFIG_SIZE 1
11472 #define SQLITE_SESSION_OBJCONFIG_ROWID 2
11473
11474 /*
11475 ** CAPI3REF: Enable Or Disable A Session Object
11476 ** METHOD: sqlite3_session
11477 **
11478 ** Enable or disable the recording of changes by a session object. When
11479 ** enabled, a session object records changes made to the database. When
11480 ** disabled - it does not. A newly created session object is enabled.
11481 ** Refer to the documentation for [sqlite3session_changeset()] for further
11482 ** details regarding how enabling and disabling a session object affects
11483 ** the eventual changesets.
11484 **
11485 ** Passing zero to this function disables the session. Passing a value
11486 ** greater than zero enables it. Passing a value less than zero is a
11487 ** no-op, and may be used to query the current state of the session.
11488 **
11489 ** The return value indicates the final state of the session object: 0 if
11490 ** the session is disabled, or 1 if it is enabled.
11491 */
11492 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11493
11494 /*
11495 ** CAPI3REF: Set Or Clear the Indirect Change Flag
11496 ** METHOD: sqlite3_session
11497 **
11498 ** Each change recorded by a session object is marked as either direct or
11499 ** indirect. A change is marked as indirect if either:
11500 **
11501 ** <ul>
11502 ** <li> The session object "indirect" flag is set when the change is
11503 ** made, or
11504 ** <li> The change is made by an SQL trigger or foreign key action
11505 ** instead of directly as a result of a users SQL statement.
11506 ** </ul>
11507 **
11508 ** If a single row is affected by more than one operation within a session,
11509 ** then the change is considered indirect if all operations meet the criteria
11510 ** for an indirect change above, or direct otherwise.
11511 **
11512 ** This function is used to set, clear or query the session object indirect
11513 ** flag. If the second argument passed to this function is zero, then the
11514 ** indirect flag is cleared. If it is greater than zero, the indirect flag
11515 ** is set. Passing a value less than zero does not modify the current value
11516 ** of the indirect flag, and may be used to query the current state of the
11517 ** indirect flag for the specified session object.
11518 **
11519 ** The return value indicates the final state of the indirect flag: 0 if
11520 ** it is clear, or 1 if it is set.
11521 */
11522 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11523
11524 /*
11525 ** CAPI3REF: Attach A Table To A Session Object
11526 ** METHOD: sqlite3_session
11527 **
11528 ** If argument zTab is not NULL, then it is the name of a table to attach
11529 ** to the session object passed as the first argument. All subsequent changes
11530 ** made to the table while the session object is enabled will be recorded. See
11531 ** documentation for [sqlite3session_changeset()] for further details.
11532 **
11533 ** Or, if argument zTab is NULL, then changes are recorded for all tables
11534 ** in the database. If additional tables are added to the database (by
11535 ** executing "CREATE TABLE" statements) after this call is made, changes for
11536 ** the new tables are also recorded.
11537 **
11538 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11539 ** defined as part of their CREATE TABLE statement. It does not matter if the
11540 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11541 ** KEY may consist of a single column, or may be a composite key.
11542 **
11543 ** It is not an error if the named table does not exist in the database. Nor
11544 ** is it an error if the named table does not have a PRIMARY KEY. However,
11545 ** no changes will be recorded in either of these scenarios.
11546 **
11547 ** Changes are not recorded for individual rows that have NULL values stored
11548 ** in one or more of their PRIMARY KEY columns.
11549 **
11550 ** SQLITE_OK is returned if the call completes without error. Or, if an error
11551 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11552 **
11553 ** <h3>Special sqlite_stat1 Handling</h3>
11554 **
11555 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11556 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11557 ** <pre>
11558 ** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11559 ** </pre>
11560 **
11561 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11562 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11563 ** are recorded for rows for which (idx IS NULL) is true. However, for such
11564 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
11565 ** patchset instead of a NULL value. This allows such changesets to be
11566 ** manipulated by legacy implementations of sqlite3changeset_invert(),
11567 ** concat() and similar.
11568 **
11569 ** The sqlite3changeset_apply() function automatically converts the
11570 ** zero-length blob back to a NULL value when updating the sqlite_stat1
11571 ** table. However, if the application calls sqlite3changeset_new(),
11572 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11573 ** iterator directly (including on a changeset iterator passed to a
11574 ** conflict-handler callback) then the X'' value is returned. The application
11575 ** must translate X'' to NULL itself if required.
11576 **
11577 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11578 ** changes made to the sqlite_stat1 table. Legacy versions of the
11579 ** sqlite3changeset_apply() function silently ignore any modifications to the
11580 ** sqlite_stat1 table that are part of a changeset or patchset.
11581 */
11582 SQLITE_API int sqlite3session_attach(
11583 sqlite3_session *pSession, /* Session object */
11584 const char *zTab /* Table name */
11585 );
11586
11587 /*
11588 ** CAPI3REF: Set a table filter on a Session Object.
11589 ** METHOD: sqlite3_session
11590 **
11591 ** The second argument (xFilter) is the "filter callback". For changes to rows
11592 ** in tables that are not attached to the Session object, the filter is called
11593 ** to determine whether changes to the table's rows should be tracked or not.
11594 ** If xFilter returns 0, changes are not tracked. Note that once a table is
11595 ** attached, xFilter will not be called again.
11596 */
11597 SQLITE_API void sqlite3session_table_filter(
11598 sqlite3_session *pSession, /* Session object */
11599 int(*xFilter)(
11600 void *pCtx, /* Copy of third arg to _filter_table() */
11601 const char *zTab /* Table name */
11602 ),
11603 void *pCtx /* First argument passed to xFilter */
11604 );
11605
11606 /*
11607 ** CAPI3REF: Generate A Changeset From A Session Object
11608 ** METHOD: sqlite3_session
11609 **
11610 ** Obtain a changeset containing changes to the tables attached to the
11611 ** session object passed as the first argument. If successful,
11612 ** set *ppChangeset to point to a buffer containing the changeset
11613 ** and *pnChangeset to the size of the changeset in bytes before returning
11614 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11615 ** zero and return an SQLite error code.
11616 **
11617 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11618 ** each representing a change to a single row of an attached table. An INSERT
11619 ** change contains the values of each field of a new database row. A DELETE
11620 ** contains the original values of each field of a deleted database row. An
11621 ** UPDATE change contains the original values of each field of an updated
11622 ** database row along with the updated values for each updated non-primary-key
11623 ** column. It is not possible for an UPDATE change to represent a change that
11624 ** modifies the values of primary key columns. If such a change is made, it
11625 ** is represented in a changeset as a DELETE followed by an INSERT.
11626 **
11627 ** Changes are not recorded for rows that have NULL values stored in one or
11628 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11629 ** no corresponding change is present in the changesets returned by this
11630 ** function. If an existing row with one or more NULL values stored in
11631 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11632 ** only an INSERT is appears in the changeset. Similarly, if an existing row
11633 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
11634 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11635 ** DELETE change only.
11636 **
11637 ** The contents of a changeset may be traversed using an iterator created
11638 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
11639 ** a database with a compatible schema using the [sqlite3changeset_apply()]
11640 ** API.
11641 **
11642 ** Within a changeset generated by this function, all changes related to a
11643 ** single table are grouped together. In other words, when iterating through
11644 ** a changeset or when applying a changeset to a database, all changes related
11645 ** to a single table are processed before moving on to the next table. Tables
11646 ** are sorted in the same order in which they were attached (or auto-attached)
11647 ** to the sqlite3_session object. The order in which the changes related to
11648 ** a single table are stored is undefined.
11649 **
11650 ** Following a successful call to this function, it is the responsibility of
11651 ** the caller to eventually free the buffer that *ppChangeset points to using
11652 ** [sqlite3_free()].
11653 **
11654 ** <h3>Changeset Generation</h3>
11655 **
11656 ** Once a table has been attached to a session object, the session object
11657 ** records the primary key values of all new rows inserted into the table.
11658 ** It also records the original primary key and other column values of any
11659 ** deleted or updated rows. For each unique primary key value, data is only
11660 ** recorded once - the first time a row with said primary key is inserted,
11661 ** updated or deleted in the lifetime of the session.
11662 **
11663 ** There is one exception to the previous paragraph: when a row is inserted,
11664 ** updated or deleted, if one or more of its primary key columns contain a
11665 ** NULL value, no record of the change is made.
11666 **
11667 ** The session object therefore accumulates two types of records - those
11668 ** that consist of primary key values only (created when the user inserts
11669 ** a new record) and those that consist of the primary key values and the
11670 ** original values of other table columns (created when the users deletes
11671 ** or updates a record).
11672 **
11673 ** When this function is called, the requested changeset is created using
11674 ** both the accumulated records and the current contents of the database
11675 ** file. Specifically:
11676 **
11677 ** <ul>
11678 ** <li> For each record generated by an insert, the database is queried
11679 ** for a row with a matching primary key. If one is found, an INSERT
11680 ** change is added to the changeset. If no such row is found, no change
11681 ** is added to the changeset.
11682 **
11683 ** <li> For each record generated by an update or delete, the database is
11684 ** queried for a row with a matching primary key. If such a row is
11685 ** found and one or more of the non-primary key fields have been
11686 ** modified from their original values, an UPDATE change is added to
11687 ** the changeset. Or, if no such row is found in the table, a DELETE
11688 ** change is added to the changeset. If there is a row with a matching
11689 ** primary key in the database, but all fields contain their original
11690 ** values, no change is added to the changeset.
11691 ** </ul>
11692 **
11693 ** This means, amongst other things, that if a row is inserted and then later
11694 ** deleted while a session object is active, neither the insert nor the delete
11695 ** will be present in the changeset. Or if a row is deleted and then later a
11696 ** row with the same primary key values inserted while a session object is
11697 ** active, the resulting changeset will contain an UPDATE change instead of
11698 ** a DELETE and an INSERT.
11699 **
11700 ** When a session object is disabled (see the [sqlite3session_enable()] API),
11701 ** it does not accumulate records when rows are inserted, updated or deleted.
11702 ** This may appear to have some counter-intuitive effects if a single row
11703 ** is written to more than once during a session. For example, if a row
11704 ** is inserted while a session object is enabled, then later deleted while
11705 ** the same session object is disabled, no INSERT record will appear in the
11706 ** changeset, even though the delete took place while the session was disabled.
11707 ** Or, if one field of a row is updated while a session is enabled, and
11708 ** then another field of the same row is updated while the session is disabled,
11709 ** the resulting changeset will contain an UPDATE change that updates both
11710 ** fields.
11711 */
11712 SQLITE_API int sqlite3session_changeset(
11713 sqlite3_session *pSession, /* Session object */
11714 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11715 void **ppChangeset /* OUT: Buffer containing changeset */
11716 );
11717
11718 /*
11719 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11720 ** METHOD: sqlite3_session
11721 **
11722 ** By default, this function always returns 0. For it to return
11723 ** a useful result, the sqlite3_session object must have been configured
11724 ** to enable this API using sqlite3session_object_config() with the
11725 ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11726 **
11727 ** When enabled, this function returns an upper limit, in bytes, for the size
11728 ** of the changeset that might be produced if sqlite3session_changeset() were
11729 ** called. The final changeset size might be equal to or smaller than the
11730 ** size in bytes returned by this function.
11731 */
11732 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11733
11734 /*
11735 ** CAPI3REF: Load The Difference Between Tables Into A Session
11736 ** METHOD: sqlite3_session
11737 **
11738 ** If it is not already attached to the session object passed as the first
11739 ** argument, this function attaches table zTbl in the same manner as the
11740 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11741 ** does not have a primary key, this function is a no-op (but does not return
11742 ** an error).
11743 **
11744 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11745 ** attached to the same database handle as the session object that contains
11746 ** a table compatible with the table attached to the session by this function.
11747 ** A table is considered compatible if it:
11748 **
11749 ** <ul>
11750 ** <li> Has the same name,
11751 ** <li> Has the same set of columns declared in the same order, and
11752 ** <li> Has the same PRIMARY KEY definition.
11753 ** </ul>
11754 **
11755 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11756 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
11757 ** but no changes are added to the session object. As with other session
11758 ** APIs, tables without PRIMARY KEYs are simply ignored.
11759 **
11760 ** This function adds a set of changes to the session object that could be
11761 ** used to update the table in database zFrom (call this the "from-table")
11762 ** so that its content is the same as the table attached to the session
11763 ** object (call this the "to-table"). Specifically:
11764 **
11765 ** <ul>
11766 ** <li> For each row (primary key) that exists in the to-table but not in
11767 ** the from-table, an INSERT record is added to the session object.
11768 **
11769 ** <li> For each row (primary key) that exists in the to-table but not in
11770 ** the from-table, a DELETE record is added to the session object.
11771 **
11772 ** <li> For each row (primary key) that exists in both tables, but features
11773 ** different non-PK values in each, an UPDATE record is added to the
11774 ** session.
11775 ** </ul>
11776 **
11777 ** To clarify, if this function is called and then a changeset constructed
11778 ** using [sqlite3session_changeset()], then after applying that changeset to
11779 ** database zFrom the contents of the two compatible tables would be
11780 ** identical.
11781 **
11782 ** Unless the call to this function is a no-op as described above, it is an
11783 ** error if database zFrom does not exist or does not contain the required
11784 ** compatible table.
11785 **
11786 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11787 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11788 ** may be set to point to a buffer containing an English language error
11789 ** message. It is the responsibility of the caller to free this buffer using
11790 ** sqlite3_free().
11791 */
11792 SQLITE_API int sqlite3session_diff(
11793 sqlite3_session *pSession,
11794 const char *zFromDb,
11795 const char *zTbl,
11796 char **pzErrMsg
11797 );
11798
11799
11800 /*
11801 ** CAPI3REF: Generate A Patchset From A Session Object
11802 ** METHOD: sqlite3_session
11803 **
11804 ** The differences between a patchset and a changeset are that:
11805 **
11806 ** <ul>
11807 ** <li> DELETE records consist of the primary key fields only. The
11808 ** original values of other fields are omitted.
11809 ** <li> The original values of any modified fields are omitted from
11810 ** UPDATE records.
11811 ** </ul>
11812 **
11813 ** A patchset blob may be used with up to date versions of all
11814 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11815 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11816 ** attempting to use a patchset blob with old versions of the
11817 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11818 **
11819 ** Because the non-primary key "old.*" fields are omitted, no
11820 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11821 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
11822 ** in the same way as for changesets.
11823 **
11824 ** Changes within a patchset are ordered in the same way as for changesets
11825 ** generated by the sqlite3session_changeset() function (i.e. all changes for
11826 ** a single table are grouped together, tables appear in the order in which
11827 ** they were attached to the session object).
11828 */
11829 SQLITE_API int sqlite3session_patchset(
11830 sqlite3_session *pSession, /* Session object */
11831 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11832 void **ppPatchset /* OUT: Buffer containing patchset */
11833 );
11834
11835 /*
11836 ** CAPI3REF: Test if a changeset has recorded any changes.
11837 **
11838 ** Return non-zero if no changes to attached tables have been recorded by
11839 ** the session object passed as the first argument. Otherwise, if one or
11840 ** more changes have been recorded, return zero.
11841 **
11842 ** Even if this function returns zero, it is possible that calling
11843 ** [sqlite3session_changeset()] on the session handle may still return a
11844 ** changeset that contains no changes. This can happen when a row in
11845 ** an attached table is modified and then later on the original values
11846 ** are restored. However, if this function returns non-zero, then it is
11847 ** guaranteed that a call to sqlite3session_changeset() will return a
11848 ** changeset containing zero changes.
11849 */
11850 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11851
11852 /*
11853 ** CAPI3REF: Query for the amount of heap memory used by a session object.
11854 **
11855 ** This API returns the total amount of heap memory in bytes currently
11856 ** used by the session object passed as the only argument.
11857 */
11858 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11859
11860 /*
11861 ** CAPI3REF: Create An Iterator To Traverse A Changeset
11862 ** CONSTRUCTOR: sqlite3_changeset_iter
11863 **
11864 ** Create an iterator used to iterate through the contents of a changeset.
11865 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11866 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11867 ** SQLite error code is returned.
11868 **
11869 ** The following functions can be used to advance and query a changeset
11870 ** iterator created by this function:
11871 **
11872 ** <ul>
11873 ** <li> [sqlite3changeset_next()]
11874 ** <li> [sqlite3changeset_op()]
11875 ** <li> [sqlite3changeset_new()]
11876 ** <li> [sqlite3changeset_old()]
11877 ** </ul>
11878 **
11879 ** It is the responsibility of the caller to eventually destroy the iterator
11880 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11881 ** changeset (pChangeset) must remain valid until after the iterator is
11882 ** destroyed.
11883 **
11884 ** Assuming the changeset blob was created by one of the
11885 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11886 ** [sqlite3changeset_invert()] functions, all changes within the changeset
11887 ** that apply to a single table are grouped together. This means that when
11888 ** an application iterates through a changeset using an iterator created by
11889 ** this function, all changes that relate to a single table are visited
11890 ** consecutively. There is no chance that the iterator will visit a change
11891 ** the applies to table X, then one for table Y, and then later on visit
11892 ** another change for table X.
11893 **
11894 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11895 ** may be modified by passing a combination of
11896 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11897 **
11898 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11899 ** and therefore subject to change.
11900 */
11901 SQLITE_API int sqlite3changeset_start(
11902 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11903 int nChangeset, /* Size of changeset blob in bytes */
11904 void *pChangeset /* Pointer to blob containing changeset */
11905 );
11906 SQLITE_API int sqlite3changeset_start_v2(
11907 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11908 int nChangeset, /* Size of changeset blob in bytes */
11909 void *pChangeset, /* Pointer to blob containing changeset */
11910 int flags /* SESSION_CHANGESETSTART_* flags */
11911 );
11912
11913 /*
11914 ** CAPI3REF: Flags for sqlite3changeset_start_v2
11915 **
11916 ** The following flags may passed via the 4th parameter to
11917 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11918 **
11919 ** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
11920 ** Invert the changeset while iterating through it. This is equivalent to
11921 ** inverting a changeset using sqlite3changeset_invert() before applying it.
11922 ** It is an error to specify this flag with a patchset.
11923 */
11924 #define SQLITE_CHANGESETSTART_INVERT 0x0002
11925
11926
11927 /*
11928 ** CAPI3REF: Advance A Changeset Iterator
11929 ** METHOD: sqlite3_changeset_iter
11930 **
11931 ** This function may only be used with iterators created by the function
11932 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
11933 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11934 ** is returned and the call has no effect.
11935 **
11936 ** Immediately after an iterator is created by sqlite3changeset_start(), it
11937 ** does not point to any change in the changeset. Assuming the changeset
11938 ** is not empty, the first call to this function advances the iterator to
11939 ** point to the first change in the changeset. Each subsequent call advances
11940 ** the iterator to point to the next change in the changeset (if any). If
11941 ** no error occurs and the iterator points to a valid change after a call
11942 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11943 ** Otherwise, if all changes in the changeset have already been visited,
11944 ** SQLITE_DONE is returned.
11945 **
11946 ** If an error occurs, an SQLite error code is returned. Possible error
11947 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11948 ** SQLITE_NOMEM.
11949 */
11950 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11951
11952 /*
11953 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11954 ** METHOD: sqlite3_changeset_iter
11955 **
11956 ** The pIter argument passed to this function may either be an iterator
11957 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11958 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11959 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11960 ** is not the case, this function returns [SQLITE_MISUSE].
11961 **
11962 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11963 ** outputs are set through these pointers:
11964 **
11965 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11966 ** depending on the type of change that the iterator currently points to;
11967 **
11968 ** *pnCol is set to the number of columns in the table affected by the change; and
11969 **
11970 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11971 ** the name of the table affected by the current change. The buffer remains
11972 ** valid until either sqlite3changeset_next() is called on the iterator
11973 ** or until the conflict-handler function returns.
11974 **
11975 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11976 ** is an indirect change, or false (0) otherwise. See the documentation for
11977 ** [sqlite3session_indirect()] for a description of direct and indirect
11978 ** changes.
11979 **
11980 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11981 ** SQLite error code is returned. The values of the output variables may not
11982 ** be trusted in this case.
11983 */
11984 SQLITE_API int sqlite3changeset_op(
11985 sqlite3_changeset_iter *pIter, /* Iterator object */
11986 const char **pzTab, /* OUT: Pointer to table name */
11987 int *pnCol, /* OUT: Number of columns in table */
11988 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11989 int *pbIndirect /* OUT: True for an 'indirect' change */
11990 );
11991
11992 /*
11993 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
11994 ** METHOD: sqlite3_changeset_iter
11995 **
11996 ** For each modified table, a changeset includes the following:
11997 **
11998 ** <ul>
11999 ** <li> The number of columns in the table, and
12000 ** <li> Which of those columns make up the tables PRIMARY KEY.
12001 ** </ul>
12002 **
12003 ** This function is used to find which columns comprise the PRIMARY KEY of
12004 ** the table modified by the change that iterator pIter currently points to.
12005 ** If successful, *pabPK is set to point to an array of nCol entries, where
12006 ** nCol is the number of columns in the table. Elements of *pabPK are set to
12007 ** 0x01 if the corresponding column is part of the tables primary key, or
12008 ** 0x00 if it is not.
12009 **
12010 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
12011 ** in the table.
12012 **
12013 ** If this function is called when the iterator does not point to a valid
12014 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
12015 ** SQLITE_OK is returned and the output variables populated as described
12016 ** above.
12017 */
12018 SQLITE_API int sqlite3changeset_pk(
12019 sqlite3_changeset_iter *pIter, /* Iterator object */
12020 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
12021 int *pnCol /* OUT: Number of entries in output array */
12022 );
12023
12024 /*
12025 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
12026 ** METHOD: sqlite3_changeset_iter
12027 **
12028 ** The pIter argument passed to this function may either be an iterator
12029 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12030 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
12031 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12032 ** Furthermore, it may only be called if the type of change that the iterator
12033 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
12034 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12035 **
12036 ** Argument iVal must be greater than or equal to 0, and less than the number
12037 ** of columns in the table affected by the current change. Otherwise,
12038 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12039 **
12040 ** If successful, this function sets *ppValue to point to a protected
12041 ** sqlite3_value object containing the iVal'th value from the vector of
12042 ** original row values stored as part of the UPDATE or DELETE change and
12043 ** returns SQLITE_OK. The name of the function comes from the fact that this
12044 ** is similar to the "old.*" columns available to update or delete triggers.
12045 **
12046 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
12047 ** is returned and *ppValue is set to NULL.
12048 */
12049 SQLITE_API int sqlite3changeset_old(
12050 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12051 int iVal, /* Column number */
12052 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
12053 );
12054
12055 /*
12056 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
12057 ** METHOD: sqlite3_changeset_iter
12058 **
12059 ** The pIter argument passed to this function may either be an iterator
12060 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
12061 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
12062 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
12063 ** Furthermore, it may only be called if the type of change that the iterator
12064 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
12065 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
12066 **
12067 ** Argument iVal must be greater than or equal to 0, and less than the number
12068 ** of columns in the table affected by the current change. Otherwise,
12069 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12070 **
12071 ** If successful, this function sets *ppValue to point to a protected
12072 ** sqlite3_value object containing the iVal'th value from the vector of
12073 ** new row values stored as part of the UPDATE or INSERT change and
12074 ** returns SQLITE_OK. If the change is an UPDATE and does not include
12075 ** a new value for the requested column, *ppValue is set to NULL and
12076 ** SQLITE_OK returned. The name of the function comes from the fact that
12077 ** this is similar to the "new.*" columns available to update or delete
12078 ** triggers.
12079 **
12080 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
12081 ** is returned and *ppValue is set to NULL.
12082 */
12083 SQLITE_API int sqlite3changeset_new(
12084 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12085 int iVal, /* Column number */
12086 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
12087 );
12088
12089 /*
12090 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
12091 ** METHOD: sqlite3_changeset_iter
12092 **
12093 ** This function should only be used with iterator objects passed to a
12094 ** conflict-handler callback by [sqlite3changeset_apply()] with either
12095 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
12096 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
12097 ** is set to NULL.
12098 **
12099 ** Argument iVal must be greater than or equal to 0, and less than the number
12100 ** of columns in the table affected by the current change. Otherwise,
12101 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
12102 **
12103 ** If successful, this function sets *ppValue to point to a protected
12104 ** sqlite3_value object containing the iVal'th value from the
12105 ** "conflicting row" associated with the current conflict-handler callback
12106 ** and returns SQLITE_OK.
12107 **
12108 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
12109 ** is returned and *ppValue is set to NULL.
12110 */
12111 SQLITE_API int sqlite3changeset_conflict(
12112 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12113 int iVal, /* Column number */
12114 sqlite3_value **ppValue /* OUT: Value from conflicting row */
12115 );
12116
12117 /*
12118 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
12119 ** METHOD: sqlite3_changeset_iter
12120 **
12121 ** This function may only be called with an iterator passed to an
12122 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
12123 ** it sets the output variable to the total number of known foreign key
12124 ** violations in the destination database and returns SQLITE_OK.
12125 **
12126 ** In all other cases this function returns SQLITE_MISUSE.
12127 */
12128 SQLITE_API int sqlite3changeset_fk_conflicts(
12129 sqlite3_changeset_iter *pIter, /* Changeset iterator */
12130 int *pnOut /* OUT: Number of FK violations */
12131 );
12132
12133
12134 /*
12135 ** CAPI3REF: Finalize A Changeset Iterator
12136 ** METHOD: sqlite3_changeset_iter
12137 **
12138 ** This function is used to finalize an iterator allocated with
12139 ** [sqlite3changeset_start()].
12140 **
12141 ** This function should only be called on iterators created using the
12142 ** [sqlite3changeset_start()] function. If an application calls this
12143 ** function with an iterator passed to a conflict-handler by
12144 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
12145 ** call has no effect.
12146 **
12147 ** If an error was encountered within a call to an sqlite3changeset_xxx()
12148 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12149 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12150 ** to that error is returned by this function. Otherwise, SQLITE_OK is
12151 ** returned. This is to allow the following pattern (pseudo-code):
12152 **
12153 ** <pre>
12154 ** sqlite3changeset_start();
12155 ** while( SQLITE_ROW==sqlite3changeset_next() ){
12156 ** // Do something with change.
12157 ** }
12158 ** rc = sqlite3changeset_finalize();
12159 ** if( rc!=SQLITE_OK ){
12160 ** // An error has occurred
12161 ** }
12162 ** </pre>
12163 */
12164 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12165
12166 /*
12167 ** CAPI3REF: Invert A Changeset
12168 **
12169 ** This function is used to "invert" a changeset object. Applying an inverted
12170 ** changeset to a database reverses the effects of applying the uninverted
12171 ** changeset. Specifically:
12172 **
12173 ** <ul>
12174 ** <li> Each DELETE change is changed to an INSERT, and
12175 ** <li> Each INSERT change is changed to a DELETE, and
12176 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12177 ** </ul>
12178 **
12179 ** This function does not change the order in which changes appear within
12180 ** the changeset. It merely reverses the sense of each individual change.
12181 **
12182 ** If successful, a pointer to a buffer containing the inverted changeset
12183 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12184 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12185 ** zeroed and an SQLite error code returned.
12186 **
12187 ** It is the responsibility of the caller to eventually call sqlite3_free()
12188 ** on the *ppOut pointer to free the buffer allocation following a successful
12189 ** call to this function.
12190 **
12191 ** WARNING/TODO: This function currently assumes that the input is a valid
12192 ** changeset. If it is not, the results are undefined.
12193 */
12194 SQLITE_API int sqlite3changeset_invert(
12195 int nIn, const void *pIn, /* Input changeset */
12196 int *pnOut, void **ppOut /* OUT: Inverse of input */
12197 );
12198
12199 /*
12200 ** CAPI3REF: Concatenate Two Changeset Objects
12201 **
12202 ** This function is used to concatenate two changesets, A and B, into a
12203 ** single changeset. The result is a changeset equivalent to applying
12204 ** changeset A followed by changeset B.
12205 **
12206 ** This function combines the two input changesets using an
12207 ** sqlite3_changegroup object. Calling it produces similar results as the
12208 ** following code fragment:
12209 **
12210 ** <pre>
12211 ** sqlite3_changegroup *pGrp;
12212 ** rc = sqlite3_changegroup_new(&pGrp);
12213 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12214 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12215 ** if( rc==SQLITE_OK ){
12216 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12217 ** }else{
12218 ** *ppOut = 0;
12219 ** *pnOut = 0;
12220 ** }
12221 ** </pre>
12222 **
12223 ** Refer to the sqlite3_changegroup documentation below for details.
12224 */
12225 SQLITE_API int sqlite3changeset_concat(
12226 int nA, /* Number of bytes in buffer pA */
12227 void *pA, /* Pointer to buffer containing changeset A */
12228 int nB, /* Number of bytes in buffer pB */
12229 void *pB, /* Pointer to buffer containing changeset B */
12230 int *pnOut, /* OUT: Number of bytes in output changeset */
12231 void **ppOut /* OUT: Buffer containing output changeset */
12232 );
12233
12234 /*
12235 ** CAPI3REF: Changegroup Handle
12236 **
12237 ** A changegroup is an object used to combine two or more
12238 ** [changesets] or [patchsets]
12239 */
12240 typedef struct sqlite3_changegroup sqlite3_changegroup;
12241
12242 /*
12243 ** CAPI3REF: Create A New Changegroup Object
12244 ** CONSTRUCTOR: sqlite3_changegroup
12245 **
12246 ** An sqlite3_changegroup object is used to combine two or more changesets
12247 ** (or patchsets) into a single changeset (or patchset). A single changegroup
12248 ** object may combine changesets or patchsets, but not both. The output is
12249 ** always in the same format as the input.
12250 **
12251 ** If successful, this function returns SQLITE_OK and populates (*pp) with
12252 ** a pointer to a new sqlite3_changegroup object before returning. The caller
12253 ** should eventually free the returned object using a call to
12254 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12255 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12256 **
12257 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
12258 **
12259 ** <ul>
12260 ** <li> It is created using a call to sqlite3changegroup_new().
12261 **
12262 ** <li> Zero or more changesets (or patchsets) are added to the object
12263 ** by calling sqlite3changegroup_add().
12264 **
12265 ** <li> The result of combining all input changesets together is obtained
12266 ** by the application via a call to sqlite3changegroup_output().
12267 **
12268 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
12269 ** </ul>
12270 **
12271 ** Any number of calls to add() and output() may be made between the calls to
12272 ** new() and delete(), and in any order.
12273 **
12274 ** As well as the regular sqlite3changegroup_add() and
12275 ** sqlite3changegroup_output() functions, also available are the streaming
12276 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12277 */
12278 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12279
12280 /*
12281 ** CAPI3REF: Add a Schema to a Changegroup
12282 ** METHOD: sqlite3_changegroup_schema
12283 **
12284 ** This method may be used to optionally enforce the rule that the changesets
12285 ** added to the changegroup handle must match the schema of database zDb
12286 ** ("main", "temp", or the name of an attached database). If
12287 ** sqlite3changegroup_add() is called to add a changeset that is not compatible
12288 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12289 ** object is left in an undefined state.
12290 **
12291 ** A changeset schema is considered compatible with the database schema in
12292 ** the same way as for sqlite3changeset_apply(). Specifically, for each
12293 ** table in the changeset, there exists a database table with:
12294 **
12295 ** <ul>
12296 ** <li> The name identified by the changeset, and
12297 ** <li> at least as many columns as recorded in the changeset, and
12298 ** <li> the primary key columns in the same position as recorded in
12299 ** the changeset.
12300 ** </ul>
12301 **
12302 ** The output of the changegroup object always has the same schema as the
12303 ** database nominated using this function. In cases where changesets passed
12304 ** to sqlite3changegroup_add() have fewer columns than the corresponding table
12305 ** in the database schema, these are filled in using the default column
12306 ** values from the database schema. This makes it possible to combined
12307 ** changesets that have different numbers of columns for a single table
12308 ** within a changegroup, provided that they are otherwise compatible.
12309 */
12310 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12311
12312 /*
12313 ** CAPI3REF: Add A Changeset To A Changegroup
12314 ** METHOD: sqlite3_changegroup
12315 **
12316 ** Add all changes within the changeset (or patchset) in buffer pData (size
12317 ** nData bytes) to the changegroup.
12318 **
12319 ** If the buffer contains a patchset, then all prior calls to this function
12320 ** on the same changegroup object must also have specified patchsets. Or, if
12321 ** the buffer contains a changeset, so must have the earlier calls to this
12322 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12323 ** to the changegroup.
12324 **
12325 ** Rows within the changeset and changegroup are identified by the values in
12326 ** their PRIMARY KEY columns. A change in the changeset is considered to
12327 ** apply to the same row as a change already present in the changegroup if
12328 ** the two rows have the same primary key.
12329 **
12330 ** Changes to rows that do not already appear in the changegroup are
12331 ** simply copied into it. Or, if both the new changeset and the changegroup
12332 ** contain changes that apply to a single row, the final contents of the
12333 ** changegroup depends on the type of each change, as follows:
12334 **
12335 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12336 ** <tr><th style="white-space:pre">Existing Change </th>
12337 ** <th style="white-space:pre">New Change </th>
12338 ** <th>Output Change
12339 ** <tr><td>INSERT <td>INSERT <td>
12340 ** The new change is ignored. This case does not occur if the new
12341 ** changeset was recorded immediately after the changesets already
12342 ** added to the changegroup.
12343 ** <tr><td>INSERT <td>UPDATE <td>
12344 ** The INSERT change remains in the changegroup. The values in the
12345 ** INSERT change are modified as if the row was inserted by the
12346 ** existing change and then updated according to the new change.
12347 ** <tr><td>INSERT <td>DELETE <td>
12348 ** The existing INSERT is removed from the changegroup. The DELETE is
12349 ** not added.
12350 ** <tr><td>UPDATE <td>INSERT <td>
12351 ** The new change is ignored. This case does not occur if the new
12352 ** changeset was recorded immediately after the changesets already
12353 ** added to the changegroup.
12354 ** <tr><td>UPDATE <td>UPDATE <td>
12355 ** The existing UPDATE remains within the changegroup. It is amended
12356 ** so that the accompanying values are as if the row was updated once
12357 ** by the existing change and then again by the new change.
12358 ** <tr><td>UPDATE <td>DELETE <td>
12359 ** The existing UPDATE is replaced by the new DELETE within the
12360 ** changegroup.
12361 ** <tr><td>DELETE <td>INSERT <td>
12362 ** If one or more of the column values in the row inserted by the
12363 ** new change differ from those in the row deleted by the existing
12364 ** change, the existing DELETE is replaced by an UPDATE within the
12365 ** changegroup. Otherwise, if the inserted row is exactly the same
12366 ** as the deleted row, the existing DELETE is simply discarded.
12367 ** <tr><td>DELETE <td>UPDATE <td>
12368 ** The new change is ignored. This case does not occur if the new
12369 ** changeset was recorded immediately after the changesets already
12370 ** added to the changegroup.
12371 ** <tr><td>DELETE <td>DELETE <td>
12372 ** The new change is ignored. This case does not occur if the new
12373 ** changeset was recorded immediately after the changesets already
12374 ** added to the changegroup.
12375 ** </table>
12376 **
12377 ** If the new changeset contains changes to a table that is already present
12378 ** in the changegroup, then the number of columns and the position of the
12379 ** primary key columns for the table must be consistent. If this is not the
12380 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12381 ** object has been configured with a database schema using the
12382 ** sqlite3changegroup_schema() API, then it is possible to combine changesets
12383 ** with different numbers of columns for a single table, provided that
12384 ** they are otherwise compatible.
12385 **
12386 ** If the input changeset appears to be corrupt and the corruption is
12387 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12388 ** occurs during processing, this function returns SQLITE_NOMEM.
12389 **
12390 ** In all cases, if an error occurs the state of the final contents of the
12391 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12392 */
12393 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12394
12395 /*
12396 ** CAPI3REF: Add A Single Change To A Changegroup
12397 ** METHOD: sqlite3_changegroup
12398 **
12399 ** This function adds the single change currently indicated by the iterator
12400 ** passed as the second argument to the changegroup object. The rules for
12401 ** adding the change are just as described for [sqlite3changegroup_add()].
12402 **
12403 ** If the change is successfully added to the changegroup, SQLITE_OK is
12404 ** returned. Otherwise, an SQLite error code is returned.
12405 **
12406 ** The iterator must point to a valid entry when this function is called.
12407 ** If it does not, SQLITE_ERROR is returned and no change is added to the
12408 ** changegroup. Additionally, the iterator must not have been opened with
12409 ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12410 ** returned.
12411 */
12412 SQLITE_API int sqlite3changegroup_add_change(
12413 sqlite3_changegroup*,
12414 sqlite3_changeset_iter*
12415 );
12416
12417
12418
12419 /*
12420 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12421 ** METHOD: sqlite3_changegroup
12422 **
12423 ** Obtain a buffer containing a changeset (or patchset) representing the
12424 ** current contents of the changegroup. If the inputs to the changegroup
12425 ** were themselves changesets, the output is a changeset. Or, if the
12426 ** inputs were patchsets, the output is also a patchset.
12427 **
12428 ** As with the output of the sqlite3session_changeset() and
12429 ** sqlite3session_patchset() functions, all changes related to a single
12430 ** table are grouped together in the output of this function. Tables appear
12431 ** in the same order as for the very first changeset added to the changegroup.
12432 ** If the second or subsequent changesets added to the changegroup contain
12433 ** changes for tables that do not appear in the first changeset, they are
12434 ** appended onto the end of the output changeset, again in the order in
12435 ** which they are first encountered.
12436 **
12437 ** If an error occurs, an SQLite error code is returned and the output
12438 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12439 ** is returned and the output variables are set to the size of and a
12440 ** pointer to the output buffer, respectively. In this case it is the
12441 ** responsibility of the caller to eventually free the buffer using a
12442 ** call to sqlite3_free().
12443 */
12444 SQLITE_API int sqlite3changegroup_output(
12445 sqlite3_changegroup*,
12446 int *pnData, /* OUT: Size of output buffer in bytes */
12447 void **ppData /* OUT: Pointer to output buffer */
12448 );
12449
12450 /*
12451 ** CAPI3REF: Delete A Changegroup Object
12452 ** DESTRUCTOR: sqlite3_changegroup
12453 */
12454 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12455
12456 /*
12457 ** CAPI3REF: Apply A Changeset To A Database
12458 **
12459 ** Apply a changeset or patchset to a database. These functions attempt to
12460 ** update the "main" database attached to handle db with the changes found in
12461 ** the changeset passed via the second and third arguments.
12462 **
12463 ** All changes made by these functions are enclosed in a savepoint transaction.
12464 ** If any other error (aside from a constraint failure when attempting to
12465 ** write to the target database) occurs, then the savepoint transaction is
12466 ** rolled back, restoring the target database to its original state, and an
12467 ** SQLite error code returned. Additionally, starting with version 3.51.0,
12468 ** an error code and error message that may be accessed using the
12469 ** [sqlite3_errcode()] and [sqlite3_errmsg()] APIs are left in the database
12470 ** handle.
12471 **
12472 ** The fourth argument (xFilter) passed to these functions is the "filter
12473 ** callback". This may be passed NULL, in which case all changes in the
12474 ** changeset are applied to the database. For sqlite3changeset_apply() and
12475 ** sqlite3_changeset_apply_v2(), if it is not NULL, then it is invoked once
12476 ** for each table affected by at least one change in the changeset. In this
12477 ** case the table name is passed as the second argument, and a copy of
12478 ** the context pointer passed as the sixth argument to apply() or apply_v2()
12479 ** as the first. If the "filter callback" returns zero, then no attempt is
12480 ** made to apply any changes to the table. Otherwise, if the return value is
12481 ** non-zero, all changes related to the table are attempted.
12482 **
12483 ** For sqlite3_changeset_apply_v3(), the xFilter callback is invoked once
12484 ** per change. The second argument in this case is an sqlite3_changeset_iter
12485 ** that may be queried using the usual APIs for the details of the current
12486 ** change. If the "filter callback" returns zero in this case, then no attempt
12487 ** is made to apply the current change. If it returns non-zero, the change
12488 ** is applied.
12489 **
12490 ** For each table that is not excluded by the filter callback, this function
12491 ** tests that the target database contains a compatible table. A table is
12492 ** considered compatible if all of the following are true:
12493 **
12494 ** <ul>
12495 ** <li> The table has the same name as the name recorded in the
12496 ** changeset, and
12497 ** <li> The table has at least as many columns as recorded in the
12498 ** changeset, and
12499 ** <li> The table has primary key columns in the same position as
12500 ** recorded in the changeset.
12501 ** </ul>
12502 **
12503 ** If there is no compatible table, it is not an error, but none of the
12504 ** changes associated with the table are applied. A warning message is issued
12505 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12506 ** one such warning is issued for each table in the changeset.
12507 **
12508 ** For each change for which there is a compatible table, an attempt is made
12509 ** to modify the table contents according to each UPDATE, INSERT or DELETE
12510 ** change that is not excluded by a filter callback. If a change cannot be
12511 ** applied cleanly, the conflict handler function passed as the fifth argument
12512 ** to sqlite3changeset_apply() may be invoked. A description of exactly when
12513 ** the conflict handler is invoked for each type of change is below.
12514 **
12515 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12516 ** of passing anything other than a valid function pointer as the xConflict
12517 ** argument are undefined.
12518 **
12519 ** Each time the conflict handler function is invoked, it must return one
12520 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12521 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12522 ** if the second argument passed to the conflict handler is either
12523 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12524 ** returns an illegal value, any changes already made are rolled back and
12525 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12526 ** actions are taken by sqlite3changeset_apply() depending on the value
12527 ** returned by each invocation of the conflict-handler function. Refer to
12528 ** the documentation for the three
12529 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
12530 **
12531 ** <dl>
12532 ** <dt>DELETE Changes<dd>
12533 ** For each DELETE change, the function checks if the target database
12534 ** contains a row with the same primary key value (or values) as the
12535 ** original row values stored in the changeset. If it does, and the values
12536 ** stored in all non-primary key columns also match the values stored in
12537 ** the changeset the row is deleted from the target database.
12538 **
12539 ** If a row with matching primary key values is found, but one or more of
12540 ** the non-primary key fields contains a value different from the original
12541 ** row value stored in the changeset, the conflict-handler function is
12542 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12543 ** database table has more columns than are recorded in the changeset,
12544 ** only the values of those non-primary key fields are compared against
12545 ** the current database contents - any trailing database table columns
12546 ** are ignored.
12547 **
12548 ** If no row with matching primary key values is found in the database,
12549 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12550 ** passed as the second argument.
12551 **
12552 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12553 ** (which can only happen if a foreign key constraint is violated), the
12554 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12555 ** passed as the second argument. This includes the case where the DELETE
12556 ** operation is attempted because an earlier call to the conflict handler
12557 ** function returned [SQLITE_CHANGESET_REPLACE].
12558 **
12559 ** <dt>INSERT Changes<dd>
12560 ** For each INSERT change, an attempt is made to insert the new row into
12561 ** the database. If the changeset row contains fewer fields than the
12562 ** database table, the trailing fields are populated with their default
12563 ** values.
12564 **
12565 ** If the attempt to insert the row fails because the database already
12566 ** contains a row with the same primary key values, the conflict handler
12567 ** function is invoked with the second argument set to
12568 ** [SQLITE_CHANGESET_CONFLICT].
12569 **
12570 ** If the attempt to insert the row fails because of some other constraint
12571 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12572 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12573 ** This includes the case where the INSERT operation is re-attempted because
12574 ** an earlier call to the conflict handler function returned
12575 ** [SQLITE_CHANGESET_REPLACE].
12576 **
12577 ** <dt>UPDATE Changes<dd>
12578 ** For each UPDATE change, the function checks if the target database
12579 ** contains a row with the same primary key value (or values) as the
12580 ** original row values stored in the changeset. If it does, and the values
12581 ** stored in all modified non-primary key columns also match the values
12582 ** stored in the changeset the row is updated within the target database.
12583 **
12584 ** If a row with matching primary key values is found, but one or more of
12585 ** the modified non-primary key fields contains a value different from an
12586 ** original row value stored in the changeset, the conflict-handler function
12587 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12588 ** UPDATE changes only contain values for non-primary key fields that are
12589 ** to be modified, only those fields need to match the original values to
12590 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12591 **
12592 ** If no row with matching primary key values is found in the database,
12593 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12594 ** passed as the second argument.
12595 **
12596 ** If the UPDATE operation is attempted, but SQLite returns
12597 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12598 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12599 ** This includes the case where the UPDATE operation is attempted after
12600 ** an earlier call to the conflict handler function returned
12601 ** [SQLITE_CHANGESET_REPLACE].
12602 ** </dl>
12603 **
12604 ** It is safe to execute SQL statements, including those that write to the
12605 ** table that the callback related to, from within the xConflict callback.
12606 ** This can be used to further customize the application's conflict
12607 ** resolution strategy.
12608 **
12609 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12610 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12611 ** may set (*ppRebase) to point to a "rebase" that may be used with the
12612 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12613 ** is set to the size of the buffer in bytes. It is the responsibility of the
12614 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
12615 ** is only allocated and populated if one or more conflicts were encountered
12616 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
12617 ** APIs for further details.
12618 **
12619 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12620 ** may be modified by passing a combination of
12621 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12622 **
12623 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12624 ** and therefore subject to change.
12625 */
12626 SQLITE_API int sqlite3changeset_apply(
12627 sqlite3 *db, /* Apply change to "main" db of this handle */
12628 int nChangeset, /* Size of changeset in bytes */
12629 void *pChangeset, /* Changeset blob */
12630 int(*xFilter)(
12631 void *pCtx, /* Copy of sixth arg to _apply() */
12632 const char *zTab /* Table name */
12633 ),
12634 int(*xConflict)(
12635 void *pCtx, /* Copy of sixth arg to _apply() */
12636 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12637 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12638 ),
12639 void *pCtx /* First argument passed to xConflict */
12640 );
12641 SQLITE_API int sqlite3changeset_apply_v2(
12642 sqlite3 *db, /* Apply change to "main" db of this handle */
12643 int nChangeset, /* Size of changeset in bytes */
12644 void *pChangeset, /* Changeset blob */
12645 int(*xFilter)(
12646 void *pCtx, /* Copy of sixth arg to _apply() */
12647 const char *zTab /* Table name */
12648 ),
12649 int(*xConflict)(
12650 void *pCtx, /* Copy of sixth arg to _apply() */
12651 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12652 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12653 ),
12654 void *pCtx, /* First argument passed to xConflict */
12655 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12656 int flags /* SESSION_CHANGESETAPPLY_* flags */
12657 );
12658 SQLITE_API int sqlite3changeset_apply_v3(
12659 sqlite3 *db, /* Apply change to "main" db of this handle */
12660 int nChangeset, /* Size of changeset in bytes */
12661 void *pChangeset, /* Changeset blob */
12662 int(*xFilter)(
12663 void *pCtx, /* Copy of sixth arg to _apply() */
12664 sqlite3_changeset_iter *p /* Handle describing change */
12665 ),
12666 int(*xConflict)(
12667 void *pCtx, /* Copy of sixth arg to _apply() */
12668 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12669 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12670 ),
12671 void *pCtx, /* First argument passed to xConflict */
12672 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12673 int flags /* SESSION_CHANGESETAPPLY_* flags */
12674 );
12675
12676 /*
12677 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
12678 **
12679 ** The following flags may passed via the 9th parameter to
12680 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12681 **
12682 ** <dl>
12683 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12684 ** Usually, the sessions module encloses all operations performed by
12685 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12686 ** SAVEPOINT is committed if the changeset or patchset is successfully
12687 ** applied, or rolled back if an error occurs. Specifying this flag
12688 ** causes the sessions module to omit this savepoint. In this case, if the
12689 ** caller has an open transaction or savepoint when apply_v2() is called,
12690 ** it may revert the partially applied changeset by rolling it back.
12691 **
12692 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12693 ** Invert the changeset before applying it. This is equivalent to inverting
12694 ** a changeset using sqlite3changeset_invert() before applying it. It is
12695 ** an error to specify this flag with a patchset.
12696 **
12697 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12698 ** Do not invoke the conflict handler callback for any changes that
12699 ** would not actually modify the database even if they were applied.
12700 ** Specifically, this means that the conflict handler is not invoked
12701 ** for:
12702 ** <ul>
12703 ** <li>a delete change if the row being deleted cannot be found,
12704 ** <li>an update change if the modified fields are already set to
12705 ** their new values in the conflicting row, or
12706 ** <li>an insert change if all fields of the conflicting row match
12707 ** the row being inserted.
12708 ** </ul>
12709 **
12710 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12711 ** If this flag it set, then all foreign key constraints in the target
12712 ** database behave as if they were declared with "ON UPDATE NO ACTION ON
12713 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12714 ** or SET DEFAULT.
12715 */
12716 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12717 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12718 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12719 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12720
12721 /*
12722 ** CAPI3REF: Constants Passed To The Conflict Handler
12723 **
12724 ** Values that may be passed as the second argument to a conflict-handler.
12725 **
12726 ** <dl>
12727 ** <dt>SQLITE_CHANGESET_DATA<dd>
12728 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
12729 ** when processing a DELETE or UPDATE change if a row with the required
12730 ** PRIMARY KEY fields is present in the database, but one or more other
12731 ** (non primary-key) fields modified by the update do not contain the
12732 ** expected "before" values.
12733 **
12734 ** The conflicting row, in this case, is the database row with the matching
12735 ** primary key.
12736 **
12737 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12738 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12739 ** argument when processing a DELETE or UPDATE change if a row with the
12740 ** required PRIMARY KEY fields is not present in the database.
12741 **
12742 ** There is no conflicting row in this case. The results of invoking the
12743 ** sqlite3changeset_conflict() API are undefined.
12744 **
12745 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12746 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
12747 ** handler while processing an INSERT change if the operation would result
12748 ** in duplicate primary key values.
12749 **
12750 ** The conflicting row in this case is the database row with the matching
12751 ** primary key.
12752 **
12753 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12754 ** If foreign key handling is enabled, and applying a changeset leaves the
12755 ** database in a state containing foreign key violations, the conflict
12756 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12757 ** exactly once before the changeset is committed. If the conflict handler
12758 ** returns CHANGESET_OMIT, the changes, including those that caused the
12759 ** foreign key constraint violation, are committed. Or, if it returns
12760 ** CHANGESET_ABORT, the changeset is rolled back.
12761 **
12762 ** No current or conflicting row information is provided. The only function
12763 ** it is possible to call on the supplied sqlite3_changeset_iter handle
12764 ** is sqlite3changeset_fk_conflicts().
12765 **
12766 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12767 ** If any other constraint violation occurs while applying a change (i.e.
12768 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12769 ** invoked with CHANGESET_CONSTRAINT as the second argument.
12770 **
12771 ** There is no conflicting row in this case. The results of invoking the
12772 ** sqlite3changeset_conflict() API are undefined.
12773 **
12774 ** </dl>
12775 */
12776 #define SQLITE_CHANGESET_DATA 1
12777 #define SQLITE_CHANGESET_NOTFOUND 2
12778 #define SQLITE_CHANGESET_CONFLICT 3
12779 #define SQLITE_CHANGESET_CONSTRAINT 4
12780 #define SQLITE_CHANGESET_FOREIGN_KEY 5
12781
12782 /*
12783 ** CAPI3REF: Constants Returned By The Conflict Handler
12784 **
12785 ** A conflict handler callback must return one of the following three values.
12786 **
12787 ** <dl>
12788 ** <dt>SQLITE_CHANGESET_OMIT<dd>
12789 ** If a conflict handler returns this value no special action is taken. The
12790 ** change that caused the conflict is not applied. The session module
12791 ** continues to the next change in the changeset.
12792 **
12793 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
12794 ** This value may only be returned if the second argument to the conflict
12795 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12796 ** is not the case, any changes applied so far are rolled back and the
12797 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12798 **
12799 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12800 ** handler, then the conflicting row is either updated or deleted, depending
12801 ** on the type of change.
12802 **
12803 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12804 ** handler, then the conflicting row is removed from the database and a
12805 ** second attempt to apply the change is made. If this second attempt fails,
12806 ** the original row is restored to the database before continuing.
12807 **
12808 ** <dt>SQLITE_CHANGESET_ABORT<dd>
12809 ** If this value is returned, any changes applied so far are rolled back
12810 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12811 ** </dl>
12812 */
12813 #define SQLITE_CHANGESET_OMIT 0
12814 #define SQLITE_CHANGESET_REPLACE 1
12815 #define SQLITE_CHANGESET_ABORT 2
12816
12817 /*
12818 ** CAPI3REF: Rebasing changesets
12819 ** EXPERIMENTAL
12820 **
12821 ** Suppose there is a site hosting a database in state S0. And that
12822 ** modifications are made that move that database to state S1 and a
12823 ** changeset recorded (the "local" changeset). Then, a changeset based
12824 ** on S0 is received from another site (the "remote" changeset) and
12825 ** applied to the database. The database is then in state
12826 ** (S1+"remote"), where the exact state depends on any conflict
12827 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
12828 ** Rebasing a changeset is to update it to take those conflict
12829 ** resolution decisions into account, so that the same conflicts
12830 ** do not have to be resolved elsewhere in the network.
12831 **
12832 ** For example, if both the local and remote changesets contain an
12833 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12834 **
12835 ** local: INSERT INTO t1 VALUES(1, 'v1');
12836 ** remote: INSERT INTO t1 VALUES(1, 'v2');
12837 **
12838 ** and the conflict resolution is REPLACE, then the INSERT change is
12839 ** removed from the local changeset (it was overridden). Or, if the
12840 ** conflict resolution was "OMIT", then the local changeset is modified
12841 ** to instead contain:
12842 **
12843 ** UPDATE t1 SET b = 'v2' WHERE a=1;
12844 **
12845 ** Changes within the local changeset are rebased as follows:
12846 **
12847 ** <dl>
12848 ** <dt>Local INSERT<dd>
12849 ** This may only conflict with a remote INSERT. If the conflict
12850 ** resolution was OMIT, then add an UPDATE change to the rebased
12851 ** changeset. Or, if the conflict resolution was REPLACE, add
12852 ** nothing to the rebased changeset.
12853 **
12854 ** <dt>Local DELETE<dd>
12855 ** This may conflict with a remote UPDATE or DELETE. In both cases the
12856 ** only possible resolution is OMIT. If the remote operation was a
12857 ** DELETE, then add no change to the rebased changeset. If the remote
12858 ** operation was an UPDATE, then the old.* fields of change are updated
12859 ** to reflect the new.* values in the UPDATE.
12860 **
12861 ** <dt>Local UPDATE<dd>
12862 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
12863 ** with a DELETE, and the conflict resolution was OMIT, then the update
12864 ** is changed into an INSERT. Any undefined values in the new.* record
12865 ** from the update change are filled in using the old.* values from
12866 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12867 ** the UPDATE change is simply omitted from the rebased changeset.
12868 **
12869 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
12870 ** the old.* values are rebased using the new.* values in the remote
12871 ** change. Or, if the resolution is REPLACE, then the change is copied
12872 ** into the rebased changeset with updates to columns also updated by
12873 ** the conflicting remote UPDATE removed. If this means no columns would
12874 ** be updated, the change is omitted.
12875 ** </dl>
12876 **
12877 ** A local change may be rebased against multiple remote changes
12878 ** simultaneously. If a single key is modified by multiple remote
12879 ** changesets, they are combined as follows before the local changeset
12880 ** is rebased:
12881 **
12882 ** <ul>
12883 ** <li> If there has been one or more REPLACE resolutions on a
12884 ** key, it is rebased according to a REPLACE.
12885 **
12886 ** <li> If there have been no REPLACE resolutions on a key, then
12887 ** the local changeset is rebased according to the most recent
12888 ** of the OMIT resolutions.
12889 ** </ul>
12890 **
12891 ** Note that conflict resolutions from multiple remote changesets are
12892 ** combined on a per-field basis, not per-row. This means that in the
12893 ** case of multiple remote UPDATE operations, some fields of a single
12894 ** local change may be rebased for REPLACE while others are rebased for
12895 ** OMIT.
12896 **
12897 ** In order to rebase a local changeset, the remote changeset must first
12898 ** be applied to the local database using sqlite3changeset_apply_v2() and
12899 ** the buffer of rebase information captured. Then:
12900 **
12901 ** <ol>
12902 ** <li> An sqlite3_rebaser object is created by calling
12903 ** sqlite3rebaser_create().
12904 ** <li> The new object is configured with the rebase buffer obtained from
12905 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12906 ** If the local changeset is to be rebased against multiple remote
12907 ** changesets, then sqlite3rebaser_configure() should be called
12908 ** multiple times, in the same order that the multiple
12909 ** sqlite3changeset_apply_v2() calls were made.
12910 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12911 ** <li> The sqlite3_rebaser object is deleted by calling
12912 ** sqlite3rebaser_delete().
12913 ** </ol>
12914 */
12915 typedef struct sqlite3_rebaser sqlite3_rebaser;
12916
12917 /*
12918 ** CAPI3REF: Create a changeset rebaser object.
12919 ** EXPERIMENTAL
12920 **
12921 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12922 ** point to the new object and return SQLITE_OK. Otherwise, if an error
12923 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12924 ** to NULL.
12925 */
12926 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12927
12928 /*
12929 ** CAPI3REF: Configure a changeset rebaser object.
12930 ** EXPERIMENTAL
12931 **
12932 ** Configure the changeset rebaser object to rebase changesets according
12933 ** to the conflict resolutions described by buffer pRebase (size nRebase
12934 ** bytes), which must have been obtained from a previous call to
12935 ** sqlite3changeset_apply_v2().
12936 */
12937 SQLITE_API int sqlite3rebaser_configure(
12938 sqlite3_rebaser*,
12939 int nRebase, const void *pRebase
12940 );
12941
12942 /*
12943 ** CAPI3REF: Rebase a changeset
12944 ** EXPERIMENTAL
12945 **
12946 ** Argument pIn must point to a buffer containing a changeset nIn bytes
12947 ** in size. This function allocates and populates a buffer with a copy
12948 ** of the changeset rebased according to the configuration of the
12949 ** rebaser object passed as the first argument. If successful, (*ppOut)
12950 ** is set to point to the new buffer containing the rebased changeset and
12951 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12952 ** responsibility of the caller to eventually free the new buffer using
12953 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12954 ** are set to zero and an SQLite error code returned.
12955 */
12956 SQLITE_API int sqlite3rebaser_rebase(
12957 sqlite3_rebaser*,
12958 int nIn, const void *pIn,
12959 int *pnOut, void **ppOut
12960 );
12961
12962 /*
12963 ** CAPI3REF: Delete a changeset rebaser object.
12964 ** EXPERIMENTAL
12965 **
12966 ** Delete the changeset rebaser object and all associated resources. There
12967 ** should be one call to this function for each successful invocation
12968 ** of sqlite3rebaser_create().
12969 */
12970 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12971
12972 /*
12973 ** CAPI3REF: Streaming Versions of API functions.
12974 **
12975 ** The six streaming API xxx_strm() functions serve similar purposes to the
12976 ** corresponding non-streaming API functions:
12977 **
12978 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12979 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12980 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12981 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12982 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12983 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12984 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12985 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12986 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12987 ** </table>
12988 **
12989 ** Non-streaming functions that accept changesets (or patchsets) as input
12990 ** require that the entire changeset be stored in a single buffer in memory.
12991 ** Similarly, those that return a changeset or patchset do so by returning
12992 ** a pointer to a single large buffer allocated using sqlite3_malloc().
12993 ** Normally this is convenient. However, if an application running in a
12994 ** low-memory environment is required to handle very large changesets, the
12995 ** large contiguous memory allocations required can become onerous.
12996 **
12997 ** In order to avoid this problem, instead of a single large buffer, input
12998 ** is passed to a streaming API functions by way of a callback function that
12999 ** the sessions module invokes to incrementally request input data as it is
13000 ** required. In all cases, a pair of API function parameters such as
13001 **
13002 ** <pre>
13003 ** &nbsp; int nChangeset,
13004 ** &nbsp; void *pChangeset,
13005 ** </pre>
13006 **
13007 ** Is replaced by:
13008 **
13009 ** <pre>
13010 ** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
13011 ** &nbsp; void *pIn,
13012 ** </pre>
13013 **
13014 ** Each time the xInput callback is invoked by the sessions module, the first
13015 ** argument passed is a copy of the supplied pIn context pointer. The second
13016 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
13017 ** error occurs the xInput method should copy up to (*pnData) bytes of data
13018 ** into the buffer and set (*pnData) to the actual number of bytes copied
13019 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
13020 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
13021 ** error code should be returned. In all cases, if an xInput callback returns
13022 ** an error, all processing is abandoned and the streaming API function
13023 ** returns a copy of the error code to the caller.
13024 **
13025 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
13026 ** invoked by the sessions module at any point during the lifetime of the
13027 ** iterator. If such an xInput callback returns an error, the iterator enters
13028 ** an error state, whereby all subsequent calls to iterator functions
13029 ** immediately fail with the same error code as returned by xInput.
13030 **
13031 ** Similarly, streaming API functions that return changesets (or patchsets)
13032 ** return them in chunks by way of a callback function instead of via a
13033 ** pointer to a single large buffer. In this case, a pair of parameters such
13034 ** as:
13035 **
13036 ** <pre>
13037 ** &nbsp; int *pnChangeset,
13038 ** &nbsp; void **ppChangeset,
13039 ** </pre>
13040 **
13041 ** Is replaced by:
13042 **
13043 ** <pre>
13044 ** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
13045 ** &nbsp; void *pOut
13046 ** </pre>
13047 **
13048 ** The xOutput callback is invoked zero or more times to return data to
13049 ** the application. The first parameter passed to each call is a copy of the
13050 ** pOut pointer supplied by the application. The second parameter, pData,
13051 ** points to a buffer nData bytes in size containing the chunk of output
13052 ** data being returned. If the xOutput callback successfully processes the
13053 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
13054 ** it should return some other SQLite error code. In this case processing
13055 ** is immediately abandoned and the streaming API function returns a copy
13056 ** of the xOutput error code to the application.
13057 **
13058 ** The sessions module never invokes an xOutput callback with the third
13059 ** parameter set to a value less than or equal to zero. Other than this,
13060 ** no guarantees are made as to the size of the chunks of data returned.
13061 */
13062 SQLITE_API int sqlite3changeset_apply_strm(
13063 sqlite3 *db, /* Apply change to "main" db of this handle */
13064 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13065 void *pIn, /* First arg for xInput */
13066 int(*xFilter)(
13067 void *pCtx, /* Copy of sixth arg to _apply() */
13068 const char *zTab /* Table name */
13069 ),
13070 int(*xConflict)(
13071 void *pCtx, /* Copy of sixth arg to _apply() */
13072 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13073 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13074 ),
13075 void *pCtx /* First argument passed to xConflict */
13076 );
13077 SQLITE_API int sqlite3changeset_apply_v2_strm(
13078 sqlite3 *db, /* Apply change to "main" db of this handle */
13079 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13080 void *pIn, /* First arg for xInput */
13081 int(*xFilter)(
13082 void *pCtx, /* Copy of sixth arg to _apply() */
13083 const char *zTab /* Table name */
13084 ),
13085 int(*xConflict)(
13086 void *pCtx, /* Copy of sixth arg to _apply() */
13087 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13088 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13089 ),
13090 void *pCtx, /* First argument passed to xConflict */
13091 void **ppRebase, int *pnRebase,
13092 int flags
13093 );
13094 SQLITE_API int sqlite3changeset_apply_v3_strm(
13095 sqlite3 *db, /* Apply change to "main" db of this handle */
13096 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
13097 void *pIn, /* First arg for xInput */
13098 int(*xFilter)(
13099 void *pCtx, /* Copy of sixth arg to _apply() */
13100 sqlite3_changeset_iter *p
13101 ),
13102 int(*xConflict)(
13103 void *pCtx, /* Copy of sixth arg to _apply() */
13104 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
13105 sqlite3_changeset_iter *p /* Handle describing change and conflict */
13106 ),
13107 void *pCtx, /* First argument passed to xConflict */
13108 void **ppRebase, int *pnRebase,
13109 int flags
13110 );
13111 SQLITE_API int sqlite3changeset_concat_strm(
13112 int (*xInputA)(void *pIn, void *pData, int *pnData),
13113 void *pInA,
13114 int (*xInputB)(void *pIn, void *pData, int *pnData),
13115 void *pInB,
13116 int (*xOutput)(void *pOut, const void *pData, int nData),
13117 void *pOut
13118 );
13119 SQLITE_API int sqlite3changeset_invert_strm(
13120 int (*xInput)(void *pIn, void *pData, int *pnData),
13121 void *pIn,
13122 int (*xOutput)(void *pOut, const void *pData, int nData),
13123 void *pOut
13124 );
13125 SQLITE_API int sqlite3changeset_start_strm(
13126 sqlite3_changeset_iter **pp,
13127 int (*xInput)(void *pIn, void *pData, int *pnData),
13128 void *pIn
13129 );
13130 SQLITE_API int sqlite3changeset_start_v2_strm(
13131 sqlite3_changeset_iter **pp,
13132 int (*xInput)(void *pIn, void *pData, int *pnData),
13133 void *pIn,
13134 int flags
13135 );
13136 SQLITE_API int sqlite3session_changeset_strm(
13137 sqlite3_session *pSession,
13138 int (*xOutput)(void *pOut, const void *pData, int nData),
13139 void *pOut
13140 );
13141 SQLITE_API int sqlite3session_patchset_strm(
13142 sqlite3_session *pSession,
13143 int (*xOutput)(void *pOut, const void *pData, int nData),
13144 void *pOut
13145 );
13146 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
13147 int (*xInput)(void *pIn, void *pData, int *pnData),
13148 void *pIn
13149 );
13150 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
13151 int (*xOutput)(void *pOut, const void *pData, int nData),
13152 void *pOut
13153 );
13154 SQLITE_API int sqlite3rebaser_rebase_strm(
13155 sqlite3_rebaser *pRebaser,
13156 int (*xInput)(void *pIn, void *pData, int *pnData),
13157 void *pIn,
13158 int (*xOutput)(void *pOut, const void *pData, int nData),
13159 void *pOut
13160 );
13161
13162 /*
13163 ** CAPI3REF: Configure global parameters
13164 **
13165 ** The sqlite3session_config() interface is used to make global configuration
13166 ** changes to the sessions module in order to tune it to the specific needs
13167 ** of the application.
13168 **
13169 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
13170 ** while any other thread is inside any other sessions method then the
13171 ** results are undefined. Furthermore, if it is invoked after any sessions
13172 ** related objects have been created, the results are also undefined.
13173 **
13174 ** The first argument to the sqlite3session_config() function must be one
13175 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
13176 ** interpretation of the (void*) value passed as the second parameter and
13177 ** the effect of calling this function depends on the value of the first
13178 ** parameter.
13179 **
13180 ** <dl>
13181 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
13182 ** By default, the sessions module streaming interfaces attempt to input
13183 ** and output data in approximately 1 KiB chunks. This operand may be used
13184 ** to set and query the value of this configuration setting. The pointer
13185 ** passed as the second argument must point to a value of type (int).
13186 ** If this value is greater than 0, it is used as the new streaming data
13187 ** chunk size for both input and output. Before returning, the (int) value
13188 ** pointed to by pArg is set to the final value of the streaming interface
13189 ** chunk size.
13190 ** </dl>
13191 **
13192 ** This function returns SQLITE_OK if successful, or an SQLite error code
13193 ** otherwise.
13194 */
13195 SQLITE_API int sqlite3session_config(int op, void *pArg);
13196
13197 /*
13198 ** CAPI3REF: Values for sqlite3session_config().
13199 */
13200 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
13201
13202 /*
13203 ** Make sure we can call this stuff from C++.
13204 */
13205 #ifdef __cplusplus
13206 }
13207 #endif
13208
13209 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13210
13211 /******** End of sqlite3session.h *********/
13212 /******** Begin file fts5.h *********/
13213 /*
13214 ** 2014 May 31
13215 **
13216 ** The author disclaims copyright to this source code. In place of
13217 ** a legal notice, here is a blessing:
13218 **
13219 ** May you do good and not evil.
13220 ** May you find forgiveness for yourself and forgive others.
13221 ** May you share freely, never taking more than you give.
13222 **
13223 ******************************************************************************
13224 **
13225 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
13226 ** FTS5 may be extended with:
13227 **
13228 ** * custom tokenizers, and
13229 ** * custom auxiliary functions.
13230 */
13231
13232
13233 #ifndef _FTS5_H
13234 #define _FTS5_H
13235
13236
13237 #ifdef __cplusplus
13238 extern "C" {
13239 #endif
13240
13241 /*************************************************************************
13242 ** CUSTOM AUXILIARY FUNCTIONS
13243 **
13244 ** Virtual table implementations may overload SQL functions by implementing
13245 ** the sqlite3_module.xFindFunction() method.
13246 */
13247
13248 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13249 typedef struct Fts5Context Fts5Context;
13250 typedef struct Fts5PhraseIter Fts5PhraseIter;
13251
13252 typedef void (*fts5_extension_function)(
13253 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13254 Fts5Context *pFts, /* First arg to pass to pApi functions */
13255 sqlite3_context *pCtx, /* Context for returning result/error */
13256 int nVal, /* Number of values in apVal[] array */
13257 sqlite3_value **apVal /* Array of trailing arguments */
13258 );
13259
13260 struct Fts5PhraseIter {
13261 const unsigned char *a;
13262 const unsigned char *b;
13263 };
13264
13265 /*
13266 ** EXTENSION API FUNCTIONS
13267 **
13268 ** xUserData(pFts):
13269 ** Return a copy of the pUserData pointer passed to the xCreateFunction()
13270 ** API when the extension function was registered.
13271 **
13272 ** xColumnTotalSize(pFts, iCol, pnToken):
13273 ** If parameter iCol is less than zero, set output variable *pnToken
13274 ** to the total number of tokens in the FTS5 table. Or, if iCol is
13275 ** non-negative but less than the number of columns in the table, return
13276 ** the total number of tokens in column iCol, considering all rows in
13277 ** the FTS5 table.
13278 **
13279 ** If parameter iCol is greater than or equal to the number of columns
13280 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13281 ** an OOM condition or IO error), an appropriate SQLite error code is
13282 ** returned.
13283 **
13284 ** xColumnCount(pFts):
13285 ** Return the number of columns in the table.
13286 **
13287 ** xColumnSize(pFts, iCol, pnToken):
13288 ** If parameter iCol is less than zero, set output variable *pnToken
13289 ** to the total number of tokens in the current row. Or, if iCol is
13290 ** non-negative but less than the number of columns in the table, set
13291 ** *pnToken to the number of tokens in column iCol of the current row.
13292 **
13293 ** If parameter iCol is greater than or equal to the number of columns
13294 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13295 ** an OOM condition or IO error), an appropriate SQLite error code is
13296 ** returned.
13297 **
13298 ** This function may be quite inefficient if used with an FTS5 table
13299 ** created with the "columnsize=0" option.
13300 **
13301 ** xColumnText:
13302 ** If parameter iCol is less than zero, or greater than or equal to the
13303 ** number of columns in the table, SQLITE_RANGE is returned.
13304 **
13305 ** Otherwise, this function attempts to retrieve the text of column iCol of
13306 ** the current document. If successful, (*pz) is set to point to a buffer
13307 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13308 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13309 ** if an error occurs, an SQLite error code is returned and the final values
13310 ** of (*pz) and (*pn) are undefined.
13311 **
13312 ** xPhraseCount:
13313 ** Returns the number of phrases in the current query expression.
13314 **
13315 ** xPhraseSize:
13316 ** If parameter iCol is less than zero, or greater than or equal to the
13317 ** number of phrases in the current query, as returned by xPhraseCount,
13318 ** 0 is returned. Otherwise, this function returns the number of tokens in
13319 ** phrase iPhrase of the query. Phrases are numbered starting from zero.
13320 **
13321 ** xInstCount:
13322 ** Set *pnInst to the total number of occurrences of all phrases within
13323 ** the query within the current row. Return SQLITE_OK if successful, or
13324 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13325 **
13326 ** This API can be quite slow if used with an FTS5 table created with the
13327 ** "detail=none" or "detail=column" option. If the FTS5 table is created
13328 ** with either "detail=none" or "detail=column" and "content=" option
13329 ** (i.e. if it is a contentless table), then this API always returns 0.
13330 **
13331 ** xInst:
13332 ** Query for the details of phrase match iIdx within the current row.
13333 ** Phrase matches are numbered starting from zero, so the iIdx argument
13334 ** should be greater than or equal to zero and smaller than the value
13335 ** output by xInstCount(). If iIdx is less than zero or greater than
13336 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13337 **
13338 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13339 ** to the column in which it occurs and *piOff the token offset of the
13340 ** first token of the phrase. SQLITE_OK is returned if successful, or an
13341 ** error code (i.e. SQLITE_NOMEM) if an error occurs.
13342 **
13343 ** This API can be quite slow if used with an FTS5 table created with the
13344 ** "detail=none" or "detail=column" option.
13345 **
13346 ** xRowid:
13347 ** Returns the rowid of the current row.
13348 **
13349 ** xTokenize:
13350 ** Tokenize text using the tokenizer belonging to the FTS5 table.
13351 **
13352 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13353 ** This API function is used to query the FTS table for phrase iPhrase
13354 ** of the current query. Specifically, a query equivalent to:
13355 **
13356 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13357 **
13358 ** with $p set to a phrase equivalent to the phrase iPhrase of the
13359 ** current query is executed. Any column filter that applies to
13360 ** phrase iPhrase of the current query is included in $p. For each
13361 ** row visited, the callback function passed as the fourth argument
13362 ** is invoked. The context and API objects passed to the callback
13363 ** function may be used to access the properties of each matched row.
13364 ** Invoking Api.xUserData() returns a copy of the pointer passed as
13365 ** the third argument to pUserData.
13366 **
13367 ** If parameter iPhrase is less than zero, or greater than or equal to
13368 ** the number of phrases in the query, as returned by xPhraseCount(),
13369 ** this function returns SQLITE_RANGE.
13370 **
13371 ** If the callback function returns any value other than SQLITE_OK, the
13372 ** query is abandoned and the xQueryPhrase function returns immediately.
13373 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13374 ** Otherwise, the error code is propagated upwards.
13375 **
13376 ** If the query runs to completion without incident, SQLITE_OK is returned.
13377 ** Or, if some error occurs before the query completes or is aborted by
13378 ** the callback, an SQLite error code is returned.
13379 **
13380 **
13381 ** xSetAuxdata(pFts5, pAux, xDelete)
13382 **
13383 ** Save the pointer passed as the second argument as the extension function's
13384 ** "auxiliary data". The pointer may then be retrieved by the current or any
13385 ** future invocation of the same fts5 extension function made as part of
13386 ** the same MATCH query using the xGetAuxdata() API.
13387 **
13388 ** Each extension function is allocated a single auxiliary data slot for
13389 ** each FTS query (MATCH expression). If the extension function is invoked
13390 ** more than once for a single FTS query, then all invocations share a
13391 ** single auxiliary data context.
13392 **
13393 ** If there is already an auxiliary data pointer when this function is
13394 ** invoked, then it is replaced by the new pointer. If an xDelete callback
13395 ** was specified along with the original pointer, it is invoked at this
13396 ** point.
13397 **
13398 ** The xDelete callback, if one is specified, is also invoked on the
13399 ** auxiliary data pointer after the FTS5 query has finished.
13400 **
13401 ** If an error (e.g. an OOM condition) occurs within this function,
13402 ** the auxiliary data is set to NULL and an error code returned. If the
13403 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
13404 ** pointer before returning.
13405 **
13406 **
13407 ** xGetAuxdata(pFts5, bClear)
13408 **
13409 ** Returns the current auxiliary data pointer for the fts5 extension
13410 ** function. See the xSetAuxdata() method for details.
13411 **
13412 ** If the bClear argument is non-zero, then the auxiliary data is cleared
13413 ** (set to NULL) before this function returns. In this case the xDelete,
13414 ** if any, is not invoked.
13415 **
13416 **
13417 ** xRowCount(pFts5, pnRow)
13418 **
13419 ** This function is used to retrieve the total number of rows in the table.
13420 ** In other words, the same value that would be returned by:
13421 **
13422 ** SELECT count(*) FROM ftstable;
13423 **
13424 ** xPhraseFirst()
13425 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13426 ** method, to iterate through all instances of a single query phrase within
13427 ** the current row. This is the same information as is accessible via the
13428 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13429 ** to use, this API may be faster under some circumstances. To iterate
13430 ** through instances of phrase iPhrase, use the following code:
13431 **
13432 ** Fts5PhraseIter iter;
13433 ** int iCol, iOff;
13434 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13435 ** iCol>=0;
13436 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13437 ** ){
13438 ** // An instance of phrase iPhrase at offset iOff of column iCol
13439 ** }
13440 **
13441 ** The Fts5PhraseIter structure is defined above. Applications should not
13442 ** modify this structure directly - it should only be used as shown above
13443 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
13444 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13445 **
13446 ** This API can be quite slow if used with an FTS5 table created with the
13447 ** "detail=none" or "detail=column" option. If the FTS5 table is created
13448 ** with either "detail=none" or "detail=column" and "content=" option
13449 ** (i.e. if it is a contentless table), then this API always iterates
13450 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13451 **
13452 ** In all cases, matches are visited in (column ASC, offset ASC) order.
13453 ** i.e. all those in column 0, sorted by offset, followed by those in
13454 ** column 1, etc.
13455 **
13456 ** xPhraseNext()
13457 ** See xPhraseFirst above.
13458 **
13459 ** xPhraseFirstColumn()
13460 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13461 ** and xPhraseNext() APIs described above. The difference is that instead
13462 ** of iterating through all instances of a phrase in the current row, these
13463 ** APIs are used to iterate through the set of columns in the current row
13464 ** that contain one or more instances of a specified phrase. For example:
13465 **
13466 ** Fts5PhraseIter iter;
13467 ** int iCol;
13468 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13469 ** iCol>=0;
13470 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13471 ** ){
13472 ** // Column iCol contains at least one instance of phrase iPhrase
13473 ** }
13474 **
13475 ** This API can be quite slow if used with an FTS5 table created with the
13476 ** "detail=none" option. If the FTS5 table is created with either
13477 ** "detail=none" "content=" option (i.e. if it is a contentless table),
13478 ** then this API always iterates through an empty set (all calls to
13479 ** xPhraseFirstColumn() set iCol to -1).
13480 **
13481 ** The information accessed using this API and its companion
13482 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13483 ** (or xInst/xInstCount). The chief advantage of this API is that it is
13484 ** significantly more efficient than those alternatives when used with
13485 ** "detail=column" tables.
13486 **
13487 ** xPhraseNextColumn()
13488 ** See xPhraseFirstColumn above.
13489 **
13490 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13491 ** This is used to access token iToken of phrase iPhrase of the current
13492 ** query. Before returning, output parameter *ppToken is set to point
13493 ** to a buffer containing the requested token, and *pnToken to the
13494 ** size of this buffer in bytes.
13495 **
13496 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13497 ** or equal to the number of phrases in the query as reported by
13498 ** xPhraseCount(), or if iToken is equal to or greater than the number of
13499 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13500 are both zeroed.
13501 **
13502 ** The output text is not a copy of the query text that specified the
13503 ** token. It is the output of the tokenizer module. For tokendata=1
13504 ** tables, this includes any embedded 0x00 and trailing data.
13505 **
13506 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13507 ** This is used to access token iToken of phrase hit iIdx within the
13508 ** current row. If iIdx is less than zero or greater than or equal to the
13509 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13510 ** output variable (*ppToken) is set to point to a buffer containing the
13511 ** matching document token, and (*pnToken) to the size of that buffer in
13512 ** bytes.
13513 **
13514 ** The output text is not a copy of the document text that was tokenized.
13515 ** It is the output of the tokenizer module. For tokendata=1 tables, this
13516 ** includes any embedded 0x00 and trailing data.
13517 **
13518 ** This API may be slow in some cases if the token identified by parameters
13519 ** iIdx and iToken matched a prefix token in the query. In most cases, the
13520 ** first call to this API for each prefix token in the query is forced
13521 ** to scan the portion of the full-text index that matches the prefix
13522 ** token to collect the extra data required by this API. If the prefix
13523 ** token matches a large number of token instances in the document set,
13524 ** this may be a performance problem.
13525 **
13526 ** If the user knows in advance that a query may use this API for a
13527 ** prefix token, FTS5 may be configured to collect all required data as part
13528 ** of the initial querying of the full-text index, avoiding the second scan
13529 ** entirely. This also causes prefix queries that do not use this API to
13530 ** run more slowly and use more memory. FTS5 may be configured in this way
13531 ** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13532 ** option, or on a per-query basis using the
13533 ** [fts5_insttoken | fts5_insttoken()] user function.
13534 **
13535 ** This API can be quite slow if used with an FTS5 table created with the
13536 ** "detail=none" or "detail=column" option.
13537 **
13538 ** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13539 ** If parameter iCol is less than zero, or greater than or equal to the
13540 ** number of columns in the table, SQLITE_RANGE is returned.
13541 **
13542 ** Otherwise, this function attempts to retrieve the locale associated
13543 ** with column iCol of the current row. Usually, there is no associated
13544 ** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13545 ** to NULL and 0, respectively. However, if the fts5_locale() function
13546 ** was used to associate a locale with the value when it was inserted
13547 ** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13548 ** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13549 ** is set to the size in bytes of the buffer, not including the
13550 ** nul-terminator.
13551 **
13552 ** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13553 ** SQLite error code is returned. The final value of the output parameters
13554 ** is undefined in this case.
13555 **
13556 ** xTokenize_v2:
13557 ** Tokenize text using the tokenizer belonging to the FTS5 table. This
13558 ** API is the same as the xTokenize() API, except that it allows a tokenizer
13559 ** locale to be specified.
13560 */
13561 struct Fts5ExtensionApi {
13562 int iVersion; /* Currently always set to 4 */
13563
13564 void *(*xUserData)(Fts5Context*);
13565
13566 int (*xColumnCount)(Fts5Context*);
13567 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13568 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13569
13570 int (*xTokenize)(Fts5Context*,
13571 const char *pText, int nText, /* Text to tokenize */
13572 void *pCtx, /* Context passed to xToken() */
13573 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13574 );
13575
13576 int (*xPhraseCount)(Fts5Context*);
13577 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13578
13579 int (*xInstCount)(Fts5Context*, int *pnInst);
13580 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13581
13582 sqlite3_int64 (*xRowid)(Fts5Context*);
13583 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13584 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13585
13586 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13587 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13588 );
13589 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13590 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13591
13592 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13593 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13594
13595 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13596 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13597
13598 /* Below this point are iVersion>=3 only */
13599 int (*xQueryToken)(Fts5Context*,
13600 int iPhrase, int iToken,
13601 const char **ppToken, int *pnToken
13602 );
13603 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13604
13605 /* Below this point are iVersion>=4 only */
13606 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13607 int (*xTokenize_v2)(Fts5Context*,
13608 const char *pText, int nText, /* Text to tokenize */
13609 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13610 void *pCtx, /* Context passed to xToken() */
13611 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13612 );
13613 };
13614
13615 /*
13616 ** CUSTOM AUXILIARY FUNCTIONS
13617 *************************************************************************/
13618
13619 /*************************************************************************
13620 ** CUSTOM TOKENIZERS
13621 **
13622 ** Applications may also register custom tokenizer types. A tokenizer
13623 ** is registered by providing fts5 with a populated instance of the
13624 ** following structure. All structure methods must be defined, setting
13625 ** any member of the fts5_tokenizer struct to NULL leads to undefined
13626 ** behaviour. The structure methods are expected to function as follows:
13627 **
13628 ** xCreate:
13629 ** This function is used to allocate and initialize a tokenizer instance.
13630 ** A tokenizer instance is required to actually tokenize text.
13631 **
13632 ** The first argument passed to this function is a copy of the (void*)
13633 ** pointer provided by the application when the fts5_tokenizer_v2 object
13634 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
13635 ** The second and third arguments are an array of nul-terminated strings
13636 ** containing the tokenizer arguments, if any, specified following the
13637 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13638 ** to create the FTS5 table.
13639 **
13640 ** The final argument is an output variable. If successful, (*ppOut)
13641 ** should be set to point to the new tokenizer handle and SQLITE_OK
13642 ** returned. If an error occurs, some value other than SQLITE_OK should
13643 ** be returned. In this case, fts5 assumes that the final value of *ppOut
13644 ** is undefined.
13645 **
13646 ** xDelete:
13647 ** This function is invoked to delete a tokenizer handle previously
13648 ** allocated using xCreate(). Fts5 guarantees that this function will
13649 ** be invoked exactly once for each successful call to xCreate().
13650 **
13651 ** xTokenize:
13652 ** This function is expected to tokenize the nText byte string indicated
13653 ** by argument pText. pText may or may not be nul-terminated. The first
13654 ** argument passed to this function is a pointer to an Fts5Tokenizer object
13655 ** returned by an earlier call to xCreate().
13656 **
13657 ** The third argument indicates the reason that FTS5 is requesting
13658 ** tokenization of the supplied text. This is always one of the following
13659 ** four values:
13660 **
13661 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13662 ** or removed from the FTS table. The tokenizer is being invoked to
13663 ** determine the set of tokens to add to (or delete from) the
13664 ** FTS index.
13665 **
13666 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13667 ** against the FTS index. The tokenizer is being called to tokenize
13668 ** a bareword or quoted string specified as part of the query.
13669 **
13670 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13671 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13672 ** followed by a "*" character, indicating that the last token
13673 ** returned by the tokenizer will be treated as a token prefix.
13674 **
13675 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13676 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
13677 ** function. Or an fts5_api.xColumnSize() request made by the same
13678 ** on a columnsize=0 database.
13679 ** </ul>
13680 **
13681 ** The sixth and seventh arguments passed to xTokenize() - pLocale and
13682 ** nLocale - are a pointer to a buffer containing the locale to use for
13683 ** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13684 ** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13685 ** which case nLocale is always 0) to indicate that the tokenizer should
13686 ** use its default locale.
13687 **
13688 ** For each token in the input string, the supplied callback xToken() must
13689 ** be invoked. The first argument to it should be a copy of the pointer
13690 ** passed as the second argument to xTokenize(). The third and fourth
13691 ** arguments are a pointer to a buffer containing the token text, and the
13692 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13693 ** of the first byte of and first byte immediately following the text from
13694 ** which the token is derived within the input.
13695 **
13696 ** The second argument passed to the xToken() callback ("tflags") should
13697 ** normally be set to 0. The exception is if the tokenizer supports
13698 ** synonyms. In this case see the discussion below for details.
13699 **
13700 ** FTS5 assumes the xToken() callback is invoked for each token in the
13701 ** order that they occur within the input text.
13702 **
13703 ** If an xToken() callback returns any value other than SQLITE_OK, then
13704 ** the tokenization should be abandoned and the xTokenize() method should
13705 ** immediately return a copy of the xToken() return value. Or, if the
13706 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13707 ** if an error occurs with the xTokenize() implementation itself, it
13708 ** may abandon the tokenization and return any error code other than
13709 ** SQLITE_OK or SQLITE_DONE.
13710 **
13711 ** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13712 ** then the xTokenize() method has two additional arguments - pLocale
13713 ** and nLocale. These specify the locale that the tokenizer should use
13714 ** for the current request. If pLocale and nLocale are both 0, then the
13715 ** tokenizer should use its default locale. Otherwise, pLocale points to
13716 ** an nLocale byte buffer containing the name of the locale to use as utf-8
13717 ** text. pLocale is not nul-terminated.
13718 **
13719 ** FTS5_TOKENIZER
13720 **
13721 ** There is also an fts5_tokenizer object. This is an older, deprecated,
13722 ** version of fts5_tokenizer_v2. It is similar except that:
13723 **
13724 ** <ul>
13725 ** <li> There is no "iVersion" field, and
13726 ** <li> The xTokenize() method does not take a locale argument.
13727 ** </ul>
13728 **
13729 ** Legacy fts5_tokenizer tokenizers must be registered using the
13730 ** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13731 **
13732 ** Tokenizer implementations registered using either API may be retrieved
13733 ** using both xFindTokenizer() and xFindTokenizer_v2().
13734 **
13735 ** SYNONYM SUPPORT
13736 **
13737 ** Custom tokenizers may also support synonyms. Consider a case in which a
13738 ** user wishes to query for a phrase such as "first place". Using the
13739 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
13740 ** of "first place" within the document set, but not alternative forms
13741 ** such as "1st place". In some applications, it would be better to match
13742 ** all instances of "first place" or "1st place" regardless of which form
13743 ** the user specified in the MATCH query text.
13744 **
13745 ** There are several ways to approach this in FTS5:
13746 **
13747 ** <ol><li> By mapping all synonyms to a single token. In this case, using
13748 ** the above example, this means that the tokenizer returns the
13749 ** same token for inputs "first" and "1st". Say that token is in
13750 ** fact "first", so that when the user inserts the document "I won
13751 ** 1st place" entries are added to the index for tokens "i", "won",
13752 ** "first" and "place". If the user then queries for '1st + place',
13753 ** the tokenizer substitutes "first" for "1st" and the query works
13754 ** as expected.
13755 **
13756 ** <li> By querying the index for all synonyms of each query term
13757 ** separately. In this case, when tokenizing query text, the
13758 ** tokenizer may provide multiple synonyms for a single term
13759 ** within the document. FTS5 then queries the index for each
13760 ** synonym individually. For example, faced with the query:
13761 **
13762 ** <codeblock>
13763 ** ... MATCH 'first place'</codeblock>
13764 **
13765 ** the tokenizer offers both "1st" and "first" as synonyms for the
13766 ** first token in the MATCH query and FTS5 effectively runs a query
13767 ** similar to:
13768 **
13769 ** <codeblock>
13770 ** ... MATCH '(first OR 1st) place'</codeblock>
13771 **
13772 ** except that, for the purposes of auxiliary functions, the query
13773 ** still appears to contain just two phrases - "(first OR 1st)"
13774 ** being treated as a single phrase.
13775 **
13776 ** <li> By adding multiple synonyms for a single term to the FTS index.
13777 ** Using this method, when tokenizing document text, the tokenizer
13778 ** provides multiple synonyms for each token. So that when a
13779 ** document such as "I won first place" is tokenized, entries are
13780 ** added to the FTS index for "i", "won", "first", "1st" and
13781 ** "place".
13782 **
13783 ** This way, even if the tokenizer does not provide synonyms
13784 ** when tokenizing query text (it should not - to do so would be
13785 ** inefficient), it doesn't matter if the user queries for
13786 ** 'first + place' or '1st + place', as there are entries in the
13787 ** FTS index corresponding to both forms of the first token.
13788 ** </ol>
13789 **
13790 ** Whether it is parsing document or query text, any call to xToken that
13791 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13792 ** is considered to supply a synonym for the previous token. For example,
13793 ** when parsing the document "I won first place", a tokenizer that supports
13794 ** synonyms would call xToken() 5 times, as follows:
13795 **
13796 ** <codeblock>
13797 ** xToken(pCtx, 0, "i", 1, 0, 1);
13798 ** xToken(pCtx, 0, "won", 3, 2, 5);
13799 ** xToken(pCtx, 0, "first", 5, 6, 11);
13800 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13801 ** xToken(pCtx, 0, "place", 5, 12, 17);
13802 **</codeblock>
13803 **
13804 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13805 ** xToken() is called. Multiple synonyms may be specified for a single token
13806 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13807 ** There is no limit to the number of synonyms that may be provided for a
13808 ** single token.
13809 **
13810 ** In many cases, method (1) above is the best approach. It does not add
13811 ** extra data to the FTS index or require FTS5 to query for multiple terms,
13812 ** so it is efficient in terms of disk space and query speed. However, it
13813 ** does not support prefix queries very well. If, as suggested above, the
13814 ** token "first" is substituted for "1st" by the tokenizer, then the query:
13815 **
13816 ** <codeblock>
13817 ** ... MATCH '1s*'</codeblock>
13818 **
13819 ** will not match documents that contain the token "1st" (as the tokenizer
13820 ** will probably not map "1s" to any prefix of "first").
13821 **
13822 ** For full prefix support, method (3) may be preferred. In this case,
13823 ** because the index contains entries for both "first" and "1st", prefix
13824 ** queries such as 'fi*' or '1s*' will match correctly. However, because
13825 ** extra entries are added to the FTS index, this method uses more space
13826 ** within the database.
13827 **
13828 ** Method (2) offers a midpoint between (1) and (3). Using this method,
13829 ** a query such as '1s*' will match documents that contain the literal
13830 ** token "1st", but not "first" (assuming the tokenizer is not able to
13831 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
13832 ** will match against "1st" and "first". This method does not require
13833 ** extra disk space, as no extra entries are added to the FTS index.
13834 ** On the other hand, it may require more CPU cycles to run MATCH queries,
13835 ** as separate queries of the FTS index are required for each synonym.
13836 **
13837 ** When using methods (2) or (3), it is important that the tokenizer only
13838 ** provide synonyms when tokenizing document text (method (3)) or query
13839 ** text (method (2)), not both. Doing so will not cause any errors, but is
13840 ** inefficient.
13841 */
13842 typedef struct Fts5Tokenizer Fts5Tokenizer;
13843 typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13844 struct fts5_tokenizer_v2 {
13845 int iVersion; /* Currently always 2 */
13846
13847 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13848 void (*xDelete)(Fts5Tokenizer*);
13849 int (*xTokenize)(Fts5Tokenizer*,
13850 void *pCtx,
13851 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13852 const char *pText, int nText,
13853 const char *pLocale, int nLocale,
13854 int (*xToken)(
13855 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13856 int tflags, /* Mask of FTS5_TOKEN_* flags */
13857 const char *pToken, /* Pointer to buffer containing token */
13858 int nToken, /* Size of token in bytes */
13859 int iStart, /* Byte offset of token within input text */
13860 int iEnd /* Byte offset of end of token within input text */
13861 )
13862 );
13863 };
13864
13865 /*
13866 ** New code should use the fts5_tokenizer_v2 type to define tokenizer
13867 ** implementations. The following type is included for legacy applications
13868 ** that still use it.
13869 */
13870 typedef struct fts5_tokenizer fts5_tokenizer;
13871 struct fts5_tokenizer {
13872 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13873 void (*xDelete)(Fts5Tokenizer*);
13874 int (*xTokenize)(Fts5Tokenizer*,
13875 void *pCtx,
13876 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13877 const char *pText, int nText,
13878 int (*xToken)(
13879 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13880 int tflags, /* Mask of FTS5_TOKEN_* flags */
13881 const char *pToken, /* Pointer to buffer containing token */
13882 int nToken, /* Size of token in bytes */
13883 int iStart, /* Byte offset of token within input text */
13884 int iEnd /* Byte offset of end of token within input text */
13885 )
13886 );
13887 };
13888
13889
13890 /* Flags that may be passed as the third argument to xTokenize() */
13891 #define FTS5_TOKENIZE_QUERY 0x0001
13892 #define FTS5_TOKENIZE_PREFIX 0x0002
13893 #define FTS5_TOKENIZE_DOCUMENT 0x0004
13894 #define FTS5_TOKENIZE_AUX 0x0008
13895
13896 /* Flags that may be passed by the tokenizer implementation back to FTS5
13897 ** as the third argument to the supplied xToken callback. */
13898 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13899
13900 /*
13901 ** END OF CUSTOM TOKENIZERS
13902 *************************************************************************/
13903
13904 /*************************************************************************
13905 ** FTS5 EXTENSION REGISTRATION API
13906 */
13907 typedef struct fts5_api fts5_api;
13908 struct fts5_api {
13909 int iVersion; /* Currently always set to 3 */
13910
13911 /* Create a new tokenizer */
13912 int (*xCreateTokenizer)(
13913 fts5_api *pApi,
13914 const char *zName,
13915 void *pUserData,
13916 fts5_tokenizer *pTokenizer,
13917 void (*xDestroy)(void*)
13918 );
13919
13920 /* Find an existing tokenizer */
13921 int (*xFindTokenizer)(
13922 fts5_api *pApi,
13923 const char *zName,
13924 void **ppUserData,
13925 fts5_tokenizer *pTokenizer
13926 );
13927
13928 /* Create a new auxiliary function */
13929 int (*xCreateFunction)(
13930 fts5_api *pApi,
13931 const char *zName,
13932 void *pUserData,
13933 fts5_extension_function xFunction,
13934 void (*xDestroy)(void*)
13935 );
13936
13937 /* APIs below this point are only available if iVersion>=3 */
13938
13939 /* Create a new tokenizer */
13940 int (*xCreateTokenizer_v2)(
13941 fts5_api *pApi,
13942 const char *zName,
13943 void *pUserData,
13944 fts5_tokenizer_v2 *pTokenizer,
13945 void (*xDestroy)(void*)
13946 );
13947
13948 /* Find an existing tokenizer */
13949 int (*xFindTokenizer_v2)(
13950 fts5_api *pApi,
13951 const char *zName,
13952 void **ppUserData,
13953 fts5_tokenizer_v2 **ppTokenizer
13954 );
13955 };
13956
13957 /*
13958 ** END OF REGISTRATION API
13959 *************************************************************************/
13960
13961 #ifdef __cplusplus
13962 } /* end of the 'extern "C"' block */
13963 #endif
13964
13965 #endif /* _FTS5_H */
13966
13967 /******** End of fts5.h *********/
13968 #endif /* SQLITE3_H */