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 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.32.3" 127 #define SQLITE_VERSION_NUMBER 3032003 128 #define SQLITE_SOURCE_ID "2020-06-18 14:00:33 7ebdfa80be8e8e73324b8d66b3460222eb74c7e9dfd655b48d6ca7e1933cc8fd" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #else 193 # define sqlite3_compileoption_used(X) 0 194 # define sqlite3_compileoption_get(X) ((void*)0) 195 #endif 196 197 /* 198 ** CAPI3REF: Test To See If The Library Is Threadsafe 199 ** 200 ** ^The sqlite3_threadsafe() function returns zero if and only if 201 ** SQLite was compiled with mutexing code omitted due to the 202 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 203 ** 204 ** SQLite can be compiled with or without mutexes. When 205 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206 ** are enabled and SQLite is threadsafe. When the 207 ** [SQLITE_THREADSAFE] macro is 0, 208 ** the mutexes are omitted. Without the mutexes, it is not safe 209 ** to use SQLite concurrently from more than one thread. 210 ** 211 ** Enabling mutexes incurs a measurable performance penalty. 212 ** So if speed is of utmost importance, it makes sense to disable 213 ** the mutexes. But for maximum safety, mutexes should be enabled. 214 ** ^The default behavior is for mutexes to be enabled. 215 ** 216 ** This interface can be used by an application to make sure that the 217 ** version of SQLite that it is linking against was compiled with 218 ** the desired setting of the [SQLITE_THREADSAFE] macro. 219 ** 220 ** This interface only reports on the compile-time mutex setting 221 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223 ** can be fully or partially disabled using a call to [sqlite3_config()] 224 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226 ** sqlite3_threadsafe() function shows only the compile-time setting of 227 ** thread safety, not any run-time changes to that setting made by 228 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229 ** is unchanged by calls to sqlite3_config().)^ 230 ** 231 ** See the [threading mode] documentation for additional information. 232 */ 233 SQLITE_API int sqlite3_threadsafe(void); 234 235 /* 236 ** CAPI3REF: Database Connection Handle 237 ** KEYWORDS: {database connection} {database connections} 238 ** 239 ** Each open SQLite database is represented by a pointer to an instance of 240 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243 ** and [sqlite3_close_v2()] are its destructors. There are many other 244 ** interfaces (such as 245 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 247 ** sqlite3 object. 248 */ 249 typedef struct sqlite3 sqlite3; 250 251 /* 252 ** CAPI3REF: 64-Bit Integer Types 253 ** KEYWORDS: sqlite_int64 sqlite_uint64 254 ** 255 ** Because there is no cross-platform way to specify 64-bit integer types 256 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 257 ** 258 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260 ** compatibility only. 261 ** 262 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 265 ** between 0 and +18446744073709551615 inclusive. 266 */ 267 #ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269 # ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271 # else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273 # endif 274 #elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277 #else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280 #endif 281 typedef sqlite_int64 sqlite3_int64; 282 typedef sqlite_uint64 sqlite3_uint64; 283 284 /* 285 ** If compiling for a processor that lacks floating point support, 286 ** substitute integer for floating-point. 287 */ 288 #ifdef SQLITE_OMIT_FLOATING_POINT 289 # define double sqlite3_int64 290 #endif 291 292 /* 293 ** CAPI3REF: Closing A Database Connection 294 ** DESTRUCTOR: sqlite3 295 ** 296 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297 ** for the [sqlite3] object. 298 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299 ** the [sqlite3] object is successfully destroyed and all associated 300 ** resources are deallocated. 301 ** 302 ** Ideally, applications should [sqlite3_finalize | finalize] all 303 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 304 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 305 ** with the [sqlite3] object prior to attempting to close the object. 306 ** ^If the database connection is associated with unfinalized prepared 307 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 308 ** sqlite3_close() will leave the database connection open and return 309 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 310 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 311 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 312 ** connection immediately, it marks the database connection as an unusable 313 ** "zombie" and makes arrangements to automatically deallocate the database 314 ** connection after all prepared statements are finalized, all BLOB handles 315 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 316 ** is intended for use with host languages that are garbage collected, and 317 ** where the order in which destructors are called is arbitrary. 318 ** 319 ** ^If an [sqlite3] object is destroyed while a transaction is open, 320 ** the transaction is automatically rolled back. 321 ** 322 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 323 ** must be either a NULL 324 ** pointer or an [sqlite3] object pointer obtained 325 ** from [sqlite3_open()], [sqlite3_open16()], or 326 ** [sqlite3_open_v2()], and not previously closed. 327 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 328 ** argument is a harmless no-op. 329 */ 330 SQLITE_API int sqlite3_close(sqlite3*); 331 SQLITE_API int sqlite3_close_v2(sqlite3*); 332 333 /* 334 ** The type for a callback function. 335 ** This is legacy and deprecated. It is included for historical 336 ** compatibility and is not documented. 337 */ 338 typedef int (*sqlite3_callback)(void*,int,char**, char**); 339 340 /* 341 ** CAPI3REF: One-Step Query Execution Interface 342 ** METHOD: sqlite3 343 ** 344 ** The sqlite3_exec() interface is a convenience wrapper around 345 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 346 ** that allows an application to run multiple statements of SQL 347 ** without having to use a lot of C code. 348 ** 349 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 350 ** semicolon-separate SQL statements passed into its 2nd argument, 351 ** in the context of the [database connection] passed in as its 1st 352 ** argument. ^If the callback function of the 3rd argument to 353 ** sqlite3_exec() is not NULL, then it is invoked for each result row 354 ** coming out of the evaluated SQL statements. ^The 4th argument to 355 ** sqlite3_exec() is relayed through to the 1st argument of each 356 ** callback invocation. ^If the callback pointer to sqlite3_exec() 357 ** is NULL, then no callback is ever invoked and result rows are 358 ** ignored. 359 ** 360 ** ^If an error occurs while evaluating the SQL statements passed into 361 ** sqlite3_exec(), then execution of the current statement stops and 362 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 363 ** is not NULL then any error message is written into memory obtained 364 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 365 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 366 ** on error message strings returned through the 5th parameter of 367 ** sqlite3_exec() after the error message string is no longer needed. 368 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 369 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 370 ** NULL before returning. 371 ** 372 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 373 ** routine returns SQLITE_ABORT without invoking the callback again and 374 ** without running any subsequent SQL statements. 375 ** 376 ** ^The 2nd argument to the sqlite3_exec() callback function is the 377 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 378 ** callback is an array of pointers to strings obtained as if from 379 ** [sqlite3_column_text()], one for each column. ^If an element of a 380 ** result row is NULL then the corresponding string pointer for the 381 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 382 ** sqlite3_exec() callback is an array of pointers to strings where each 383 ** entry represents the name of corresponding result column as obtained 384 ** from [sqlite3_column_name()]. 385 ** 386 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 387 ** to an empty string, or a pointer that contains only whitespace and/or 388 ** SQL comments, then no SQL statements are evaluated and the database 389 ** is not changed. 390 ** 391 ** Restrictions: 392 ** 393 ** <ul> 394 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 395 ** is a valid and open [database connection]. 396 ** <li> The application must not close the [database connection] specified by 397 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 398 ** <li> The application must not modify the SQL statement text passed into 399 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 400 ** </ul> 401 */ 402 SQLITE_API int sqlite3_exec( 403 sqlite3*, /* An open database */ 404 const char *sql, /* SQL to be evaluated */ 405 int (*callback)(void*,int,char**,char**), /* Callback function */ 406 void *, /* 1st argument to callback */ 407 char **errmsg /* Error msg written here */ 408 ); 409 410 /* 411 ** CAPI3REF: Result Codes 412 ** KEYWORDS: {result code definitions} 413 ** 414 ** Many SQLite functions return an integer result code from the set shown 415 ** here in order to indicate success or failure. 416 ** 417 ** New error codes may be added in future versions of SQLite. 418 ** 419 ** See also: [extended result code definitions] 420 */ 421 #define SQLITE_OK 0 /* Successful result */ 422 /* beginning-of-error-codes */ 423 #define SQLITE_ERROR 1 /* Generic error */ 424 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 425 #define SQLITE_PERM 3 /* Access permission denied */ 426 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 427 #define SQLITE_BUSY 5 /* The database file is locked */ 428 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 429 #define SQLITE_NOMEM 7 /* A malloc() failed */ 430 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 431 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 432 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 433 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 434 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 435 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 436 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 437 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 438 #define SQLITE_EMPTY 16 /* Internal use only */ 439 #define SQLITE_SCHEMA 17 /* The database schema changed */ 440 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 441 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 442 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 443 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 444 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 445 #define SQLITE_AUTH 23 /* Authorization denied */ 446 #define SQLITE_FORMAT 24 /* Not used */ 447 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 448 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 449 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 450 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 451 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 452 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 453 /* end-of-error-codes */ 454 455 /* 456 ** CAPI3REF: Extended Result Codes 457 ** KEYWORDS: {extended result code definitions} 458 ** 459 ** In its default configuration, SQLite API routines return one of 30 integer 460 ** [result codes]. However, experience has shown that many of 461 ** these result codes are too coarse-grained. They do not provide as 462 ** much information about problems as programmers might like. In an effort to 463 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 464 ** and later) include 465 ** support for additional result codes that provide more detailed information 466 ** about errors. These [extended result codes] are enabled or disabled 467 ** on a per database connection basis using the 468 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 469 ** the most recent error can be obtained using 470 ** [sqlite3_extended_errcode()]. 471 */ 472 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 473 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 474 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 475 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 476 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 477 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 478 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 479 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 480 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 481 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 482 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 483 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 484 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 485 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 486 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 487 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 488 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 489 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 490 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 491 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 492 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 493 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 494 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 495 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 496 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 497 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 498 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 499 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 500 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 501 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 502 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 503 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 504 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 505 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 506 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 507 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 508 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 509 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 510 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 511 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 512 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 513 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 514 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 515 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 516 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 517 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 518 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 519 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 520 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 521 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 522 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 523 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 524 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 525 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 526 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 527 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 528 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 529 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 530 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 531 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 532 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 533 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 534 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 535 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 536 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 537 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 538 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 539 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 540 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 541 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 542 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 543 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 544 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 545 546 /* 547 ** CAPI3REF: Flags For File Open Operations 548 ** 549 ** These bit values are intended for use in the 550 ** 3rd parameter to the [sqlite3_open_v2()] interface and 551 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 552 */ 553 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 554 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 555 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 557 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 558 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 559 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 560 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 561 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 562 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 563 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 564 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 565 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 566 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 567 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 568 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 569 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 570 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 571 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 572 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 573 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 574 575 /* Reserved: 0x00F00000 */ 576 577 /* 578 ** CAPI3REF: Device Characteristics 579 ** 580 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 581 ** object returns an integer which is a vector of these 582 ** bit values expressing I/O characteristics of the mass storage 583 ** device that holds the file that the [sqlite3_io_methods] 584 ** refers to. 585 ** 586 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 587 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 588 ** mean that writes of blocks that are nnn bytes in size and 589 ** are aligned to an address which is an integer multiple of 590 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 591 ** that when data is appended to a file, the data is appended 592 ** first then the size of the file is extended, never the other 593 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 594 ** information is written to disk in the same order as calls 595 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 596 ** after reboot following a crash or power loss, the only bytes in a 597 ** file that were written at the application level might have changed 598 ** and that adjacent bytes, even bytes within the same sector are 599 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 600 ** flag indicates that a file cannot be deleted when open. The 601 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 602 ** read-only media and cannot be changed even by processes with 603 ** elevated privileges. 604 ** 605 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 606 ** filesystem supports doing multiple write operations atomically when those 607 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 608 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 609 */ 610 #define SQLITE_IOCAP_ATOMIC 0x00000001 611 #define SQLITE_IOCAP_ATOMIC512 0x00000002 612 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 613 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 614 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 615 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 616 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 617 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 618 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 619 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 620 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 621 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 622 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 623 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 624 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 625 626 /* 627 ** CAPI3REF: File Locking Levels 628 ** 629 ** SQLite uses one of these integer values as the second 630 ** argument to calls it makes to the xLock() and xUnlock() methods 631 ** of an [sqlite3_io_methods] object. 632 */ 633 #define SQLITE_LOCK_NONE 0 634 #define SQLITE_LOCK_SHARED 1 635 #define SQLITE_LOCK_RESERVED 2 636 #define SQLITE_LOCK_PENDING 3 637 #define SQLITE_LOCK_EXCLUSIVE 4 638 639 /* 640 ** CAPI3REF: Synchronization Type Flags 641 ** 642 ** When SQLite invokes the xSync() method of an 643 ** [sqlite3_io_methods] object it uses a combination of 644 ** these integer values as the second argument. 645 ** 646 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 647 ** sync operation only needs to flush data to mass storage. Inode 648 ** information need not be flushed. If the lower four bits of the flag 649 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 650 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 651 ** to use Mac OS X style fullsync instead of fsync(). 652 ** 653 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 654 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 655 ** settings. The [synchronous pragma] determines when calls to the 656 ** xSync VFS method occur and applies uniformly across all platforms. 657 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 658 ** energetic or rigorous or forceful the sync operations are and 659 ** only make a difference on Mac OSX for the default SQLite code. 660 ** (Third-party VFS implementations might also make the distinction 661 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 662 ** operating systems natively supported by SQLite, only Mac OSX 663 ** cares about the difference.) 664 */ 665 #define SQLITE_SYNC_NORMAL 0x00002 666 #define SQLITE_SYNC_FULL 0x00003 667 #define SQLITE_SYNC_DATAONLY 0x00010 668 669 /* 670 ** CAPI3REF: OS Interface Open File Handle 671 ** 672 ** An [sqlite3_file] object represents an open file in the 673 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 674 ** implementations will 675 ** want to subclass this object by appending additional fields 676 ** for their own use. The pMethods entry is a pointer to an 677 ** [sqlite3_io_methods] object that defines methods for performing 678 ** I/O operations on the open file. 679 */ 680 typedef struct sqlite3_file sqlite3_file; 681 struct sqlite3_file { 682 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 683 }; 684 685 /* 686 ** CAPI3REF: OS Interface File Virtual Methods Object 687 ** 688 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 689 ** [sqlite3_file] object (or, more commonly, a subclass of the 690 ** [sqlite3_file] object) with a pointer to an instance of this object. 691 ** This object defines the methods used to perform various operations 692 ** against the open file represented by the [sqlite3_file] object. 693 ** 694 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 695 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 696 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 697 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 698 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 699 ** to NULL. 700 ** 701 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 702 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 703 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 704 ** flag may be ORed in to indicate that only the data of the file 705 ** and not its inode needs to be synced. 706 ** 707 ** The integer values to xLock() and xUnlock() are one of 708 ** <ul> 709 ** <li> [SQLITE_LOCK_NONE], 710 ** <li> [SQLITE_LOCK_SHARED], 711 ** <li> [SQLITE_LOCK_RESERVED], 712 ** <li> [SQLITE_LOCK_PENDING], or 713 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 714 ** </ul> 715 ** xLock() increases the lock. xUnlock() decreases the lock. 716 ** The xCheckReservedLock() method checks whether any database connection, 717 ** either in this process or in some other process, is holding a RESERVED, 718 ** PENDING, or EXCLUSIVE lock on the file. It returns true 719 ** if such a lock exists and false otherwise. 720 ** 721 ** The xFileControl() method is a generic interface that allows custom 722 ** VFS implementations to directly control an open file using the 723 ** [sqlite3_file_control()] interface. The second "op" argument is an 724 ** integer opcode. The third argument is a generic pointer intended to 725 ** point to a structure that may contain arguments or space in which to 726 ** write return values. Potential uses for xFileControl() might be 727 ** functions to enable blocking locks with timeouts, to change the 728 ** locking strategy (for example to use dot-file locks), to inquire 729 ** about the status of a lock, or to break stale locks. The SQLite 730 ** core reserves all opcodes less than 100 for its own use. 731 ** A [file control opcodes | list of opcodes] less than 100 is available. 732 ** Applications that define a custom xFileControl method should use opcodes 733 ** greater than 100 to avoid conflicts. VFS implementations should 734 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 735 ** recognize. 736 ** 737 ** The xSectorSize() method returns the sector size of the 738 ** device that underlies the file. The sector size is the 739 ** minimum write that can be performed without disturbing 740 ** other bytes in the file. The xDeviceCharacteristics() 741 ** method returns a bit vector describing behaviors of the 742 ** underlying device: 743 ** 744 ** <ul> 745 ** <li> [SQLITE_IOCAP_ATOMIC] 746 ** <li> [SQLITE_IOCAP_ATOMIC512] 747 ** <li> [SQLITE_IOCAP_ATOMIC1K] 748 ** <li> [SQLITE_IOCAP_ATOMIC2K] 749 ** <li> [SQLITE_IOCAP_ATOMIC4K] 750 ** <li> [SQLITE_IOCAP_ATOMIC8K] 751 ** <li> [SQLITE_IOCAP_ATOMIC16K] 752 ** <li> [SQLITE_IOCAP_ATOMIC32K] 753 ** <li> [SQLITE_IOCAP_ATOMIC64K] 754 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 755 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 756 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 757 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 758 ** <li> [SQLITE_IOCAP_IMMUTABLE] 759 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 760 ** </ul> 761 ** 762 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 763 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 764 ** mean that writes of blocks that are nnn bytes in size and 765 ** are aligned to an address which is an integer multiple of 766 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 767 ** that when data is appended to a file, the data is appended 768 ** first then the size of the file is extended, never the other 769 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 770 ** information is written to disk in the same order as calls 771 ** to xWrite(). 772 ** 773 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 774 ** in the unread portions of the buffer with zeros. A VFS that 775 ** fails to zero-fill short reads might seem to work. However, 776 ** failure to zero-fill short reads will eventually lead to 777 ** database corruption. 778 */ 779 typedef struct sqlite3_io_methods sqlite3_io_methods; 780 struct sqlite3_io_methods { 781 int iVersion; 782 int (*xClose)(sqlite3_file*); 783 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 784 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 785 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 786 int (*xSync)(sqlite3_file*, int flags); 787 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 788 int (*xLock)(sqlite3_file*, int); 789 int (*xUnlock)(sqlite3_file*, int); 790 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 791 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 792 int (*xSectorSize)(sqlite3_file*); 793 int (*xDeviceCharacteristics)(sqlite3_file*); 794 /* Methods above are valid for version 1 */ 795 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 796 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 797 void (*xShmBarrier)(sqlite3_file*); 798 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 799 /* Methods above are valid for version 2 */ 800 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 801 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 802 /* Methods above are valid for version 3 */ 803 /* Additional methods may be added in future releases */ 804 }; 805 806 /* 807 ** CAPI3REF: Standard File Control Opcodes 808 ** KEYWORDS: {file control opcodes} {file control opcode} 809 ** 810 ** These integer constants are opcodes for the xFileControl method 811 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 812 ** interface. 813 ** 814 ** <ul> 815 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 816 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 817 ** opcode causes the xFileControl method to write the current state of 818 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 819 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 820 ** into an integer that the pArg argument points to. This capability 821 ** is used during testing and is only available when the SQLITE_TEST 822 ** compile-time option is used. 823 ** 824 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 825 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 826 ** layer a hint of how large the database file will grow to be during the 827 ** current transaction. This hint is not guaranteed to be accurate but it 828 ** is often close. The underlying VFS might choose to preallocate database 829 ** file space based on this hint in order to help writes to the database 830 ** file run faster. 831 ** 832 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 833 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 834 ** implements [sqlite3_deserialize()] to set an upper bound on the size 835 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 836 ** If the integer pointed to is negative, then it is filled in with the 837 ** current limit. Otherwise the limit is set to the larger of the value 838 ** of the integer pointed to and the current database size. The integer 839 ** pointed to is set to the new limit. 840 ** 841 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 842 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 843 ** extends and truncates the database file in chunks of a size specified 844 ** by the user. The fourth argument to [sqlite3_file_control()] should 845 ** point to an integer (type int) containing the new chunk-size to use 846 ** for the nominated database. Allocating database file space in large 847 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 848 ** improve performance on some systems. 849 ** 850 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 851 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 852 ** to the [sqlite3_file] object associated with a particular database 853 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 854 ** 855 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 856 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 857 ** to the [sqlite3_file] object associated with the journal file (either 858 ** the [rollback journal] or the [write-ahead log]) for a particular database 859 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 860 ** 861 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 862 ** No longer in use. 863 ** 864 ** <li>[[SQLITE_FCNTL_SYNC]] 865 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 866 ** sent to the VFS immediately before the xSync method is invoked on a 867 ** database file descriptor. Or, if the xSync method is not invoked 868 ** because the user has configured SQLite with 869 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 870 ** of the xSync method. In most cases, the pointer argument passed with 871 ** this file-control is NULL. However, if the database file is being synced 872 ** as part of a multi-database commit, the argument points to a nul-terminated 873 ** string containing the transactions master-journal file name. VFSes that 874 ** do not need this signal should silently ignore this opcode. Applications 875 ** should not call [sqlite3_file_control()] with this opcode as doing so may 876 ** disrupt the operation of the specialized VFSes that do require it. 877 ** 878 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 879 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 880 ** and sent to the VFS after a transaction has been committed immediately 881 ** but before the database is unlocked. VFSes that do not need this signal 882 ** should silently ignore this opcode. Applications should not call 883 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 884 ** operation of the specialized VFSes that do require it. 885 ** 886 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 887 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 888 ** retry counts and intervals for certain disk I/O operations for the 889 ** windows [VFS] in order to provide robustness in the presence of 890 ** anti-virus programs. By default, the windows VFS will retry file read, 891 ** file write, and file delete operations up to 10 times, with a delay 892 ** of 25 milliseconds before the first retry and with the delay increasing 893 ** by an additional 25 milliseconds with each subsequent retry. This 894 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 895 ** to be adjusted. The values are changed for all database connections 896 ** within the same process. The argument is a pointer to an array of two 897 ** integers where the first integer is the new retry count and the second 898 ** integer is the delay. If either integer is negative, then the setting 899 ** is not changed but instead the prior value of that setting is written 900 ** into the array entry, allowing the current retry settings to be 901 ** interrogated. The zDbName parameter is ignored. 902 ** 903 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 904 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 905 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 906 ** write ahead log ([WAL file]) and shared memory 907 ** files used for transaction control 908 ** are automatically deleted when the latest connection to the database 909 ** closes. Setting persistent WAL mode causes those files to persist after 910 ** close. Persisting the files is useful when other processes that do not 911 ** have write permission on the directory containing the database file want 912 ** to read the database file, as the WAL and shared memory files must exist 913 ** in order for the database to be readable. The fourth parameter to 914 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 915 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 916 ** WAL mode. If the integer is -1, then it is overwritten with the current 917 ** WAL persistence setting. 918 ** 919 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 920 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 921 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 922 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 923 ** xDeviceCharacteristics methods. The fourth parameter to 924 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 925 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 926 ** mode. If the integer is -1, then it is overwritten with the current 927 ** zero-damage mode setting. 928 ** 929 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 930 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 931 ** a write transaction to indicate that, unless it is rolled back for some 932 ** reason, the entire database file will be overwritten by the current 933 ** transaction. This is used by VACUUM operations. 934 ** 935 ** <li>[[SQLITE_FCNTL_VFSNAME]] 936 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 937 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 938 ** final bottom-level VFS are written into memory obtained from 939 ** [sqlite3_malloc()] and the result is stored in the char* variable 940 ** that the fourth parameter of [sqlite3_file_control()] points to. 941 ** The caller is responsible for freeing the memory when done. As with 942 ** all file-control actions, there is no guarantee that this will actually 943 ** do anything. Callers should initialize the char* variable to a NULL 944 ** pointer in case this file-control is not implemented. This file-control 945 ** is intended for diagnostic use only. 946 ** 947 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 948 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 949 ** [VFSes] currently in use. ^(The argument X in 950 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 951 ** of type "[sqlite3_vfs] **". This opcodes will set *X 952 ** to a pointer to the top-level VFS.)^ 953 ** ^When there are multiple VFS shims in the stack, this opcode finds the 954 ** upper-most shim only. 955 ** 956 ** <li>[[SQLITE_FCNTL_PRAGMA]] 957 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 958 ** file control is sent to the open [sqlite3_file] object corresponding 959 ** to the database file to which the pragma statement refers. ^The argument 960 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 961 ** pointers to strings (char**) in which the second element of the array 962 ** is the name of the pragma and the third element is the argument to the 963 ** pragma or NULL if the pragma has no argument. ^The handler for an 964 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 965 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 966 ** or the equivalent and that string will become the result of the pragma or 967 ** the error message if the pragma fails. ^If the 968 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 969 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 970 ** file control returns [SQLITE_OK], then the parser assumes that the 971 ** VFS has handled the PRAGMA itself and the parser generates a no-op 972 ** prepared statement if result string is NULL, or that returns a copy 973 ** of the result string if the string is non-NULL. 974 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 975 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 976 ** that the VFS encountered an error while handling the [PRAGMA] and the 977 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 978 ** file control occurs at the beginning of pragma statement analysis and so 979 ** it is able to override built-in [PRAGMA] statements. 980 ** 981 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 982 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 983 ** file-control may be invoked by SQLite on the database file handle 984 ** shortly after it is opened in order to provide a custom VFS with access 985 ** to the connection's busy-handler callback. The argument is of type (void**) 986 ** - an array of two (void *) values. The first (void *) actually points 987 ** to a function of type (int (*)(void *)). In order to invoke the connection's 988 ** busy-handler, this function should be invoked with the second (void *) in 989 ** the array as the only argument. If it returns non-zero, then the operation 990 ** should be retried. If it returns zero, the custom VFS should abandon the 991 ** current operation. 992 ** 993 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 994 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 995 ** to have SQLite generate a 996 ** temporary filename using the same algorithm that is followed to generate 997 ** temporary filenames for TEMP tables and other internal uses. The 998 ** argument should be a char** which will be filled with the filename 999 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1000 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1001 ** 1002 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1003 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1004 ** maximum number of bytes that will be used for memory-mapped I/O. 1005 ** The argument is a pointer to a value of type sqlite3_int64 that 1006 ** is an advisory maximum number of bytes in the file to memory map. The 1007 ** pointer is overwritten with the old value. The limit is not changed if 1008 ** the value originally pointed to is negative, and so the current limit 1009 ** can be queried by passing in a pointer to a negative number. This 1010 ** file-control is used internally to implement [PRAGMA mmap_size]. 1011 ** 1012 ** <li>[[SQLITE_FCNTL_TRACE]] 1013 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1014 ** to the VFS about what the higher layers of the SQLite stack are doing. 1015 ** This file control is used by some VFS activity tracing [shims]. 1016 ** The argument is a zero-terminated string. Higher layers in the 1017 ** SQLite stack may generate instances of this file control if 1018 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1019 ** 1020 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1021 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1022 ** pointer to an integer and it writes a boolean into that integer depending 1023 ** on whether or not the file has been renamed, moved, or deleted since it 1024 ** was first opened. 1025 ** 1026 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1027 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1028 ** underlying native file handle associated with a file handle. This file 1029 ** control interprets its argument as a pointer to a native file handle and 1030 ** writes the resulting value there. 1031 ** 1032 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1033 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1034 ** opcode causes the xFileControl method to swap the file handle with the one 1035 ** pointed to by the pArg argument. This capability is used during testing 1036 ** and only needs to be supported when SQLITE_TEST is defined. 1037 ** 1038 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1039 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1040 ** be advantageous to block on the next WAL lock if the lock is not immediately 1041 ** available. The WAL subsystem issues this signal during rare 1042 ** circumstances in order to fix a problem with priority inversion. 1043 ** Applications should <em>not</em> use this file-control. 1044 ** 1045 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1046 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1047 ** VFS should return SQLITE_NOTFOUND for this opcode. 1048 ** 1049 ** <li>[[SQLITE_FCNTL_RBU]] 1050 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1051 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1052 ** this opcode. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1055 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1056 ** the file descriptor is placed in "batch write mode", which 1057 ** means all subsequent write operations will be deferred and done 1058 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1059 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1060 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1061 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1062 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1063 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1064 ** except for calls to the xWrite method and the xFileControl method 1065 ** with [SQLITE_FCNTL_SIZE_HINT]. 1066 ** 1067 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1068 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1069 ** operations since the previous successful call to 1070 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1071 ** This file control returns [SQLITE_OK] if and only if the writes were 1072 ** all performed successfully and have been committed to persistent storage. 1073 ** ^Regardless of whether or not it is successful, this file control takes 1074 ** the file descriptor out of batch write mode so that all subsequent 1075 ** write operations are independent. 1076 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1077 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1078 ** 1079 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1080 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1081 ** operations since the previous successful call to 1082 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1083 ** ^This file control takes the file descriptor out of batch write mode 1084 ** so that all subsequent write operations are independent. 1085 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1086 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1087 ** 1088 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1089 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1090 ** to block for up to M milliseconds before failing when attempting to 1091 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1092 ** The parameter is a pointer to a 32-bit signed integer that contains 1093 ** the value that M is to be set to. Before returning, the 32-bit signed 1094 ** integer is overwritten with the previous value of M. 1095 ** 1096 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1097 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1098 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1099 ** The "data version" for the pager is written into the pointer. The 1100 ** "data version" changes whenever any change occurs to the corresponding 1101 ** database file, either through SQL statements on the same database 1102 ** connection or through transactions committed by separate database 1103 ** connections possibly in other processes. The [sqlite3_total_changes()] 1104 ** interface can be used to find if any database on the connection has changed, 1105 ** but that interface responds to changes on TEMP as well as MAIN and does 1106 ** not provide a mechanism to detect changes to MAIN only. Also, the 1107 ** [sqlite3_total_changes()] interface responds to internal changes only and 1108 ** omits changes made by other database connections. The 1109 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1110 ** a single attached database that occur due to other database connections, 1111 ** but omits changes implemented by the database connection on which it is 1112 ** called. This file control is the only mechanism to detect changes that 1113 ** happen either internally or externally and that are associated with 1114 ** a particular attached database. 1115 ** 1116 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1117 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1118 ** in wal mode before the client starts to copy pages from the wal 1119 ** file to the database file. 1120 ** 1121 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1122 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1123 ** in wal mode after the client has finished copying pages from the wal 1124 ** file to the database file, but before the *-shm file is updated to 1125 ** record the fact that the pages have been checkpointed. 1126 ** </ul> 1127 */ 1128 #define SQLITE_FCNTL_LOCKSTATE 1 1129 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1130 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1131 #define SQLITE_FCNTL_LAST_ERRNO 4 1132 #define SQLITE_FCNTL_SIZE_HINT 5 1133 #define SQLITE_FCNTL_CHUNK_SIZE 6 1134 #define SQLITE_FCNTL_FILE_POINTER 7 1135 #define SQLITE_FCNTL_SYNC_OMITTED 8 1136 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1137 #define SQLITE_FCNTL_PERSIST_WAL 10 1138 #define SQLITE_FCNTL_OVERWRITE 11 1139 #define SQLITE_FCNTL_VFSNAME 12 1140 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1141 #define SQLITE_FCNTL_PRAGMA 14 1142 #define SQLITE_FCNTL_BUSYHANDLER 15 1143 #define SQLITE_FCNTL_TEMPFILENAME 16 1144 #define SQLITE_FCNTL_MMAP_SIZE 18 1145 #define SQLITE_FCNTL_TRACE 19 1146 #define SQLITE_FCNTL_HAS_MOVED 20 1147 #define SQLITE_FCNTL_SYNC 21 1148 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1149 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1150 #define SQLITE_FCNTL_WAL_BLOCK 24 1151 #define SQLITE_FCNTL_ZIPVFS 25 1152 #define SQLITE_FCNTL_RBU 26 1153 #define SQLITE_FCNTL_VFS_POINTER 27 1154 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1155 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1156 #define SQLITE_FCNTL_PDB 30 1157 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1158 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1159 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1160 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1161 #define SQLITE_FCNTL_DATA_VERSION 35 1162 #define SQLITE_FCNTL_SIZE_LIMIT 36 1163 #define SQLITE_FCNTL_CKPT_DONE 37 1164 #define SQLITE_FCNTL_RESERVE_BYTES 38 1165 #define SQLITE_FCNTL_CKPT_START 39 1166 1167 /* deprecated names */ 1168 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1169 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1170 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1171 1172 1173 /* 1174 ** CAPI3REF: Mutex Handle 1175 ** 1176 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1177 ** abstract type for a mutex object. The SQLite core never looks 1178 ** at the internal representation of an [sqlite3_mutex]. It only 1179 ** deals with pointers to the [sqlite3_mutex] object. 1180 ** 1181 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1182 */ 1183 typedef struct sqlite3_mutex sqlite3_mutex; 1184 1185 /* 1186 ** CAPI3REF: Loadable Extension Thunk 1187 ** 1188 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1189 ** the third parameter to entry points of [loadable extensions]. This 1190 ** structure must be typedefed in order to work around compiler warnings 1191 ** on some platforms. 1192 */ 1193 typedef struct sqlite3_api_routines sqlite3_api_routines; 1194 1195 /* 1196 ** CAPI3REF: OS Interface Object 1197 ** 1198 ** An instance of the sqlite3_vfs object defines the interface between 1199 ** the SQLite core and the underlying operating system. The "vfs" 1200 ** in the name of the object stands for "virtual file system". See 1201 ** the [VFS | VFS documentation] for further information. 1202 ** 1203 ** The VFS interface is sometimes extended by adding new methods onto 1204 ** the end. Each time such an extension occurs, the iVersion field 1205 ** is incremented. The iVersion value started out as 1 in 1206 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1207 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1208 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1209 ** may be appended to the sqlite3_vfs object and the iVersion value 1210 ** may increase again in future versions of SQLite. 1211 ** Note that due to an oversight, the structure 1212 ** of the sqlite3_vfs object changed in the transition from 1213 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1214 ** and yet the iVersion field was not increased. 1215 ** 1216 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1217 ** structure used by this VFS. mxPathname is the maximum length of 1218 ** a pathname in this VFS. 1219 ** 1220 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1221 ** the pNext pointer. The [sqlite3_vfs_register()] 1222 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1223 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1224 ** searches the list. Neither the application code nor the VFS 1225 ** implementation should use the pNext pointer. 1226 ** 1227 ** The pNext field is the only field in the sqlite3_vfs 1228 ** structure that SQLite will ever modify. SQLite will only access 1229 ** or modify this field while holding a particular static mutex. 1230 ** The application should never modify anything within the sqlite3_vfs 1231 ** object once the object has been registered. 1232 ** 1233 ** The zName field holds the name of the VFS module. The name must 1234 ** be unique across all VFS modules. 1235 ** 1236 ** [[sqlite3_vfs.xOpen]] 1237 ** ^SQLite guarantees that the zFilename parameter to xOpen 1238 ** is either a NULL pointer or string obtained 1239 ** from xFullPathname() with an optional suffix added. 1240 ** ^If a suffix is added to the zFilename parameter, it will 1241 ** consist of a single "-" character followed by no more than 1242 ** 11 alphanumeric and/or "-" characters. 1243 ** ^SQLite further guarantees that 1244 ** the string will be valid and unchanged until xClose() is 1245 ** called. Because of the previous sentence, 1246 ** the [sqlite3_file] can safely store a pointer to the 1247 ** filename if it needs to remember the filename for some reason. 1248 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1249 ** must invent its own temporary name for the file. ^Whenever the 1250 ** xFilename parameter is NULL it will also be the case that the 1251 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1252 ** 1253 ** The flags argument to xOpen() includes all bits set in 1254 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1255 ** or [sqlite3_open16()] is used, then flags includes at least 1256 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1257 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1258 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1259 ** 1260 ** ^(SQLite will also add one of the following flags to the xOpen() 1261 ** call, depending on the object being opened: 1262 ** 1263 ** <ul> 1264 ** <li> [SQLITE_OPEN_MAIN_DB] 1265 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1266 ** <li> [SQLITE_OPEN_TEMP_DB] 1267 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1268 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1269 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1270 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1271 ** <li> [SQLITE_OPEN_WAL] 1272 ** </ul>)^ 1273 ** 1274 ** The file I/O implementation can use the object type flags to 1275 ** change the way it deals with files. For example, an application 1276 ** that does not care about crash recovery or rollback might make 1277 ** the open of a journal file a no-op. Writes to this journal would 1278 ** also be no-ops, and any attempt to read the journal would return 1279 ** SQLITE_IOERR. Or the implementation might recognize that a database 1280 ** file will be doing page-aligned sector reads and writes in a random 1281 ** order and set up its I/O subsystem accordingly. 1282 ** 1283 ** SQLite might also add one of the following flags to the xOpen method: 1284 ** 1285 ** <ul> 1286 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1287 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1288 ** </ul> 1289 ** 1290 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1291 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1292 ** will be set for TEMP databases and their journals, transient 1293 ** databases, and subjournals. 1294 ** 1295 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1296 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1297 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1298 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1299 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1300 ** be created, and that it is an error if it already exists. 1301 ** It is <i>not</i> used to indicate the file should be opened 1302 ** for exclusive access. 1303 ** 1304 ** ^At least szOsFile bytes of memory are allocated by SQLite 1305 ** to hold the [sqlite3_file] structure passed as the third 1306 ** argument to xOpen. The xOpen method does not have to 1307 ** allocate the structure; it should just fill it in. Note that 1308 ** the xOpen method must set the sqlite3_file.pMethods to either 1309 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1310 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1311 ** element will be valid after xOpen returns regardless of the success 1312 ** or failure of the xOpen call. 1313 ** 1314 ** [[sqlite3_vfs.xAccess]] 1315 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1316 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1317 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1318 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1319 ** flag is never actually used and is not implemented in the built-in 1320 ** VFSes of SQLite. The file is named by the second argument and can be a 1321 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1322 ** non-zero error code if there is an I/O error or if the name of 1323 ** the file given in the second argument is illegal. If SQLITE_OK 1324 ** is returned, then non-zero or zero is written into *pResOut to indicate 1325 ** whether or not the file is accessible. 1326 ** 1327 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1328 ** output buffer xFullPathname. The exact size of the output buffer 1329 ** is also passed as a parameter to both methods. If the output buffer 1330 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1331 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1332 ** to prevent this by setting mxPathname to a sufficiently large value. 1333 ** 1334 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1335 ** interfaces are not strictly a part of the filesystem, but they are 1336 ** included in the VFS structure for completeness. 1337 ** The xRandomness() function attempts to return nBytes bytes 1338 ** of good-quality randomness into zOut. The return value is 1339 ** the actual number of bytes of randomness obtained. 1340 ** The xSleep() method causes the calling thread to sleep for at 1341 ** least the number of microseconds given. ^The xCurrentTime() 1342 ** method returns a Julian Day Number for the current date and time as 1343 ** a floating point value. 1344 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1345 ** Day Number multiplied by 86400000 (the number of milliseconds in 1346 ** a 24-hour day). 1347 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1348 ** date and time if that method is available (if iVersion is 2 or 1349 ** greater and the function pointer is not NULL) and will fall back 1350 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1351 ** 1352 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1353 ** are not used by the SQLite core. These optional interfaces are provided 1354 ** by some VFSes to facilitate testing of the VFS code. By overriding 1355 ** system calls with functions under its control, a test program can 1356 ** simulate faults and error conditions that would otherwise be difficult 1357 ** or impossible to induce. The set of system calls that can be overridden 1358 ** varies from one VFS to another, and from one version of the same VFS to the 1359 ** next. Applications that use these interfaces must be prepared for any 1360 ** or all of these interfaces to be NULL or for their behavior to change 1361 ** from one release to the next. Applications must not attempt to access 1362 ** any of these methods if the iVersion of the VFS is less than 3. 1363 */ 1364 typedef struct sqlite3_vfs sqlite3_vfs; 1365 typedef void (*sqlite3_syscall_ptr)(void); 1366 struct sqlite3_vfs { 1367 int iVersion; /* Structure version number (currently 3) */ 1368 int szOsFile; /* Size of subclassed sqlite3_file */ 1369 int mxPathname; /* Maximum file pathname length */ 1370 sqlite3_vfs *pNext; /* Next registered VFS */ 1371 const char *zName; /* Name of this virtual file system */ 1372 void *pAppData; /* Pointer to application-specific data */ 1373 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1374 int flags, int *pOutFlags); 1375 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1376 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1377 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1378 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1379 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1380 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1381 void (*xDlClose)(sqlite3_vfs*, void*); 1382 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1383 int (*xSleep)(sqlite3_vfs*, int microseconds); 1384 int (*xCurrentTime)(sqlite3_vfs*, double*); 1385 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1386 /* 1387 ** The methods above are in version 1 of the sqlite_vfs object 1388 ** definition. Those that follow are added in version 2 or later 1389 */ 1390 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1391 /* 1392 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1393 ** Those below are for version 3 and greater. 1394 */ 1395 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1396 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1397 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1398 /* 1399 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1400 ** New fields may be appended in future versions. The iVersion 1401 ** value will increment whenever this happens. 1402 */ 1403 }; 1404 1405 /* 1406 ** CAPI3REF: Flags for the xAccess VFS method 1407 ** 1408 ** These integer constants can be used as the third parameter to 1409 ** the xAccess method of an [sqlite3_vfs] object. They determine 1410 ** what kind of permissions the xAccess method is looking for. 1411 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1412 ** simply checks whether the file exists. 1413 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1414 ** checks whether the named directory is both readable and writable 1415 ** (in other words, if files can be added, removed, and renamed within 1416 ** the directory). 1417 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1418 ** [temp_store_directory pragma], though this could change in a future 1419 ** release of SQLite. 1420 ** With SQLITE_ACCESS_READ, the xAccess method 1421 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1422 ** currently unused, though it might be used in a future release of 1423 ** SQLite. 1424 */ 1425 #define SQLITE_ACCESS_EXISTS 0 1426 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1427 #define SQLITE_ACCESS_READ 2 /* Unused */ 1428 1429 /* 1430 ** CAPI3REF: Flags for the xShmLock VFS method 1431 ** 1432 ** These integer constants define the various locking operations 1433 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1434 ** following are the only legal combinations of flags to the 1435 ** xShmLock method: 1436 ** 1437 ** <ul> 1438 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1439 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1440 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1441 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1442 ** </ul> 1443 ** 1444 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1445 ** was given on the corresponding lock. 1446 ** 1447 ** The xShmLock method can transition between unlocked and SHARED or 1448 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1449 ** and EXCLUSIVE. 1450 */ 1451 #define SQLITE_SHM_UNLOCK 1 1452 #define SQLITE_SHM_LOCK 2 1453 #define SQLITE_SHM_SHARED 4 1454 #define SQLITE_SHM_EXCLUSIVE 8 1455 1456 /* 1457 ** CAPI3REF: Maximum xShmLock index 1458 ** 1459 ** The xShmLock method on [sqlite3_io_methods] may use values 1460 ** between 0 and this upper bound as its "offset" argument. 1461 ** The SQLite core will never attempt to acquire or release a 1462 ** lock outside of this range 1463 */ 1464 #define SQLITE_SHM_NLOCK 8 1465 1466 1467 /* 1468 ** CAPI3REF: Initialize The SQLite Library 1469 ** 1470 ** ^The sqlite3_initialize() routine initializes the 1471 ** SQLite library. ^The sqlite3_shutdown() routine 1472 ** deallocates any resources that were allocated by sqlite3_initialize(). 1473 ** These routines are designed to aid in process initialization and 1474 ** shutdown on embedded systems. Workstation applications using 1475 ** SQLite normally do not need to invoke either of these routines. 1476 ** 1477 ** A call to sqlite3_initialize() is an "effective" call if it is 1478 ** the first time sqlite3_initialize() is invoked during the lifetime of 1479 ** the process, or if it is the first time sqlite3_initialize() is invoked 1480 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1481 ** of sqlite3_initialize() does any initialization. All other calls 1482 ** are harmless no-ops.)^ 1483 ** 1484 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1485 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1486 ** an effective call to sqlite3_shutdown() does any deinitialization. 1487 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1488 ** 1489 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1490 ** is not. The sqlite3_shutdown() interface must only be called from a 1491 ** single thread. All open [database connections] must be closed and all 1492 ** other SQLite resources must be deallocated prior to invoking 1493 ** sqlite3_shutdown(). 1494 ** 1495 ** Among other things, ^sqlite3_initialize() will invoke 1496 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1497 ** will invoke sqlite3_os_end(). 1498 ** 1499 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1500 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1501 ** the library (perhaps it is unable to allocate a needed resource such 1502 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1503 ** 1504 ** ^The sqlite3_initialize() routine is called internally by many other 1505 ** SQLite interfaces so that an application usually does not need to 1506 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1507 ** calls sqlite3_initialize() so the SQLite library will be automatically 1508 ** initialized when [sqlite3_open()] is called if it has not be initialized 1509 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1510 ** compile-time option, then the automatic calls to sqlite3_initialize() 1511 ** are omitted and the application must call sqlite3_initialize() directly 1512 ** prior to using any other SQLite interface. For maximum portability, 1513 ** it is recommended that applications always invoke sqlite3_initialize() 1514 ** directly prior to using any other SQLite interface. Future releases 1515 ** of SQLite may require this. In other words, the behavior exhibited 1516 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1517 ** default behavior in some future release of SQLite. 1518 ** 1519 ** The sqlite3_os_init() routine does operating-system specific 1520 ** initialization of the SQLite library. The sqlite3_os_end() 1521 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1522 ** performed by these routines include allocation or deallocation 1523 ** of static resources, initialization of global variables, 1524 ** setting up a default [sqlite3_vfs] module, or setting up 1525 ** a default configuration using [sqlite3_config()]. 1526 ** 1527 ** The application should never invoke either sqlite3_os_init() 1528 ** or sqlite3_os_end() directly. The application should only invoke 1529 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1530 ** interface is called automatically by sqlite3_initialize() and 1531 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1532 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1533 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1534 ** When [custom builds | built for other platforms] 1535 ** (using the [SQLITE_OS_OTHER=1] compile-time 1536 ** option) the application must supply a suitable implementation for 1537 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1538 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1539 ** must return [SQLITE_OK] on success and some other [error code] upon 1540 ** failure. 1541 */ 1542 SQLITE_API int sqlite3_initialize(void); 1543 SQLITE_API int sqlite3_shutdown(void); 1544 SQLITE_API int sqlite3_os_init(void); 1545 SQLITE_API int sqlite3_os_end(void); 1546 1547 /* 1548 ** CAPI3REF: Configuring The SQLite Library 1549 ** 1550 ** The sqlite3_config() interface is used to make global configuration 1551 ** changes to SQLite in order to tune SQLite to the specific needs of 1552 ** the application. The default configuration is recommended for most 1553 ** applications and so this routine is usually not necessary. It is 1554 ** provided to support rare applications with unusual needs. 1555 ** 1556 ** <b>The sqlite3_config() interface is not threadsafe. The application 1557 ** must ensure that no other SQLite interfaces are invoked by other 1558 ** threads while sqlite3_config() is running.</b> 1559 ** 1560 ** The sqlite3_config() interface 1561 ** may only be invoked prior to library initialization using 1562 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1563 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1564 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1565 ** Note, however, that ^sqlite3_config() can be called as part of the 1566 ** implementation of an application-defined [sqlite3_os_init()]. 1567 ** 1568 ** The first argument to sqlite3_config() is an integer 1569 ** [configuration option] that determines 1570 ** what property of SQLite is to be configured. Subsequent arguments 1571 ** vary depending on the [configuration option] 1572 ** in the first argument. 1573 ** 1574 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1575 ** ^If the option is unknown or SQLite is unable to set the option 1576 ** then this routine returns a non-zero [error code]. 1577 */ 1578 SQLITE_API int sqlite3_config(int, ...); 1579 1580 /* 1581 ** CAPI3REF: Configure database connections 1582 ** METHOD: sqlite3 1583 ** 1584 ** The sqlite3_db_config() interface is used to make configuration 1585 ** changes to a [database connection]. The interface is similar to 1586 ** [sqlite3_config()] except that the changes apply to a single 1587 ** [database connection] (specified in the first argument). 1588 ** 1589 ** The second argument to sqlite3_db_config(D,V,...) is the 1590 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1591 ** that indicates what aspect of the [database connection] is being configured. 1592 ** Subsequent arguments vary depending on the configuration verb. 1593 ** 1594 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1595 ** the call is considered successful. 1596 */ 1597 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1598 1599 /* 1600 ** CAPI3REF: Memory Allocation Routines 1601 ** 1602 ** An instance of this object defines the interface between SQLite 1603 ** and low-level memory allocation routines. 1604 ** 1605 ** This object is used in only one place in the SQLite interface. 1606 ** A pointer to an instance of this object is the argument to 1607 ** [sqlite3_config()] when the configuration option is 1608 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1609 ** By creating an instance of this object 1610 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1611 ** during configuration, an application can specify an alternative 1612 ** memory allocation subsystem for SQLite to use for all of its 1613 ** dynamic memory needs. 1614 ** 1615 ** Note that SQLite comes with several [built-in memory allocators] 1616 ** that are perfectly adequate for the overwhelming majority of applications 1617 ** and that this object is only useful to a tiny minority of applications 1618 ** with specialized memory allocation requirements. This object is 1619 ** also used during testing of SQLite in order to specify an alternative 1620 ** memory allocator that simulates memory out-of-memory conditions in 1621 ** order to verify that SQLite recovers gracefully from such 1622 ** conditions. 1623 ** 1624 ** The xMalloc, xRealloc, and xFree methods must work like the 1625 ** malloc(), realloc() and free() functions from the standard C library. 1626 ** ^SQLite guarantees that the second argument to 1627 ** xRealloc is always a value returned by a prior call to xRoundup. 1628 ** 1629 ** xSize should return the allocated size of a memory allocation 1630 ** previously obtained from xMalloc or xRealloc. The allocated size 1631 ** is always at least as big as the requested size but may be larger. 1632 ** 1633 ** The xRoundup method returns what would be the allocated size of 1634 ** a memory allocation given a particular requested size. Most memory 1635 ** allocators round up memory allocations at least to the next multiple 1636 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1637 ** Every memory allocation request coming in through [sqlite3_malloc()] 1638 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1639 ** that causes the corresponding memory allocation to fail. 1640 ** 1641 ** The xInit method initializes the memory allocator. For example, 1642 ** it might allocate any required mutexes or initialize internal data 1643 ** structures. The xShutdown method is invoked (indirectly) by 1644 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1645 ** by xInit. The pAppData pointer is used as the only parameter to 1646 ** xInit and xShutdown. 1647 ** 1648 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1649 ** the xInit method, so the xInit method need not be threadsafe. The 1650 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1651 ** not need to be threadsafe either. For all other methods, SQLite 1652 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1653 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1654 ** it is by default) and so the methods are automatically serialized. 1655 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1656 ** methods must be threadsafe or else make their own arrangements for 1657 ** serialization. 1658 ** 1659 ** SQLite will never invoke xInit() more than once without an intervening 1660 ** call to xShutdown(). 1661 */ 1662 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1663 struct sqlite3_mem_methods { 1664 void *(*xMalloc)(int); /* Memory allocation function */ 1665 void (*xFree)(void*); /* Free a prior allocation */ 1666 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1667 int (*xSize)(void*); /* Return the size of an allocation */ 1668 int (*xRoundup)(int); /* Round up request size to allocation size */ 1669 int (*xInit)(void*); /* Initialize the memory allocator */ 1670 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1671 void *pAppData; /* Argument to xInit() and xShutdown() */ 1672 }; 1673 1674 /* 1675 ** CAPI3REF: Configuration Options 1676 ** KEYWORDS: {configuration option} 1677 ** 1678 ** These constants are the available integer configuration options that 1679 ** can be passed as the first argument to the [sqlite3_config()] interface. 1680 ** 1681 ** New configuration options may be added in future releases of SQLite. 1682 ** Existing configuration options might be discontinued. Applications 1683 ** should check the return code from [sqlite3_config()] to make sure that 1684 ** the call worked. The [sqlite3_config()] interface will return a 1685 ** non-zero [error code] if a discontinued or unsupported configuration option 1686 ** is invoked. 1687 ** 1688 ** <dl> 1689 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1690 ** <dd>There are no arguments to this option. ^This option sets the 1691 ** [threading mode] to Single-thread. In other words, it disables 1692 ** all mutexing and puts SQLite into a mode where it can only be used 1693 ** by a single thread. ^If SQLite is compiled with 1694 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1695 ** it is not possible to change the [threading mode] from its default 1696 ** value of Single-thread and so [sqlite3_config()] will return 1697 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1698 ** configuration option.</dd> 1699 ** 1700 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1701 ** <dd>There are no arguments to this option. ^This option sets the 1702 ** [threading mode] to Multi-thread. In other words, it disables 1703 ** mutexing on [database connection] and [prepared statement] objects. 1704 ** The application is responsible for serializing access to 1705 ** [database connections] and [prepared statements]. But other mutexes 1706 ** are enabled so that SQLite will be safe to use in a multi-threaded 1707 ** environment as long as no two threads attempt to use the same 1708 ** [database connection] at the same time. ^If SQLite is compiled with 1709 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1710 ** it is not possible to set the Multi-thread [threading mode] and 1711 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1712 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1713 ** 1714 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1715 ** <dd>There are no arguments to this option. ^This option sets the 1716 ** [threading mode] to Serialized. In other words, this option enables 1717 ** all mutexes including the recursive 1718 ** mutexes on [database connection] and [prepared statement] objects. 1719 ** In this mode (which is the default when SQLite is compiled with 1720 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1721 ** to [database connections] and [prepared statements] so that the 1722 ** application is free to use the same [database connection] or the 1723 ** same [prepared statement] in different threads at the same time. 1724 ** ^If SQLite is compiled with 1725 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1726 ** it is not possible to set the Serialized [threading mode] and 1727 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1728 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1729 ** 1730 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1731 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1732 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1733 ** The argument specifies 1734 ** alternative low-level memory allocation routines to be used in place of 1735 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1736 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1737 ** before the [sqlite3_config()] call returns.</dd> 1738 ** 1739 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1740 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1741 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1742 ** The [sqlite3_mem_methods] 1743 ** structure is filled with the currently defined memory allocation routines.)^ 1744 ** This option can be used to overload the default memory allocation 1745 ** routines with a wrapper that simulations memory allocation failure or 1746 ** tracks memory usage, for example. </dd> 1747 ** 1748 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1749 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1750 ** type int, interpreted as a boolean, which if true provides a hint to 1751 ** SQLite that it should avoid large memory allocations if possible. 1752 ** SQLite will run faster if it is free to make large memory allocations, 1753 ** but some application might prefer to run slower in exchange for 1754 ** guarantees about memory fragmentation that are possible if large 1755 ** allocations are avoided. This hint is normally off. 1756 ** </dd> 1757 ** 1758 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1759 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1760 ** interpreted as a boolean, which enables or disables the collection of 1761 ** memory allocation statistics. ^(When memory allocation statistics are 1762 ** disabled, the following SQLite interfaces become non-operational: 1763 ** <ul> 1764 ** <li> [sqlite3_hard_heap_limit64()] 1765 ** <li> [sqlite3_memory_used()] 1766 ** <li> [sqlite3_memory_highwater()] 1767 ** <li> [sqlite3_soft_heap_limit64()] 1768 ** <li> [sqlite3_status64()] 1769 ** </ul>)^ 1770 ** ^Memory allocation statistics are enabled by default unless SQLite is 1771 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1772 ** allocation statistics are disabled by default. 1773 ** </dd> 1774 ** 1775 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1776 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1777 ** </dd> 1778 ** 1779 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1780 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1781 ** that SQLite can use for the database page cache with the default page 1782 ** cache implementation. 1783 ** This configuration option is a no-op if an application-defined page 1784 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1785 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1786 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1787 ** and the number of cache lines (N). 1788 ** The sz argument should be the size of the largest database page 1789 ** (a power of two between 512 and 65536) plus some extra bytes for each 1790 ** page header. ^The number of extra bytes needed by the page header 1791 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1792 ** ^It is harmless, apart from the wasted memory, 1793 ** for the sz parameter to be larger than necessary. The pMem 1794 ** argument must be either a NULL pointer or a pointer to an 8-byte 1795 ** aligned block of memory of at least sz*N bytes, otherwise 1796 ** subsequent behavior is undefined. 1797 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1798 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1799 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1800 ** is exhausted. 1801 ** ^If pMem is NULL and N is non-zero, then each database connection 1802 ** does an initial bulk allocation for page cache memory 1803 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1804 ** of -1024*N bytes if N is negative, . ^If additional 1805 ** page cache memory is needed beyond what is provided by the initial 1806 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1807 ** additional cache line. </dd> 1808 ** 1809 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1810 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1811 ** that SQLite will use for all of its dynamic memory allocation needs 1812 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1813 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1814 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1815 ** [SQLITE_ERROR] if invoked otherwise. 1816 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1817 ** An 8-byte aligned pointer to the memory, 1818 ** the number of bytes in the memory buffer, and the minimum allocation size. 1819 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1820 ** to using its default memory allocator (the system malloc() implementation), 1821 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1822 ** memory pointer is not NULL then the alternative memory 1823 ** allocator is engaged to handle all of SQLites memory allocation needs. 1824 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1825 ** boundary or subsequent behavior of SQLite will be undefined. 1826 ** The minimum allocation size is capped at 2**12. Reasonable values 1827 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1828 ** 1829 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1830 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1831 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1832 ** The argument specifies alternative low-level mutex routines to be used 1833 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1834 ** the content of the [sqlite3_mutex_methods] structure before the call to 1835 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1836 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1837 ** the entire mutexing subsystem is omitted from the build and hence calls to 1838 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1839 ** return [SQLITE_ERROR].</dd> 1840 ** 1841 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1842 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1843 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1844 ** [sqlite3_mutex_methods] 1845 ** structure is filled with the currently defined mutex routines.)^ 1846 ** This option can be used to overload the default mutex allocation 1847 ** routines with a wrapper used to track mutex usage for performance 1848 ** profiling or testing, for example. ^If SQLite is compiled with 1849 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1850 ** the entire mutexing subsystem is omitted from the build and hence calls to 1851 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1852 ** return [SQLITE_ERROR].</dd> 1853 ** 1854 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1855 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1856 ** the default size of lookaside memory on each [database connection]. 1857 ** The first argument is the 1858 ** size of each lookaside buffer slot and the second is the number of 1859 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1860 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1861 ** option to [sqlite3_db_config()] can be used to change the lookaside 1862 ** configuration on individual connections.)^ </dd> 1863 ** 1864 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1865 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1866 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1867 ** the interface to a custom page cache implementation.)^ 1868 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1869 ** 1870 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1871 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1872 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1873 ** the current page cache implementation into that object.)^ </dd> 1874 ** 1875 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1876 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1877 ** global [error log]. 1878 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1879 ** function with a call signature of void(*)(void*,int,const char*), 1880 ** and a pointer to void. ^If the function pointer is not NULL, it is 1881 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1882 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1883 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1884 ** passed through as the first parameter to the application-defined logger 1885 ** function whenever that function is invoked. ^The second parameter to 1886 ** the logger function is a copy of the first parameter to the corresponding 1887 ** [sqlite3_log()] call and is intended to be a [result code] or an 1888 ** [extended result code]. ^The third parameter passed to the logger is 1889 ** log message after formatting via [sqlite3_snprintf()]. 1890 ** The SQLite logging interface is not reentrant; the logger function 1891 ** supplied by the application must not invoke any SQLite interface. 1892 ** In a multi-threaded application, the application-defined logger 1893 ** function must be threadsafe. </dd> 1894 ** 1895 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1896 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1897 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1898 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1899 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1900 ** [sqlite3_open16()] or 1901 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1902 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1903 ** connection is opened. ^If it is globally disabled, filenames are 1904 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1905 ** database connection is opened. ^(By default, URI handling is globally 1906 ** disabled. The default value may be changed by compiling with the 1907 ** [SQLITE_USE_URI] symbol defined.)^ 1908 ** 1909 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1910 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1911 ** argument which is interpreted as a boolean in order to enable or disable 1912 ** the use of covering indices for full table scans in the query optimizer. 1913 ** ^The default setting is determined 1914 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1915 ** if that compile-time option is omitted. 1916 ** The ability to disable the use of covering indices for full table scans 1917 ** is because some incorrectly coded legacy applications might malfunction 1918 ** when the optimization is enabled. Providing the ability to 1919 ** disable the optimization allows the older, buggy application code to work 1920 ** without change even with newer versions of SQLite. 1921 ** 1922 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1923 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1924 ** <dd> These options are obsolete and should not be used by new code. 1925 ** They are retained for backwards compatibility but are now no-ops. 1926 ** </dd> 1927 ** 1928 ** [[SQLITE_CONFIG_SQLLOG]] 1929 ** <dt>SQLITE_CONFIG_SQLLOG 1930 ** <dd>This option is only available if sqlite is compiled with the 1931 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1932 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1933 ** The second should be of type (void*). The callback is invoked by the library 1934 ** in three separate circumstances, identified by the value passed as the 1935 ** fourth parameter. If the fourth parameter is 0, then the database connection 1936 ** passed as the second argument has just been opened. The third argument 1937 ** points to a buffer containing the name of the main database file. If the 1938 ** fourth parameter is 1, then the SQL statement that the third parameter 1939 ** points to has just been executed. Or, if the fourth parameter is 2, then 1940 ** the connection being passed as the second parameter is being closed. The 1941 ** third parameter is passed NULL In this case. An example of using this 1942 ** configuration option can be seen in the "test_sqllog.c" source file in 1943 ** the canonical SQLite source tree.</dd> 1944 ** 1945 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1946 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1947 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1948 ** that are the default mmap size limit (the default setting for 1949 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1950 ** ^The default setting can be overridden by each database connection using 1951 ** either the [PRAGMA mmap_size] command, or by using the 1952 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1953 ** will be silently truncated if necessary so that it does not exceed the 1954 ** compile-time maximum mmap size set by the 1955 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1956 ** ^If either argument to this option is negative, then that argument is 1957 ** changed to its compile-time default. 1958 ** 1959 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1960 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1961 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1962 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1963 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1964 ** that specifies the maximum size of the created heap. 1965 ** 1966 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1967 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1968 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1969 ** is a pointer to an integer and writes into that integer the number of extra 1970 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1971 ** The amount of extra space required can change depending on the compiler, 1972 ** target platform, and SQLite version. 1973 ** 1974 ** [[SQLITE_CONFIG_PMASZ]] 1975 ** <dt>SQLITE_CONFIG_PMASZ 1976 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1977 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1978 ** sorter to that integer. The default minimum PMA Size is set by the 1979 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1980 ** to help with sort operations when multithreaded sorting 1981 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1982 ** to be sorted exceeds the page size times the minimum of the 1983 ** [PRAGMA cache_size] setting and this value. 1984 ** 1985 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1986 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1987 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1988 ** becomes the [statement journal] spill-to-disk threshold. 1989 ** [Statement journals] are held in memory until their size (in bytes) 1990 ** exceeds this threshold, at which point they are written to disk. 1991 ** Or if the threshold is -1, statement journals are always held 1992 ** exclusively in memory. 1993 ** Since many statement journals never become large, setting the spill 1994 ** threshold to a value such as 64KiB can greatly reduce the amount of 1995 ** I/O required to support statement rollback. 1996 ** The default value for this setting is controlled by the 1997 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1998 ** 1999 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2000 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2001 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2002 ** of type (int) - the new value of the sorter-reference size threshold. 2003 ** Usually, when SQLite uses an external sort to order records according 2004 ** to an ORDER BY clause, all fields required by the caller are present in the 2005 ** sorted records. However, if SQLite determines based on the declared type 2006 ** of a table column that its values are likely to be very large - larger 2007 ** than the configured sorter-reference size threshold - then a reference 2008 ** is stored in each sorted record and the required column values loaded 2009 ** from the database as records are returned in sorted order. The default 2010 ** value for this option is to never use this optimization. Specifying a 2011 ** negative value for this option restores the default behaviour. 2012 ** This option is only available if SQLite is compiled with the 2013 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2014 ** 2015 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2016 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2017 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2018 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2019 ** database created using [sqlite3_deserialize()]. This default maximum 2020 ** size can be adjusted up or down for individual databases using the 2021 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2022 ** configuration setting is never used, then the default maximum is determined 2023 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2024 ** compile-time option is not set, then the default maximum is 1073741824. 2025 ** </dl> 2026 */ 2027 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2028 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2029 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2030 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2031 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2032 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2033 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2034 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2035 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2036 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2037 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2038 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2039 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2040 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2041 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2042 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2043 #define SQLITE_CONFIG_URI 17 /* int */ 2044 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2045 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2046 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2047 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2048 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2049 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2050 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2051 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2052 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2053 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2054 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2055 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2056 2057 /* 2058 ** CAPI3REF: Database Connection Configuration Options 2059 ** 2060 ** These constants are the available integer configuration options that 2061 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2062 ** 2063 ** New configuration options may be added in future releases of SQLite. 2064 ** Existing configuration options might be discontinued. Applications 2065 ** should check the return code from [sqlite3_db_config()] to make sure that 2066 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2067 ** non-zero [error code] if a discontinued or unsupported configuration option 2068 ** is invoked. 2069 ** 2070 ** <dl> 2071 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2072 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2073 ** <dd> ^This option takes three additional arguments that determine the 2074 ** [lookaside memory allocator] configuration for the [database connection]. 2075 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2076 ** pointer to a memory buffer to use for lookaside memory. 2077 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2078 ** may be NULL in which case SQLite will allocate the 2079 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2080 ** size of each lookaside buffer slot. ^The third argument is the number of 2081 ** slots. The size of the buffer in the first argument must be greater than 2082 ** or equal to the product of the second and third arguments. The buffer 2083 ** must be aligned to an 8-byte boundary. ^If the second argument to 2084 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2085 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2086 ** configuration for a database connection can only be changed when that 2087 ** connection is not currently using lookaside memory, or in other words 2088 ** when the "current value" returned by 2089 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2090 ** Any attempt to change the lookaside memory configuration when lookaside 2091 ** memory is in use leaves the configuration unchanged and returns 2092 ** [SQLITE_BUSY].)^</dd> 2093 ** 2094 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2095 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2096 ** <dd> ^This option is used to enable or disable the enforcement of 2097 ** [foreign key constraints]. There should be two additional arguments. 2098 ** The first argument is an integer which is 0 to disable FK enforcement, 2099 ** positive to enable FK enforcement or negative to leave FK enforcement 2100 ** unchanged. The second parameter is a pointer to an integer into which 2101 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2102 ** following this call. The second parameter may be a NULL pointer, in 2103 ** which case the FK enforcement setting is not reported back. </dd> 2104 ** 2105 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2106 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2107 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2108 ** There should be two additional arguments. 2109 ** The first argument is an integer which is 0 to disable triggers, 2110 ** positive to enable triggers or negative to leave the setting unchanged. 2111 ** The second parameter is a pointer to an integer into which 2112 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2113 ** following this call. The second parameter may be a NULL pointer, in 2114 ** which case the trigger setting is not reported back. </dd> 2115 ** 2116 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2117 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2118 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2119 ** There should be two additional arguments. 2120 ** The first argument is an integer which is 0 to disable views, 2121 ** positive to enable views or negative to leave the setting unchanged. 2122 ** The second parameter is a pointer to an integer into which 2123 ** is written 0 or 1 to indicate whether views are disabled or enabled 2124 ** following this call. The second parameter may be a NULL pointer, in 2125 ** which case the view setting is not reported back. </dd> 2126 ** 2127 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2128 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2129 ** <dd> ^This option is used to enable or disable the 2130 ** [fts3_tokenizer()] function which is part of the 2131 ** [FTS3] full-text search engine extension. 2132 ** There should be two additional arguments. 2133 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2134 ** positive to enable fts3_tokenizer() or negative to leave the setting 2135 ** unchanged. 2136 ** The second parameter is a pointer to an integer into which 2137 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2138 ** following this call. The second parameter may be a NULL pointer, in 2139 ** which case the new setting is not reported back. </dd> 2140 ** 2141 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2142 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2143 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2144 ** interface independently of the [load_extension()] SQL function. 2145 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2146 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2147 ** There should be two additional arguments. 2148 ** When the first argument to this interface is 1, then only the C-API is 2149 ** enabled and the SQL function remains disabled. If the first argument to 2150 ** this interface is 0, then both the C-API and the SQL function are disabled. 2151 ** If the first argument is -1, then no changes are made to state of either the 2152 ** C-API or the SQL function. 2153 ** The second parameter is a pointer to an integer into which 2154 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2155 ** is disabled or enabled following this call. The second parameter may 2156 ** be a NULL pointer, in which case the new setting is not reported back. 2157 ** </dd> 2158 ** 2159 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2160 ** <dd> ^This option is used to change the name of the "main" database 2161 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2162 ** which will become the new schema name in place of "main". ^SQLite 2163 ** does not make a copy of the new main schema name string, so the application 2164 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2165 ** until after the database connection closes. 2166 ** </dd> 2167 ** 2168 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2169 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2170 ** <dd> Usually, when a database in wal mode is closed or detached from a 2171 ** database handle, SQLite checks if this will mean that there are now no 2172 ** connections at all to the database. If so, it performs a checkpoint 2173 ** operation before closing the connection. This option may be used to 2174 ** override this behaviour. The first parameter passed to this operation 2175 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2176 ** default) to enable them, and negative to leave the setting unchanged. 2177 ** The second parameter is a pointer to an integer 2178 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2179 ** have been disabled - 0 if they are not disabled, 1 if they are. 2180 ** </dd> 2181 ** 2182 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2183 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2184 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2185 ** a single SQL query statement will always use the same algorithm regardless 2186 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2187 ** that look at the values of bound parameters, which can make some queries 2188 ** slower. But the QPSG has the advantage of more predictable behavior. With 2189 ** the QPSG active, SQLite will always use the same query plan in the field as 2190 ** was used during testing in the lab. 2191 ** The first argument to this setting is an integer which is 0 to disable 2192 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2193 ** unchanged. The second parameter is a pointer to an integer into which 2194 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2195 ** following this call. 2196 ** </dd> 2197 ** 2198 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2199 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2200 ** include output for any operations performed by trigger programs. This 2201 ** option is used to set or clear (the default) a flag that governs this 2202 ** behavior. The first parameter passed to this operation is an integer - 2203 ** positive to enable output for trigger programs, or zero to disable it, 2204 ** or negative to leave the setting unchanged. 2205 ** The second parameter is a pointer to an integer into which is written 2206 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2207 ** it is not disabled, 1 if it is. 2208 ** </dd> 2209 ** 2210 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2211 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2212 ** [VACUUM] in order to reset a database back to an empty database 2213 ** with no schema and no content. The following process works even for 2214 ** a badly corrupted database file: 2215 ** <ol> 2216 ** <li> If the database connection is newly opened, make sure it has read the 2217 ** database schema by preparing then discarding some query against the 2218 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2219 ** errors. This step is only necessary if the application desires to keep 2220 ** the database in WAL mode after the reset if it was in WAL mode before 2221 ** the reset. 2222 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2223 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2224 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2225 ** </ol> 2226 ** Because resetting a database is destructive and irreversible, the 2227 ** process requires the use of this obscure API and multiple steps to help 2228 ** ensure that it does not happen by accident. 2229 ** 2230 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2231 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2232 ** "defensive" flag for a database connection. When the defensive 2233 ** flag is enabled, language features that allow ordinary SQL to 2234 ** deliberately corrupt the database file are disabled. The disabled 2235 ** features include but are not limited to the following: 2236 ** <ul> 2237 ** <li> The [PRAGMA writable_schema=ON] statement. 2238 ** <li> The [PRAGMA journal_mode=OFF] statement. 2239 ** <li> Writes to the [sqlite_dbpage] virtual table. 2240 ** <li> Direct writes to [shadow tables]. 2241 ** </ul> 2242 ** </dd> 2243 ** 2244 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2245 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2246 ** "writable_schema" flag. This has the same effect and is logically equivalent 2247 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2248 ** The first argument to this setting is an integer which is 0 to disable 2249 ** the writable_schema, positive to enable writable_schema, or negative to 2250 ** leave the setting unchanged. The second parameter is a pointer to an 2251 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2252 ** is enabled or disabled following this call. 2253 ** </dd> 2254 ** 2255 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2256 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2257 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2258 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2259 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2260 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2261 ** additional information. This feature can also be turned on and off 2262 ** using the [PRAGMA legacy_alter_table] statement. 2263 ** </dd> 2264 ** 2265 ** [[SQLITE_DBCONFIG_DQS_DML]] 2266 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2267 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2268 ** the legacy [double-quoted string literal] misfeature for DML statements 2269 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2270 ** default value of this setting is determined by the [-DSQLITE_DQS] 2271 ** compile-time option. 2272 ** </dd> 2273 ** 2274 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2275 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2276 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2277 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2278 ** such as CREATE TABLE and CREATE INDEX. The 2279 ** default value of this setting is determined by the [-DSQLITE_DQS] 2280 ** compile-time option. 2281 ** </dd> 2282 ** 2283 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2284 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2285 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2286 ** assume that database schemas (the contents of the [sqlite_master] tables) 2287 ** are untainted by malicious content. 2288 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2289 ** takes additional defensive steps to protect the application from harm 2290 ** including: 2291 ** <ul> 2292 ** <li> Prohibit the use of SQL functions inside triggers, views, 2293 ** CHECK constraints, DEFAULT clauses, expression indexes, 2294 ** partial indexes, or generated columns 2295 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2296 ** <li> Prohibit the use of virtual tables inside of triggers or views 2297 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2298 ** </ul> 2299 ** This setting defaults to "on" for legacy compatibility, however 2300 ** all applications are advised to turn it off if possible. This setting 2301 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2302 ** </dd> 2303 ** 2304 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2305 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2306 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2307 ** the legacy file format flag. When activated, this flag causes all newly 2308 ** created database file to have a schema format version number (the 4-byte 2309 ** integer found at offset 44 into the database header) of 1. This in turn 2310 ** means that the resulting database file will be readable and writable by 2311 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2312 ** newly created databases are generally not understandable by SQLite versions 2313 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2314 ** is now scarcely any need to generated database files that are compatible 2315 ** all the way back to version 3.0.0, and so this setting is of little 2316 ** practical use, but is provided so that SQLite can continue to claim the 2317 ** ability to generate new database files that are compatible with version 2318 ** 3.0.0. 2319 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2320 ** the [VACUUM] command will fail with an obscure error when attempting to 2321 ** process a table with generated columns and a descending index. This is 2322 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2323 ** either generated columns or decending indexes. 2324 ** </dd> 2325 ** </dl> 2326 */ 2327 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2328 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2329 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2330 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2331 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2332 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2333 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2334 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2335 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2336 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2337 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2338 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2339 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2340 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2341 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2342 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2343 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2344 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2345 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2346 2347 /* 2348 ** CAPI3REF: Enable Or Disable Extended Result Codes 2349 ** METHOD: sqlite3 2350 ** 2351 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2352 ** [extended result codes] feature of SQLite. ^The extended result 2353 ** codes are disabled by default for historical compatibility. 2354 */ 2355 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2356 2357 /* 2358 ** CAPI3REF: Last Insert Rowid 2359 ** METHOD: sqlite3 2360 ** 2361 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2362 ** has a unique 64-bit signed 2363 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2364 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2365 ** names are not also used by explicitly declared columns. ^If 2366 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2367 ** is another alias for the rowid. 2368 ** 2369 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2370 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2371 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2372 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2373 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2374 ** zero. 2375 ** 2376 ** As well as being set automatically as rows are inserted into database 2377 ** tables, the value returned by this function may be set explicitly by 2378 ** [sqlite3_set_last_insert_rowid()] 2379 ** 2380 ** Some virtual table implementations may INSERT rows into rowid tables as 2381 ** part of committing a transaction (e.g. to flush data accumulated in memory 2382 ** to disk). In this case subsequent calls to this function return the rowid 2383 ** associated with these internal INSERT operations, which leads to 2384 ** unintuitive results. Virtual table implementations that do write to rowid 2385 ** tables in this way can avoid this problem by restoring the original 2386 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2387 ** control to the user. 2388 ** 2389 ** ^(If an [INSERT] occurs within a trigger then this routine will 2390 ** return the [rowid] of the inserted row as long as the trigger is 2391 ** running. Once the trigger program ends, the value returned 2392 ** by this routine reverts to what it was before the trigger was fired.)^ 2393 ** 2394 ** ^An [INSERT] that fails due to a constraint violation is not a 2395 ** successful [INSERT] and does not change the value returned by this 2396 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2397 ** and INSERT OR ABORT make no changes to the return value of this 2398 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2399 ** encounters a constraint violation, it does not fail. The 2400 ** INSERT continues to completion after deleting rows that caused 2401 ** the constraint problem so INSERT OR REPLACE will always change 2402 ** the return value of this interface.)^ 2403 ** 2404 ** ^For the purposes of this routine, an [INSERT] is considered to 2405 ** be successful even if it is subsequently rolled back. 2406 ** 2407 ** This function is accessible to SQL statements via the 2408 ** [last_insert_rowid() SQL function]. 2409 ** 2410 ** If a separate thread performs a new [INSERT] on the same 2411 ** database connection while the [sqlite3_last_insert_rowid()] 2412 ** function is running and thus changes the last insert [rowid], 2413 ** then the value returned by [sqlite3_last_insert_rowid()] is 2414 ** unpredictable and might not equal either the old or the new 2415 ** last insert [rowid]. 2416 */ 2417 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2418 2419 /* 2420 ** CAPI3REF: Set the Last Insert Rowid value. 2421 ** METHOD: sqlite3 2422 ** 2423 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2424 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2425 ** without inserting a row into the database. 2426 */ 2427 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2428 2429 /* 2430 ** CAPI3REF: Count The Number Of Rows Modified 2431 ** METHOD: sqlite3 2432 ** 2433 ** ^This function returns the number of rows modified, inserted or 2434 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2435 ** statement on the database connection specified by the only parameter. 2436 ** ^Executing any other type of SQL statement does not modify the value 2437 ** returned by this function. 2438 ** 2439 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2440 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2441 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2442 ** 2443 ** Changes to a view that are intercepted by 2444 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2445 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2446 ** DELETE statement run on a view is always zero. Only changes made to real 2447 ** tables are counted. 2448 ** 2449 ** Things are more complicated if the sqlite3_changes() function is 2450 ** executed while a trigger program is running. This may happen if the 2451 ** program uses the [changes() SQL function], or if some other callback 2452 ** function invokes sqlite3_changes() directly. Essentially: 2453 ** 2454 ** <ul> 2455 ** <li> ^(Before entering a trigger program the value returned by 2456 ** sqlite3_changes() function is saved. After the trigger program 2457 ** has finished, the original value is restored.)^ 2458 ** 2459 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2460 ** statement sets the value returned by sqlite3_changes() 2461 ** upon completion as normal. Of course, this value will not include 2462 ** any changes performed by sub-triggers, as the sqlite3_changes() 2463 ** value will be saved and restored after each sub-trigger has run.)^ 2464 ** </ul> 2465 ** 2466 ** ^This means that if the changes() SQL function (or similar) is used 2467 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2468 ** returns the value as set when the calling statement began executing. 2469 ** ^If it is used by the second or subsequent such statement within a trigger 2470 ** program, the value returned reflects the number of rows modified by the 2471 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2472 ** 2473 ** If a separate thread makes changes on the same database connection 2474 ** while [sqlite3_changes()] is running then the value returned 2475 ** is unpredictable and not meaningful. 2476 ** 2477 ** See also: 2478 ** <ul> 2479 ** <li> the [sqlite3_total_changes()] interface 2480 ** <li> the [count_changes pragma] 2481 ** <li> the [changes() SQL function] 2482 ** <li> the [data_version pragma] 2483 ** </ul> 2484 */ 2485 SQLITE_API int sqlite3_changes(sqlite3*); 2486 2487 /* 2488 ** CAPI3REF: Total Number Of Rows Modified 2489 ** METHOD: sqlite3 2490 ** 2491 ** ^This function returns the total number of rows inserted, modified or 2492 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2493 ** since the database connection was opened, including those executed as 2494 ** part of trigger programs. ^Executing any other type of SQL statement 2495 ** does not affect the value returned by sqlite3_total_changes(). 2496 ** 2497 ** ^Changes made as part of [foreign key actions] are included in the 2498 ** count, but those made as part of REPLACE constraint resolution are 2499 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2500 ** are not counted. 2501 ** 2502 ** The [sqlite3_total_changes(D)] interface only reports the number 2503 ** of rows that changed due to SQL statement run against database 2504 ** connection D. Any changes by other database connections are ignored. 2505 ** To detect changes against a database file from other database 2506 ** connections use the [PRAGMA data_version] command or the 2507 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2508 ** 2509 ** If a separate thread makes changes on the same database connection 2510 ** while [sqlite3_total_changes()] is running then the value 2511 ** returned is unpredictable and not meaningful. 2512 ** 2513 ** See also: 2514 ** <ul> 2515 ** <li> the [sqlite3_changes()] interface 2516 ** <li> the [count_changes pragma] 2517 ** <li> the [changes() SQL function] 2518 ** <li> the [data_version pragma] 2519 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2520 ** </ul> 2521 */ 2522 SQLITE_API int sqlite3_total_changes(sqlite3*); 2523 2524 /* 2525 ** CAPI3REF: Interrupt A Long-Running Query 2526 ** METHOD: sqlite3 2527 ** 2528 ** ^This function causes any pending database operation to abort and 2529 ** return at its earliest opportunity. This routine is typically 2530 ** called in response to a user action such as pressing "Cancel" 2531 ** or Ctrl-C where the user wants a long query operation to halt 2532 ** immediately. 2533 ** 2534 ** ^It is safe to call this routine from a thread different from the 2535 ** thread that is currently running the database operation. But it 2536 ** is not safe to call this routine with a [database connection] that 2537 ** is closed or might close before sqlite3_interrupt() returns. 2538 ** 2539 ** ^If an SQL operation is very nearly finished at the time when 2540 ** sqlite3_interrupt() is called, then it might not have an opportunity 2541 ** to be interrupted and might continue to completion. 2542 ** 2543 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2544 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2545 ** that is inside an explicit transaction, then the entire transaction 2546 ** will be rolled back automatically. 2547 ** 2548 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2549 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2550 ** that are started after the sqlite3_interrupt() call and before the 2551 ** running statement count reaches zero are interrupted as if they had been 2552 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2553 ** that are started after the running statement count reaches zero are 2554 ** not effected by the sqlite3_interrupt(). 2555 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2556 ** SQL statements is a no-op and has no effect on SQL statements 2557 ** that are started after the sqlite3_interrupt() call returns. 2558 */ 2559 SQLITE_API void sqlite3_interrupt(sqlite3*); 2560 2561 /* 2562 ** CAPI3REF: Determine If An SQL Statement Is Complete 2563 ** 2564 ** These routines are useful during command-line input to determine if the 2565 ** currently entered text seems to form a complete SQL statement or 2566 ** if additional input is needed before sending the text into 2567 ** SQLite for parsing. ^These routines return 1 if the input string 2568 ** appears to be a complete SQL statement. ^A statement is judged to be 2569 ** complete if it ends with a semicolon token and is not a prefix of a 2570 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2571 ** string literals or quoted identifier names or comments are not 2572 ** independent tokens (they are part of the token in which they are 2573 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2574 ** and comments that follow the final semicolon are ignored. 2575 ** 2576 ** ^These routines return 0 if the statement is incomplete. ^If a 2577 ** memory allocation fails, then SQLITE_NOMEM is returned. 2578 ** 2579 ** ^These routines do not parse the SQL statements thus 2580 ** will not detect syntactically incorrect SQL. 2581 ** 2582 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2583 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2584 ** automatically by sqlite3_complete16(). If that initialization fails, 2585 ** then the return value from sqlite3_complete16() will be non-zero 2586 ** regardless of whether or not the input SQL is complete.)^ 2587 ** 2588 ** The input to [sqlite3_complete()] must be a zero-terminated 2589 ** UTF-8 string. 2590 ** 2591 ** The input to [sqlite3_complete16()] must be a zero-terminated 2592 ** UTF-16 string in native byte order. 2593 */ 2594 SQLITE_API int sqlite3_complete(const char *sql); 2595 SQLITE_API int sqlite3_complete16(const void *sql); 2596 2597 /* 2598 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2599 ** KEYWORDS: {busy-handler callback} {busy handler} 2600 ** METHOD: sqlite3 2601 ** 2602 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2603 ** that might be invoked with argument P whenever 2604 ** an attempt is made to access a database table associated with 2605 ** [database connection] D when another thread 2606 ** or process has the table locked. 2607 ** The sqlite3_busy_handler() interface is used to implement 2608 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2609 ** 2610 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2611 ** is returned immediately upon encountering the lock. ^If the busy callback 2612 ** is not NULL, then the callback might be invoked with two arguments. 2613 ** 2614 ** ^The first argument to the busy handler is a copy of the void* pointer which 2615 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2616 ** the busy handler callback is the number of times that the busy handler has 2617 ** been invoked previously for the same locking event. ^If the 2618 ** busy callback returns 0, then no additional attempts are made to 2619 ** access the database and [SQLITE_BUSY] is returned 2620 ** to the application. 2621 ** ^If the callback returns non-zero, then another attempt 2622 ** is made to access the database and the cycle repeats. 2623 ** 2624 ** The presence of a busy handler does not guarantee that it will be invoked 2625 ** when there is lock contention. ^If SQLite determines that invoking the busy 2626 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2627 ** to the application instead of invoking the 2628 ** busy handler. 2629 ** Consider a scenario where one process is holding a read lock that 2630 ** it is trying to promote to a reserved lock and 2631 ** a second process is holding a reserved lock that it is trying 2632 ** to promote to an exclusive lock. The first process cannot proceed 2633 ** because it is blocked by the second and the second process cannot 2634 ** proceed because it is blocked by the first. If both processes 2635 ** invoke the busy handlers, neither will make any progress. Therefore, 2636 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2637 ** will induce the first process to release its read lock and allow 2638 ** the second process to proceed. 2639 ** 2640 ** ^The default busy callback is NULL. 2641 ** 2642 ** ^(There can only be a single busy handler defined for each 2643 ** [database connection]. Setting a new busy handler clears any 2644 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2645 ** or evaluating [PRAGMA busy_timeout=N] will change the 2646 ** busy handler and thus clear any previously set busy handler. 2647 ** 2648 ** The busy callback should not take any actions which modify the 2649 ** database connection that invoked the busy handler. In other words, 2650 ** the busy handler is not reentrant. Any such actions 2651 ** result in undefined behavior. 2652 ** 2653 ** A busy handler must not close the database connection 2654 ** or [prepared statement] that invoked the busy handler. 2655 */ 2656 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2657 2658 /* 2659 ** CAPI3REF: Set A Busy Timeout 2660 ** METHOD: sqlite3 2661 ** 2662 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2663 ** for a specified amount of time when a table is locked. ^The handler 2664 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2665 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2666 ** the handler returns 0 which causes [sqlite3_step()] to return 2667 ** [SQLITE_BUSY]. 2668 ** 2669 ** ^Calling this routine with an argument less than or equal to zero 2670 ** turns off all busy handlers. 2671 ** 2672 ** ^(There can only be a single busy handler for a particular 2673 ** [database connection] at any given moment. If another busy handler 2674 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2675 ** this routine, that other busy handler is cleared.)^ 2676 ** 2677 ** See also: [PRAGMA busy_timeout] 2678 */ 2679 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2680 2681 /* 2682 ** CAPI3REF: Convenience Routines For Running Queries 2683 ** METHOD: sqlite3 2684 ** 2685 ** This is a legacy interface that is preserved for backwards compatibility. 2686 ** Use of this interface is not recommended. 2687 ** 2688 ** Definition: A <b>result table</b> is memory data structure created by the 2689 ** [sqlite3_get_table()] interface. A result table records the 2690 ** complete query results from one or more queries. 2691 ** 2692 ** The table conceptually has a number of rows and columns. But 2693 ** these numbers are not part of the result table itself. These 2694 ** numbers are obtained separately. Let N be the number of rows 2695 ** and M be the number of columns. 2696 ** 2697 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2698 ** There are (N+1)*M elements in the array. The first M pointers point 2699 ** to zero-terminated strings that contain the names of the columns. 2700 ** The remaining entries all point to query results. NULL values result 2701 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2702 ** string representation as returned by [sqlite3_column_text()]. 2703 ** 2704 ** A result table might consist of one or more memory allocations. 2705 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2706 ** A result table should be deallocated using [sqlite3_free_table()]. 2707 ** 2708 ** ^(As an example of the result table format, suppose a query result 2709 ** is as follows: 2710 ** 2711 ** <blockquote><pre> 2712 ** Name | Age 2713 ** ----------------------- 2714 ** Alice | 43 2715 ** Bob | 28 2716 ** Cindy | 21 2717 ** </pre></blockquote> 2718 ** 2719 ** There are two columns (M==2) and three rows (N==3). Thus the 2720 ** result table has 8 entries. Suppose the result table is stored 2721 ** in an array named azResult. Then azResult holds this content: 2722 ** 2723 ** <blockquote><pre> 2724 ** azResult[0] = "Name"; 2725 ** azResult[1] = "Age"; 2726 ** azResult[2] = "Alice"; 2727 ** azResult[3] = "43"; 2728 ** azResult[4] = "Bob"; 2729 ** azResult[5] = "28"; 2730 ** azResult[6] = "Cindy"; 2731 ** azResult[7] = "21"; 2732 ** </pre></blockquote>)^ 2733 ** 2734 ** ^The sqlite3_get_table() function evaluates one or more 2735 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2736 ** string of its 2nd parameter and returns a result table to the 2737 ** pointer given in its 3rd parameter. 2738 ** 2739 ** After the application has finished with the result from sqlite3_get_table(), 2740 ** it must pass the result table pointer to sqlite3_free_table() in order to 2741 ** release the memory that was malloced. Because of the way the 2742 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2743 ** function must not try to call [sqlite3_free()] directly. Only 2744 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2745 ** 2746 ** The sqlite3_get_table() interface is implemented as a wrapper around 2747 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2748 ** to any internal data structures of SQLite. It uses only the public 2749 ** interface defined here. As a consequence, errors that occur in the 2750 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2751 ** reflected in subsequent calls to [sqlite3_errcode()] or 2752 ** [sqlite3_errmsg()]. 2753 */ 2754 SQLITE_API int sqlite3_get_table( 2755 sqlite3 *db, /* An open database */ 2756 const char *zSql, /* SQL to be evaluated */ 2757 char ***pazResult, /* Results of the query */ 2758 int *pnRow, /* Number of result rows written here */ 2759 int *pnColumn, /* Number of result columns written here */ 2760 char **pzErrmsg /* Error msg written here */ 2761 ); 2762 SQLITE_API void sqlite3_free_table(char **result); 2763 2764 /* 2765 ** CAPI3REF: Formatted String Printing Functions 2766 ** 2767 ** These routines are work-alikes of the "printf()" family of functions 2768 ** from the standard C library. 2769 ** These routines understand most of the common formatting options from 2770 ** the standard library printf() 2771 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2772 ** See the [built-in printf()] documentation for details. 2773 ** 2774 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2775 ** results into memory obtained from [sqlite3_malloc64()]. 2776 ** The strings returned by these two routines should be 2777 ** released by [sqlite3_free()]. ^Both routines return a 2778 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2779 ** memory to hold the resulting string. 2780 ** 2781 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2782 ** the standard C library. The result is written into the 2783 ** buffer supplied as the second parameter whose size is given by 2784 ** the first parameter. Note that the order of the 2785 ** first two parameters is reversed from snprintf().)^ This is an 2786 ** historical accident that cannot be fixed without breaking 2787 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2788 ** returns a pointer to its buffer instead of the number of 2789 ** characters actually written into the buffer.)^ We admit that 2790 ** the number of characters written would be a more useful return 2791 ** value but we cannot change the implementation of sqlite3_snprintf() 2792 ** now without breaking compatibility. 2793 ** 2794 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2795 ** guarantees that the buffer is always zero-terminated. ^The first 2796 ** parameter "n" is the total size of the buffer, including space for 2797 ** the zero terminator. So the longest string that can be completely 2798 ** written will be n-1 characters. 2799 ** 2800 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2801 ** 2802 ** See also: [built-in printf()], [printf() SQL function] 2803 */ 2804 SQLITE_API char *sqlite3_mprintf(const char*,...); 2805 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2806 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2807 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2808 2809 /* 2810 ** CAPI3REF: Memory Allocation Subsystem 2811 ** 2812 ** The SQLite core uses these three routines for all of its own 2813 ** internal memory allocation needs. "Core" in the previous sentence 2814 ** does not include operating-system specific [VFS] implementation. The 2815 ** Windows VFS uses native malloc() and free() for some operations. 2816 ** 2817 ** ^The sqlite3_malloc() routine returns a pointer to a block 2818 ** of memory at least N bytes in length, where N is the parameter. 2819 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2820 ** memory, it returns a NULL pointer. ^If the parameter N to 2821 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2822 ** a NULL pointer. 2823 ** 2824 ** ^The sqlite3_malloc64(N) routine works just like 2825 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2826 ** of a signed 32-bit integer. 2827 ** 2828 ** ^Calling sqlite3_free() with a pointer previously returned 2829 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2830 ** that it might be reused. ^The sqlite3_free() routine is 2831 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2832 ** to sqlite3_free() is harmless. After being freed, memory 2833 ** should neither be read nor written. Even reading previously freed 2834 ** memory might result in a segmentation fault or other severe error. 2835 ** Memory corruption, a segmentation fault, or other severe error 2836 ** might result if sqlite3_free() is called with a non-NULL pointer that 2837 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2838 ** 2839 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2840 ** prior memory allocation X to be at least N bytes. 2841 ** ^If the X parameter to sqlite3_realloc(X,N) 2842 ** is a NULL pointer then its behavior is identical to calling 2843 ** sqlite3_malloc(N). 2844 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2845 ** negative then the behavior is exactly the same as calling 2846 ** sqlite3_free(X). 2847 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2848 ** of at least N bytes in size or NULL if insufficient memory is available. 2849 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2850 ** of the prior allocation are copied into the beginning of buffer returned 2851 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2852 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2853 ** prior allocation is not freed. 2854 ** 2855 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2856 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2857 ** of a 32-bit signed integer. 2858 ** 2859 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2860 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2861 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2862 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2863 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2864 ** sqlite3_msize(X) returns zero. If X points to something that is not 2865 ** the beginning of memory allocation, or if it points to a formerly 2866 ** valid memory allocation that has now been freed, then the behavior 2867 ** of sqlite3_msize(X) is undefined and possibly harmful. 2868 ** 2869 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2870 ** sqlite3_malloc64(), and sqlite3_realloc64() 2871 ** is always aligned to at least an 8 byte boundary, or to a 2872 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2873 ** option is used. 2874 ** 2875 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2876 ** must be either NULL or else pointers obtained from a prior 2877 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2878 ** not yet been released. 2879 ** 2880 ** The application must not read or write any part of 2881 ** a block of memory after it has been released using 2882 ** [sqlite3_free()] or [sqlite3_realloc()]. 2883 */ 2884 SQLITE_API void *sqlite3_malloc(int); 2885 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2886 SQLITE_API void *sqlite3_realloc(void*, int); 2887 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2888 SQLITE_API void sqlite3_free(void*); 2889 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2890 2891 /* 2892 ** CAPI3REF: Memory Allocator Statistics 2893 ** 2894 ** SQLite provides these two interfaces for reporting on the status 2895 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2896 ** routines, which form the built-in memory allocation subsystem. 2897 ** 2898 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2899 ** of memory currently outstanding (malloced but not freed). 2900 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2901 ** value of [sqlite3_memory_used()] since the high-water mark 2902 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2903 ** [sqlite3_memory_highwater()] include any overhead 2904 ** added by SQLite in its implementation of [sqlite3_malloc()], 2905 ** but not overhead added by the any underlying system library 2906 ** routines that [sqlite3_malloc()] may call. 2907 ** 2908 ** ^The memory high-water mark is reset to the current value of 2909 ** [sqlite3_memory_used()] if and only if the parameter to 2910 ** [sqlite3_memory_highwater()] is true. ^The value returned 2911 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2912 ** prior to the reset. 2913 */ 2914 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2915 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2916 2917 /* 2918 ** CAPI3REF: Pseudo-Random Number Generator 2919 ** 2920 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2921 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2922 ** already uses the largest possible [ROWID]. The PRNG is also used for 2923 ** the built-in random() and randomblob() SQL functions. This interface allows 2924 ** applications to access the same PRNG for other purposes. 2925 ** 2926 ** ^A call to this routine stores N bytes of randomness into buffer P. 2927 ** ^The P parameter can be a NULL pointer. 2928 ** 2929 ** ^If this routine has not been previously called or if the previous 2930 ** call had N less than one or a NULL pointer for P, then the PRNG is 2931 ** seeded using randomness obtained from the xRandomness method of 2932 ** the default [sqlite3_vfs] object. 2933 ** ^If the previous call to this routine had an N of 1 or more and a 2934 ** non-NULL P then the pseudo-randomness is generated 2935 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2936 ** method. 2937 */ 2938 SQLITE_API void sqlite3_randomness(int N, void *P); 2939 2940 /* 2941 ** CAPI3REF: Compile-Time Authorization Callbacks 2942 ** METHOD: sqlite3 2943 ** KEYWORDS: {authorizer callback} 2944 ** 2945 ** ^This routine registers an authorizer callback with a particular 2946 ** [database connection], supplied in the first argument. 2947 ** ^The authorizer callback is invoked as SQL statements are being compiled 2948 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2949 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2950 ** and [sqlite3_prepare16_v3()]. ^At various 2951 ** points during the compilation process, as logic is being created 2952 ** to perform various actions, the authorizer callback is invoked to 2953 ** see if those actions are allowed. ^The authorizer callback should 2954 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2955 ** specific action but allow the SQL statement to continue to be 2956 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2957 ** rejected with an error. ^If the authorizer callback returns 2958 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2959 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2960 ** the authorizer will fail with an error message. 2961 ** 2962 ** When the callback returns [SQLITE_OK], that means the operation 2963 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2964 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2965 ** authorizer will fail with an error message explaining that 2966 ** access is denied. 2967 ** 2968 ** ^The first parameter to the authorizer callback is a copy of the third 2969 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2970 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2971 ** the particular action to be authorized. ^The third through sixth parameters 2972 ** to the callback are either NULL pointers or zero-terminated strings 2973 ** that contain additional details about the action to be authorized. 2974 ** Applications must always be prepared to encounter a NULL pointer in any 2975 ** of the third through the sixth parameters of the authorization callback. 2976 ** 2977 ** ^If the action code is [SQLITE_READ] 2978 ** and the callback returns [SQLITE_IGNORE] then the 2979 ** [prepared statement] statement is constructed to substitute 2980 ** a NULL value in place of the table column that would have 2981 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2982 ** return can be used to deny an untrusted user access to individual 2983 ** columns of a table. 2984 ** ^When a table is referenced by a [SELECT] but no column values are 2985 ** extracted from that table (for example in a query like 2986 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2987 ** is invoked once for that table with a column name that is an empty string. 2988 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2989 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2990 ** [truncate optimization] is disabled and all rows are deleted individually. 2991 ** 2992 ** An authorizer is used when [sqlite3_prepare | preparing] 2993 ** SQL statements from an untrusted source, to ensure that the SQL statements 2994 ** do not try to access data they are not allowed to see, or that they do not 2995 ** try to execute malicious statements that damage the database. For 2996 ** example, an application may allow a user to enter arbitrary 2997 ** SQL queries for evaluation by a database. But the application does 2998 ** not want the user to be able to make arbitrary changes to the 2999 ** database. An authorizer could then be put in place while the 3000 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3001 ** disallows everything except [SELECT] statements. 3002 ** 3003 ** Applications that need to process SQL from untrusted sources 3004 ** might also consider lowering resource limits using [sqlite3_limit()] 3005 ** and limiting database size using the [max_page_count] [PRAGMA] 3006 ** in addition to using an authorizer. 3007 ** 3008 ** ^(Only a single authorizer can be in place on a database connection 3009 ** at a time. Each call to sqlite3_set_authorizer overrides the 3010 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3011 ** The authorizer is disabled by default. 3012 ** 3013 ** The authorizer callback must not do anything that will modify 3014 ** the database connection that invoked the authorizer callback. 3015 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3016 ** database connections for the meaning of "modify" in this paragraph. 3017 ** 3018 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3019 ** statement might be re-prepared during [sqlite3_step()] due to a 3020 ** schema change. Hence, the application should ensure that the 3021 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3022 ** 3023 ** ^Note that the authorizer callback is invoked only during 3024 ** [sqlite3_prepare()] or its variants. Authorization is not 3025 ** performed during statement evaluation in [sqlite3_step()], unless 3026 ** as stated in the previous paragraph, sqlite3_step() invokes 3027 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3028 */ 3029 SQLITE_API int sqlite3_set_authorizer( 3030 sqlite3*, 3031 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3032 void *pUserData 3033 ); 3034 3035 /* 3036 ** CAPI3REF: Authorizer Return Codes 3037 ** 3038 ** The [sqlite3_set_authorizer | authorizer callback function] must 3039 ** return either [SQLITE_OK] or one of these two constants in order 3040 ** to signal SQLite whether or not the action is permitted. See the 3041 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3042 ** information. 3043 ** 3044 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3045 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3046 */ 3047 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3048 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3049 3050 /* 3051 ** CAPI3REF: Authorizer Action Codes 3052 ** 3053 ** The [sqlite3_set_authorizer()] interface registers a callback function 3054 ** that is invoked to authorize certain SQL statement actions. The 3055 ** second parameter to the callback is an integer code that specifies 3056 ** what action is being authorized. These are the integer action codes that 3057 ** the authorizer callback may be passed. 3058 ** 3059 ** These action code values signify what kind of operation is to be 3060 ** authorized. The 3rd and 4th parameters to the authorization 3061 ** callback function will be parameters or NULL depending on which of these 3062 ** codes is used as the second parameter. ^(The 5th parameter to the 3063 ** authorizer callback is the name of the database ("main", "temp", 3064 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3065 ** is the name of the inner-most trigger or view that is responsible for 3066 ** the access attempt or NULL if this access attempt is directly from 3067 ** top-level SQL code. 3068 */ 3069 /******************************************* 3rd ************ 4th ***********/ 3070 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3071 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3072 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3073 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3074 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3075 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3076 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3077 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3078 #define SQLITE_DELETE 9 /* Table Name NULL */ 3079 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3080 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3081 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3082 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3083 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3084 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3085 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3086 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3087 #define SQLITE_INSERT 18 /* Table Name NULL */ 3088 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3089 #define SQLITE_READ 20 /* Table Name Column Name */ 3090 #define SQLITE_SELECT 21 /* NULL NULL */ 3091 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3092 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3093 #define SQLITE_ATTACH 24 /* Filename NULL */ 3094 #define SQLITE_DETACH 25 /* Database Name NULL */ 3095 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3096 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3097 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3098 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3099 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3100 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3101 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3102 #define SQLITE_COPY 0 /* No longer used */ 3103 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3104 3105 /* 3106 ** CAPI3REF: Tracing And Profiling Functions 3107 ** METHOD: sqlite3 3108 ** 3109 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3110 ** instead of the routines described here. 3111 ** 3112 ** These routines register callback functions that can be used for 3113 ** tracing and profiling the execution of SQL statements. 3114 ** 3115 ** ^The callback function registered by sqlite3_trace() is invoked at 3116 ** various times when an SQL statement is being run by [sqlite3_step()]. 3117 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3118 ** SQL statement text as the statement first begins executing. 3119 ** ^(Additional sqlite3_trace() callbacks might occur 3120 ** as each triggered subprogram is entered. The callbacks for triggers 3121 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3122 ** 3123 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3124 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3125 ** 3126 ** ^The callback function registered by sqlite3_profile() is invoked 3127 ** as each SQL statement finishes. ^The profile callback contains 3128 ** the original statement text and an estimate of wall-clock time 3129 ** of how long that statement took to run. ^The profile callback 3130 ** time is in units of nanoseconds, however the current implementation 3131 ** is only capable of millisecond resolution so the six least significant 3132 ** digits in the time are meaningless. Future versions of SQLite 3133 ** might provide greater resolution on the profiler callback. Invoking 3134 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3135 ** profile callback. 3136 */ 3137 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3138 void(*xTrace)(void*,const char*), void*); 3139 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3140 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3141 3142 /* 3143 ** CAPI3REF: SQL Trace Event Codes 3144 ** KEYWORDS: SQLITE_TRACE 3145 ** 3146 ** These constants identify classes of events that can be monitored 3147 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3148 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3149 ** the following constants. ^The first argument to the trace callback 3150 ** is one of the following constants. 3151 ** 3152 ** New tracing constants may be added in future releases. 3153 ** 3154 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3155 ** ^The T argument is one of the integer type codes above. 3156 ** ^The C argument is a copy of the context pointer passed in as the 3157 ** fourth argument to [sqlite3_trace_v2()]. 3158 ** The P and X arguments are pointers whose meanings depend on T. 3159 ** 3160 ** <dl> 3161 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3162 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3163 ** first begins running and possibly at other times during the 3164 ** execution of the prepared statement, such as at the start of each 3165 ** trigger subprogram. ^The P argument is a pointer to the 3166 ** [prepared statement]. ^The X argument is a pointer to a string which 3167 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3168 ** that indicates the invocation of a trigger. ^The callback can compute 3169 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3170 ** interface by using the X argument when X begins with "--" and invoking 3171 ** [sqlite3_expanded_sql(P)] otherwise. 3172 ** 3173 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3174 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3175 ** information as is provided by the [sqlite3_profile()] callback. 3176 ** ^The P argument is a pointer to the [prepared statement] and the 3177 ** X argument points to a 64-bit integer which is the estimated of 3178 ** the number of nanosecond that the prepared statement took to run. 3179 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3180 ** 3181 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3182 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3183 ** statement generates a single row of result. 3184 ** ^The P argument is a pointer to the [prepared statement] and the 3185 ** X argument is unused. 3186 ** 3187 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3188 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3189 ** connection closes. 3190 ** ^The P argument is a pointer to the [database connection] object 3191 ** and the X argument is unused. 3192 ** </dl> 3193 */ 3194 #define SQLITE_TRACE_STMT 0x01 3195 #define SQLITE_TRACE_PROFILE 0x02 3196 #define SQLITE_TRACE_ROW 0x04 3197 #define SQLITE_TRACE_CLOSE 0x08 3198 3199 /* 3200 ** CAPI3REF: SQL Trace Hook 3201 ** METHOD: sqlite3 3202 ** 3203 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3204 ** function X against [database connection] D, using property mask M 3205 ** and context pointer P. ^If the X callback is 3206 ** NULL or if the M mask is zero, then tracing is disabled. The 3207 ** M argument should be the bitwise OR-ed combination of 3208 ** zero or more [SQLITE_TRACE] constants. 3209 ** 3210 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3211 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3212 ** 3213 ** ^The X callback is invoked whenever any of the events identified by 3214 ** mask M occur. ^The integer return value from the callback is currently 3215 ** ignored, though this may change in future releases. Callback 3216 ** implementations should return zero to ensure future compatibility. 3217 ** 3218 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3219 ** ^The T argument is one of the [SQLITE_TRACE] 3220 ** constants to indicate why the callback was invoked. 3221 ** ^The C argument is a copy of the context pointer. 3222 ** The P and X arguments are pointers whose meanings depend on T. 3223 ** 3224 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3225 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3226 ** are deprecated. 3227 */ 3228 SQLITE_API int sqlite3_trace_v2( 3229 sqlite3*, 3230 unsigned uMask, 3231 int(*xCallback)(unsigned,void*,void*,void*), 3232 void *pCtx 3233 ); 3234 3235 /* 3236 ** CAPI3REF: Query Progress Callbacks 3237 ** METHOD: sqlite3 3238 ** 3239 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3240 ** function X to be invoked periodically during long running calls to 3241 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3242 ** database connection D. An example use for this 3243 ** interface is to keep a GUI updated during a large query. 3244 ** 3245 ** ^The parameter P is passed through as the only parameter to the 3246 ** callback function X. ^The parameter N is the approximate number of 3247 ** [virtual machine instructions] that are evaluated between successive 3248 ** invocations of the callback X. ^If N is less than one then the progress 3249 ** handler is disabled. 3250 ** 3251 ** ^Only a single progress handler may be defined at one time per 3252 ** [database connection]; setting a new progress handler cancels the 3253 ** old one. ^Setting parameter X to NULL disables the progress handler. 3254 ** ^The progress handler is also disabled by setting N to a value less 3255 ** than 1. 3256 ** 3257 ** ^If the progress callback returns non-zero, the operation is 3258 ** interrupted. This feature can be used to implement a 3259 ** "Cancel" button on a GUI progress dialog box. 3260 ** 3261 ** The progress handler callback must not do anything that will modify 3262 ** the database connection that invoked the progress handler. 3263 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3264 ** database connections for the meaning of "modify" in this paragraph. 3265 ** 3266 */ 3267 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3268 3269 /* 3270 ** CAPI3REF: Opening A New Database Connection 3271 ** CONSTRUCTOR: sqlite3 3272 ** 3273 ** ^These routines open an SQLite database file as specified by the 3274 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3275 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3276 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3277 ** returned in *ppDb, even if an error occurs. The only exception is that 3278 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3279 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3280 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3281 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3282 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3283 ** an English language description of the error following a failure of any 3284 ** of the sqlite3_open() routines. 3285 ** 3286 ** ^The default encoding will be UTF-8 for databases created using 3287 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3288 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3289 ** 3290 ** Whether or not an error occurs when it is opened, resources 3291 ** associated with the [database connection] handle should be released by 3292 ** passing it to [sqlite3_close()] when it is no longer required. 3293 ** 3294 ** The sqlite3_open_v2() interface works like sqlite3_open() 3295 ** except that it accepts two additional parameters for additional control 3296 ** over the new database connection. ^(The flags parameter to 3297 ** sqlite3_open_v2() must include, at a minimum, one of the following 3298 ** three flag combinations:)^ 3299 ** 3300 ** <dl> 3301 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3302 ** <dd>The database is opened in read-only mode. If the database does not 3303 ** already exist, an error is returned.</dd>)^ 3304 ** 3305 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3306 ** <dd>The database is opened for reading and writing if possible, or reading 3307 ** only if the file is write protected by the operating system. In either 3308 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3309 ** 3310 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3311 ** <dd>The database is opened for reading and writing, and is created if 3312 ** it does not already exist. This is the behavior that is always used for 3313 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3314 ** </dl> 3315 ** 3316 ** In addition to the required flags, the following optional flags are 3317 ** also supported: 3318 ** 3319 ** <dl> 3320 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3321 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3322 ** 3323 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3324 ** <dd>The database will be opened as an in-memory database. The database 3325 ** is named by the "filename" argument for the purposes of cache-sharing, 3326 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3327 ** </dd>)^ 3328 ** 3329 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3330 ** <dd>The new database connection will use the "multi-thread" 3331 ** [threading mode].)^ This means that separate threads are allowed 3332 ** to use SQLite at the same time, as long as each thread is using 3333 ** a different [database connection]. 3334 ** 3335 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3336 ** <dd>The new database connection will use the "serialized" 3337 ** [threading mode].)^ This means the multiple threads can safely 3338 ** attempt to use the same database connection at the same time. 3339 ** (Mutexes will block any actual concurrency, but in this mode 3340 ** there is no harm in trying.) 3341 ** 3342 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3343 ** <dd>The database is opened [shared cache] enabled, overriding 3344 ** the default shared cache setting provided by 3345 ** [sqlite3_enable_shared_cache()].)^ 3346 ** 3347 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3348 ** <dd>The database is opened [shared cache] disabled, overriding 3349 ** the default shared cache setting provided by 3350 ** [sqlite3_enable_shared_cache()].)^ 3351 ** 3352 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3353 ** <dd>The database filename is not allowed to be a symbolic link</dd> 3354 ** </dl>)^ 3355 ** 3356 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3357 ** required combinations shown above optionally combined with other 3358 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3359 ** then the behavior is undefined. 3360 ** 3361 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3362 ** [sqlite3_vfs] object that defines the operating system interface that 3363 ** the new database connection should use. ^If the fourth parameter is 3364 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3365 ** 3366 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3367 ** is created for the connection. ^This in-memory database will vanish when 3368 ** the database connection is closed. Future versions of SQLite might 3369 ** make use of additional special filenames that begin with the ":" character. 3370 ** It is recommended that when a database filename actually does begin with 3371 ** a ":" character you should prefix the filename with a pathname such as 3372 ** "./" to avoid ambiguity. 3373 ** 3374 ** ^If the filename is an empty string, then a private, temporary 3375 ** on-disk database will be created. ^This private database will be 3376 ** automatically deleted as soon as the database connection is closed. 3377 ** 3378 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3379 ** 3380 ** ^If [URI filename] interpretation is enabled, and the filename argument 3381 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3382 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3383 ** set in the third argument to sqlite3_open_v2(), or if it has 3384 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3385 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3386 ** URI filename interpretation is turned off 3387 ** by default, but future releases of SQLite might enable URI filename 3388 ** interpretation by default. See "[URI filenames]" for additional 3389 ** information. 3390 ** 3391 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3392 ** authority, then it must be either an empty string or the string 3393 ** "localhost". ^If the authority is not an empty string or "localhost", an 3394 ** error is returned to the caller. ^The fragment component of a URI, if 3395 ** present, is ignored. 3396 ** 3397 ** ^SQLite uses the path component of the URI as the name of the disk file 3398 ** which contains the database. ^If the path begins with a '/' character, 3399 ** then it is interpreted as an absolute path. ^If the path does not begin 3400 ** with a '/' (meaning that the authority section is omitted from the URI) 3401 ** then the path is interpreted as a relative path. 3402 ** ^(On windows, the first component of an absolute path 3403 ** is a drive specification (e.g. "C:").)^ 3404 ** 3405 ** [[core URI query parameters]] 3406 ** The query component of a URI may contain parameters that are interpreted 3407 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3408 ** SQLite and its built-in [VFSes] interpret the 3409 ** following query parameters: 3410 ** 3411 ** <ul> 3412 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3413 ** a VFS object that provides the operating system interface that should 3414 ** be used to access the database file on disk. ^If this option is set to 3415 ** an empty string the default VFS object is used. ^Specifying an unknown 3416 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3417 ** present, then the VFS specified by the option takes precedence over 3418 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3419 ** 3420 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3421 ** "rwc", or "memory". Attempting to set it to any other value is 3422 ** an error)^. 3423 ** ^If "ro" is specified, then the database is opened for read-only 3424 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3425 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3426 ** "rw", then the database is opened for read-write (but not create) 3427 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3428 ** been set. ^Value "rwc" is equivalent to setting both 3429 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3430 ** set to "memory" then a pure [in-memory database] that never reads 3431 ** or writes from disk is used. ^It is an error to specify a value for 3432 ** the mode parameter that is less restrictive than that specified by 3433 ** the flags passed in the third parameter to sqlite3_open_v2(). 3434 ** 3435 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3436 ** "private". ^Setting it to "shared" is equivalent to setting the 3437 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3438 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3439 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3440 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3441 ** a URI filename, its value overrides any behavior requested by setting 3442 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3443 ** 3444 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3445 ** [powersafe overwrite] property does or does not apply to the 3446 ** storage media on which the database file resides. 3447 ** 3448 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3449 ** which if set disables file locking in rollback journal modes. This 3450 ** is useful for accessing a database on a filesystem that does not 3451 ** support locking. Caution: Database corruption might result if two 3452 ** or more processes write to the same database and any one of those 3453 ** processes uses nolock=1. 3454 ** 3455 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3456 ** parameter that indicates that the database file is stored on 3457 ** read-only media. ^When immutable is set, SQLite assumes that the 3458 ** database file cannot be changed, even by a process with higher 3459 ** privilege, and so the database is opened read-only and all locking 3460 ** and change detection is disabled. Caution: Setting the immutable 3461 ** property on a database file that does in fact change can result 3462 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3463 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3464 ** 3465 ** </ul> 3466 ** 3467 ** ^Specifying an unknown parameter in the query component of a URI is not an 3468 ** error. Future versions of SQLite might understand additional query 3469 ** parameters. See "[query parameters with special meaning to SQLite]" for 3470 ** additional information. 3471 ** 3472 ** [[URI filename examples]] <h3>URI filename examples</h3> 3473 ** 3474 ** <table border="1" align=center cellpadding=5> 3475 ** <tr><th> URI filenames <th> Results 3476 ** <tr><td> file:data.db <td> 3477 ** Open the file "data.db" in the current directory. 3478 ** <tr><td> file:/home/fred/data.db<br> 3479 ** file:///home/fred/data.db <br> 3480 ** file://localhost/home/fred/data.db <br> <td> 3481 ** Open the database file "/home/fred/data.db". 3482 ** <tr><td> file://darkstar/home/fred/data.db <td> 3483 ** An error. "darkstar" is not a recognized authority. 3484 ** <tr><td style="white-space:nowrap"> 3485 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3486 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3487 ** C:. Note that the %20 escaping in this example is not strictly 3488 ** necessary - space characters can be used literally 3489 ** in URI filenames. 3490 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3491 ** Open file "data.db" in the current directory for read-only access. 3492 ** Regardless of whether or not shared-cache mode is enabled by 3493 ** default, use a private cache. 3494 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3495 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3496 ** that uses dot-files in place of posix advisory locking. 3497 ** <tr><td> file:data.db?mode=readonly <td> 3498 ** An error. "readonly" is not a valid option for the "mode" parameter. 3499 ** </table> 3500 ** 3501 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3502 ** query components of a URI. A hexadecimal escape sequence consists of a 3503 ** percent sign - "%" - followed by exactly two hexadecimal digits 3504 ** specifying an octet value. ^Before the path or query components of a 3505 ** URI filename are interpreted, they are encoded using UTF-8 and all 3506 ** hexadecimal escape sequences replaced by a single byte containing the 3507 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3508 ** the results are undefined. 3509 ** 3510 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3511 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3512 ** codepage is currently defined. Filenames containing international 3513 ** characters must be converted to UTF-8 prior to passing them into 3514 ** sqlite3_open() or sqlite3_open_v2(). 3515 ** 3516 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3517 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3518 ** features that require the use of temporary files may fail. 3519 ** 3520 ** See also: [sqlite3_temp_directory] 3521 */ 3522 SQLITE_API int sqlite3_open( 3523 const char *filename, /* Database filename (UTF-8) */ 3524 sqlite3 **ppDb /* OUT: SQLite db handle */ 3525 ); 3526 SQLITE_API int sqlite3_open16( 3527 const void *filename, /* Database filename (UTF-16) */ 3528 sqlite3 **ppDb /* OUT: SQLite db handle */ 3529 ); 3530 SQLITE_API int sqlite3_open_v2( 3531 const char *filename, /* Database filename (UTF-8) */ 3532 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3533 int flags, /* Flags */ 3534 const char *zVfs /* Name of VFS module to use */ 3535 ); 3536 3537 /* 3538 ** CAPI3REF: Obtain Values For URI Parameters 3539 ** 3540 ** These are utility routines, useful to [VFS|custom VFS implementations], 3541 ** that check if a database file was a URI that contained a specific query 3542 ** parameter, and if so obtains the value of that query parameter. 3543 ** 3544 ** The first parameter to these interfaces (hereafter referred to 3545 ** as F) must be one of: 3546 ** <ul> 3547 ** <li> A database filename pointer created by the SQLite core and 3548 ** passed into the xOpen() method of a VFS implemention, or 3549 ** <li> A filename obtained from [sqlite3_db_filename()], or 3550 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3551 ** </ul> 3552 ** If the F parameter is not one of the above, then the behavior is 3553 ** undefined and probably undesirable. Older versions of SQLite were 3554 ** more tolerant of invalid F parameters than newer versions. 3555 ** 3556 ** If F is a suitable filename (as described in the previous paragraph) 3557 ** and if P is the name of the query parameter, then 3558 ** sqlite3_uri_parameter(F,P) returns the value of the P 3559 ** parameter if it exists or a NULL pointer if P does not appear as a 3560 ** query parameter on F. If P is a query parameter of F and it 3561 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3562 ** a pointer to an empty string. 3563 ** 3564 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3565 ** parameter and returns true (1) or false (0) according to the value 3566 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3567 ** value of query parameter P is one of "yes", "true", or "on" in any 3568 ** case or if the value begins with a non-zero number. The 3569 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3570 ** query parameter P is one of "no", "false", or "off" in any case or 3571 ** if the value begins with a numeric zero. If P is not a query 3572 ** parameter on F or if the value of P does not match any of the 3573 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3574 ** 3575 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3576 ** 64-bit signed integer and returns that integer, or D if P does not 3577 ** exist. If the value of P is something other than an integer, then 3578 ** zero is returned. 3579 ** 3580 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3581 ** the value) of the N-th query parameter for filename F, or a NULL 3582 ** pointer if N is less than zero or greater than the number of query 3583 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3584 ** the name of the first query parameter, 1 for the second parameter, and 3585 ** so forth. 3586 ** 3587 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3588 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3589 ** is not a database file pathname pointer that the SQLite core passed 3590 ** into the xOpen VFS method, then the behavior of this routine is undefined 3591 ** and probably undesirable. 3592 ** 3593 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3594 ** parameter can also be the name of a rollback journal file or WAL file 3595 ** in addition to the main database file. Prior to version 3.31.0, these 3596 ** routines would only work if F was the name of the main database file. 3597 ** When the F parameter is the name of the rollback journal or WAL file, 3598 ** it has access to all the same query parameters as were found on the 3599 ** main database file. 3600 ** 3601 ** See the [URI filename] documentation for additional information. 3602 */ 3603 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3604 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3605 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3606 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N); 3607 3608 /* 3609 ** CAPI3REF: Translate filenames 3610 ** 3611 ** These routines are available to [VFS|custom VFS implementations] for 3612 ** translating filenames between the main database file, the journal file, 3613 ** and the WAL file. 3614 ** 3615 ** If F is the name of an sqlite database file, journal file, or WAL file 3616 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3617 ** returns the name of the corresponding database file. 3618 ** 3619 ** If F is the name of an sqlite database file, journal file, or WAL file 3620 ** passed by the SQLite core into the VFS, or if F is a database filename 3621 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3622 ** returns the name of the corresponding rollback journal file. 3623 ** 3624 ** If F is the name of an sqlite database file, journal file, or WAL file 3625 ** that was passed by the SQLite core into the VFS, or if F is a database 3626 ** filename obtained from [sqlite3_db_filename()], then 3627 ** sqlite3_filename_wal(F) returns the name of the corresponding 3628 ** WAL file. 3629 ** 3630 ** In all of the above, if F is not the name of a database, journal or WAL 3631 ** filename passed into the VFS from the SQLite core and F is not the 3632 ** return value from [sqlite3_db_filename()], then the result is 3633 ** undefined and is likely a memory access violation. 3634 */ 3635 SQLITE_API const char *sqlite3_filename_database(const char*); 3636 SQLITE_API const char *sqlite3_filename_journal(const char*); 3637 SQLITE_API const char *sqlite3_filename_wal(const char*); 3638 3639 /* 3640 ** CAPI3REF: Database File Corresponding To A Journal 3641 ** 3642 ** ^If X is the name of a rollback or WAL-mode journal file that is 3643 ** passed into the xOpen method of [sqlite3_vfs], then 3644 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3645 ** object that represents the main database file. 3646 ** 3647 ** This routine is intended for use in custom [VFS] implementations 3648 ** only. It is not a general-purpose interface. 3649 ** The argument sqlite3_file_object(X) must be a filename pointer that 3650 ** has been passed into [sqlite3_vfs].xOpen method where the 3651 ** flags parameter to xOpen contains one of the bits 3652 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3653 ** of this routine results in undefined and probably undesirable 3654 ** behavior. 3655 */ 3656 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3657 3658 /* 3659 ** CAPI3REF: Create and Destroy VFS Filenames 3660 ** 3661 ** These interfces are provided for use by [VFS shim] implementations and 3662 ** are not useful outside of that context. 3663 ** 3664 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3665 ** database filename D with corresponding journal file J and WAL file W and 3666 ** with N URI parameters key/values pairs in the array P. The result from 3667 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3668 ** is safe to pass to routines like: 3669 ** <ul> 3670 ** <li> [sqlite3_uri_parameter()], 3671 ** <li> [sqlite3_uri_boolean()], 3672 ** <li> [sqlite3_uri_int64()], 3673 ** <li> [sqlite3_uri_key()], 3674 ** <li> [sqlite3_filename_database()], 3675 ** <li> [sqlite3_filename_journal()], or 3676 ** <li> [sqlite3_filename_wal()]. 3677 ** </ul> 3678 ** If a memory allocation error occurs, sqlite3_create_filename() might 3679 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3680 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3681 ** 3682 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3683 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3684 ** to a key and value for a query parameter. The P parameter may be a NULL 3685 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3686 ** NULL pointers and key pointers should not be empty strings. 3687 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3688 ** be NULL pointers, though they can be empty strings. 3689 ** 3690 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3691 ** previously obtained from sqlite3_create_filename(). Invoking 3692 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3693 ** 3694 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3695 ** than a NULL pointer or a pointer previously acquired from 3696 ** sqlite3_create_filename(), then bad things such as heap 3697 ** corruption or segfaults may occur. The value Y should be 3698 ** used again after sqlite3_free_filename(Y) has been called. This means 3699 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3700 ** then the corresponding [sqlite3_module.xClose() method should also be 3701 ** invoked prior to calling sqlite3_free_filename(Y). 3702 */ 3703 SQLITE_API char *sqlite3_create_filename( 3704 const char *zDatabase, 3705 const char *zJournal, 3706 const char *zWal, 3707 int nParam, 3708 const char **azParam 3709 ); 3710 SQLITE_API void sqlite3_free_filename(char*); 3711 3712 /* 3713 ** CAPI3REF: Error Codes And Messages 3714 ** METHOD: sqlite3 3715 ** 3716 ** ^If the most recent sqlite3_* API call associated with 3717 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3718 ** returns the numeric [result code] or [extended result code] for that 3719 ** API call. 3720 ** ^The sqlite3_extended_errcode() 3721 ** interface is the same except that it always returns the 3722 ** [extended result code] even when extended result codes are 3723 ** disabled. 3724 ** 3725 ** The values returned by sqlite3_errcode() and/or 3726 ** sqlite3_extended_errcode() might change with each API call. 3727 ** Except, there are some interfaces that are guaranteed to never 3728 ** change the value of the error code. The error-code preserving 3729 ** interfaces are: 3730 ** 3731 ** <ul> 3732 ** <li> sqlite3_errcode() 3733 ** <li> sqlite3_extended_errcode() 3734 ** <li> sqlite3_errmsg() 3735 ** <li> sqlite3_errmsg16() 3736 ** </ul> 3737 ** 3738 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3739 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3740 ** ^(Memory to hold the error message string is managed internally. 3741 ** The application does not need to worry about freeing the result. 3742 ** However, the error string might be overwritten or deallocated by 3743 ** subsequent calls to other SQLite interface functions.)^ 3744 ** 3745 ** ^The sqlite3_errstr() interface returns the English-language text 3746 ** that describes the [result code], as UTF-8. 3747 ** ^(Memory to hold the error message string is managed internally 3748 ** and must not be freed by the application)^. 3749 ** 3750 ** When the serialized [threading mode] is in use, it might be the 3751 ** case that a second error occurs on a separate thread in between 3752 ** the time of the first error and the call to these interfaces. 3753 ** When that happens, the second error will be reported since these 3754 ** interfaces always report the most recent result. To avoid 3755 ** this, each thread can obtain exclusive use of the [database connection] D 3756 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3757 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3758 ** all calls to the interfaces listed here are completed. 3759 ** 3760 ** If an interface fails with SQLITE_MISUSE, that means the interface 3761 ** was invoked incorrectly by the application. In that case, the 3762 ** error code and message may or may not be set. 3763 */ 3764 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3765 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3766 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3767 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3768 SQLITE_API const char *sqlite3_errstr(int); 3769 3770 /* 3771 ** CAPI3REF: Prepared Statement Object 3772 ** KEYWORDS: {prepared statement} {prepared statements} 3773 ** 3774 ** An instance of this object represents a single SQL statement that 3775 ** has been compiled into binary form and is ready to be evaluated. 3776 ** 3777 ** Think of each SQL statement as a separate computer program. The 3778 ** original SQL text is source code. A prepared statement object 3779 ** is the compiled object code. All SQL must be converted into a 3780 ** prepared statement before it can be run. 3781 ** 3782 ** The life-cycle of a prepared statement object usually goes like this: 3783 ** 3784 ** <ol> 3785 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3786 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3787 ** interfaces. 3788 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3789 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3790 ** to step 2. Do this zero or more times. 3791 ** <li> Destroy the object using [sqlite3_finalize()]. 3792 ** </ol> 3793 */ 3794 typedef struct sqlite3_stmt sqlite3_stmt; 3795 3796 /* 3797 ** CAPI3REF: Run-time Limits 3798 ** METHOD: sqlite3 3799 ** 3800 ** ^(This interface allows the size of various constructs to be limited 3801 ** on a connection by connection basis. The first parameter is the 3802 ** [database connection] whose limit is to be set or queried. The 3803 ** second parameter is one of the [limit categories] that define a 3804 ** class of constructs to be size limited. The third parameter is the 3805 ** new limit for that construct.)^ 3806 ** 3807 ** ^If the new limit is a negative number, the limit is unchanged. 3808 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3809 ** [limits | hard upper bound] 3810 ** set at compile-time by a C preprocessor macro called 3811 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3812 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3813 ** ^Attempts to increase a limit above its hard upper bound are 3814 ** silently truncated to the hard upper bound. 3815 ** 3816 ** ^Regardless of whether or not the limit was changed, the 3817 ** [sqlite3_limit()] interface returns the prior value of the limit. 3818 ** ^Hence, to find the current value of a limit without changing it, 3819 ** simply invoke this interface with the third parameter set to -1. 3820 ** 3821 ** Run-time limits are intended for use in applications that manage 3822 ** both their own internal database and also databases that are controlled 3823 ** by untrusted external sources. An example application might be a 3824 ** web browser that has its own databases for storing history and 3825 ** separate databases controlled by JavaScript applications downloaded 3826 ** off the Internet. The internal databases can be given the 3827 ** large, default limits. Databases managed by external sources can 3828 ** be given much smaller limits designed to prevent a denial of service 3829 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3830 ** interface to further control untrusted SQL. The size of the database 3831 ** created by an untrusted script can be contained using the 3832 ** [max_page_count] [PRAGMA]. 3833 ** 3834 ** New run-time limit categories may be added in future releases. 3835 */ 3836 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3837 3838 /* 3839 ** CAPI3REF: Run-Time Limit Categories 3840 ** KEYWORDS: {limit category} {*limit categories} 3841 ** 3842 ** These constants define various performance limits 3843 ** that can be lowered at run-time using [sqlite3_limit()]. 3844 ** The synopsis of the meanings of the various limits is shown below. 3845 ** Additional information is available at [limits | Limits in SQLite]. 3846 ** 3847 ** <dl> 3848 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3849 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3850 ** 3851 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3852 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3853 ** 3854 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3855 ** <dd>The maximum number of columns in a table definition or in the 3856 ** result set of a [SELECT] or the maximum number of columns in an index 3857 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3858 ** 3859 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3860 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3861 ** 3862 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3863 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3864 ** 3865 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3866 ** <dd>The maximum number of instructions in a virtual machine program 3867 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3868 ** the equivalent tries to allocate space for more than this many opcodes 3869 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3870 ** 3871 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3872 ** <dd>The maximum number of arguments on a function.</dd>)^ 3873 ** 3874 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3875 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3876 ** 3877 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3878 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3879 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3880 ** [GLOB] operators.</dd>)^ 3881 ** 3882 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3883 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3884 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3885 ** 3886 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3887 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3888 ** 3889 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3890 ** <dd>The maximum number of auxiliary worker threads that a single 3891 ** [prepared statement] may start.</dd>)^ 3892 ** </dl> 3893 */ 3894 #define SQLITE_LIMIT_LENGTH 0 3895 #define SQLITE_LIMIT_SQL_LENGTH 1 3896 #define SQLITE_LIMIT_COLUMN 2 3897 #define SQLITE_LIMIT_EXPR_DEPTH 3 3898 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3899 #define SQLITE_LIMIT_VDBE_OP 5 3900 #define SQLITE_LIMIT_FUNCTION_ARG 6 3901 #define SQLITE_LIMIT_ATTACHED 7 3902 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3903 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3904 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3905 #define SQLITE_LIMIT_WORKER_THREADS 11 3906 3907 /* 3908 ** CAPI3REF: Prepare Flags 3909 ** 3910 ** These constants define various flags that can be passed into 3911 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3912 ** [sqlite3_prepare16_v3()] interfaces. 3913 ** 3914 ** New flags may be added in future releases of SQLite. 3915 ** 3916 ** <dl> 3917 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3918 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3919 ** that the prepared statement will be retained for a long time and 3920 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3921 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3922 ** be used just once or at most a few times and then destroyed using 3923 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3924 ** on this hint by avoiding the use of [lookaside memory] so as not to 3925 ** deplete the limited store of lookaside memory. Future versions of 3926 ** SQLite may act on this hint differently. 3927 ** 3928 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3929 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3930 ** to be required for any prepared statement that wanted to use the 3931 ** [sqlite3_normalized_sql()] interface. However, the 3932 ** [sqlite3_normalized_sql()] interface is now available to all 3933 ** prepared statements, regardless of whether or not they use this 3934 ** flag. 3935 ** 3936 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3937 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3938 ** to return an error (error code SQLITE_ERROR) if the statement uses 3939 ** any virtual tables. 3940 ** </dl> 3941 */ 3942 #define SQLITE_PREPARE_PERSISTENT 0x01 3943 #define SQLITE_PREPARE_NORMALIZE 0x02 3944 #define SQLITE_PREPARE_NO_VTAB 0x04 3945 3946 /* 3947 ** CAPI3REF: Compiling An SQL Statement 3948 ** KEYWORDS: {SQL statement compiler} 3949 ** METHOD: sqlite3 3950 ** CONSTRUCTOR: sqlite3_stmt 3951 ** 3952 ** To execute an SQL statement, it must first be compiled into a byte-code 3953 ** program using one of these routines. Or, in other words, these routines 3954 ** are constructors for the [prepared statement] object. 3955 ** 3956 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3957 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3958 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3959 ** for special purposes. 3960 ** 3961 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3962 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3963 ** as a convenience. The UTF-16 interfaces work by converting the 3964 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3965 ** 3966 ** The first argument, "db", is a [database connection] obtained from a 3967 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3968 ** [sqlite3_open16()]. The database connection must not have been closed. 3969 ** 3970 ** The second argument, "zSql", is the statement to be compiled, encoded 3971 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3972 ** and sqlite3_prepare_v3() 3973 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3974 ** and sqlite3_prepare16_v3() use UTF-16. 3975 ** 3976 ** ^If the nByte argument is negative, then zSql is read up to the 3977 ** first zero terminator. ^If nByte is positive, then it is the 3978 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3979 ** statement is generated. 3980 ** If the caller knows that the supplied string is nul-terminated, then 3981 ** there is a small performance advantage to passing an nByte parameter that 3982 ** is the number of bytes in the input string <i>including</i> 3983 ** the nul-terminator. 3984 ** 3985 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3986 ** past the end of the first SQL statement in zSql. These routines only 3987 ** compile the first statement in zSql, so *pzTail is left pointing to 3988 ** what remains uncompiled. 3989 ** 3990 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3991 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3992 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3993 ** string or a comment) then *ppStmt is set to NULL. 3994 ** The calling procedure is responsible for deleting the compiled 3995 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3996 ** ppStmt may not be NULL. 3997 ** 3998 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3999 ** otherwise an [error code] is returned. 4000 ** 4001 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4002 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4003 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4004 ** are retained for backwards compatibility, but their use is discouraged. 4005 ** ^In the "vX" interfaces, the prepared statement 4006 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4007 ** original SQL text. This causes the [sqlite3_step()] interface to 4008 ** behave differently in three ways: 4009 ** 4010 ** <ol> 4011 ** <li> 4012 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4013 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4014 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4015 ** retries will occur before sqlite3_step() gives up and returns an error. 4016 ** </li> 4017 ** 4018 ** <li> 4019 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4020 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4021 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4022 ** and the application would have to make a second call to [sqlite3_reset()] 4023 ** in order to find the underlying cause of the problem. With the "v2" prepare 4024 ** interfaces, the underlying reason for the error is returned immediately. 4025 ** </li> 4026 ** 4027 ** <li> 4028 ** ^If the specific value bound to a [parameter | host parameter] in the 4029 ** WHERE clause might influence the choice of query plan for a statement, 4030 ** then the statement will be automatically recompiled, as if there had been 4031 ** a schema change, on the first [sqlite3_step()] call following any change 4032 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4033 ** ^The specific value of a WHERE-clause [parameter] might influence the 4034 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4035 ** or [GLOB] operator or if the parameter is compared to an indexed column 4036 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4037 ** </li> 4038 ** </ol> 4039 ** 4040 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4041 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4042 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4043 ** sqlite3_prepare_v2() interface works exactly the same as 4044 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4045 */ 4046 SQLITE_API int sqlite3_prepare( 4047 sqlite3 *db, /* Database handle */ 4048 const char *zSql, /* SQL statement, UTF-8 encoded */ 4049 int nByte, /* Maximum length of zSql in bytes. */ 4050 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4051 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4052 ); 4053 SQLITE_API int sqlite3_prepare_v2( 4054 sqlite3 *db, /* Database handle */ 4055 const char *zSql, /* SQL statement, UTF-8 encoded */ 4056 int nByte, /* Maximum length of zSql in bytes. */ 4057 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4058 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4059 ); 4060 SQLITE_API int sqlite3_prepare_v3( 4061 sqlite3 *db, /* Database handle */ 4062 const char *zSql, /* SQL statement, UTF-8 encoded */ 4063 int nByte, /* Maximum length of zSql in bytes. */ 4064 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4065 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4066 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4067 ); 4068 SQLITE_API int sqlite3_prepare16( 4069 sqlite3 *db, /* Database handle */ 4070 const void *zSql, /* SQL statement, UTF-16 encoded */ 4071 int nByte, /* Maximum length of zSql in bytes. */ 4072 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4073 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4074 ); 4075 SQLITE_API int sqlite3_prepare16_v2( 4076 sqlite3 *db, /* Database handle */ 4077 const void *zSql, /* SQL statement, UTF-16 encoded */ 4078 int nByte, /* Maximum length of zSql in bytes. */ 4079 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4080 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4081 ); 4082 SQLITE_API int sqlite3_prepare16_v3( 4083 sqlite3 *db, /* Database handle */ 4084 const void *zSql, /* SQL statement, UTF-16 encoded */ 4085 int nByte, /* Maximum length of zSql in bytes. */ 4086 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4087 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4088 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4089 ); 4090 4091 /* 4092 ** CAPI3REF: Retrieving Statement SQL 4093 ** METHOD: sqlite3_stmt 4094 ** 4095 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4096 ** SQL text used to create [prepared statement] P if P was 4097 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4098 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4099 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4100 ** string containing the SQL text of prepared statement P with 4101 ** [bound parameters] expanded. 4102 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4103 ** string containing the normalized SQL text of prepared statement P. The 4104 ** semantics used to normalize a SQL statement are unspecified and subject 4105 ** to change. At a minimum, literal values will be replaced with suitable 4106 ** placeholders. 4107 ** 4108 ** ^(For example, if a prepared statement is created using the SQL 4109 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4110 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4111 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4112 ** will return "SELECT 2345,NULL".)^ 4113 ** 4114 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4115 ** is available to hold the result, or if the result would exceed the 4116 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4117 ** 4118 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4119 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4120 ** option causes sqlite3_expanded_sql() to always return NULL. 4121 ** 4122 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4123 ** are managed by SQLite and are automatically freed when the prepared 4124 ** statement is finalized. 4125 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4126 ** is obtained from [sqlite3_malloc()] and must be free by the application 4127 ** by passing it to [sqlite3_free()]. 4128 */ 4129 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4130 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4131 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4132 4133 /* 4134 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4135 ** METHOD: sqlite3_stmt 4136 ** 4137 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4138 ** and only if the [prepared statement] X makes no direct changes to 4139 ** the content of the database file. 4140 ** 4141 ** Note that [application-defined SQL functions] or 4142 ** [virtual tables] might change the database indirectly as a side effect. 4143 ** ^(For example, if an application defines a function "eval()" that 4144 ** calls [sqlite3_exec()], then the following SQL statement would 4145 ** change the database file through side-effects: 4146 ** 4147 ** <blockquote><pre> 4148 ** SELECT eval('DELETE FROM t1') FROM t2; 4149 ** </pre></blockquote> 4150 ** 4151 ** But because the [SELECT] statement does not change the database file 4152 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4153 ** 4154 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4155 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4156 ** since the statements themselves do not actually modify the database but 4157 ** rather they control the timing of when other statements modify the 4158 ** database. ^The [ATTACH] and [DETACH] statements also cause 4159 ** sqlite3_stmt_readonly() to return true since, while those statements 4160 ** change the configuration of a database connection, they do not make 4161 ** changes to the content of the database files on disk. 4162 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4163 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4164 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4165 ** sqlite3_stmt_readonly() returns false for those commands. 4166 */ 4167 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4168 4169 /* 4170 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4171 ** METHOD: sqlite3_stmt 4172 ** 4173 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4174 ** prepared statement S is an EXPLAIN statement, or 2 if the 4175 ** statement S is an EXPLAIN QUERY PLAN. 4176 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4177 ** an ordinary statement or a NULL pointer. 4178 */ 4179 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4180 4181 /* 4182 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4183 ** METHOD: sqlite3_stmt 4184 ** 4185 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4186 ** [prepared statement] S has been stepped at least once using 4187 ** [sqlite3_step(S)] but has neither run to completion (returned 4188 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4189 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4190 ** interface returns false if S is a NULL pointer. If S is not a 4191 ** NULL pointer and is not a pointer to a valid [prepared statement] 4192 ** object, then the behavior is undefined and probably undesirable. 4193 ** 4194 ** This interface can be used in combination [sqlite3_next_stmt()] 4195 ** to locate all prepared statements associated with a database 4196 ** connection that are in need of being reset. This can be used, 4197 ** for example, in diagnostic routines to search for prepared 4198 ** statements that are holding a transaction open. 4199 */ 4200 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4201 4202 /* 4203 ** CAPI3REF: Dynamically Typed Value Object 4204 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4205 ** 4206 ** SQLite uses the sqlite3_value object to represent all values 4207 ** that can be stored in a database table. SQLite uses dynamic typing 4208 ** for the values it stores. ^Values stored in sqlite3_value objects 4209 ** can be integers, floating point values, strings, BLOBs, or NULL. 4210 ** 4211 ** An sqlite3_value object may be either "protected" or "unprotected". 4212 ** Some interfaces require a protected sqlite3_value. Other interfaces 4213 ** will accept either a protected or an unprotected sqlite3_value. 4214 ** Every interface that accepts sqlite3_value arguments specifies 4215 ** whether or not it requires a protected sqlite3_value. The 4216 ** [sqlite3_value_dup()] interface can be used to construct a new 4217 ** protected sqlite3_value from an unprotected sqlite3_value. 4218 ** 4219 ** The terms "protected" and "unprotected" refer to whether or not 4220 ** a mutex is held. An internal mutex is held for a protected 4221 ** sqlite3_value object but no mutex is held for an unprotected 4222 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4223 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4224 ** or if SQLite is run in one of reduced mutex modes 4225 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4226 ** then there is no distinction between protected and unprotected 4227 ** sqlite3_value objects and they can be used interchangeably. However, 4228 ** for maximum code portability it is recommended that applications 4229 ** still make the distinction between protected and unprotected 4230 ** sqlite3_value objects even when not strictly required. 4231 ** 4232 ** ^The sqlite3_value objects that are passed as parameters into the 4233 ** implementation of [application-defined SQL functions] are protected. 4234 ** ^The sqlite3_value object returned by 4235 ** [sqlite3_column_value()] is unprotected. 4236 ** Unprotected sqlite3_value objects may only be used as arguments 4237 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4238 ** [sqlite3_value_dup()]. 4239 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4240 ** interfaces require protected sqlite3_value objects. 4241 */ 4242 typedef struct sqlite3_value sqlite3_value; 4243 4244 /* 4245 ** CAPI3REF: SQL Function Context Object 4246 ** 4247 ** The context in which an SQL function executes is stored in an 4248 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4249 ** is always first parameter to [application-defined SQL functions]. 4250 ** The application-defined SQL function implementation will pass this 4251 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4252 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4253 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4254 ** and/or [sqlite3_set_auxdata()]. 4255 */ 4256 typedef struct sqlite3_context sqlite3_context; 4257 4258 /* 4259 ** CAPI3REF: Binding Values To Prepared Statements 4260 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4261 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4262 ** METHOD: sqlite3_stmt 4263 ** 4264 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4265 ** literals may be replaced by a [parameter] that matches one of following 4266 ** templates: 4267 ** 4268 ** <ul> 4269 ** <li> ? 4270 ** <li> ?NNN 4271 ** <li> :VVV 4272 ** <li> @VVV 4273 ** <li> $VVV 4274 ** </ul> 4275 ** 4276 ** In the templates above, NNN represents an integer literal, 4277 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4278 ** parameters (also called "host parameter names" or "SQL parameters") 4279 ** can be set using the sqlite3_bind_*() routines defined here. 4280 ** 4281 ** ^The first argument to the sqlite3_bind_*() routines is always 4282 ** a pointer to the [sqlite3_stmt] object returned from 4283 ** [sqlite3_prepare_v2()] or its variants. 4284 ** 4285 ** ^The second argument is the index of the SQL parameter to be set. 4286 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4287 ** SQL parameter is used more than once, second and subsequent 4288 ** occurrences have the same index as the first occurrence. 4289 ** ^The index for named parameters can be looked up using the 4290 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4291 ** for "?NNN" parameters is the value of NNN. 4292 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4293 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4294 ** 4295 ** ^The third argument is the value to bind to the parameter. 4296 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4297 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4298 ** is ignored and the end result is the same as sqlite3_bind_null(). 4299 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4300 ** it should be a pointer to well-formed UTF8 text. 4301 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4302 ** it should be a pointer to well-formed UTF16 text. 4303 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4304 ** it should be a pointer to a well-formed unicode string that is 4305 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4306 ** otherwise. 4307 ** 4308 ** [[byte-order determination rules]] ^The byte-order of 4309 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4310 ** found in first character, which is removed, or in the absence of a BOM 4311 ** the byte order is the native byte order of the host 4312 ** machine for sqlite3_bind_text16() or the byte order specified in 4313 ** the 6th parameter for sqlite3_bind_text64().)^ 4314 ** ^If UTF16 input text contains invalid unicode 4315 ** characters, then SQLite might change those invalid characters 4316 ** into the unicode replacement character: U+FFFD. 4317 ** 4318 ** ^(In those routines that have a fourth argument, its value is the 4319 ** number of bytes in the parameter. To be clear: the value is the 4320 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4321 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4322 ** is negative, then the length of the string is 4323 ** the number of bytes up to the first zero terminator. 4324 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4325 ** the behavior is undefined. 4326 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4327 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4328 ** that parameter must be the byte offset 4329 ** where the NUL terminator would occur assuming the string were NUL 4330 ** terminated. If any NUL characters occurs at byte offsets less than 4331 ** the value of the fourth parameter then the resulting string value will 4332 ** contain embedded NULs. The result of expressions involving strings 4333 ** with embedded NULs is undefined. 4334 ** 4335 ** ^The fifth argument to the BLOB and string binding interfaces 4336 ** is a destructor used to dispose of the BLOB or 4337 ** string after SQLite has finished with it. ^The destructor is called 4338 ** to dispose of the BLOB or string even if the call to the bind API fails, 4339 ** except the destructor is not called if the third parameter is a NULL 4340 ** pointer or the fourth parameter is negative. 4341 ** ^If the fifth argument is 4342 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4343 ** information is in static, unmanaged space and does not need to be freed. 4344 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4345 ** SQLite makes its own private copy of the data immediately, before 4346 ** the sqlite3_bind_*() routine returns. 4347 ** 4348 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4349 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4350 ** to specify the encoding of the text in the third parameter. If 4351 ** the sixth argument to sqlite3_bind_text64() is not one of the 4352 ** allowed values shown above, or if the text encoding is different 4353 ** from the encoding specified by the sixth parameter, then the behavior 4354 ** is undefined. 4355 ** 4356 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4357 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4358 ** (just an integer to hold its size) while it is being processed. 4359 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4360 ** content is later written using 4361 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4362 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4363 ** 4364 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4365 ** [prepared statement] S to have an SQL value of NULL, but to also be 4366 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4367 ** a pointer to a destructor function for P. ^SQLite will invoke the 4368 ** destructor D with a single argument of P when it is finished using 4369 ** P. The T parameter should be a static string, preferably a string 4370 ** literal. The sqlite3_bind_pointer() routine is part of the 4371 ** [pointer passing interface] added for SQLite 3.20.0. 4372 ** 4373 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4374 ** for the [prepared statement] or with a prepared statement for which 4375 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4376 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4377 ** routine is passed a [prepared statement] that has been finalized, the 4378 ** result is undefined and probably harmful. 4379 ** 4380 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4381 ** ^Unbound parameters are interpreted as NULL. 4382 ** 4383 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4384 ** [error code] if anything goes wrong. 4385 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4386 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4387 ** [SQLITE_MAX_LENGTH]. 4388 ** ^[SQLITE_RANGE] is returned if the parameter 4389 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4390 ** 4391 ** See also: [sqlite3_bind_parameter_count()], 4392 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4393 */ 4394 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4395 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4396 void(*)(void*)); 4397 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4398 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4399 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4400 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4401 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4402 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4403 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4404 void(*)(void*), unsigned char encoding); 4405 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4406 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4407 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4408 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4409 4410 /* 4411 ** CAPI3REF: Number Of SQL Parameters 4412 ** METHOD: sqlite3_stmt 4413 ** 4414 ** ^This routine can be used to find the number of [SQL parameters] 4415 ** in a [prepared statement]. SQL parameters are tokens of the 4416 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4417 ** placeholders for values that are [sqlite3_bind_blob | bound] 4418 ** to the parameters at a later time. 4419 ** 4420 ** ^(This routine actually returns the index of the largest (rightmost) 4421 ** parameter. For all forms except ?NNN, this will correspond to the 4422 ** number of unique parameters. If parameters of the ?NNN form are used, 4423 ** there may be gaps in the list.)^ 4424 ** 4425 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4426 ** [sqlite3_bind_parameter_name()], and 4427 ** [sqlite3_bind_parameter_index()]. 4428 */ 4429 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4430 4431 /* 4432 ** CAPI3REF: Name Of A Host Parameter 4433 ** METHOD: sqlite3_stmt 4434 ** 4435 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4436 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4437 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4438 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4439 ** respectively. 4440 ** In other words, the initial ":" or "$" or "@" or "?" 4441 ** is included as part of the name.)^ 4442 ** ^Parameters of the form "?" without a following integer have no name 4443 ** and are referred to as "nameless" or "anonymous parameters". 4444 ** 4445 ** ^The first host parameter has an index of 1, not 0. 4446 ** 4447 ** ^If the value N is out of range or if the N-th parameter is 4448 ** nameless, then NULL is returned. ^The returned string is 4449 ** always in UTF-8 encoding even if the named parameter was 4450 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4451 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4452 ** 4453 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4454 ** [sqlite3_bind_parameter_count()], and 4455 ** [sqlite3_bind_parameter_index()]. 4456 */ 4457 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4458 4459 /* 4460 ** CAPI3REF: Index Of A Parameter With A Given Name 4461 ** METHOD: sqlite3_stmt 4462 ** 4463 ** ^Return the index of an SQL parameter given its name. ^The 4464 ** index value returned is suitable for use as the second 4465 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4466 ** is returned if no matching parameter is found. ^The parameter 4467 ** name must be given in UTF-8 even if the original statement 4468 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4469 ** [sqlite3_prepare16_v3()]. 4470 ** 4471 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4472 ** [sqlite3_bind_parameter_count()], and 4473 ** [sqlite3_bind_parameter_name()]. 4474 */ 4475 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4476 4477 /* 4478 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4479 ** METHOD: sqlite3_stmt 4480 ** 4481 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4482 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4483 ** ^Use this routine to reset all host parameters to NULL. 4484 */ 4485 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4486 4487 /* 4488 ** CAPI3REF: Number Of Columns In A Result Set 4489 ** METHOD: sqlite3_stmt 4490 ** 4491 ** ^Return the number of columns in the result set returned by the 4492 ** [prepared statement]. ^If this routine returns 0, that means the 4493 ** [prepared statement] returns no data (for example an [UPDATE]). 4494 ** ^However, just because this routine returns a positive number does not 4495 ** mean that one or more rows of data will be returned. ^A SELECT statement 4496 ** will always have a positive sqlite3_column_count() but depending on the 4497 ** WHERE clause constraints and the table content, it might return no rows. 4498 ** 4499 ** See also: [sqlite3_data_count()] 4500 */ 4501 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4502 4503 /* 4504 ** CAPI3REF: Column Names In A Result Set 4505 ** METHOD: sqlite3_stmt 4506 ** 4507 ** ^These routines return the name assigned to a particular column 4508 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4509 ** interface returns a pointer to a zero-terminated UTF-8 string 4510 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4511 ** UTF-16 string. ^The first parameter is the [prepared statement] 4512 ** that implements the [SELECT] statement. ^The second parameter is the 4513 ** column number. ^The leftmost column is number 0. 4514 ** 4515 ** ^The returned string pointer is valid until either the [prepared statement] 4516 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4517 ** reprepared by the first call to [sqlite3_step()] for a particular run 4518 ** or until the next call to 4519 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4520 ** 4521 ** ^If sqlite3_malloc() fails during the processing of either routine 4522 ** (for example during a conversion from UTF-8 to UTF-16) then a 4523 ** NULL pointer is returned. 4524 ** 4525 ** ^The name of a result column is the value of the "AS" clause for 4526 ** that column, if there is an AS clause. If there is no AS clause 4527 ** then the name of the column is unspecified and may change from 4528 ** one release of SQLite to the next. 4529 */ 4530 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4531 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4532 4533 /* 4534 ** CAPI3REF: Source Of Data In A Query Result 4535 ** METHOD: sqlite3_stmt 4536 ** 4537 ** ^These routines provide a means to determine the database, table, and 4538 ** table column that is the origin of a particular result column in 4539 ** [SELECT] statement. 4540 ** ^The name of the database or table or column can be returned as 4541 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4542 ** the database name, the _table_ routines return the table name, and 4543 ** the origin_ routines return the column name. 4544 ** ^The returned string is valid until the [prepared statement] is destroyed 4545 ** using [sqlite3_finalize()] or until the statement is automatically 4546 ** reprepared by the first call to [sqlite3_step()] for a particular run 4547 ** or until the same information is requested 4548 ** again in a different encoding. 4549 ** 4550 ** ^The names returned are the original un-aliased names of the 4551 ** database, table, and column. 4552 ** 4553 ** ^The first argument to these interfaces is a [prepared statement]. 4554 ** ^These functions return information about the Nth result column returned by 4555 ** the statement, where N is the second function argument. 4556 ** ^The left-most column is column 0 for these routines. 4557 ** 4558 ** ^If the Nth column returned by the statement is an expression or 4559 ** subquery and is not a column value, then all of these functions return 4560 ** NULL. ^These routines might also return NULL if a memory allocation error 4561 ** occurs. ^Otherwise, they return the name of the attached database, table, 4562 ** or column that query result column was extracted from. 4563 ** 4564 ** ^As with all other SQLite APIs, those whose names end with "16" return 4565 ** UTF-16 encoded strings and the other functions return UTF-8. 4566 ** 4567 ** ^These APIs are only available if the library was compiled with the 4568 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4569 ** 4570 ** If two or more threads call one or more 4571 ** [sqlite3_column_database_name | column metadata interfaces] 4572 ** for the same [prepared statement] and result column 4573 ** at the same time then the results are undefined. 4574 */ 4575 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4576 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4577 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4578 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4579 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4580 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4581 4582 /* 4583 ** CAPI3REF: Declared Datatype Of A Query Result 4584 ** METHOD: sqlite3_stmt 4585 ** 4586 ** ^(The first parameter is a [prepared statement]. 4587 ** If this statement is a [SELECT] statement and the Nth column of the 4588 ** returned result set of that [SELECT] is a table column (not an 4589 ** expression or subquery) then the declared type of the table 4590 ** column is returned.)^ ^If the Nth column of the result set is an 4591 ** expression or subquery, then a NULL pointer is returned. 4592 ** ^The returned string is always UTF-8 encoded. 4593 ** 4594 ** ^(For example, given the database schema: 4595 ** 4596 ** CREATE TABLE t1(c1 VARIANT); 4597 ** 4598 ** and the following statement to be compiled: 4599 ** 4600 ** SELECT c1 + 1, c1 FROM t1; 4601 ** 4602 ** this routine would return the string "VARIANT" for the second result 4603 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4604 ** 4605 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4606 ** is declared to contain a particular type does not mean that the 4607 ** data stored in that column is of the declared type. SQLite is 4608 ** strongly typed, but the typing is dynamic not static. ^Type 4609 ** is associated with individual values, not with the containers 4610 ** used to hold those values. 4611 */ 4612 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4613 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4614 4615 /* 4616 ** CAPI3REF: Evaluate An SQL Statement 4617 ** METHOD: sqlite3_stmt 4618 ** 4619 ** After a [prepared statement] has been prepared using any of 4620 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4621 ** or [sqlite3_prepare16_v3()] or one of the legacy 4622 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4623 ** must be called one or more times to evaluate the statement. 4624 ** 4625 ** The details of the behavior of the sqlite3_step() interface depend 4626 ** on whether the statement was prepared using the newer "vX" interfaces 4627 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4628 ** [sqlite3_prepare16_v2()] or the older legacy 4629 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4630 ** new "vX" interface is recommended for new applications but the legacy 4631 ** interface will continue to be supported. 4632 ** 4633 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4634 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4635 ** ^With the "v2" interface, any of the other [result codes] or 4636 ** [extended result codes] might be returned as well. 4637 ** 4638 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4639 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4640 ** or occurs outside of an explicit transaction, then you can retry the 4641 ** statement. If the statement is not a [COMMIT] and occurs within an 4642 ** explicit transaction then you should rollback the transaction before 4643 ** continuing. 4644 ** 4645 ** ^[SQLITE_DONE] means that the statement has finished executing 4646 ** successfully. sqlite3_step() should not be called again on this virtual 4647 ** machine without first calling [sqlite3_reset()] to reset the virtual 4648 ** machine back to its initial state. 4649 ** 4650 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4651 ** is returned each time a new row of data is ready for processing by the 4652 ** caller. The values may be accessed using the [column access functions]. 4653 ** sqlite3_step() is called again to retrieve the next row of data. 4654 ** 4655 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4656 ** violation) has occurred. sqlite3_step() should not be called again on 4657 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4658 ** ^With the legacy interface, a more specific error code (for example, 4659 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4660 ** can be obtained by calling [sqlite3_reset()] on the 4661 ** [prepared statement]. ^In the "v2" interface, 4662 ** the more specific error code is returned directly by sqlite3_step(). 4663 ** 4664 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4665 ** Perhaps it was called on a [prepared statement] that has 4666 ** already been [sqlite3_finalize | finalized] or on one that had 4667 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4668 ** be the case that the same database connection is being used by two or 4669 ** more threads at the same moment in time. 4670 ** 4671 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4672 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4673 ** other than [SQLITE_ROW] before any subsequent invocation of 4674 ** sqlite3_step(). Failure to reset the prepared statement using 4675 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4676 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4677 ** sqlite3_step() began 4678 ** calling [sqlite3_reset()] automatically in this circumstance rather 4679 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4680 ** break because any application that ever receives an SQLITE_MISUSE error 4681 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4682 ** can be used to restore the legacy behavior. 4683 ** 4684 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4685 ** API always returns a generic error code, [SQLITE_ERROR], following any 4686 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4687 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4688 ** specific [error codes] that better describes the error. 4689 ** We admit that this is a goofy design. The problem has been fixed 4690 ** with the "v2" interface. If you prepare all of your SQL statements 4691 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4692 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4693 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4694 ** then the more specific [error codes] are returned directly 4695 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4696 */ 4697 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4698 4699 /* 4700 ** CAPI3REF: Number of columns in a result set 4701 ** METHOD: sqlite3_stmt 4702 ** 4703 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4704 ** current row of the result set of [prepared statement] P. 4705 ** ^If prepared statement P does not have results ready to return 4706 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4707 ** interfaces) then sqlite3_data_count(P) returns 0. 4708 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4709 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4710 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4711 ** will return non-zero if previous call to [sqlite3_step](P) returned 4712 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4713 ** where it always returns zero since each step of that multi-step 4714 ** pragma returns 0 columns of data. 4715 ** 4716 ** See also: [sqlite3_column_count()] 4717 */ 4718 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4719 4720 /* 4721 ** CAPI3REF: Fundamental Datatypes 4722 ** KEYWORDS: SQLITE_TEXT 4723 ** 4724 ** ^(Every value in SQLite has one of five fundamental datatypes: 4725 ** 4726 ** <ul> 4727 ** <li> 64-bit signed integer 4728 ** <li> 64-bit IEEE floating point number 4729 ** <li> string 4730 ** <li> BLOB 4731 ** <li> NULL 4732 ** </ul>)^ 4733 ** 4734 ** These constants are codes for each of those types. 4735 ** 4736 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4737 ** for a completely different meaning. Software that links against both 4738 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4739 ** SQLITE_TEXT. 4740 */ 4741 #define SQLITE_INTEGER 1 4742 #define SQLITE_FLOAT 2 4743 #define SQLITE_BLOB 4 4744 #define SQLITE_NULL 5 4745 #ifdef SQLITE_TEXT 4746 # undef SQLITE_TEXT 4747 #else 4748 # define SQLITE_TEXT 3 4749 #endif 4750 #define SQLITE3_TEXT 3 4751 4752 /* 4753 ** CAPI3REF: Result Values From A Query 4754 ** KEYWORDS: {column access functions} 4755 ** METHOD: sqlite3_stmt 4756 ** 4757 ** <b>Summary:</b> 4758 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4759 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4760 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4761 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4762 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4763 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4764 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4765 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4766 ** [sqlite3_value|unprotected sqlite3_value] object. 4767 ** <tr><td> <td> <td> 4768 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4769 ** or a UTF-8 TEXT result in bytes 4770 ** <tr><td><b>sqlite3_column_bytes16 </b> 4771 ** <td>→ <td>Size of UTF-16 4772 ** TEXT in bytes 4773 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4774 ** datatype of the result 4775 ** </table></blockquote> 4776 ** 4777 ** <b>Details:</b> 4778 ** 4779 ** ^These routines return information about a single column of the current 4780 ** result row of a query. ^In every case the first argument is a pointer 4781 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4782 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4783 ** and the second argument is the index of the column for which information 4784 ** should be returned. ^The leftmost column of the result set has the index 0. 4785 ** ^The number of columns in the result can be determined using 4786 ** [sqlite3_column_count()]. 4787 ** 4788 ** If the SQL statement does not currently point to a valid row, or if the 4789 ** column index is out of range, the result is undefined. 4790 ** These routines may only be called when the most recent call to 4791 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4792 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4793 ** If any of these routines are called after [sqlite3_reset()] or 4794 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4795 ** something other than [SQLITE_ROW], the results are undefined. 4796 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4797 ** are called from a different thread while any of these routines 4798 ** are pending, then the results are undefined. 4799 ** 4800 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4801 ** each return the value of a result column in a specific data format. If 4802 ** the result column is not initially in the requested format (for example, 4803 ** if the query returns an integer but the sqlite3_column_text() interface 4804 ** is used to extract the value) then an automatic type conversion is performed. 4805 ** 4806 ** ^The sqlite3_column_type() routine returns the 4807 ** [SQLITE_INTEGER | datatype code] for the initial data type 4808 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4809 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4810 ** The return value of sqlite3_column_type() can be used to decide which 4811 ** of the first six interface should be used to extract the column value. 4812 ** The value returned by sqlite3_column_type() is only meaningful if no 4813 ** automatic type conversions have occurred for the value in question. 4814 ** After a type conversion, the result of calling sqlite3_column_type() 4815 ** is undefined, though harmless. Future 4816 ** versions of SQLite may change the behavior of sqlite3_column_type() 4817 ** following a type conversion. 4818 ** 4819 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4820 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4821 ** of that BLOB or string. 4822 ** 4823 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4824 ** routine returns the number of bytes in that BLOB or string. 4825 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4826 ** the string to UTF-8 and then returns the number of bytes. 4827 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4828 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4829 ** the number of bytes in that string. 4830 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4831 ** 4832 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4833 ** routine returns the number of bytes in that BLOB or string. 4834 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4835 ** the string to UTF-16 and then returns the number of bytes. 4836 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4837 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4838 ** the number of bytes in that string. 4839 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4840 ** 4841 ** ^The values returned by [sqlite3_column_bytes()] and 4842 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4843 ** of the string. ^For clarity: the values returned by 4844 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4845 ** bytes in the string, not the number of characters. 4846 ** 4847 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4848 ** even empty strings, are always zero-terminated. ^The return 4849 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4850 ** 4851 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4852 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4853 ** an unprotected sqlite3_value object may only be used safely with 4854 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4855 ** If the [unprotected sqlite3_value] object returned by 4856 ** [sqlite3_column_value()] is used in any other way, including calls 4857 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4858 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4859 ** Hence, the sqlite3_column_value() interface 4860 ** is normally only useful within the implementation of 4861 ** [application-defined SQL functions] or [virtual tables], not within 4862 ** top-level application code. 4863 ** 4864 ** The these routines may attempt to convert the datatype of the result. 4865 ** ^For example, if the internal representation is FLOAT and a text result 4866 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4867 ** conversion automatically. ^(The following table details the conversions 4868 ** that are applied: 4869 ** 4870 ** <blockquote> 4871 ** <table border="1"> 4872 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4873 ** 4874 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4875 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4876 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4877 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4878 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4879 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4880 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4881 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4882 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4883 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4884 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4885 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4886 ** <tr><td> TEXT <td> BLOB <td> No change 4887 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4888 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4889 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4890 ** </table> 4891 ** </blockquote>)^ 4892 ** 4893 ** Note that when type conversions occur, pointers returned by prior 4894 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4895 ** sqlite3_column_text16() may be invalidated. 4896 ** Type conversions and pointer invalidations might occur 4897 ** in the following cases: 4898 ** 4899 ** <ul> 4900 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4901 ** sqlite3_column_text16() is called. A zero-terminator might 4902 ** need to be added to the string.</li> 4903 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4904 ** sqlite3_column_text16() is called. The content must be converted 4905 ** to UTF-16.</li> 4906 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4907 ** sqlite3_column_text() is called. The content must be converted 4908 ** to UTF-8.</li> 4909 ** </ul> 4910 ** 4911 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4912 ** not invalidate a prior pointer, though of course the content of the buffer 4913 ** that the prior pointer references will have been modified. Other kinds 4914 ** of conversion are done in place when it is possible, but sometimes they 4915 ** are not possible and in those cases prior pointers are invalidated. 4916 ** 4917 ** The safest policy is to invoke these routines 4918 ** in one of the following ways: 4919 ** 4920 ** <ul> 4921 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4922 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4923 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4924 ** </ul> 4925 ** 4926 ** In other words, you should call sqlite3_column_text(), 4927 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4928 ** into the desired format, then invoke sqlite3_column_bytes() or 4929 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4930 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4931 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4932 ** with calls to sqlite3_column_bytes(). 4933 ** 4934 ** ^The pointers returned are valid until a type conversion occurs as 4935 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4936 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4937 ** and BLOBs is freed automatically. Do not pass the pointers returned 4938 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4939 ** [sqlite3_free()]. 4940 ** 4941 ** As long as the input parameters are correct, these routines will only 4942 ** fail if an out-of-memory error occurs during a format conversion. 4943 ** Only the following subset of interfaces are subject to out-of-memory 4944 ** errors: 4945 ** 4946 ** <ul> 4947 ** <li> sqlite3_column_blob() 4948 ** <li> sqlite3_column_text() 4949 ** <li> sqlite3_column_text16() 4950 ** <li> sqlite3_column_bytes() 4951 ** <li> sqlite3_column_bytes16() 4952 ** </ul> 4953 ** 4954 ** If an out-of-memory error occurs, then the return value from these 4955 ** routines is the same as if the column had contained an SQL NULL value. 4956 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4957 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4958 ** return value is obtained and before any 4959 ** other SQLite interface is called on the same [database connection]. 4960 */ 4961 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4962 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4963 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4964 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4965 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4966 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4967 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4968 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4969 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4970 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4971 4972 /* 4973 ** CAPI3REF: Destroy A Prepared Statement Object 4974 ** DESTRUCTOR: sqlite3_stmt 4975 ** 4976 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4977 ** ^If the most recent evaluation of the statement encountered no errors 4978 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4979 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4980 ** sqlite3_finalize(S) returns the appropriate [error code] or 4981 ** [extended error code]. 4982 ** 4983 ** ^The sqlite3_finalize(S) routine can be called at any point during 4984 ** the life cycle of [prepared statement] S: 4985 ** before statement S is ever evaluated, after 4986 ** one or more calls to [sqlite3_reset()], or after any call 4987 ** to [sqlite3_step()] regardless of whether or not the statement has 4988 ** completed execution. 4989 ** 4990 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4991 ** 4992 ** The application must finalize every [prepared statement] in order to avoid 4993 ** resource leaks. It is a grievous error for the application to try to use 4994 ** a prepared statement after it has been finalized. Any use of a prepared 4995 ** statement after it has been finalized can result in undefined and 4996 ** undesirable behavior such as segfaults and heap corruption. 4997 */ 4998 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4999 5000 /* 5001 ** CAPI3REF: Reset A Prepared Statement Object 5002 ** METHOD: sqlite3_stmt 5003 ** 5004 ** The sqlite3_reset() function is called to reset a [prepared statement] 5005 ** object back to its initial state, ready to be re-executed. 5006 ** ^Any SQL statement variables that had values bound to them using 5007 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5008 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5009 ** 5010 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5011 ** back to the beginning of its program. 5012 ** 5013 ** ^If the most recent call to [sqlite3_step(S)] for the 5014 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5015 ** or if [sqlite3_step(S)] has never before been called on S, 5016 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5017 ** 5018 ** ^If the most recent call to [sqlite3_step(S)] for the 5019 ** [prepared statement] S indicated an error, then 5020 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5021 ** 5022 ** ^The [sqlite3_reset(S)] interface does not change the values 5023 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5024 */ 5025 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5026 5027 /* 5028 ** CAPI3REF: Create Or Redefine SQL Functions 5029 ** KEYWORDS: {function creation routines} 5030 ** METHOD: sqlite3 5031 ** 5032 ** ^These functions (collectively known as "function creation routines") 5033 ** are used to add SQL functions or aggregates or to redefine the behavior 5034 ** of existing SQL functions or aggregates. The only differences between 5035 ** the three "sqlite3_create_function*" routines are the text encoding 5036 ** expected for the second parameter (the name of the function being 5037 ** created) and the presence or absence of a destructor callback for 5038 ** the application data pointer. Function sqlite3_create_window_function() 5039 ** is similar, but allows the user to supply the extra callback functions 5040 ** needed by [aggregate window functions]. 5041 ** 5042 ** ^The first parameter is the [database connection] to which the SQL 5043 ** function is to be added. ^If an application uses more than one database 5044 ** connection then application-defined SQL functions must be added 5045 ** to each database connection separately. 5046 ** 5047 ** ^The second parameter is the name of the SQL function to be created or 5048 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5049 ** representation, exclusive of the zero-terminator. ^Note that the name 5050 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5051 ** ^Any attempt to create a function with a longer name 5052 ** will result in [SQLITE_MISUSE] being returned. 5053 ** 5054 ** ^The third parameter (nArg) 5055 ** is the number of arguments that the SQL function or 5056 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5057 ** aggregate may take any number of arguments between 0 and the limit 5058 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5059 ** parameter is less than -1 or greater than 127 then the behavior is 5060 ** undefined. 5061 ** 5062 ** ^The fourth parameter, eTextRep, specifies what 5063 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5064 ** its parameters. The application should set this parameter to 5065 ** [SQLITE_UTF16LE] if the function implementation invokes 5066 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5067 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5068 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5069 ** otherwise. ^The same SQL function may be registered multiple times using 5070 ** different preferred text encodings, with different implementations for 5071 ** each encoding. 5072 ** ^When multiple implementations of the same function are available, SQLite 5073 ** will pick the one that involves the least amount of data conversion. 5074 ** 5075 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5076 ** to signal that the function will always return the same result given 5077 ** the same inputs within a single SQL statement. Most SQL functions are 5078 ** deterministic. The built-in [random()] SQL function is an example of a 5079 ** function that is not deterministic. The SQLite query planner is able to 5080 ** perform additional optimizations on deterministic functions, so use 5081 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5082 ** 5083 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5084 ** flag, which if present prevents the function from being invoked from 5085 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5086 ** index expressions, or the WHERE clause of partial indexes. 5087 ** 5088 ** <span style="background-color:#ffff90;"> 5089 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5090 ** all application-defined SQL functions that do not need to be 5091 ** used inside of triggers, view, CHECK constraints, or other elements of 5092 ** the database schema. This flags is especially recommended for SQL 5093 ** functions that have side effects or reveal internal application state. 5094 ** Without this flag, an attacker might be able to modify the schema of 5095 ** a database file to include invocations of the function with parameters 5096 ** chosen by the attacker, which the application will then execute when 5097 ** the database file is opened and read. 5098 ** </span> 5099 ** 5100 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5101 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5102 ** 5103 ** ^The sixth, seventh and eighth parameters passed to the three 5104 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5105 ** pointers to C-language functions that implement the SQL function or 5106 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5107 ** callback only; NULL pointers must be passed as the xStep and xFinal 5108 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5109 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5110 ** SQL function or aggregate, pass NULL pointers for all three function 5111 ** callbacks. 5112 ** 5113 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5114 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5115 ** C-language callbacks that implement the new function. xStep and xFinal 5116 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5117 ** which case a regular aggregate function is created, or must both be 5118 ** non-NULL, in which case the new function may be used as either an aggregate 5119 ** or aggregate window function. More details regarding the implementation 5120 ** of aggregate window functions are 5121 ** [user-defined window functions|available here]. 5122 ** 5123 ** ^(If the final parameter to sqlite3_create_function_v2() or 5124 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5125 ** the application data pointer. The destructor is invoked when the function 5126 ** is deleted, either by being overloaded or when the database connection 5127 ** closes.)^ ^The destructor is also invoked if the call to 5128 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5129 ** invoked, it is passed a single argument which is a copy of the application 5130 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5131 ** 5132 ** ^It is permitted to register multiple implementations of the same 5133 ** functions with the same name but with either differing numbers of 5134 ** arguments or differing preferred text encodings. ^SQLite will use 5135 ** the implementation that most closely matches the way in which the 5136 ** SQL function is used. ^A function implementation with a non-negative 5137 ** nArg parameter is a better match than a function implementation with 5138 ** a negative nArg. ^A function where the preferred text encoding 5139 ** matches the database encoding is a better 5140 ** match than a function where the encoding is different. 5141 ** ^A function where the encoding difference is between UTF16le and UTF16be 5142 ** is a closer match than a function where the encoding difference is 5143 ** between UTF8 and UTF16. 5144 ** 5145 ** ^Built-in functions may be overloaded by new application-defined functions. 5146 ** 5147 ** ^An application-defined function is permitted to call other 5148 ** SQLite interfaces. However, such calls must not 5149 ** close the database connection nor finalize or reset the prepared 5150 ** statement in which the function is running. 5151 */ 5152 SQLITE_API int sqlite3_create_function( 5153 sqlite3 *db, 5154 const char *zFunctionName, 5155 int nArg, 5156 int eTextRep, 5157 void *pApp, 5158 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5159 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5160 void (*xFinal)(sqlite3_context*) 5161 ); 5162 SQLITE_API int sqlite3_create_function16( 5163 sqlite3 *db, 5164 const void *zFunctionName, 5165 int nArg, 5166 int eTextRep, 5167 void *pApp, 5168 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5169 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5170 void (*xFinal)(sqlite3_context*) 5171 ); 5172 SQLITE_API int sqlite3_create_function_v2( 5173 sqlite3 *db, 5174 const char *zFunctionName, 5175 int nArg, 5176 int eTextRep, 5177 void *pApp, 5178 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5179 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5180 void (*xFinal)(sqlite3_context*), 5181 void(*xDestroy)(void*) 5182 ); 5183 SQLITE_API int sqlite3_create_window_function( 5184 sqlite3 *db, 5185 const char *zFunctionName, 5186 int nArg, 5187 int eTextRep, 5188 void *pApp, 5189 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5190 void (*xFinal)(sqlite3_context*), 5191 void (*xValue)(sqlite3_context*), 5192 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5193 void(*xDestroy)(void*) 5194 ); 5195 5196 /* 5197 ** CAPI3REF: Text Encodings 5198 ** 5199 ** These constant define integer codes that represent the various 5200 ** text encodings supported by SQLite. 5201 */ 5202 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5203 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5204 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5205 #define SQLITE_UTF16 4 /* Use native byte order */ 5206 #define SQLITE_ANY 5 /* Deprecated */ 5207 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5208 5209 /* 5210 ** CAPI3REF: Function Flags 5211 ** 5212 ** These constants may be ORed together with the 5213 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5214 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5215 ** [sqlite3_create_function_v2()]. 5216 ** 5217 ** <dl> 5218 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5219 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5220 ** the same output when the input parameters are the same. 5221 ** The [abs|abs() function] is deterministic, for example, but 5222 ** [randomblob|randomblob()] is not. Functions must 5223 ** be deterministic in order to be used in certain contexts such as 5224 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5225 ** SQLite might also optimize deterministic functions by factoring them 5226 ** out of inner loops. 5227 ** </dd> 5228 ** 5229 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5230 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5231 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5232 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5233 ** [expression indexes], [partial indexes], or [generated columns]. 5234 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5235 ** for all [application-defined SQL functions], and especially for functions 5236 ** that have side-effects or that could potentially leak sensitive 5237 ** information. 5238 ** </dd> 5239 ** 5240 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5241 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5242 ** to cause problems even if misused. An innocuous function should have 5243 ** no side effects and should not depend on any values other than its 5244 ** input parameters. The [abs|abs() function] is an example of an 5245 ** innocuous function. 5246 ** The [load_extension() SQL function] is not innocuous because of its 5247 ** side effects. 5248 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5249 ** exactly the same. The [random|random() function] is an example of a 5250 ** function that is innocuous but not deterministic. 5251 ** <p>Some heightened security settings 5252 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5253 ** disable the use of SQL functions inside views and triggers and in 5254 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5255 ** [expression indexes], [partial indexes], and [generated columns] unless 5256 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5257 ** are innocuous. Developers are advised to avoid using the 5258 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5259 ** function has been carefully audited and found to be free of potentially 5260 ** security-adverse side-effects and information-leaks. 5261 ** </dd> 5262 ** 5263 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5264 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5265 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5266 ** Specifying this flag makes no difference for scalar or aggregate user 5267 ** functions. However, if it is not specified for a user-defined window 5268 ** function, then any sub-types belonging to arguments passed to the window 5269 ** function may be discarded before the window function is called (i.e. 5270 ** sqlite3_value_subtype() will always return 0). 5271 ** </dd> 5272 ** </dl> 5273 */ 5274 #define SQLITE_DETERMINISTIC 0x000000800 5275 #define SQLITE_DIRECTONLY 0x000080000 5276 #define SQLITE_SUBTYPE 0x000100000 5277 #define SQLITE_INNOCUOUS 0x000200000 5278 5279 /* 5280 ** CAPI3REF: Deprecated Functions 5281 ** DEPRECATED 5282 ** 5283 ** These functions are [deprecated]. In order to maintain 5284 ** backwards compatibility with older code, these functions continue 5285 ** to be supported. However, new applications should avoid 5286 ** the use of these functions. To encourage programmers to avoid 5287 ** these functions, we will not explain what they do. 5288 */ 5289 #ifndef SQLITE_OMIT_DEPRECATED 5290 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5291 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5292 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5293 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5294 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5295 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5296 void*,sqlite3_int64); 5297 #endif 5298 5299 /* 5300 ** CAPI3REF: Obtaining SQL Values 5301 ** METHOD: sqlite3_value 5302 ** 5303 ** <b>Summary:</b> 5304 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5305 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5306 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5307 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5308 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5309 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5310 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5311 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5312 ** the native byteorder 5313 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5314 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5315 ** <tr><td> <td> <td> 5316 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5317 ** or a UTF-8 TEXT in bytes 5318 ** <tr><td><b>sqlite3_value_bytes16 </b> 5319 ** <td>→ <td>Size of UTF-16 5320 ** TEXT in bytes 5321 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5322 ** datatype of the value 5323 ** <tr><td><b>sqlite3_value_numeric_type </b> 5324 ** <td>→ <td>Best numeric datatype of the value 5325 ** <tr><td><b>sqlite3_value_nochange </b> 5326 ** <td>→ <td>True if the column is unchanged in an UPDATE 5327 ** against a virtual table. 5328 ** <tr><td><b>sqlite3_value_frombind </b> 5329 ** <td>→ <td>True if value originated from a [bound parameter] 5330 ** </table></blockquote> 5331 ** 5332 ** <b>Details:</b> 5333 ** 5334 ** These routines extract type, size, and content information from 5335 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5336 ** are used to pass parameter information into the functions that 5337 ** implement [application-defined SQL functions] and [virtual tables]. 5338 ** 5339 ** These routines work only with [protected sqlite3_value] objects. 5340 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5341 ** is not threadsafe. 5342 ** 5343 ** ^These routines work just like the corresponding [column access functions] 5344 ** except that these routines take a single [protected sqlite3_value] object 5345 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5346 ** 5347 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5348 ** in the native byte-order of the host machine. ^The 5349 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5350 ** extract UTF-16 strings as big-endian and little-endian respectively. 5351 ** 5352 ** ^If [sqlite3_value] object V was initialized 5353 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5354 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5355 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5356 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5357 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5358 ** 5359 ** ^(The sqlite3_value_type(V) interface returns the 5360 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5361 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5362 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5363 ** Other interfaces might change the datatype for an sqlite3_value object. 5364 ** For example, if the datatype is initially SQLITE_INTEGER and 5365 ** sqlite3_value_text(V) is called to extract a text value for that 5366 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5367 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5368 ** occurs is undefined and may change from one release of SQLite to the next. 5369 ** 5370 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5371 ** numeric affinity to the value. This means that an attempt is 5372 ** made to convert the value to an integer or floating point. If 5373 ** such a conversion is possible without loss of information (in other 5374 ** words, if the value is a string that looks like a number) 5375 ** then the conversion is performed. Otherwise no conversion occurs. 5376 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5377 ** 5378 ** ^Within the [xUpdate] method of a [virtual table], the 5379 ** sqlite3_value_nochange(X) interface returns true if and only if 5380 ** the column corresponding to X is unchanged by the UPDATE operation 5381 ** that the xUpdate method call was invoked to implement and if 5382 ** and the prior [xColumn] method call that was invoked to extracted 5383 ** the value for that column returned without setting a result (probably 5384 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5385 ** was unchanging). ^Within an [xUpdate] method, any value for which 5386 ** sqlite3_value_nochange(X) is true will in all other respects appear 5387 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5388 ** than within an [xUpdate] method call for an UPDATE statement, then 5389 ** the return value is arbitrary and meaningless. 5390 ** 5391 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5392 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5393 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5394 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5395 ** 5396 ** Please pay particular attention to the fact that the pointer returned 5397 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5398 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5399 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5400 ** or [sqlite3_value_text16()]. 5401 ** 5402 ** These routines must be called from the same thread as 5403 ** the SQL function that supplied the [sqlite3_value*] parameters. 5404 ** 5405 ** As long as the input parameter is correct, these routines can only 5406 ** fail if an out-of-memory error occurs during a format conversion. 5407 ** Only the following subset of interfaces are subject to out-of-memory 5408 ** errors: 5409 ** 5410 ** <ul> 5411 ** <li> sqlite3_value_blob() 5412 ** <li> sqlite3_value_text() 5413 ** <li> sqlite3_value_text16() 5414 ** <li> sqlite3_value_text16le() 5415 ** <li> sqlite3_value_text16be() 5416 ** <li> sqlite3_value_bytes() 5417 ** <li> sqlite3_value_bytes16() 5418 ** </ul> 5419 ** 5420 ** If an out-of-memory error occurs, then the return value from these 5421 ** routines is the same as if the column had contained an SQL NULL value. 5422 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5423 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5424 ** return value is obtained and before any 5425 ** other SQLite interface is called on the same [database connection]. 5426 */ 5427 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5428 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5429 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5430 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5431 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5432 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5433 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5434 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5435 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5436 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5437 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5438 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5439 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5440 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5441 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5442 5443 /* 5444 ** CAPI3REF: Finding The Subtype Of SQL Values 5445 ** METHOD: sqlite3_value 5446 ** 5447 ** The sqlite3_value_subtype(V) function returns the subtype for 5448 ** an [application-defined SQL function] argument V. The subtype 5449 ** information can be used to pass a limited amount of context from 5450 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5451 ** routine to set the subtype for the return value of an SQL function. 5452 */ 5453 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5454 5455 /* 5456 ** CAPI3REF: Copy And Free SQL Values 5457 ** METHOD: sqlite3_value 5458 ** 5459 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5460 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5461 ** is a [protected sqlite3_value] object even if the input is not. 5462 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5463 ** memory allocation fails. 5464 ** 5465 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5466 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5467 ** then sqlite3_value_free(V) is a harmless no-op. 5468 */ 5469 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5470 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5471 5472 /* 5473 ** CAPI3REF: Obtain Aggregate Function Context 5474 ** METHOD: sqlite3_context 5475 ** 5476 ** Implementations of aggregate SQL functions use this 5477 ** routine to allocate memory for storing their state. 5478 ** 5479 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5480 ** for a particular aggregate function, SQLite allocates 5481 ** N bytes of memory, zeroes out that memory, and returns a pointer 5482 ** to the new memory. ^On second and subsequent calls to 5483 ** sqlite3_aggregate_context() for the same aggregate function instance, 5484 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5485 ** called once for each invocation of the xStep callback and then one 5486 ** last time when the xFinal callback is invoked. ^(When no rows match 5487 ** an aggregate query, the xStep() callback of the aggregate function 5488 ** implementation is never called and xFinal() is called exactly once. 5489 ** In those cases, sqlite3_aggregate_context() might be called for the 5490 ** first time from within xFinal().)^ 5491 ** 5492 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5493 ** when first called if N is less than or equal to zero or if a memory 5494 ** allocate error occurs. 5495 ** 5496 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5497 ** determined by the N parameter on first successful call. Changing the 5498 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5499 ** the same aggregate function instance will not resize the memory 5500 ** allocation.)^ Within the xFinal callback, it is customary to set 5501 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5502 ** pointless memory allocations occur. 5503 ** 5504 ** ^SQLite automatically frees the memory allocated by 5505 ** sqlite3_aggregate_context() when the aggregate query concludes. 5506 ** 5507 ** The first parameter must be a copy of the 5508 ** [sqlite3_context | SQL function context] that is the first parameter 5509 ** to the xStep or xFinal callback routine that implements the aggregate 5510 ** function. 5511 ** 5512 ** This routine must be called from the same thread in which 5513 ** the aggregate SQL function is running. 5514 */ 5515 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5516 5517 /* 5518 ** CAPI3REF: User Data For Functions 5519 ** METHOD: sqlite3_context 5520 ** 5521 ** ^The sqlite3_user_data() interface returns a copy of 5522 ** the pointer that was the pUserData parameter (the 5th parameter) 5523 ** of the [sqlite3_create_function()] 5524 ** and [sqlite3_create_function16()] routines that originally 5525 ** registered the application defined function. 5526 ** 5527 ** This routine must be called from the same thread in which 5528 ** the application-defined function is running. 5529 */ 5530 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5531 5532 /* 5533 ** CAPI3REF: Database Connection For Functions 5534 ** METHOD: sqlite3_context 5535 ** 5536 ** ^The sqlite3_context_db_handle() interface returns a copy of 5537 ** the pointer to the [database connection] (the 1st parameter) 5538 ** of the [sqlite3_create_function()] 5539 ** and [sqlite3_create_function16()] routines that originally 5540 ** registered the application defined function. 5541 */ 5542 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5543 5544 /* 5545 ** CAPI3REF: Function Auxiliary Data 5546 ** METHOD: sqlite3_context 5547 ** 5548 ** These functions may be used by (non-aggregate) SQL functions to 5549 ** associate metadata with argument values. If the same value is passed to 5550 ** multiple invocations of the same SQL function during query execution, under 5551 ** some circumstances the associated metadata may be preserved. An example 5552 ** of where this might be useful is in a regular-expression matching 5553 ** function. The compiled version of the regular expression can be stored as 5554 ** metadata associated with the pattern string. 5555 ** Then as long as the pattern string remains the same, 5556 ** the compiled regular expression can be reused on multiple 5557 ** invocations of the same function. 5558 ** 5559 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5560 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5561 ** value to the application-defined function. ^N is zero for the left-most 5562 ** function argument. ^If there is no metadata 5563 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5564 ** returns a NULL pointer. 5565 ** 5566 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5567 ** argument of the application-defined function. ^Subsequent 5568 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5569 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5570 ** NULL if the metadata has been discarded. 5571 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5572 ** SQLite will invoke the destructor function X with parameter P exactly 5573 ** once, when the metadata is discarded. 5574 ** SQLite is free to discard the metadata at any time, including: <ul> 5575 ** <li> ^(when the corresponding function parameter changes)^, or 5576 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5577 ** SQL statement)^, or 5578 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5579 ** parameter)^, or 5580 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5581 ** allocation error occurs.)^ </ul> 5582 ** 5583 ** Note the last bullet in particular. The destructor X in 5584 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5585 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5586 ** should be called near the end of the function implementation and the 5587 ** function implementation should not make any use of P after 5588 ** sqlite3_set_auxdata() has been called. 5589 ** 5590 ** ^(In practice, metadata is preserved between function calls for 5591 ** function parameters that are compile-time constants, including literal 5592 ** values and [parameters] and expressions composed from the same.)^ 5593 ** 5594 ** The value of the N parameter to these interfaces should be non-negative. 5595 ** Future enhancements may make use of negative N values to define new 5596 ** kinds of function caching behavior. 5597 ** 5598 ** These routines must be called from the same thread in which 5599 ** the SQL function is running. 5600 */ 5601 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5602 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5603 5604 5605 /* 5606 ** CAPI3REF: Constants Defining Special Destructor Behavior 5607 ** 5608 ** These are special values for the destructor that is passed in as the 5609 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5610 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5611 ** and will never change. It does not need to be destroyed. ^The 5612 ** SQLITE_TRANSIENT value means that the content will likely change in 5613 ** the near future and that SQLite should make its own private copy of 5614 ** the content before returning. 5615 ** 5616 ** The typedef is necessary to work around problems in certain 5617 ** C++ compilers. 5618 */ 5619 typedef void (*sqlite3_destructor_type)(void*); 5620 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5621 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5622 5623 /* 5624 ** CAPI3REF: Setting The Result Of An SQL Function 5625 ** METHOD: sqlite3_context 5626 ** 5627 ** These routines are used by the xFunc or xFinal callbacks that 5628 ** implement SQL functions and aggregates. See 5629 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5630 ** for additional information. 5631 ** 5632 ** These functions work very much like the [parameter binding] family of 5633 ** functions used to bind values to host parameters in prepared statements. 5634 ** Refer to the [SQL parameter] documentation for additional information. 5635 ** 5636 ** ^The sqlite3_result_blob() interface sets the result from 5637 ** an application-defined function to be the BLOB whose content is pointed 5638 ** to by the second parameter and which is N bytes long where N is the 5639 ** third parameter. 5640 ** 5641 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5642 ** interfaces set the result of the application-defined function to be 5643 ** a BLOB containing all zero bytes and N bytes in size. 5644 ** 5645 ** ^The sqlite3_result_double() interface sets the result from 5646 ** an application-defined function to be a floating point value specified 5647 ** by its 2nd argument. 5648 ** 5649 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5650 ** cause the implemented SQL function to throw an exception. 5651 ** ^SQLite uses the string pointed to by the 5652 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5653 ** as the text of an error message. ^SQLite interprets the error 5654 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5655 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5656 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5657 ** ^If the third parameter to sqlite3_result_error() 5658 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5659 ** message all text up through the first zero character. 5660 ** ^If the third parameter to sqlite3_result_error() or 5661 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5662 ** bytes (not characters) from the 2nd parameter as the error message. 5663 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5664 ** routines make a private copy of the error message text before 5665 ** they return. Hence, the calling function can deallocate or 5666 ** modify the text after they return without harm. 5667 ** ^The sqlite3_result_error_code() function changes the error code 5668 ** returned by SQLite as a result of an error in a function. ^By default, 5669 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5670 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5671 ** 5672 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5673 ** error indicating that a string or BLOB is too long to represent. 5674 ** 5675 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5676 ** error indicating that a memory allocation failed. 5677 ** 5678 ** ^The sqlite3_result_int() interface sets the return value 5679 ** of the application-defined function to be the 32-bit signed integer 5680 ** value given in the 2nd argument. 5681 ** ^The sqlite3_result_int64() interface sets the return value 5682 ** of the application-defined function to be the 64-bit signed integer 5683 ** value given in the 2nd argument. 5684 ** 5685 ** ^The sqlite3_result_null() interface sets the return value 5686 ** of the application-defined function to be NULL. 5687 ** 5688 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5689 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5690 ** set the return value of the application-defined function to be 5691 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5692 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5693 ** ^The sqlite3_result_text64() interface sets the return value of an 5694 ** application-defined function to be a text string in an encoding 5695 ** specified by the fifth (and last) parameter, which must be one 5696 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5697 ** ^SQLite takes the text result from the application from 5698 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5699 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5700 ** is negative, then SQLite takes result text from the 2nd parameter 5701 ** through the first zero character. 5702 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5703 ** is non-negative, then as many bytes (not characters) of the text 5704 ** pointed to by the 2nd parameter are taken as the application-defined 5705 ** function result. If the 3rd parameter is non-negative, then it 5706 ** must be the byte offset into the string where the NUL terminator would 5707 ** appear if the string where NUL terminated. If any NUL characters occur 5708 ** in the string at a byte offset that is less than the value of the 3rd 5709 ** parameter, then the resulting string will contain embedded NULs and the 5710 ** result of expressions operating on strings with embedded NULs is undefined. 5711 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5712 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5713 ** function as the destructor on the text or BLOB result when it has 5714 ** finished using that result. 5715 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5716 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5717 ** assumes that the text or BLOB result is in constant space and does not 5718 ** copy the content of the parameter nor call a destructor on the content 5719 ** when it has finished using that result. 5720 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5721 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5722 ** then SQLite makes a copy of the result into space obtained 5723 ** from [sqlite3_malloc()] before it returns. 5724 ** 5725 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5726 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5727 ** when the encoding is not UTF8, if the input UTF16 begins with a 5728 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5729 ** string and the rest of the string is interpreted according to the 5730 ** byte-order specified by the BOM. ^The byte-order specified by 5731 ** the BOM at the beginning of the text overrides the byte-order 5732 ** specified by the interface procedure. ^So, for example, if 5733 ** sqlite3_result_text16le() is invoked with text that begins 5734 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5735 ** first two bytes of input are skipped and the remaining input 5736 ** is interpreted as UTF16BE text. 5737 ** 5738 ** ^For UTF16 input text to the sqlite3_result_text16(), 5739 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5740 ** sqlite3_result_text64() routines, if the text contains invalid 5741 ** UTF16 characters, the invalid characters might be converted 5742 ** into the unicode replacement character, U+FFFD. 5743 ** 5744 ** ^The sqlite3_result_value() interface sets the result of 5745 ** the application-defined function to be a copy of the 5746 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5747 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5748 ** so that the [sqlite3_value] specified in the parameter may change or 5749 ** be deallocated after sqlite3_result_value() returns without harm. 5750 ** ^A [protected sqlite3_value] object may always be used where an 5751 ** [unprotected sqlite3_value] object is required, so either 5752 ** kind of [sqlite3_value] object can be used with this interface. 5753 ** 5754 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5755 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5756 ** also associates the host-language pointer P or type T with that 5757 ** NULL value such that the pointer can be retrieved within an 5758 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5759 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5760 ** for the P parameter. ^SQLite invokes D with P as its only argument 5761 ** when SQLite is finished with P. The T parameter should be a static 5762 ** string and preferably a string literal. The sqlite3_result_pointer() 5763 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5764 ** 5765 ** If these routines are called from within the different thread 5766 ** than the one containing the application-defined function that received 5767 ** the [sqlite3_context] pointer, the results are undefined. 5768 */ 5769 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5770 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5771 sqlite3_uint64,void(*)(void*)); 5772 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5773 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5774 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5775 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5776 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5777 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5778 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5779 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5780 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5781 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5782 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5783 void(*)(void*), unsigned char encoding); 5784 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5785 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5786 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5787 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5788 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5789 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5790 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5791 5792 5793 /* 5794 ** CAPI3REF: Setting The Subtype Of An SQL Function 5795 ** METHOD: sqlite3_context 5796 ** 5797 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5798 ** the result from the [application-defined SQL function] with 5799 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5800 ** of the subtype T are preserved in current versions of SQLite; 5801 ** higher order bits are discarded. 5802 ** The number of subtype bytes preserved by SQLite might increase 5803 ** in future releases of SQLite. 5804 */ 5805 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5806 5807 /* 5808 ** CAPI3REF: Define New Collating Sequences 5809 ** METHOD: sqlite3 5810 ** 5811 ** ^These functions add, remove, or modify a [collation] associated 5812 ** with the [database connection] specified as the first argument. 5813 ** 5814 ** ^The name of the collation is a UTF-8 string 5815 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5816 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5817 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5818 ** considered to be the same name. 5819 ** 5820 ** ^(The third argument (eTextRep) must be one of the constants: 5821 ** <ul> 5822 ** <li> [SQLITE_UTF8], 5823 ** <li> [SQLITE_UTF16LE], 5824 ** <li> [SQLITE_UTF16BE], 5825 ** <li> [SQLITE_UTF16], or 5826 ** <li> [SQLITE_UTF16_ALIGNED]. 5827 ** </ul>)^ 5828 ** ^The eTextRep argument determines the encoding of strings passed 5829 ** to the collating function callback, xCompare. 5830 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5831 ** force strings to be UTF16 with native byte order. 5832 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5833 ** on an even byte address. 5834 ** 5835 ** ^The fourth argument, pArg, is an application data pointer that is passed 5836 ** through as the first argument to the collating function callback. 5837 ** 5838 ** ^The fifth argument, xCompare, is a pointer to the collating function. 5839 ** ^Multiple collating functions can be registered using the same name but 5840 ** with different eTextRep parameters and SQLite will use whichever 5841 ** function requires the least amount of data transformation. 5842 ** ^If the xCompare argument is NULL then the collating function is 5843 ** deleted. ^When all collating functions having the same name are deleted, 5844 ** that collation is no longer usable. 5845 ** 5846 ** ^The collating function callback is invoked with a copy of the pArg 5847 ** application data pointer and with two strings in the encoding specified 5848 ** by the eTextRep argument. The two integer parameters to the collating 5849 ** function callback are the length of the two strings, in bytes. The collating 5850 ** function must return an integer that is negative, zero, or positive 5851 ** if the first string is less than, equal to, or greater than the second, 5852 ** respectively. A collating function must always return the same answer 5853 ** given the same inputs. If two or more collating functions are registered 5854 ** to the same collation name (using different eTextRep values) then all 5855 ** must give an equivalent answer when invoked with equivalent strings. 5856 ** The collating function must obey the following properties for all 5857 ** strings A, B, and C: 5858 ** 5859 ** <ol> 5860 ** <li> If A==B then B==A. 5861 ** <li> If A==B and B==C then A==C. 5862 ** <li> If A<B THEN B>A. 5863 ** <li> If A<B and B<C then A<C. 5864 ** </ol> 5865 ** 5866 ** If a collating function fails any of the above constraints and that 5867 ** collating function is registered and used, then the behavior of SQLite 5868 ** is undefined. 5869 ** 5870 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5871 ** with the addition that the xDestroy callback is invoked on pArg when 5872 ** the collating function is deleted. 5873 ** ^Collating functions are deleted when they are overridden by later 5874 ** calls to the collation creation functions or when the 5875 ** [database connection] is closed using [sqlite3_close()]. 5876 ** 5877 ** ^The xDestroy callback is <u>not</u> called if the 5878 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5879 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5880 ** check the return code and dispose of the application data pointer 5881 ** themselves rather than expecting SQLite to deal with it for them. 5882 ** This is different from every other SQLite interface. The inconsistency 5883 ** is unfortunate but cannot be changed without breaking backwards 5884 ** compatibility. 5885 ** 5886 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5887 */ 5888 SQLITE_API int sqlite3_create_collation( 5889 sqlite3*, 5890 const char *zName, 5891 int eTextRep, 5892 void *pArg, 5893 int(*xCompare)(void*,int,const void*,int,const void*) 5894 ); 5895 SQLITE_API int sqlite3_create_collation_v2( 5896 sqlite3*, 5897 const char *zName, 5898 int eTextRep, 5899 void *pArg, 5900 int(*xCompare)(void*,int,const void*,int,const void*), 5901 void(*xDestroy)(void*) 5902 ); 5903 SQLITE_API int sqlite3_create_collation16( 5904 sqlite3*, 5905 const void *zName, 5906 int eTextRep, 5907 void *pArg, 5908 int(*xCompare)(void*,int,const void*,int,const void*) 5909 ); 5910 5911 /* 5912 ** CAPI3REF: Collation Needed Callbacks 5913 ** METHOD: sqlite3 5914 ** 5915 ** ^To avoid having to register all collation sequences before a database 5916 ** can be used, a single callback function may be registered with the 5917 ** [database connection] to be invoked whenever an undefined collation 5918 ** sequence is required. 5919 ** 5920 ** ^If the function is registered using the sqlite3_collation_needed() API, 5921 ** then it is passed the names of undefined collation sequences as strings 5922 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5923 ** the names are passed as UTF-16 in machine native byte order. 5924 ** ^A call to either function replaces the existing collation-needed callback. 5925 ** 5926 ** ^(When the callback is invoked, the first argument passed is a copy 5927 ** of the second argument to sqlite3_collation_needed() or 5928 ** sqlite3_collation_needed16(). The second argument is the database 5929 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5930 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5931 ** sequence function required. The fourth parameter is the name of the 5932 ** required collation sequence.)^ 5933 ** 5934 ** The callback function should register the desired collation using 5935 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5936 ** [sqlite3_create_collation_v2()]. 5937 */ 5938 SQLITE_API int sqlite3_collation_needed( 5939 sqlite3*, 5940 void*, 5941 void(*)(void*,sqlite3*,int eTextRep,const char*) 5942 ); 5943 SQLITE_API int sqlite3_collation_needed16( 5944 sqlite3*, 5945 void*, 5946 void(*)(void*,sqlite3*,int eTextRep,const void*) 5947 ); 5948 5949 #ifdef SQLITE_ENABLE_CEROD 5950 /* 5951 ** Specify the activation key for a CEROD database. Unless 5952 ** activated, none of the CEROD routines will work. 5953 */ 5954 SQLITE_API void sqlite3_activate_cerod( 5955 const char *zPassPhrase /* Activation phrase */ 5956 ); 5957 #endif 5958 5959 /* 5960 ** CAPI3REF: Suspend Execution For A Short Time 5961 ** 5962 ** The sqlite3_sleep() function causes the current thread to suspend execution 5963 ** for at least a number of milliseconds specified in its parameter. 5964 ** 5965 ** If the operating system does not support sleep requests with 5966 ** millisecond time resolution, then the time will be rounded up to 5967 ** the nearest second. The number of milliseconds of sleep actually 5968 ** requested from the operating system is returned. 5969 ** 5970 ** ^SQLite implements this interface by calling the xSleep() 5971 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5972 ** of the default VFS is not implemented correctly, or not implemented at 5973 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5974 ** in the previous paragraphs. 5975 */ 5976 SQLITE_API int sqlite3_sleep(int); 5977 5978 /* 5979 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5980 ** 5981 ** ^(If this global variable is made to point to a string which is 5982 ** the name of a folder (a.k.a. directory), then all temporary files 5983 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5984 ** will be placed in that directory.)^ ^If this variable 5985 ** is a NULL pointer, then SQLite performs a search for an appropriate 5986 ** temporary file directory. 5987 ** 5988 ** Applications are strongly discouraged from using this global variable. 5989 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5990 ** But for all other platforms, it is highly recommended that applications 5991 ** neither read nor write this variable. This global variable is a relic 5992 ** that exists for backwards compatibility of legacy applications and should 5993 ** be avoided in new projects. 5994 ** 5995 ** It is not safe to read or modify this variable in more than one 5996 ** thread at a time. It is not safe to read or modify this variable 5997 ** if a [database connection] is being used at the same time in a separate 5998 ** thread. 5999 ** It is intended that this variable be set once 6000 ** as part of process initialization and before any SQLite interface 6001 ** routines have been called and that this variable remain unchanged 6002 ** thereafter. 6003 ** 6004 ** ^The [temp_store_directory pragma] may modify this variable and cause 6005 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6006 ** the [temp_store_directory pragma] always assumes that any string 6007 ** that this variable points to is held in memory obtained from 6008 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6009 ** using [sqlite3_free]. 6010 ** Hence, if this variable is modified directly, either it should be 6011 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6012 ** or else the use of the [temp_store_directory pragma] should be avoided. 6013 ** Except when requested by the [temp_store_directory pragma], SQLite 6014 ** does not free the memory that sqlite3_temp_directory points to. If 6015 ** the application wants that memory to be freed, it must do 6016 ** so itself, taking care to only do so after all [database connection] 6017 ** objects have been destroyed. 6018 ** 6019 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6020 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6021 ** features that require the use of temporary files may fail. Here is an 6022 ** example of how to do this using C++ with the Windows Runtime: 6023 ** 6024 ** <blockquote><pre> 6025 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6026 ** TemporaryFolder->Path->Data(); 6027 ** char zPathBuf[MAX_PATH + 1]; 6028 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6029 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6030 ** NULL, NULL); 6031 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6032 ** </pre></blockquote> 6033 */ 6034 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6035 6036 /* 6037 ** CAPI3REF: Name Of The Folder Holding Database Files 6038 ** 6039 ** ^(If this global variable is made to point to a string which is 6040 ** the name of a folder (a.k.a. directory), then all database files 6041 ** specified with a relative pathname and created or accessed by 6042 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6043 ** to be relative to that directory.)^ ^If this variable is a NULL 6044 ** pointer, then SQLite assumes that all database files specified 6045 ** with a relative pathname are relative to the current directory 6046 ** for the process. Only the windows VFS makes use of this global 6047 ** variable; it is ignored by the unix VFS. 6048 ** 6049 ** Changing the value of this variable while a database connection is 6050 ** open can result in a corrupt database. 6051 ** 6052 ** It is not safe to read or modify this variable in more than one 6053 ** thread at a time. It is not safe to read or modify this variable 6054 ** if a [database connection] is being used at the same time in a separate 6055 ** thread. 6056 ** It is intended that this variable be set once 6057 ** as part of process initialization and before any SQLite interface 6058 ** routines have been called and that this variable remain unchanged 6059 ** thereafter. 6060 ** 6061 ** ^The [data_store_directory pragma] may modify this variable and cause 6062 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6063 ** the [data_store_directory pragma] always assumes that any string 6064 ** that this variable points to is held in memory obtained from 6065 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6066 ** using [sqlite3_free]. 6067 ** Hence, if this variable is modified directly, either it should be 6068 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6069 ** or else the use of the [data_store_directory pragma] should be avoided. 6070 */ 6071 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6072 6073 /* 6074 ** CAPI3REF: Win32 Specific Interface 6075 ** 6076 ** These interfaces are available only on Windows. The 6077 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6078 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6079 ** zValue, depending on the value of the type parameter. The zValue parameter 6080 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6081 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6082 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6083 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6084 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6085 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6086 ** the current directory on the sub-platforms of Win32 where that concept is 6087 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6088 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6089 ** sqlite3_win32_set_directory interface except the string parameter must be 6090 ** UTF-8 or UTF-16, respectively. 6091 */ 6092 SQLITE_API int sqlite3_win32_set_directory( 6093 unsigned long type, /* Identifier for directory being set or reset */ 6094 void *zValue /* New value for directory being set or reset */ 6095 ); 6096 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6097 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6098 6099 /* 6100 ** CAPI3REF: Win32 Directory Types 6101 ** 6102 ** These macros are only available on Windows. They define the allowed values 6103 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6104 */ 6105 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6106 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6107 6108 /* 6109 ** CAPI3REF: Test For Auto-Commit Mode 6110 ** KEYWORDS: {autocommit mode} 6111 ** METHOD: sqlite3 6112 ** 6113 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6114 ** zero if the given database connection is or is not in autocommit mode, 6115 ** respectively. ^Autocommit mode is on by default. 6116 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6117 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6118 ** 6119 ** If certain kinds of errors occur on a statement within a multi-statement 6120 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6121 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6122 ** transaction might be rolled back automatically. The only way to 6123 ** find out whether SQLite automatically rolled back the transaction after 6124 ** an error is to use this function. 6125 ** 6126 ** If another thread changes the autocommit status of the database 6127 ** connection while this routine is running, then the return value 6128 ** is undefined. 6129 */ 6130 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6131 6132 /* 6133 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6134 ** METHOD: sqlite3_stmt 6135 ** 6136 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6137 ** to which a [prepared statement] belongs. ^The [database connection] 6138 ** returned by sqlite3_db_handle is the same [database connection] 6139 ** that was the first argument 6140 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6141 ** create the statement in the first place. 6142 */ 6143 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6144 6145 /* 6146 ** CAPI3REF: Return The Filename For A Database Connection 6147 ** METHOD: sqlite3 6148 ** 6149 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6150 ** associated with database N of connection D. 6151 ** ^If there is no attached database N on the database 6152 ** connection D, or if database N is a temporary or in-memory database, then 6153 ** this function will return either a NULL pointer or an empty string. 6154 ** 6155 ** ^The string value returned by this routine is owned and managed by 6156 ** the database connection. ^The value will be valid until the database N 6157 ** is [DETACH]-ed or until the database connection closes. 6158 ** 6159 ** ^The filename returned by this function is the output of the 6160 ** xFullPathname method of the [VFS]. ^In other words, the filename 6161 ** will be an absolute pathname, even if the filename used 6162 ** to open the database originally was a URI or relative pathname. 6163 ** 6164 ** If the filename pointer returned by this routine is not NULL, then it 6165 ** can be used as the filename input parameter to these routines: 6166 ** <ul> 6167 ** <li> [sqlite3_uri_parameter()] 6168 ** <li> [sqlite3_uri_boolean()] 6169 ** <li> [sqlite3_uri_int64()] 6170 ** <li> [sqlite3_filename_database()] 6171 ** <li> [sqlite3_filename_journal()] 6172 ** <li> [sqlite3_filename_wal()] 6173 ** </ul> 6174 */ 6175 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6176 6177 /* 6178 ** CAPI3REF: Determine if a database is read-only 6179 ** METHOD: sqlite3 6180 ** 6181 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6182 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6183 ** the name of a database on connection D. 6184 */ 6185 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6186 6187 /* 6188 ** CAPI3REF: Find the next prepared statement 6189 ** METHOD: sqlite3 6190 ** 6191 ** ^This interface returns a pointer to the next [prepared statement] after 6192 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6193 ** then this interface returns a pointer to the first prepared statement 6194 ** associated with the database connection pDb. ^If no prepared statement 6195 ** satisfies the conditions of this routine, it returns NULL. 6196 ** 6197 ** The [database connection] pointer D in a call to 6198 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6199 ** connection and in particular must not be a NULL pointer. 6200 */ 6201 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6202 6203 /* 6204 ** CAPI3REF: Commit And Rollback Notification Callbacks 6205 ** METHOD: sqlite3 6206 ** 6207 ** ^The sqlite3_commit_hook() interface registers a callback 6208 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6209 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6210 ** for the same database connection is overridden. 6211 ** ^The sqlite3_rollback_hook() interface registers a callback 6212 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6213 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6214 ** for the same database connection is overridden. 6215 ** ^The pArg argument is passed through to the callback. 6216 ** ^If the callback on a commit hook function returns non-zero, 6217 ** then the commit is converted into a rollback. 6218 ** 6219 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6220 ** return the P argument from the previous call of the same function 6221 ** on the same [database connection] D, or NULL for 6222 ** the first call for each function on D. 6223 ** 6224 ** The commit and rollback hook callbacks are not reentrant. 6225 ** The callback implementation must not do anything that will modify 6226 ** the database connection that invoked the callback. Any actions 6227 ** to modify the database connection must be deferred until after the 6228 ** completion of the [sqlite3_step()] call that triggered the commit 6229 ** or rollback hook in the first place. 6230 ** Note that running any other SQL statements, including SELECT statements, 6231 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6232 ** the database connections for the meaning of "modify" in this paragraph. 6233 ** 6234 ** ^Registering a NULL function disables the callback. 6235 ** 6236 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6237 ** operation is allowed to continue normally. ^If the commit hook 6238 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6239 ** ^The rollback hook is invoked on a rollback that results from a commit 6240 ** hook returning non-zero, just as it would be with any other rollback. 6241 ** 6242 ** ^For the purposes of this API, a transaction is said to have been 6243 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6244 ** an error or constraint causes an implicit rollback to occur. 6245 ** ^The rollback callback is not invoked if a transaction is 6246 ** automatically rolled back because the database connection is closed. 6247 ** 6248 ** See also the [sqlite3_update_hook()] interface. 6249 */ 6250 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6251 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6252 6253 /* 6254 ** CAPI3REF: Data Change Notification Callbacks 6255 ** METHOD: sqlite3 6256 ** 6257 ** ^The sqlite3_update_hook() interface registers a callback function 6258 ** with the [database connection] identified by the first argument 6259 ** to be invoked whenever a row is updated, inserted or deleted in 6260 ** a [rowid table]. 6261 ** ^Any callback set by a previous call to this function 6262 ** for the same database connection is overridden. 6263 ** 6264 ** ^The second argument is a pointer to the function to invoke when a 6265 ** row is updated, inserted or deleted in a rowid table. 6266 ** ^The first argument to the callback is a copy of the third argument 6267 ** to sqlite3_update_hook(). 6268 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6269 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6270 ** to be invoked. 6271 ** ^The third and fourth arguments to the callback contain pointers to the 6272 ** database and table name containing the affected row. 6273 ** ^The final callback parameter is the [rowid] of the row. 6274 ** ^In the case of an update, this is the [rowid] after the update takes place. 6275 ** 6276 ** ^(The update hook is not invoked when internal system tables are 6277 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 6278 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6279 ** 6280 ** ^In the current implementation, the update hook 6281 ** is not invoked when conflicting rows are deleted because of an 6282 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6283 ** invoked when rows are deleted using the [truncate optimization]. 6284 ** The exceptions defined in this paragraph might change in a future 6285 ** release of SQLite. 6286 ** 6287 ** The update hook implementation must not do anything that will modify 6288 ** the database connection that invoked the update hook. Any actions 6289 ** to modify the database connection must be deferred until after the 6290 ** completion of the [sqlite3_step()] call that triggered the update hook. 6291 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6292 ** database connections for the meaning of "modify" in this paragraph. 6293 ** 6294 ** ^The sqlite3_update_hook(D,C,P) function 6295 ** returns the P argument from the previous call 6296 ** on the same [database connection] D, or NULL for 6297 ** the first call on D. 6298 ** 6299 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6300 ** and [sqlite3_preupdate_hook()] interfaces. 6301 */ 6302 SQLITE_API void *sqlite3_update_hook( 6303 sqlite3*, 6304 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6305 void* 6306 ); 6307 6308 /* 6309 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6310 ** 6311 ** ^(This routine enables or disables the sharing of the database cache 6312 ** and schema data structures between [database connection | connections] 6313 ** to the same database. Sharing is enabled if the argument is true 6314 ** and disabled if the argument is false.)^ 6315 ** 6316 ** ^Cache sharing is enabled and disabled for an entire process. 6317 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6318 ** In prior versions of SQLite, 6319 ** sharing was enabled or disabled for each thread separately. 6320 ** 6321 ** ^(The cache sharing mode set by this interface effects all subsequent 6322 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6323 ** Existing database connections continue to use the sharing mode 6324 ** that was in effect at the time they were opened.)^ 6325 ** 6326 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6327 ** successfully. An [error code] is returned otherwise.)^ 6328 ** 6329 ** ^Shared cache is disabled by default. It is recommended that it stay 6330 ** that way. In other words, do not use this routine. This interface 6331 ** continues to be provided for historical compatibility, but its use is 6332 ** discouraged. Any use of shared cache is discouraged. If shared cache 6333 ** must be used, it is recommended that shared cache only be enabled for 6334 ** individual database connections using the [sqlite3_open_v2()] interface 6335 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6336 ** 6337 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6338 ** and will always return SQLITE_MISUSE. On those systems, 6339 ** shared cache mode should be enabled per-database connection via 6340 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6341 ** 6342 ** This interface is threadsafe on processors where writing a 6343 ** 32-bit integer is atomic. 6344 ** 6345 ** See Also: [SQLite Shared-Cache Mode] 6346 */ 6347 SQLITE_API int sqlite3_enable_shared_cache(int); 6348 6349 /* 6350 ** CAPI3REF: Attempt To Free Heap Memory 6351 ** 6352 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6353 ** of heap memory by deallocating non-essential memory allocations 6354 ** held by the database library. Memory used to cache database 6355 ** pages to improve performance is an example of non-essential memory. 6356 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6357 ** which might be more or less than the amount requested. 6358 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6359 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6360 ** 6361 ** See also: [sqlite3_db_release_memory()] 6362 */ 6363 SQLITE_API int sqlite3_release_memory(int); 6364 6365 /* 6366 ** CAPI3REF: Free Memory Used By A Database Connection 6367 ** METHOD: sqlite3 6368 ** 6369 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6370 ** memory as possible from database connection D. Unlike the 6371 ** [sqlite3_release_memory()] interface, this interface is in effect even 6372 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6373 ** omitted. 6374 ** 6375 ** See also: [sqlite3_release_memory()] 6376 */ 6377 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6378 6379 /* 6380 ** CAPI3REF: Impose A Limit On Heap Size 6381 ** 6382 ** These interfaces impose limits on the amount of heap memory that will be 6383 ** by all database connections within a single process. 6384 ** 6385 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6386 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6387 ** ^SQLite strives to keep heap memory utilization below the soft heap 6388 ** limit by reducing the number of pages held in the page cache 6389 ** as heap memory usages approaches the limit. 6390 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6391 ** below the limit, it will exceed the limit rather than generate 6392 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6393 ** is advisory only. 6394 ** 6395 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6396 ** N bytes on the amount of memory that will be allocated. ^The 6397 ** sqlite3_hard_heap_limit64(N) interface is similar to 6398 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6399 ** when the hard heap limit is reached. 6400 ** 6401 ** ^The return value from both sqlite3_soft_heap_limit64() and 6402 ** sqlite3_hard_heap_limit64() is the size of 6403 ** the heap limit prior to the call, or negative in the case of an 6404 ** error. ^If the argument N is negative 6405 ** then no change is made to the heap limit. Hence, the current 6406 ** size of heap limits can be determined by invoking 6407 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6408 ** 6409 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6410 ** 6411 ** ^The soft heap limit may not be greater than the hard heap limit. 6412 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6413 ** is invoked with a value of N that is greater than the hard heap limit, 6414 ** the the soft heap limit is set to the value of the hard heap limit. 6415 ** ^The soft heap limit is automatically enabled whenever the hard heap 6416 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6417 ** the soft heap limit is outside the range of 1..N, then the soft heap 6418 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6419 ** hard heap limit is enabled makes the soft heap limit equal to the 6420 ** hard heap limit. 6421 ** 6422 ** The memory allocation limits can also be adjusted using 6423 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6424 ** 6425 ** ^(The heap limits are not enforced in the current implementation 6426 ** if one or more of following conditions are true: 6427 ** 6428 ** <ul> 6429 ** <li> The limit value is set to zero. 6430 ** <li> Memory accounting is disabled using a combination of the 6431 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6432 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6433 ** <li> An alternative page cache implementation is specified using 6434 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6435 ** <li> The page cache allocates from its own memory pool supplied 6436 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6437 ** from the heap. 6438 ** </ul>)^ 6439 ** 6440 ** The circumstances under which SQLite will enforce the heap limits may 6441 ** changes in future releases of SQLite. 6442 */ 6443 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6444 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6445 6446 /* 6447 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6448 ** DEPRECATED 6449 ** 6450 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6451 ** interface. This routine is provided for historical compatibility 6452 ** only. All new applications should use the 6453 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6454 */ 6455 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6456 6457 6458 /* 6459 ** CAPI3REF: Extract Metadata About A Column Of A Table 6460 ** METHOD: sqlite3 6461 ** 6462 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6463 ** information about column C of table T in database D 6464 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6465 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6466 ** the final five arguments with appropriate values if the specified 6467 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6468 ** SQLITE_ERROR if the specified column does not exist. 6469 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6470 ** NULL pointer, then this routine simply checks for the existence of the 6471 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6472 ** does not. If the table name parameter T in a call to 6473 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6474 ** undefined behavior. 6475 ** 6476 ** ^The column is identified by the second, third and fourth parameters to 6477 ** this function. ^(The second parameter is either the name of the database 6478 ** (i.e. "main", "temp", or an attached database) containing the specified 6479 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6480 ** for the table using the same algorithm used by the database engine to 6481 ** resolve unqualified table references. 6482 ** 6483 ** ^The third and fourth parameters to this function are the table and column 6484 ** name of the desired column, respectively. 6485 ** 6486 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6487 ** and subsequent parameters to this function. ^Any of these arguments may be 6488 ** NULL, in which case the corresponding element of metadata is omitted. 6489 ** 6490 ** ^(<blockquote> 6491 ** <table border="1"> 6492 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6493 ** 6494 ** <tr><td> 5th <td> const char* <td> Data type 6495 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6496 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6497 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6498 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6499 ** </table> 6500 ** </blockquote>)^ 6501 ** 6502 ** ^The memory pointed to by the character pointers returned for the 6503 ** declaration type and collation sequence is valid until the next 6504 ** call to any SQLite API function. 6505 ** 6506 ** ^If the specified table is actually a view, an [error code] is returned. 6507 ** 6508 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6509 ** is not a [WITHOUT ROWID] table and an 6510 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6511 ** parameters are set for the explicitly declared column. ^(If there is no 6512 ** [INTEGER PRIMARY KEY] column, then the outputs 6513 ** for the [rowid] are set as follows: 6514 ** 6515 ** <pre> 6516 ** data type: "INTEGER" 6517 ** collation sequence: "BINARY" 6518 ** not null: 0 6519 ** primary key: 1 6520 ** auto increment: 0 6521 ** </pre>)^ 6522 ** 6523 ** ^This function causes all database schemas to be read from disk and 6524 ** parsed, if that has not already been done, and returns an error if 6525 ** any errors are encountered while loading the schema. 6526 */ 6527 SQLITE_API int sqlite3_table_column_metadata( 6528 sqlite3 *db, /* Connection handle */ 6529 const char *zDbName, /* Database name or NULL */ 6530 const char *zTableName, /* Table name */ 6531 const char *zColumnName, /* Column name */ 6532 char const **pzDataType, /* OUTPUT: Declared data type */ 6533 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6534 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6535 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6536 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6537 ); 6538 6539 /* 6540 ** CAPI3REF: Load An Extension 6541 ** METHOD: sqlite3 6542 ** 6543 ** ^This interface loads an SQLite extension library from the named file. 6544 ** 6545 ** ^The sqlite3_load_extension() interface attempts to load an 6546 ** [SQLite extension] library contained in the file zFile. If 6547 ** the file cannot be loaded directly, attempts are made to load 6548 ** with various operating-system specific extensions added. 6549 ** So for example, if "samplelib" cannot be loaded, then names like 6550 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6551 ** be tried also. 6552 ** 6553 ** ^The entry point is zProc. 6554 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6555 ** entry point name on its own. It first tries "sqlite3_extension_init". 6556 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6557 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6558 ** characters in the filename from the last "/" to the first following 6559 ** "." and omitting any initial "lib".)^ 6560 ** ^The sqlite3_load_extension() interface returns 6561 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6562 ** ^If an error occurs and pzErrMsg is not 0, then the 6563 ** [sqlite3_load_extension()] interface shall attempt to 6564 ** fill *pzErrMsg with error message text stored in memory 6565 ** obtained from [sqlite3_malloc()]. The calling function 6566 ** should free this memory by calling [sqlite3_free()]. 6567 ** 6568 ** ^Extension loading must be enabled using 6569 ** [sqlite3_enable_load_extension()] or 6570 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6571 ** prior to calling this API, 6572 ** otherwise an error will be returned. 6573 ** 6574 ** <b>Security warning:</b> It is recommended that the 6575 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6576 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6577 ** should be avoided. This will keep the SQL function [load_extension()] 6578 ** disabled and prevent SQL injections from giving attackers 6579 ** access to extension loading capabilities. 6580 ** 6581 ** See also the [load_extension() SQL function]. 6582 */ 6583 SQLITE_API int sqlite3_load_extension( 6584 sqlite3 *db, /* Load the extension into this database connection */ 6585 const char *zFile, /* Name of the shared library containing extension */ 6586 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6587 char **pzErrMsg /* Put error message here if not 0 */ 6588 ); 6589 6590 /* 6591 ** CAPI3REF: Enable Or Disable Extension Loading 6592 ** METHOD: sqlite3 6593 ** 6594 ** ^So as not to open security holes in older applications that are 6595 ** unprepared to deal with [extension loading], and as a means of disabling 6596 ** [extension loading] while evaluating user-entered SQL, the following API 6597 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6598 ** 6599 ** ^Extension loading is off by default. 6600 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6601 ** to turn extension loading on and call it with onoff==0 to turn 6602 ** it back off again. 6603 ** 6604 ** ^This interface enables or disables both the C-API 6605 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6606 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6607 ** to enable or disable only the C-API.)^ 6608 ** 6609 ** <b>Security warning:</b> It is recommended that extension loading 6610 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6611 ** rather than this interface, so the [load_extension()] SQL function 6612 ** remains disabled. This will prevent SQL injections from giving attackers 6613 ** access to extension loading capabilities. 6614 */ 6615 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6616 6617 /* 6618 ** CAPI3REF: Automatically Load Statically Linked Extensions 6619 ** 6620 ** ^This interface causes the xEntryPoint() function to be invoked for 6621 ** each new [database connection] that is created. The idea here is that 6622 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6623 ** that is to be automatically loaded into all new database connections. 6624 ** 6625 ** ^(Even though the function prototype shows that xEntryPoint() takes 6626 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6627 ** arguments and expects an integer result as if the signature of the 6628 ** entry point where as follows: 6629 ** 6630 ** <blockquote><pre> 6631 ** int xEntryPoint( 6632 ** sqlite3 *db, 6633 ** const char **pzErrMsg, 6634 ** const struct sqlite3_api_routines *pThunk 6635 ** ); 6636 ** </pre></blockquote>)^ 6637 ** 6638 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6639 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6640 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6641 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6642 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6643 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6644 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6645 ** 6646 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6647 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6648 ** will be called more than once for each database connection that is opened. 6649 ** 6650 ** See also: [sqlite3_reset_auto_extension()] 6651 ** and [sqlite3_cancel_auto_extension()] 6652 */ 6653 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6654 6655 /* 6656 ** CAPI3REF: Cancel Automatic Extension Loading 6657 ** 6658 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6659 ** initialization routine X that was registered using a prior call to 6660 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6661 ** routine returns 1 if initialization routine X was successfully 6662 ** unregistered and it returns 0 if X was not on the list of initialization 6663 ** routines. 6664 */ 6665 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6666 6667 /* 6668 ** CAPI3REF: Reset Automatic Extension Loading 6669 ** 6670 ** ^This interface disables all automatic extensions previously 6671 ** registered using [sqlite3_auto_extension()]. 6672 */ 6673 SQLITE_API void sqlite3_reset_auto_extension(void); 6674 6675 /* 6676 ** The interface to the virtual-table mechanism is currently considered 6677 ** to be experimental. The interface might change in incompatible ways. 6678 ** If this is a problem for you, do not use the interface at this time. 6679 ** 6680 ** When the virtual-table mechanism stabilizes, we will declare the 6681 ** interface fixed, support it indefinitely, and remove this comment. 6682 */ 6683 6684 /* 6685 ** Structures used by the virtual table interface 6686 */ 6687 typedef struct sqlite3_vtab sqlite3_vtab; 6688 typedef struct sqlite3_index_info sqlite3_index_info; 6689 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6690 typedef struct sqlite3_module sqlite3_module; 6691 6692 /* 6693 ** CAPI3REF: Virtual Table Object 6694 ** KEYWORDS: sqlite3_module {virtual table module} 6695 ** 6696 ** This structure, sometimes called a "virtual table module", 6697 ** defines the implementation of a [virtual table]. 6698 ** This structure consists mostly of methods for the module. 6699 ** 6700 ** ^A virtual table module is created by filling in a persistent 6701 ** instance of this structure and passing a pointer to that instance 6702 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6703 ** ^The registration remains valid until it is replaced by a different 6704 ** module or until the [database connection] closes. The content 6705 ** of this structure must not change while it is registered with 6706 ** any database connection. 6707 */ 6708 struct sqlite3_module { 6709 int iVersion; 6710 int (*xCreate)(sqlite3*, void *pAux, 6711 int argc, const char *const*argv, 6712 sqlite3_vtab **ppVTab, char**); 6713 int (*xConnect)(sqlite3*, void *pAux, 6714 int argc, const char *const*argv, 6715 sqlite3_vtab **ppVTab, char**); 6716 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6717 int (*xDisconnect)(sqlite3_vtab *pVTab); 6718 int (*xDestroy)(sqlite3_vtab *pVTab); 6719 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6720 int (*xClose)(sqlite3_vtab_cursor*); 6721 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6722 int argc, sqlite3_value **argv); 6723 int (*xNext)(sqlite3_vtab_cursor*); 6724 int (*xEof)(sqlite3_vtab_cursor*); 6725 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6726 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6727 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6728 int (*xBegin)(sqlite3_vtab *pVTab); 6729 int (*xSync)(sqlite3_vtab *pVTab); 6730 int (*xCommit)(sqlite3_vtab *pVTab); 6731 int (*xRollback)(sqlite3_vtab *pVTab); 6732 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6733 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6734 void **ppArg); 6735 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6736 /* The methods above are in version 1 of the sqlite_module object. Those 6737 ** below are for version 2 and greater. */ 6738 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6739 int (*xRelease)(sqlite3_vtab *pVTab, int); 6740 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6741 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6742 ** Those below are for version 3 and greater. */ 6743 int (*xShadowName)(const char*); 6744 }; 6745 6746 /* 6747 ** CAPI3REF: Virtual Table Indexing Information 6748 ** KEYWORDS: sqlite3_index_info 6749 ** 6750 ** The sqlite3_index_info structure and its substructures is used as part 6751 ** of the [virtual table] interface to 6752 ** pass information into and receive the reply from the [xBestIndex] 6753 ** method of a [virtual table module]. The fields under **Inputs** are the 6754 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6755 ** results into the **Outputs** fields. 6756 ** 6757 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6758 ** 6759 ** <blockquote>column OP expr</blockquote> 6760 ** 6761 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6762 ** stored in aConstraint[].op using one of the 6763 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6764 ** ^(The index of the column is stored in 6765 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6766 ** expr on the right-hand side can be evaluated (and thus the constraint 6767 ** is usable) and false if it cannot.)^ 6768 ** 6769 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6770 ** and makes other simplifications to the WHERE clause in an attempt to 6771 ** get as many WHERE clause terms into the form shown above as possible. 6772 ** ^The aConstraint[] array only reports WHERE clause terms that are 6773 ** relevant to the particular virtual table being queried. 6774 ** 6775 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6776 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6777 ** 6778 ** The colUsed field indicates which columns of the virtual table may be 6779 ** required by the current scan. Virtual table columns are numbered from 6780 ** zero in the order in which they appear within the CREATE TABLE statement 6781 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6782 ** the corresponding bit is set within the colUsed mask if the column may be 6783 ** required by SQLite. If the table has at least 64 columns and any column 6784 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6785 ** set. In other words, column iCol may be required if the expression 6786 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6787 ** non-zero. 6788 ** 6789 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6790 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6791 ** the right-hand side of the corresponding aConstraint[] is evaluated 6792 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6793 ** is true, then the constraint is assumed to be fully handled by the 6794 ** virtual table and might not be checked again by the byte code.)^ ^(The 6795 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6796 ** is left in its default setting of false, the constraint will always be 6797 ** checked separately in byte code. If the omit flag is change to true, then 6798 ** the constraint may or may not be checked in byte code. In other words, 6799 ** when the omit flag is true there is no guarantee that the constraint will 6800 ** not be checked again using byte code.)^ 6801 ** 6802 ** ^The idxNum and idxPtr values are recorded and passed into the 6803 ** [xFilter] method. 6804 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6805 ** needToFreeIdxPtr is true. 6806 ** 6807 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6808 ** the correct order to satisfy the ORDER BY clause so that no separate 6809 ** sorting step is required. 6810 ** 6811 ** ^The estimatedCost value is an estimate of the cost of a particular 6812 ** strategy. A cost of N indicates that the cost of the strategy is similar 6813 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6814 ** indicates that the expense of the operation is similar to that of a 6815 ** binary search on a unique indexed field of an SQLite table with N rows. 6816 ** 6817 ** ^The estimatedRows value is an estimate of the number of rows that 6818 ** will be returned by the strategy. 6819 ** 6820 ** The xBestIndex method may optionally populate the idxFlags field with a 6821 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6822 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6823 ** assumes that the strategy may visit at most one row. 6824 ** 6825 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6826 ** SQLite also assumes that if a call to the xUpdate() method is made as 6827 ** part of the same statement to delete or update a virtual table row and the 6828 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6829 ** any database changes. In other words, if the xUpdate() returns 6830 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6831 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6832 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6833 ** the xUpdate method are automatically rolled back by SQLite. 6834 ** 6835 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6836 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6837 ** If a virtual table extension is 6838 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6839 ** to read or write the estimatedRows field are undefined (but are likely 6840 ** to include crashing the application). The estimatedRows field should 6841 ** therefore only be used if [sqlite3_libversion_number()] returns a 6842 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6843 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6844 ** It may therefore only be used if 6845 ** sqlite3_libversion_number() returns a value greater than or equal to 6846 ** 3009000. 6847 */ 6848 struct sqlite3_index_info { 6849 /* Inputs */ 6850 int nConstraint; /* Number of entries in aConstraint */ 6851 struct sqlite3_index_constraint { 6852 int iColumn; /* Column constrained. -1 for ROWID */ 6853 unsigned char op; /* Constraint operator */ 6854 unsigned char usable; /* True if this constraint is usable */ 6855 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6856 } *aConstraint; /* Table of WHERE clause constraints */ 6857 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6858 struct sqlite3_index_orderby { 6859 int iColumn; /* Column number */ 6860 unsigned char desc; /* True for DESC. False for ASC. */ 6861 } *aOrderBy; /* The ORDER BY clause */ 6862 /* Outputs */ 6863 struct sqlite3_index_constraint_usage { 6864 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6865 unsigned char omit; /* Do not code a test for this constraint */ 6866 } *aConstraintUsage; 6867 int idxNum; /* Number used to identify the index */ 6868 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6869 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6870 int orderByConsumed; /* True if output is already ordered */ 6871 double estimatedCost; /* Estimated cost of using this index */ 6872 /* Fields below are only available in SQLite 3.8.2 and later */ 6873 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6874 /* Fields below are only available in SQLite 3.9.0 and later */ 6875 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6876 /* Fields below are only available in SQLite 3.10.0 and later */ 6877 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6878 }; 6879 6880 /* 6881 ** CAPI3REF: Virtual Table Scan Flags 6882 ** 6883 ** Virtual table implementations are allowed to set the 6884 ** [sqlite3_index_info].idxFlags field to some combination of 6885 ** these bits. 6886 */ 6887 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6888 6889 /* 6890 ** CAPI3REF: Virtual Table Constraint Operator Codes 6891 ** 6892 ** These macros define the allowed values for the 6893 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6894 ** an operator that is part of a constraint term in the wHERE clause of 6895 ** a query that uses a [virtual table]. 6896 */ 6897 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6898 #define SQLITE_INDEX_CONSTRAINT_GT 4 6899 #define SQLITE_INDEX_CONSTRAINT_LE 8 6900 #define SQLITE_INDEX_CONSTRAINT_LT 16 6901 #define SQLITE_INDEX_CONSTRAINT_GE 32 6902 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6903 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6904 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6905 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6906 #define SQLITE_INDEX_CONSTRAINT_NE 68 6907 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6908 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6909 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6910 #define SQLITE_INDEX_CONSTRAINT_IS 72 6911 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6912 6913 /* 6914 ** CAPI3REF: Register A Virtual Table Implementation 6915 ** METHOD: sqlite3 6916 ** 6917 ** ^These routines are used to register a new [virtual table module] name. 6918 ** ^Module names must be registered before 6919 ** creating a new [virtual table] using the module and before using a 6920 ** preexisting [virtual table] for the module. 6921 ** 6922 ** ^The module name is registered on the [database connection] specified 6923 ** by the first parameter. ^The name of the module is given by the 6924 ** second parameter. ^The third parameter is a pointer to 6925 ** the implementation of the [virtual table module]. ^The fourth 6926 ** parameter is an arbitrary client data pointer that is passed through 6927 ** into the [xCreate] and [xConnect] methods of the virtual table module 6928 ** when a new virtual table is be being created or reinitialized. 6929 ** 6930 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6931 ** is a pointer to a destructor for the pClientData. ^SQLite will 6932 ** invoke the destructor function (if it is not NULL) when SQLite 6933 ** no longer needs the pClientData pointer. ^The destructor will also 6934 ** be invoked if the call to sqlite3_create_module_v2() fails. 6935 ** ^The sqlite3_create_module() 6936 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6937 ** destructor. 6938 ** 6939 ** ^If the third parameter (the pointer to the sqlite3_module object) is 6940 ** NULL then no new module is create and any existing modules with the 6941 ** same name are dropped. 6942 ** 6943 ** See also: [sqlite3_drop_modules()] 6944 */ 6945 SQLITE_API int sqlite3_create_module( 6946 sqlite3 *db, /* SQLite connection to register module with */ 6947 const char *zName, /* Name of the module */ 6948 const sqlite3_module *p, /* Methods for the module */ 6949 void *pClientData /* Client data for xCreate/xConnect */ 6950 ); 6951 SQLITE_API int sqlite3_create_module_v2( 6952 sqlite3 *db, /* SQLite connection to register module with */ 6953 const char *zName, /* Name of the module */ 6954 const sqlite3_module *p, /* Methods for the module */ 6955 void *pClientData, /* Client data for xCreate/xConnect */ 6956 void(*xDestroy)(void*) /* Module destructor function */ 6957 ); 6958 6959 /* 6960 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6961 ** METHOD: sqlite3 6962 ** 6963 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6964 ** table modules from database connection D except those named on list L. 6965 ** The L parameter must be either NULL or a pointer to an array of pointers 6966 ** to strings where the array is terminated by a single NULL pointer. 6967 ** ^If the L parameter is NULL, then all virtual table modules are removed. 6968 ** 6969 ** See also: [sqlite3_create_module()] 6970 */ 6971 SQLITE_API int sqlite3_drop_modules( 6972 sqlite3 *db, /* Remove modules from this connection */ 6973 const char **azKeep /* Except, do not remove the ones named here */ 6974 ); 6975 6976 /* 6977 ** CAPI3REF: Virtual Table Instance Object 6978 ** KEYWORDS: sqlite3_vtab 6979 ** 6980 ** Every [virtual table module] implementation uses a subclass 6981 ** of this object to describe a particular instance 6982 ** of the [virtual table]. Each subclass will 6983 ** be tailored to the specific needs of the module implementation. 6984 ** The purpose of this superclass is to define certain fields that are 6985 ** common to all module implementations. 6986 ** 6987 ** ^Virtual tables methods can set an error message by assigning a 6988 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6989 ** take care that any prior string is freed by a call to [sqlite3_free()] 6990 ** prior to assigning a new string to zErrMsg. ^After the error message 6991 ** is delivered up to the client application, the string will be automatically 6992 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6993 */ 6994 struct sqlite3_vtab { 6995 const sqlite3_module *pModule; /* The module for this virtual table */ 6996 int nRef; /* Number of open cursors */ 6997 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6998 /* Virtual table implementations will typically add additional fields */ 6999 }; 7000 7001 /* 7002 ** CAPI3REF: Virtual Table Cursor Object 7003 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7004 ** 7005 ** Every [virtual table module] implementation uses a subclass of the 7006 ** following structure to describe cursors that point into the 7007 ** [virtual table] and are used 7008 ** to loop through the virtual table. Cursors are created using the 7009 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7010 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7011 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7012 ** of the module. Each module implementation will define 7013 ** the content of a cursor structure to suit its own needs. 7014 ** 7015 ** This superclass exists in order to define fields of the cursor that 7016 ** are common to all implementations. 7017 */ 7018 struct sqlite3_vtab_cursor { 7019 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7020 /* Virtual table implementations will typically add additional fields */ 7021 }; 7022 7023 /* 7024 ** CAPI3REF: Declare The Schema Of A Virtual Table 7025 ** 7026 ** ^The [xCreate] and [xConnect] methods of a 7027 ** [virtual table module] call this interface 7028 ** to declare the format (the names and datatypes of the columns) of 7029 ** the virtual tables they implement. 7030 */ 7031 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7032 7033 /* 7034 ** CAPI3REF: Overload A Function For A Virtual Table 7035 ** METHOD: sqlite3 7036 ** 7037 ** ^(Virtual tables can provide alternative implementations of functions 7038 ** using the [xFindFunction] method of the [virtual table module]. 7039 ** But global versions of those functions 7040 ** must exist in order to be overloaded.)^ 7041 ** 7042 ** ^(This API makes sure a global version of a function with a particular 7043 ** name and number of parameters exists. If no such function exists 7044 ** before this API is called, a new function is created.)^ ^The implementation 7045 ** of the new function always causes an exception to be thrown. So 7046 ** the new function is not good for anything by itself. Its only 7047 ** purpose is to be a placeholder function that can be overloaded 7048 ** by a [virtual table]. 7049 */ 7050 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7051 7052 /* 7053 ** The interface to the virtual-table mechanism defined above (back up 7054 ** to a comment remarkably similar to this one) is currently considered 7055 ** to be experimental. The interface might change in incompatible ways. 7056 ** If this is a problem for you, do not use the interface at this time. 7057 ** 7058 ** When the virtual-table mechanism stabilizes, we will declare the 7059 ** interface fixed, support it indefinitely, and remove this comment. 7060 */ 7061 7062 /* 7063 ** CAPI3REF: A Handle To An Open BLOB 7064 ** KEYWORDS: {BLOB handle} {BLOB handles} 7065 ** 7066 ** An instance of this object represents an open BLOB on which 7067 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7068 ** ^Objects of this type are created by [sqlite3_blob_open()] 7069 ** and destroyed by [sqlite3_blob_close()]. 7070 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7071 ** can be used to read or write small subsections of the BLOB. 7072 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7073 */ 7074 typedef struct sqlite3_blob sqlite3_blob; 7075 7076 /* 7077 ** CAPI3REF: Open A BLOB For Incremental I/O 7078 ** METHOD: sqlite3 7079 ** CONSTRUCTOR: sqlite3_blob 7080 ** 7081 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7082 ** in row iRow, column zColumn, table zTable in database zDb; 7083 ** in other words, the same BLOB that would be selected by: 7084 ** 7085 ** <pre> 7086 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7087 ** </pre>)^ 7088 ** 7089 ** ^(Parameter zDb is not the filename that contains the database, but 7090 ** rather the symbolic name of the database. For attached databases, this is 7091 ** the name that appears after the AS keyword in the [ATTACH] statement. 7092 ** For the main database file, the database name is "main". For TEMP 7093 ** tables, the database name is "temp".)^ 7094 ** 7095 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7096 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7097 ** read-only access. 7098 ** 7099 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7100 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7101 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7102 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7103 ** on *ppBlob after this function it returns. 7104 ** 7105 ** This function fails with SQLITE_ERROR if any of the following are true: 7106 ** <ul> 7107 ** <li> ^(Database zDb does not exist)^, 7108 ** <li> ^(Table zTable does not exist within database zDb)^, 7109 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7110 ** <li> ^(Column zColumn does not exist)^, 7111 ** <li> ^(Row iRow is not present in the table)^, 7112 ** <li> ^(The specified column of row iRow contains a value that is not 7113 ** a TEXT or BLOB value)^, 7114 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7115 ** constraint and the blob is being opened for read/write access)^, 7116 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7117 ** column zColumn is part of a [child key] definition and the blob is 7118 ** being opened for read/write access)^. 7119 ** </ul> 7120 ** 7121 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7122 ** [database connection] error code and message accessible via 7123 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7124 ** 7125 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7126 ** [sqlite3_blob_read()] interface and modified by using 7127 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7128 ** different row of the same table using the [sqlite3_blob_reopen()] 7129 ** interface. However, the column, table, or database of a [BLOB handle] 7130 ** cannot be changed after the [BLOB handle] is opened. 7131 ** 7132 ** ^(If the row that a BLOB handle points to is modified by an 7133 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7134 ** then the BLOB handle is marked as "expired". 7135 ** This is true if any column of the row is changed, even a column 7136 ** other than the one the BLOB handle is open on.)^ 7137 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7138 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7139 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7140 ** rolled back by the expiration of the BLOB. Such changes will eventually 7141 ** commit if the transaction continues to completion.)^ 7142 ** 7143 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7144 ** the opened blob. ^The size of a blob may not be changed by this 7145 ** interface. Use the [UPDATE] SQL command to change the size of a 7146 ** blob. 7147 ** 7148 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7149 ** and the built-in [zeroblob] SQL function may be used to create a 7150 ** zero-filled blob to read or write using the incremental-blob interface. 7151 ** 7152 ** To avoid a resource leak, every open [BLOB handle] should eventually 7153 ** be released by a call to [sqlite3_blob_close()]. 7154 ** 7155 ** See also: [sqlite3_blob_close()], 7156 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7157 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7158 */ 7159 SQLITE_API int sqlite3_blob_open( 7160 sqlite3*, 7161 const char *zDb, 7162 const char *zTable, 7163 const char *zColumn, 7164 sqlite3_int64 iRow, 7165 int flags, 7166 sqlite3_blob **ppBlob 7167 ); 7168 7169 /* 7170 ** CAPI3REF: Move a BLOB Handle to a New Row 7171 ** METHOD: sqlite3_blob 7172 ** 7173 ** ^This function is used to move an existing [BLOB handle] so that it points 7174 ** to a different row of the same database table. ^The new row is identified 7175 ** by the rowid value passed as the second argument. Only the row can be 7176 ** changed. ^The database, table and column on which the blob handle is open 7177 ** remain the same. Moving an existing [BLOB handle] to a new row is 7178 ** faster than closing the existing handle and opening a new one. 7179 ** 7180 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7181 ** it must exist and there must be either a blob or text value stored in 7182 ** the nominated column.)^ ^If the new row is not present in the table, or if 7183 ** it does not contain a blob or text value, or if another error occurs, an 7184 ** SQLite error code is returned and the blob handle is considered aborted. 7185 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7186 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7187 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7188 ** always returns zero. 7189 ** 7190 ** ^This function sets the database handle error code and message. 7191 */ 7192 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7193 7194 /* 7195 ** CAPI3REF: Close A BLOB Handle 7196 ** DESTRUCTOR: sqlite3_blob 7197 ** 7198 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7199 ** unconditionally. Even if this routine returns an error code, the 7200 ** handle is still closed.)^ 7201 ** 7202 ** ^If the blob handle being closed was opened for read-write access, and if 7203 ** the database is in auto-commit mode and there are no other open read-write 7204 ** blob handles or active write statements, the current transaction is 7205 ** committed. ^If an error occurs while committing the transaction, an error 7206 ** code is returned and the transaction rolled back. 7207 ** 7208 ** Calling this function with an argument that is not a NULL pointer or an 7209 ** open blob handle results in undefined behaviour. ^Calling this routine 7210 ** with a null pointer (such as would be returned by a failed call to 7211 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7212 ** is passed a valid open blob handle, the values returned by the 7213 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7214 */ 7215 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7216 7217 /* 7218 ** CAPI3REF: Return The Size Of An Open BLOB 7219 ** METHOD: sqlite3_blob 7220 ** 7221 ** ^Returns the size in bytes of the BLOB accessible via the 7222 ** successfully opened [BLOB handle] in its only argument. ^The 7223 ** incremental blob I/O routines can only read or overwriting existing 7224 ** blob content; they cannot change the size of a blob. 7225 ** 7226 ** This routine only works on a [BLOB handle] which has been created 7227 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7228 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7229 ** to this routine results in undefined and probably undesirable behavior. 7230 */ 7231 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7232 7233 /* 7234 ** CAPI3REF: Read Data From A BLOB Incrementally 7235 ** METHOD: sqlite3_blob 7236 ** 7237 ** ^(This function is used to read data from an open [BLOB handle] into a 7238 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7239 ** from the open BLOB, starting at offset iOffset.)^ 7240 ** 7241 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7242 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7243 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7244 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7245 ** can be determined using the [sqlite3_blob_bytes()] interface. 7246 ** 7247 ** ^An attempt to read from an expired [BLOB handle] fails with an 7248 ** error code of [SQLITE_ABORT]. 7249 ** 7250 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7251 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7252 ** 7253 ** This routine only works on a [BLOB handle] which has been created 7254 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7255 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7256 ** to this routine results in undefined and probably undesirable behavior. 7257 ** 7258 ** See also: [sqlite3_blob_write()]. 7259 */ 7260 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7261 7262 /* 7263 ** CAPI3REF: Write Data Into A BLOB Incrementally 7264 ** METHOD: sqlite3_blob 7265 ** 7266 ** ^(This function is used to write data into an open [BLOB handle] from a 7267 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7268 ** into the open BLOB, starting at offset iOffset.)^ 7269 ** 7270 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7271 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7272 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7273 ** [database connection] error code and message accessible via 7274 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7275 ** 7276 ** ^If the [BLOB handle] passed as the first argument was not opened for 7277 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7278 ** this function returns [SQLITE_READONLY]. 7279 ** 7280 ** This function may only modify the contents of the BLOB; it is 7281 ** not possible to increase the size of a BLOB using this API. 7282 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7283 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7284 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7285 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7286 ** than zero [SQLITE_ERROR] is returned and no data is written. 7287 ** 7288 ** ^An attempt to write to an expired [BLOB handle] fails with an 7289 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7290 ** before the [BLOB handle] expired are not rolled back by the 7291 ** expiration of the handle, though of course those changes might 7292 ** have been overwritten by the statement that expired the BLOB handle 7293 ** or by other independent statements. 7294 ** 7295 ** This routine only works on a [BLOB handle] which has been created 7296 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7297 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7298 ** to this routine results in undefined and probably undesirable behavior. 7299 ** 7300 ** See also: [sqlite3_blob_read()]. 7301 */ 7302 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7303 7304 /* 7305 ** CAPI3REF: Virtual File System Objects 7306 ** 7307 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7308 ** that SQLite uses to interact 7309 ** with the underlying operating system. Most SQLite builds come with a 7310 ** single default VFS that is appropriate for the host computer. 7311 ** New VFSes can be registered and existing VFSes can be unregistered. 7312 ** The following interfaces are provided. 7313 ** 7314 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7315 ** ^Names are case sensitive. 7316 ** ^Names are zero-terminated UTF-8 strings. 7317 ** ^If there is no match, a NULL pointer is returned. 7318 ** ^If zVfsName is NULL then the default VFS is returned. 7319 ** 7320 ** ^New VFSes are registered with sqlite3_vfs_register(). 7321 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7322 ** ^The same VFS can be registered multiple times without injury. 7323 ** ^To make an existing VFS into the default VFS, register it again 7324 ** with the makeDflt flag set. If two different VFSes with the 7325 ** same name are registered, the behavior is undefined. If a 7326 ** VFS is registered with a name that is NULL or an empty string, 7327 ** then the behavior is undefined. 7328 ** 7329 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7330 ** ^(If the default VFS is unregistered, another VFS is chosen as 7331 ** the default. The choice for the new VFS is arbitrary.)^ 7332 */ 7333 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7334 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7335 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7336 7337 /* 7338 ** CAPI3REF: Mutexes 7339 ** 7340 ** The SQLite core uses these routines for thread 7341 ** synchronization. Though they are intended for internal 7342 ** use by SQLite, code that links against SQLite is 7343 ** permitted to use any of these routines. 7344 ** 7345 ** The SQLite source code contains multiple implementations 7346 ** of these mutex routines. An appropriate implementation 7347 ** is selected automatically at compile-time. The following 7348 ** implementations are available in the SQLite core: 7349 ** 7350 ** <ul> 7351 ** <li> SQLITE_MUTEX_PTHREADS 7352 ** <li> SQLITE_MUTEX_W32 7353 ** <li> SQLITE_MUTEX_NOOP 7354 ** </ul> 7355 ** 7356 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7357 ** that does no real locking and is appropriate for use in 7358 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7359 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7360 ** and Windows. 7361 ** 7362 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7363 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7364 ** implementation is included with the library. In this case the 7365 ** application must supply a custom mutex implementation using the 7366 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7367 ** before calling sqlite3_initialize() or any other public sqlite3_ 7368 ** function that calls sqlite3_initialize(). 7369 ** 7370 ** ^The sqlite3_mutex_alloc() routine allocates a new 7371 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7372 ** routine returns NULL if it is unable to allocate the requested 7373 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7374 ** integer constants: 7375 ** 7376 ** <ul> 7377 ** <li> SQLITE_MUTEX_FAST 7378 ** <li> SQLITE_MUTEX_RECURSIVE 7379 ** <li> SQLITE_MUTEX_STATIC_MASTER 7380 ** <li> SQLITE_MUTEX_STATIC_MEM 7381 ** <li> SQLITE_MUTEX_STATIC_OPEN 7382 ** <li> SQLITE_MUTEX_STATIC_PRNG 7383 ** <li> SQLITE_MUTEX_STATIC_LRU 7384 ** <li> SQLITE_MUTEX_STATIC_PMEM 7385 ** <li> SQLITE_MUTEX_STATIC_APP1 7386 ** <li> SQLITE_MUTEX_STATIC_APP2 7387 ** <li> SQLITE_MUTEX_STATIC_APP3 7388 ** <li> SQLITE_MUTEX_STATIC_VFS1 7389 ** <li> SQLITE_MUTEX_STATIC_VFS2 7390 ** <li> SQLITE_MUTEX_STATIC_VFS3 7391 ** </ul> 7392 ** 7393 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7394 ** cause sqlite3_mutex_alloc() to create 7395 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7396 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7397 ** The mutex implementation does not need to make a distinction 7398 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7399 ** not want to. SQLite will only request a recursive mutex in 7400 ** cases where it really needs one. If a faster non-recursive mutex 7401 ** implementation is available on the host platform, the mutex subsystem 7402 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7403 ** 7404 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7405 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7406 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7407 ** used by the current version of SQLite. Future versions of SQLite 7408 ** may add additional static mutexes. Static mutexes are for internal 7409 ** use by SQLite only. Applications that use SQLite mutexes should 7410 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7411 ** SQLITE_MUTEX_RECURSIVE. 7412 ** 7413 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7414 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7415 ** returns a different mutex on every call. ^For the static 7416 ** mutex types, the same mutex is returned on every call that has 7417 ** the same type number. 7418 ** 7419 ** ^The sqlite3_mutex_free() routine deallocates a previously 7420 ** allocated dynamic mutex. Attempting to deallocate a static 7421 ** mutex results in undefined behavior. 7422 ** 7423 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7424 ** to enter a mutex. ^If another thread is already within the mutex, 7425 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7426 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7427 ** upon successful entry. ^(Mutexes created using 7428 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7429 ** In such cases, the 7430 ** mutex must be exited an equal number of times before another thread 7431 ** can enter.)^ If the same thread tries to enter any mutex other 7432 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7433 ** 7434 ** ^(Some systems (for example, Windows 95) do not support the operation 7435 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7436 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7437 ** sqlite3_mutex_try() as an optimization so this is acceptable 7438 ** behavior.)^ 7439 ** 7440 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7441 ** previously entered by the same thread. The behavior 7442 ** is undefined if the mutex is not currently entered by the 7443 ** calling thread or is not currently allocated. 7444 ** 7445 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7446 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7447 ** behave as no-ops. 7448 ** 7449 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7450 */ 7451 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7452 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7453 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7454 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7455 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7456 7457 /* 7458 ** CAPI3REF: Mutex Methods Object 7459 ** 7460 ** An instance of this structure defines the low-level routines 7461 ** used to allocate and use mutexes. 7462 ** 7463 ** Usually, the default mutex implementations provided by SQLite are 7464 ** sufficient, however the application has the option of substituting a custom 7465 ** implementation for specialized deployments or systems for which SQLite 7466 ** does not provide a suitable implementation. In this case, the application 7467 ** creates and populates an instance of this structure to pass 7468 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7469 ** Additionally, an instance of this structure can be used as an 7470 ** output variable when querying the system for the current mutex 7471 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7472 ** 7473 ** ^The xMutexInit method defined by this structure is invoked as 7474 ** part of system initialization by the sqlite3_initialize() function. 7475 ** ^The xMutexInit routine is called by SQLite exactly once for each 7476 ** effective call to [sqlite3_initialize()]. 7477 ** 7478 ** ^The xMutexEnd method defined by this structure is invoked as 7479 ** part of system shutdown by the sqlite3_shutdown() function. The 7480 ** implementation of this method is expected to release all outstanding 7481 ** resources obtained by the mutex methods implementation, especially 7482 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7483 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7484 ** 7485 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7486 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7487 ** xMutexNotheld) implement the following interfaces (respectively): 7488 ** 7489 ** <ul> 7490 ** <li> [sqlite3_mutex_alloc()] </li> 7491 ** <li> [sqlite3_mutex_free()] </li> 7492 ** <li> [sqlite3_mutex_enter()] </li> 7493 ** <li> [sqlite3_mutex_try()] </li> 7494 ** <li> [sqlite3_mutex_leave()] </li> 7495 ** <li> [sqlite3_mutex_held()] </li> 7496 ** <li> [sqlite3_mutex_notheld()] </li> 7497 ** </ul>)^ 7498 ** 7499 ** The only difference is that the public sqlite3_XXX functions enumerated 7500 ** above silently ignore any invocations that pass a NULL pointer instead 7501 ** of a valid mutex handle. The implementations of the methods defined 7502 ** by this structure are not required to handle this case. The results 7503 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7504 ** (i.e. it is acceptable to provide an implementation that segfaults if 7505 ** it is passed a NULL pointer). 7506 ** 7507 ** The xMutexInit() method must be threadsafe. It must be harmless to 7508 ** invoke xMutexInit() multiple times within the same process and without 7509 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7510 ** xMutexInit() must be no-ops. 7511 ** 7512 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7513 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7514 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7515 ** memory allocation for a fast or recursive mutex. 7516 ** 7517 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7518 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7519 ** If xMutexInit fails in any way, it is expected to clean up after itself 7520 ** prior to returning. 7521 */ 7522 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7523 struct sqlite3_mutex_methods { 7524 int (*xMutexInit)(void); 7525 int (*xMutexEnd)(void); 7526 sqlite3_mutex *(*xMutexAlloc)(int); 7527 void (*xMutexFree)(sqlite3_mutex *); 7528 void (*xMutexEnter)(sqlite3_mutex *); 7529 int (*xMutexTry)(sqlite3_mutex *); 7530 void (*xMutexLeave)(sqlite3_mutex *); 7531 int (*xMutexHeld)(sqlite3_mutex *); 7532 int (*xMutexNotheld)(sqlite3_mutex *); 7533 }; 7534 7535 /* 7536 ** CAPI3REF: Mutex Verification Routines 7537 ** 7538 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7539 ** are intended for use inside assert() statements. The SQLite core 7540 ** never uses these routines except inside an assert() and applications 7541 ** are advised to follow the lead of the core. The SQLite core only 7542 ** provides implementations for these routines when it is compiled 7543 ** with the SQLITE_DEBUG flag. External mutex implementations 7544 ** are only required to provide these routines if SQLITE_DEBUG is 7545 ** defined and if NDEBUG is not defined. 7546 ** 7547 ** These routines should return true if the mutex in their argument 7548 ** is held or not held, respectively, by the calling thread. 7549 ** 7550 ** The implementation is not required to provide versions of these 7551 ** routines that actually work. If the implementation does not provide working 7552 ** versions of these routines, it should at least provide stubs that always 7553 ** return true so that one does not get spurious assertion failures. 7554 ** 7555 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7556 ** the routine should return 1. This seems counter-intuitive since 7557 ** clearly the mutex cannot be held if it does not exist. But 7558 ** the reason the mutex does not exist is because the build is not 7559 ** using mutexes. And we do not want the assert() containing the 7560 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7561 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7562 ** interface should also return 1 when given a NULL pointer. 7563 */ 7564 #ifndef NDEBUG 7565 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7566 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7567 #endif 7568 7569 /* 7570 ** CAPI3REF: Mutex Types 7571 ** 7572 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7573 ** which is one of these integer constants. 7574 ** 7575 ** The set of static mutexes may change from one SQLite release to the 7576 ** next. Applications that override the built-in mutex logic must be 7577 ** prepared to accommodate additional static mutexes. 7578 */ 7579 #define SQLITE_MUTEX_FAST 0 7580 #define SQLITE_MUTEX_RECURSIVE 1 7581 #define SQLITE_MUTEX_STATIC_MASTER 2 7582 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7583 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7584 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7585 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7586 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7587 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7588 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7589 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7590 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7591 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7592 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7593 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7594 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7595 7596 /* 7597 ** CAPI3REF: Retrieve the mutex for a database connection 7598 ** METHOD: sqlite3 7599 ** 7600 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7601 ** serializes access to the [database connection] given in the argument 7602 ** when the [threading mode] is Serialized. 7603 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7604 ** routine returns a NULL pointer. 7605 */ 7606 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7607 7608 /* 7609 ** CAPI3REF: Low-Level Control Of Database Files 7610 ** METHOD: sqlite3 7611 ** KEYWORDS: {file control} 7612 ** 7613 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7614 ** xFileControl method for the [sqlite3_io_methods] object associated 7615 ** with a particular database identified by the second argument. ^The 7616 ** name of the database is "main" for the main database or "temp" for the 7617 ** TEMP database, or the name that appears after the AS keyword for 7618 ** databases that are added using the [ATTACH] SQL command. 7619 ** ^A NULL pointer can be used in place of "main" to refer to the 7620 ** main database file. 7621 ** ^The third and fourth parameters to this routine 7622 ** are passed directly through to the second and third parameters of 7623 ** the xFileControl method. ^The return value of the xFileControl 7624 ** method becomes the return value of this routine. 7625 ** 7626 ** A few opcodes for [sqlite3_file_control()] are handled directly 7627 ** by the SQLite core and never invoke the 7628 ** sqlite3_io_methods.xFileControl method. 7629 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7630 ** a pointer to the underlying [sqlite3_file] object to be written into 7631 ** the space pointed to by the 4th parameter. The 7632 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7633 ** the [sqlite3_file] object associated with the journal file instead of 7634 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7635 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7636 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7637 ** from the pager. 7638 ** 7639 ** ^If the second parameter (zDbName) does not match the name of any 7640 ** open database file, then SQLITE_ERROR is returned. ^This error 7641 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7642 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7643 ** also return SQLITE_ERROR. There is no way to distinguish between 7644 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7645 ** xFileControl method. 7646 ** 7647 ** See also: [file control opcodes] 7648 */ 7649 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7650 7651 /* 7652 ** CAPI3REF: Testing Interface 7653 ** 7654 ** ^The sqlite3_test_control() interface is used to read out internal 7655 ** state of SQLite and to inject faults into SQLite for testing 7656 ** purposes. ^The first parameter is an operation code that determines 7657 ** the number, meaning, and operation of all subsequent parameters. 7658 ** 7659 ** This interface is not for use by applications. It exists solely 7660 ** for verifying the correct operation of the SQLite library. Depending 7661 ** on how the SQLite library is compiled, this interface might not exist. 7662 ** 7663 ** The details of the operation codes, their meanings, the parameters 7664 ** they take, and what they do are all subject to change without notice. 7665 ** Unlike most of the SQLite API, this function is not guaranteed to 7666 ** operate consistently from one release to the next. 7667 */ 7668 SQLITE_API int sqlite3_test_control(int op, ...); 7669 7670 /* 7671 ** CAPI3REF: Testing Interface Operation Codes 7672 ** 7673 ** These constants are the valid operation code parameters used 7674 ** as the first argument to [sqlite3_test_control()]. 7675 ** 7676 ** These parameters and their meanings are subject to change 7677 ** without notice. These values are for testing purposes only. 7678 ** Applications should not use any of these parameters or the 7679 ** [sqlite3_test_control()] interface. 7680 */ 7681 #define SQLITE_TESTCTRL_FIRST 5 7682 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7683 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7684 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7685 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7686 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7687 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7688 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7689 #define SQLITE_TESTCTRL_ASSERT 12 7690 #define SQLITE_TESTCTRL_ALWAYS 13 7691 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 7692 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7693 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7694 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7695 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7696 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7697 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7698 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7699 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7700 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7701 #define SQLITE_TESTCTRL_BYTEORDER 22 7702 #define SQLITE_TESTCTRL_ISINIT 23 7703 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7704 #define SQLITE_TESTCTRL_IMPOSTER 25 7705 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7706 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 7707 #define SQLITE_TESTCTRL_PRNG_SEED 28 7708 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7709 #define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7710 7711 /* 7712 ** CAPI3REF: SQL Keyword Checking 7713 ** 7714 ** These routines provide access to the set of SQL language keywords 7715 ** recognized by SQLite. Applications can uses these routines to determine 7716 ** whether or not a specific identifier needs to be escaped (for example, 7717 ** by enclosing in double-quotes) so as not to confuse the parser. 7718 ** 7719 ** The sqlite3_keyword_count() interface returns the number of distinct 7720 ** keywords understood by SQLite. 7721 ** 7722 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7723 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7724 ** of bytes in the keyword into *L. The string that *Z points to is not 7725 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7726 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7727 ** or L are NULL or invalid pointers then calls to 7728 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7729 ** 7730 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7731 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7732 ** if it is and zero if not. 7733 ** 7734 ** The parser used by SQLite is forgiving. It is often possible to use 7735 ** a keyword as an identifier as long as such use does not result in a 7736 ** parsing ambiguity. For example, the statement 7737 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7738 ** creates a new table named "BEGIN" with three columns named 7739 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7740 ** using keywords as identifiers. Common techniques used to avoid keyword 7741 ** name collisions include: 7742 ** <ul> 7743 ** <li> Put all identifier names inside double-quotes. This is the official 7744 ** SQL way to escape identifier names. 7745 ** <li> Put identifier names inside [...]. This is not standard SQL, 7746 ** but it is what SQL Server does and so lots of programmers use this 7747 ** technique. 7748 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7749 ** with "Z". 7750 ** <li> Include a digit somewhere in every identifier name. 7751 ** </ul> 7752 ** 7753 ** Note that the number of keywords understood by SQLite can depend on 7754 ** compile-time options. For example, "VACUUM" is not a keyword if 7755 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7756 ** new keywords may be added to future releases of SQLite. 7757 */ 7758 SQLITE_API int sqlite3_keyword_count(void); 7759 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7760 SQLITE_API int sqlite3_keyword_check(const char*,int); 7761 7762 /* 7763 ** CAPI3REF: Dynamic String Object 7764 ** KEYWORDS: {dynamic string} 7765 ** 7766 ** An instance of the sqlite3_str object contains a dynamically-sized 7767 ** string under construction. 7768 ** 7769 ** The lifecycle of an sqlite3_str object is as follows: 7770 ** <ol> 7771 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7772 ** <li> ^Text is appended to the sqlite3_str object using various 7773 ** methods, such as [sqlite3_str_appendf()]. 7774 ** <li> ^The sqlite3_str object is destroyed and the string it created 7775 ** is returned using the [sqlite3_str_finish()] interface. 7776 ** </ol> 7777 */ 7778 typedef struct sqlite3_str sqlite3_str; 7779 7780 /* 7781 ** CAPI3REF: Create A New Dynamic String Object 7782 ** CONSTRUCTOR: sqlite3_str 7783 ** 7784 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7785 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7786 ** [sqlite3_str_new()] must be freed by a subsequent call to 7787 ** [sqlite3_str_finish(X)]. 7788 ** 7789 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7790 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7791 ** error the returned object might be a special singleton that will 7792 ** silently reject new text, always return SQLITE_NOMEM from 7793 ** [sqlite3_str_errcode()], always return 0 for 7794 ** [sqlite3_str_length()], and always return NULL from 7795 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7796 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7797 ** to any of the other [sqlite3_str] methods. 7798 ** 7799 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7800 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7801 ** length of the string contained in the [sqlite3_str] object will be 7802 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7803 ** of [SQLITE_MAX_LENGTH]. 7804 */ 7805 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7806 7807 /* 7808 ** CAPI3REF: Finalize A Dynamic String 7809 ** DESTRUCTOR: sqlite3_str 7810 ** 7811 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7812 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7813 ** that contains the constructed string. The calling application should 7814 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7815 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7816 ** errors were encountered during construction of the string. ^The 7817 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7818 ** string in [sqlite3_str] object X is zero bytes long. 7819 */ 7820 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7821 7822 /* 7823 ** CAPI3REF: Add Content To A Dynamic String 7824 ** METHOD: sqlite3_str 7825 ** 7826 ** These interfaces add content to an sqlite3_str object previously obtained 7827 ** from [sqlite3_str_new()]. 7828 ** 7829 ** ^The [sqlite3_str_appendf(X,F,...)] and 7830 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7831 ** functionality of SQLite to append formatted text onto the end of 7832 ** [sqlite3_str] object X. 7833 ** 7834 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7835 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7836 ** S must contain at least N non-zero bytes of content. To append a 7837 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7838 ** method instead. 7839 ** 7840 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7841 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7842 ** 7843 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7844 ** single-byte character C onto the end of [sqlite3_str] object X. 7845 ** ^This method can be used, for example, to add whitespace indentation. 7846 ** 7847 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7848 ** inside [sqlite3_str] object X back to zero bytes in length. 7849 ** 7850 ** These methods do not return a result code. ^If an error occurs, that fact 7851 ** is recorded in the [sqlite3_str] object and can be recovered by a 7852 ** subsequent call to [sqlite3_str_errcode(X)]. 7853 */ 7854 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7855 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7856 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7857 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7858 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7859 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7860 7861 /* 7862 ** CAPI3REF: Status Of A Dynamic String 7863 ** METHOD: sqlite3_str 7864 ** 7865 ** These interfaces return the current status of an [sqlite3_str] object. 7866 ** 7867 ** ^If any prior errors have occurred while constructing the dynamic string 7868 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7869 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7870 ** [SQLITE_NOMEM] following any out-of-memory error, or 7871 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7872 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7873 ** 7874 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7875 ** of the dynamic string under construction in [sqlite3_str] object X. 7876 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7877 ** zero-termination byte. 7878 ** 7879 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7880 ** content of the dynamic string under construction in X. The value 7881 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7882 ** and might be freed or altered by any subsequent method on the same 7883 ** [sqlite3_str] object. Applications must not used the pointer returned 7884 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7885 ** object. ^Applications may change the content of the string returned 7886 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7887 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7888 ** write any byte after any subsequent sqlite3_str method call. 7889 */ 7890 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7891 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7892 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7893 7894 /* 7895 ** CAPI3REF: SQLite Runtime Status 7896 ** 7897 ** ^These interfaces are used to retrieve runtime status information 7898 ** about the performance of SQLite, and optionally to reset various 7899 ** highwater marks. ^The first argument is an integer code for 7900 ** the specific parameter to measure. ^(Recognized integer codes 7901 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7902 ** ^The current value of the parameter is returned into *pCurrent. 7903 ** ^The highest recorded value is returned in *pHighwater. ^If the 7904 ** resetFlag is true, then the highest record value is reset after 7905 ** *pHighwater is written. ^(Some parameters do not record the highest 7906 ** value. For those parameters 7907 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7908 ** ^(Other parameters record only the highwater mark and not the current 7909 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7910 ** 7911 ** ^The sqlite3_status() and sqlite3_status64() routines return 7912 ** SQLITE_OK on success and a non-zero [error code] on failure. 7913 ** 7914 ** If either the current value or the highwater mark is too large to 7915 ** be represented by a 32-bit integer, then the values returned by 7916 ** sqlite3_status() are undefined. 7917 ** 7918 ** See also: [sqlite3_db_status()] 7919 */ 7920 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7921 SQLITE_API int sqlite3_status64( 7922 int op, 7923 sqlite3_int64 *pCurrent, 7924 sqlite3_int64 *pHighwater, 7925 int resetFlag 7926 ); 7927 7928 7929 /* 7930 ** CAPI3REF: Status Parameters 7931 ** KEYWORDS: {status parameters} 7932 ** 7933 ** These integer constants designate various run-time status parameters 7934 ** that can be returned by [sqlite3_status()]. 7935 ** 7936 ** <dl> 7937 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7938 ** <dd>This parameter is the current amount of memory checked out 7939 ** using [sqlite3_malloc()], either directly or indirectly. The 7940 ** figure includes calls made to [sqlite3_malloc()] by the application 7941 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7942 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7943 ** this parameter. The amount returned is the sum of the allocation 7944 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7945 ** 7946 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7947 ** <dd>This parameter records the largest memory allocation request 7948 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7949 ** internal equivalents). Only the value returned in the 7950 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7951 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7952 ** 7953 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7954 ** <dd>This parameter records the number of separate memory allocations 7955 ** currently checked out.</dd>)^ 7956 ** 7957 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7958 ** <dd>This parameter returns the number of pages used out of the 7959 ** [pagecache memory allocator] that was configured using 7960 ** [SQLITE_CONFIG_PAGECACHE]. The 7961 ** value returned is in pages, not in bytes.</dd>)^ 7962 ** 7963 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7964 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7965 ** <dd>This parameter returns the number of bytes of page cache 7966 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7967 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7968 ** returned value includes allocations that overflowed because they 7969 ** where too large (they were larger than the "sz" parameter to 7970 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7971 ** no space was left in the page cache.</dd>)^ 7972 ** 7973 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7974 ** <dd>This parameter records the largest memory allocation request 7975 ** handed to the [pagecache memory allocator]. Only the value returned in the 7976 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7977 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7978 ** 7979 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7980 ** <dd>No longer used.</dd> 7981 ** 7982 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7983 ** <dd>No longer used.</dd> 7984 ** 7985 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7986 ** <dd>No longer used.</dd> 7987 ** 7988 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7989 ** <dd>The *pHighwater parameter records the deepest parser stack. 7990 ** The *pCurrent value is undefined. The *pHighwater value is only 7991 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7992 ** </dl> 7993 ** 7994 ** New status parameters may be added from time to time. 7995 */ 7996 #define SQLITE_STATUS_MEMORY_USED 0 7997 #define SQLITE_STATUS_PAGECACHE_USED 1 7998 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7999 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8000 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8001 #define SQLITE_STATUS_MALLOC_SIZE 5 8002 #define SQLITE_STATUS_PARSER_STACK 6 8003 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8004 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8005 #define SQLITE_STATUS_MALLOC_COUNT 9 8006 8007 /* 8008 ** CAPI3REF: Database Connection Status 8009 ** METHOD: sqlite3 8010 ** 8011 ** ^This interface is used to retrieve runtime status information 8012 ** about a single [database connection]. ^The first argument is the 8013 ** database connection object to be interrogated. ^The second argument 8014 ** is an integer constant, taken from the set of 8015 ** [SQLITE_DBSTATUS options], that 8016 ** determines the parameter to interrogate. The set of 8017 ** [SQLITE_DBSTATUS options] is likely 8018 ** to grow in future releases of SQLite. 8019 ** 8020 ** ^The current value of the requested parameter is written into *pCur 8021 ** and the highest instantaneous value is written into *pHiwtr. ^If 8022 ** the resetFlg is true, then the highest instantaneous value is 8023 ** reset back down to the current value. 8024 ** 8025 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8026 ** non-zero [error code] on failure. 8027 ** 8028 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8029 */ 8030 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8031 8032 /* 8033 ** CAPI3REF: Status Parameters for database connections 8034 ** KEYWORDS: {SQLITE_DBSTATUS options} 8035 ** 8036 ** These constants are the available integer "verbs" that can be passed as 8037 ** the second argument to the [sqlite3_db_status()] interface. 8038 ** 8039 ** New verbs may be added in future releases of SQLite. Existing verbs 8040 ** might be discontinued. Applications should check the return code from 8041 ** [sqlite3_db_status()] to make sure that the call worked. 8042 ** The [sqlite3_db_status()] interface will return a non-zero error code 8043 ** if a discontinued or unsupported verb is invoked. 8044 ** 8045 ** <dl> 8046 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8047 ** <dd>This parameter returns the number of lookaside memory slots currently 8048 ** checked out.</dd>)^ 8049 ** 8050 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8051 ** <dd>This parameter returns the number of malloc attempts that were 8052 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8053 ** the current value is always zero.)^ 8054 ** 8055 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8056 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8057 ** <dd>This parameter returns the number malloc attempts that might have 8058 ** been satisfied using lookaside memory but failed due to the amount of 8059 ** memory requested being larger than the lookaside slot size. 8060 ** Only the high-water value is meaningful; 8061 ** the current value is always zero.)^ 8062 ** 8063 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8064 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8065 ** <dd>This parameter returns the number malloc attempts that might have 8066 ** been satisfied using lookaside memory but failed due to all lookaside 8067 ** memory already being in use. 8068 ** Only the high-water value is meaningful; 8069 ** the current value is always zero.)^ 8070 ** 8071 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8072 ** <dd>This parameter returns the approximate number of bytes of heap 8073 ** memory used by all pager caches associated with the database connection.)^ 8074 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8075 ** 8076 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8077 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8078 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8079 ** pager cache is shared between two or more connections the bytes of heap 8080 ** memory used by that pager cache is divided evenly between the attached 8081 ** connections.)^ In other words, if none of the pager caches associated 8082 ** with the database connection are shared, this request returns the same 8083 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8084 ** shared, the value returned by this call will be smaller than that returned 8085 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8086 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8087 ** 8088 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8089 ** <dd>This parameter returns the approximate number of bytes of heap 8090 ** memory used to store the schema for all databases associated 8091 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8092 ** ^The full amount of memory used by the schemas is reported, even if the 8093 ** schema memory is shared with other database connections due to 8094 ** [shared cache mode] being enabled. 8095 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8096 ** 8097 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8098 ** <dd>This parameter returns the approximate number of bytes of heap 8099 ** and lookaside memory used by all prepared statements associated with 8100 ** the database connection.)^ 8101 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8102 ** </dd> 8103 ** 8104 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8105 ** <dd>This parameter returns the number of pager cache hits that have 8106 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8107 ** is always 0. 8108 ** </dd> 8109 ** 8110 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8111 ** <dd>This parameter returns the number of pager cache misses that have 8112 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8113 ** is always 0. 8114 ** </dd> 8115 ** 8116 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8117 ** <dd>This parameter returns the number of dirty cache entries that have 8118 ** been written to disk. Specifically, the number of pages written to the 8119 ** wal file in wal mode databases, or the number of pages written to the 8120 ** database file in rollback mode databases. Any pages written as part of 8121 ** transaction rollback or database recovery operations are not included. 8122 ** If an IO or other error occurs while writing a page to disk, the effect 8123 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8124 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8125 ** </dd> 8126 ** 8127 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8128 ** <dd>This parameter returns the number of dirty cache entries that have 8129 ** been written to disk in the middle of a transaction due to the page 8130 ** cache overflowing. Transactions are more efficient if they are written 8131 ** to disk all at once. When pages spill mid-transaction, that introduces 8132 ** additional overhead. This parameter can be used help identify 8133 ** inefficiencies that can be resolved by increasing the cache size. 8134 ** </dd> 8135 ** 8136 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8137 ** <dd>This parameter returns zero for the current value if and only if 8138 ** all foreign key constraints (deferred or immediate) have been 8139 ** resolved.)^ ^The highwater mark is always 0. 8140 ** </dd> 8141 ** </dl> 8142 */ 8143 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8144 #define SQLITE_DBSTATUS_CACHE_USED 1 8145 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8146 #define SQLITE_DBSTATUS_STMT_USED 3 8147 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8148 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8149 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8150 #define SQLITE_DBSTATUS_CACHE_HIT 7 8151 #define SQLITE_DBSTATUS_CACHE_MISS 8 8152 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8153 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8154 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8155 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8156 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8157 8158 8159 /* 8160 ** CAPI3REF: Prepared Statement Status 8161 ** METHOD: sqlite3_stmt 8162 ** 8163 ** ^(Each prepared statement maintains various 8164 ** [SQLITE_STMTSTATUS counters] that measure the number 8165 ** of times it has performed specific operations.)^ These counters can 8166 ** be used to monitor the performance characteristics of the prepared 8167 ** statements. For example, if the number of table steps greatly exceeds 8168 ** the number of table searches or result rows, that would tend to indicate 8169 ** that the prepared statement is using a full table scan rather than 8170 ** an index. 8171 ** 8172 ** ^(This interface is used to retrieve and reset counter values from 8173 ** a [prepared statement]. The first argument is the prepared statement 8174 ** object to be interrogated. The second argument 8175 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8176 ** to be interrogated.)^ 8177 ** ^The current value of the requested counter is returned. 8178 ** ^If the resetFlg is true, then the counter is reset to zero after this 8179 ** interface call returns. 8180 ** 8181 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8182 */ 8183 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8184 8185 /* 8186 ** CAPI3REF: Status Parameters for prepared statements 8187 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8188 ** 8189 ** These preprocessor macros define integer codes that name counter 8190 ** values associated with the [sqlite3_stmt_status()] interface. 8191 ** The meanings of the various counters are as follows: 8192 ** 8193 ** <dl> 8194 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8195 ** <dd>^This is the number of times that SQLite has stepped forward in 8196 ** a table as part of a full table scan. Large numbers for this counter 8197 ** may indicate opportunities for performance improvement through 8198 ** careful use of indices.</dd> 8199 ** 8200 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8201 ** <dd>^This is the number of sort operations that have occurred. 8202 ** A non-zero value in this counter may indicate an opportunity to 8203 ** improvement performance through careful use of indices.</dd> 8204 ** 8205 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8206 ** <dd>^This is the number of rows inserted into transient indices that 8207 ** were created automatically in order to help joins run faster. 8208 ** A non-zero value in this counter may indicate an opportunity to 8209 ** improvement performance by adding permanent indices that do not 8210 ** need to be reinitialized each time the statement is run.</dd> 8211 ** 8212 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8213 ** <dd>^This is the number of virtual machine operations executed 8214 ** by the prepared statement if that number is less than or equal 8215 ** to 2147483647. The number of virtual machine operations can be 8216 ** used as a proxy for the total work done by the prepared statement. 8217 ** If the number of virtual machine operations exceeds 2147483647 8218 ** then the value returned by this statement status code is undefined. 8219 ** 8220 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8221 ** <dd>^This is the number of times that the prepare statement has been 8222 ** automatically regenerated due to schema changes or changes to 8223 ** [bound parameters] that might affect the query plan. 8224 ** 8225 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8226 ** <dd>^This is the number of times that the prepared statement has 8227 ** been run. A single "run" for the purposes of this counter is one 8228 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8229 ** The counter is incremented on the first [sqlite3_step()] call of each 8230 ** cycle. 8231 ** 8232 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8233 ** <dd>^This is the approximate number of bytes of heap memory 8234 ** used to store the prepared statement. ^This value is not actually 8235 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8236 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8237 ** </dd> 8238 ** </dl> 8239 */ 8240 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8241 #define SQLITE_STMTSTATUS_SORT 2 8242 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8243 #define SQLITE_STMTSTATUS_VM_STEP 4 8244 #define SQLITE_STMTSTATUS_REPREPARE 5 8245 #define SQLITE_STMTSTATUS_RUN 6 8246 #define SQLITE_STMTSTATUS_MEMUSED 99 8247 8248 /* 8249 ** CAPI3REF: Custom Page Cache Object 8250 ** 8251 ** The sqlite3_pcache type is opaque. It is implemented by 8252 ** the pluggable module. The SQLite core has no knowledge of 8253 ** its size or internal structure and never deals with the 8254 ** sqlite3_pcache object except by holding and passing pointers 8255 ** to the object. 8256 ** 8257 ** See [sqlite3_pcache_methods2] for additional information. 8258 */ 8259 typedef struct sqlite3_pcache sqlite3_pcache; 8260 8261 /* 8262 ** CAPI3REF: Custom Page Cache Object 8263 ** 8264 ** The sqlite3_pcache_page object represents a single page in the 8265 ** page cache. The page cache will allocate instances of this 8266 ** object. Various methods of the page cache use pointers to instances 8267 ** of this object as parameters or as their return value. 8268 ** 8269 ** See [sqlite3_pcache_methods2] for additional information. 8270 */ 8271 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8272 struct sqlite3_pcache_page { 8273 void *pBuf; /* The content of the page */ 8274 void *pExtra; /* Extra information associated with the page */ 8275 }; 8276 8277 /* 8278 ** CAPI3REF: Application Defined Page Cache. 8279 ** KEYWORDS: {page cache} 8280 ** 8281 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8282 ** register an alternative page cache implementation by passing in an 8283 ** instance of the sqlite3_pcache_methods2 structure.)^ 8284 ** In many applications, most of the heap memory allocated by 8285 ** SQLite is used for the page cache. 8286 ** By implementing a 8287 ** custom page cache using this API, an application can better control 8288 ** the amount of memory consumed by SQLite, the way in which 8289 ** that memory is allocated and released, and the policies used to 8290 ** determine exactly which parts of a database file are cached and for 8291 ** how long. 8292 ** 8293 ** The alternative page cache mechanism is an 8294 ** extreme measure that is only needed by the most demanding applications. 8295 ** The built-in page cache is recommended for most uses. 8296 ** 8297 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8298 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8299 ** the application may discard the parameter after the call to 8300 ** [sqlite3_config()] returns.)^ 8301 ** 8302 ** [[the xInit() page cache method]] 8303 ** ^(The xInit() method is called once for each effective 8304 ** call to [sqlite3_initialize()])^ 8305 ** (usually only once during the lifetime of the process). ^(The xInit() 8306 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8307 ** The intent of the xInit() method is to set up global data structures 8308 ** required by the custom page cache implementation. 8309 ** ^(If the xInit() method is NULL, then the 8310 ** built-in default page cache is used instead of the application defined 8311 ** page cache.)^ 8312 ** 8313 ** [[the xShutdown() page cache method]] 8314 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8315 ** It can be used to clean up 8316 ** any outstanding resources before process shutdown, if required. 8317 ** ^The xShutdown() method may be NULL. 8318 ** 8319 ** ^SQLite automatically serializes calls to the xInit method, 8320 ** so the xInit method need not be threadsafe. ^The 8321 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8322 ** not need to be threadsafe either. All other methods must be threadsafe 8323 ** in multithreaded applications. 8324 ** 8325 ** ^SQLite will never invoke xInit() more than once without an intervening 8326 ** call to xShutdown(). 8327 ** 8328 ** [[the xCreate() page cache methods]] 8329 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8330 ** SQLite will typically create one cache instance for each open database file, 8331 ** though this is not guaranteed. ^The 8332 ** first parameter, szPage, is the size in bytes of the pages that must 8333 ** be allocated by the cache. ^szPage will always a power of two. ^The 8334 ** second parameter szExtra is a number of bytes of extra storage 8335 ** associated with each page cache entry. ^The szExtra parameter will 8336 ** a number less than 250. SQLite will use the 8337 ** extra szExtra bytes on each page to store metadata about the underlying 8338 ** database page on disk. The value passed into szExtra depends 8339 ** on the SQLite version, the target platform, and how SQLite was compiled. 8340 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8341 ** created will be used to cache database pages of a file stored on disk, or 8342 ** false if it is used for an in-memory database. The cache implementation 8343 ** does not have to do anything special based with the value of bPurgeable; 8344 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8345 ** never invoke xUnpin() except to deliberately delete a page. 8346 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8347 ** false will always have the "discard" flag set to true. 8348 ** ^Hence, a cache created with bPurgeable false will 8349 ** never contain any unpinned pages. 8350 ** 8351 ** [[the xCachesize() page cache method]] 8352 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8353 ** suggested maximum cache-size (number of pages stored by) the cache 8354 ** instance passed as the first argument. This is the value configured using 8355 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8356 ** parameter, the implementation is not required to do anything with this 8357 ** value; it is advisory only. 8358 ** 8359 ** [[the xPagecount() page cache methods]] 8360 ** The xPagecount() method must return the number of pages currently 8361 ** stored in the cache, both pinned and unpinned. 8362 ** 8363 ** [[the xFetch() page cache methods]] 8364 ** The xFetch() method locates a page in the cache and returns a pointer to 8365 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8366 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8367 ** pointer to a buffer of szPage bytes used to store the content of a 8368 ** single database page. The pExtra element of sqlite3_pcache_page will be 8369 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8370 ** for each entry in the page cache. 8371 ** 8372 ** The page to be fetched is determined by the key. ^The minimum key value 8373 ** is 1. After it has been retrieved using xFetch, the page is considered 8374 ** to be "pinned". 8375 ** 8376 ** If the requested page is already in the page cache, then the page cache 8377 ** implementation must return a pointer to the page buffer with its content 8378 ** intact. If the requested page is not already in the cache, then the 8379 ** cache implementation should use the value of the createFlag 8380 ** parameter to help it determined what action to take: 8381 ** 8382 ** <table border=1 width=85% align=center> 8383 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8384 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8385 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8386 ** Otherwise return NULL. 8387 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8388 ** NULL if allocating a new page is effectively impossible. 8389 ** </table> 8390 ** 8391 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8392 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8393 ** failed.)^ In between the xFetch() calls, SQLite may 8394 ** attempt to unpin one or more cache pages by spilling the content of 8395 ** pinned pages to disk and synching the operating system disk cache. 8396 ** 8397 ** [[the xUnpin() page cache method]] 8398 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8399 ** as its second argument. If the third parameter, discard, is non-zero, 8400 ** then the page must be evicted from the cache. 8401 ** ^If the discard parameter is 8402 ** zero, then the page may be discarded or retained at the discretion of 8403 ** page cache implementation. ^The page cache implementation 8404 ** may choose to evict unpinned pages at any time. 8405 ** 8406 ** The cache must not perform any reference counting. A single 8407 ** call to xUnpin() unpins the page regardless of the number of prior calls 8408 ** to xFetch(). 8409 ** 8410 ** [[the xRekey() page cache methods]] 8411 ** The xRekey() method is used to change the key value associated with the 8412 ** page passed as the second argument. If the cache 8413 ** previously contains an entry associated with newKey, it must be 8414 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8415 ** to be pinned. 8416 ** 8417 ** When SQLite calls the xTruncate() method, the cache must discard all 8418 ** existing cache entries with page numbers (keys) greater than or equal 8419 ** to the value of the iLimit parameter passed to xTruncate(). If any 8420 ** of these pages are pinned, they are implicitly unpinned, meaning that 8421 ** they can be safely discarded. 8422 ** 8423 ** [[the xDestroy() page cache method]] 8424 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8425 ** All resources associated with the specified cache should be freed. ^After 8426 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8427 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8428 ** functions. 8429 ** 8430 ** [[the xShrink() page cache method]] 8431 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8432 ** free up as much of heap memory as possible. The page cache implementation 8433 ** is not obligated to free any memory, but well-behaved implementations should 8434 ** do their best. 8435 */ 8436 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8437 struct sqlite3_pcache_methods2 { 8438 int iVersion; 8439 void *pArg; 8440 int (*xInit)(void*); 8441 void (*xShutdown)(void*); 8442 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8443 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8444 int (*xPagecount)(sqlite3_pcache*); 8445 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8446 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8447 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8448 unsigned oldKey, unsigned newKey); 8449 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8450 void (*xDestroy)(sqlite3_pcache*); 8451 void (*xShrink)(sqlite3_pcache*); 8452 }; 8453 8454 /* 8455 ** This is the obsolete pcache_methods object that has now been replaced 8456 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8457 ** retained in the header file for backwards compatibility only. 8458 */ 8459 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8460 struct sqlite3_pcache_methods { 8461 void *pArg; 8462 int (*xInit)(void*); 8463 void (*xShutdown)(void*); 8464 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8465 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8466 int (*xPagecount)(sqlite3_pcache*); 8467 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8468 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8469 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8470 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8471 void (*xDestroy)(sqlite3_pcache*); 8472 }; 8473 8474 8475 /* 8476 ** CAPI3REF: Online Backup Object 8477 ** 8478 ** The sqlite3_backup object records state information about an ongoing 8479 ** online backup operation. ^The sqlite3_backup object is created by 8480 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8481 ** [sqlite3_backup_finish()]. 8482 ** 8483 ** See Also: [Using the SQLite Online Backup API] 8484 */ 8485 typedef struct sqlite3_backup sqlite3_backup; 8486 8487 /* 8488 ** CAPI3REF: Online Backup API. 8489 ** 8490 ** The backup API copies the content of one database into another. 8491 ** It is useful either for creating backups of databases or 8492 ** for copying in-memory databases to or from persistent files. 8493 ** 8494 ** See Also: [Using the SQLite Online Backup API] 8495 ** 8496 ** ^SQLite holds a write transaction open on the destination database file 8497 ** for the duration of the backup operation. 8498 ** ^The source database is read-locked only while it is being read; 8499 ** it is not locked continuously for the entire backup operation. 8500 ** ^Thus, the backup may be performed on a live source database without 8501 ** preventing other database connections from 8502 ** reading or writing to the source database while the backup is underway. 8503 ** 8504 ** ^(To perform a backup operation: 8505 ** <ol> 8506 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8507 ** backup, 8508 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8509 ** the data between the two databases, and finally 8510 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8511 ** associated with the backup operation. 8512 ** </ol>)^ 8513 ** There should be exactly one call to sqlite3_backup_finish() for each 8514 ** successful call to sqlite3_backup_init(). 8515 ** 8516 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8517 ** 8518 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8519 ** [database connection] associated with the destination database 8520 ** and the database name, respectively. 8521 ** ^The database name is "main" for the main database, "temp" for the 8522 ** temporary database, or the name specified after the AS keyword in 8523 ** an [ATTACH] statement for an attached database. 8524 ** ^The S and M arguments passed to 8525 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8526 ** and database name of the source database, respectively. 8527 ** ^The source and destination [database connections] (parameters S and D) 8528 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8529 ** an error. 8530 ** 8531 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8532 ** there is already a read or read-write transaction open on the 8533 ** destination database. 8534 ** 8535 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8536 ** returned and an error code and error message are stored in the 8537 ** destination [database connection] D. 8538 ** ^The error code and message for the failed call to sqlite3_backup_init() 8539 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8540 ** [sqlite3_errmsg16()] functions. 8541 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8542 ** [sqlite3_backup] object. 8543 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8544 ** sqlite3_backup_finish() functions to perform the specified backup 8545 ** operation. 8546 ** 8547 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8548 ** 8549 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8550 ** the source and destination databases specified by [sqlite3_backup] object B. 8551 ** ^If N is negative, all remaining source pages are copied. 8552 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8553 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8554 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8555 ** from source to destination, then it returns [SQLITE_DONE]. 8556 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8557 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8558 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8559 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8560 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8561 ** 8562 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8563 ** <ol> 8564 ** <li> the destination database was opened read-only, or 8565 ** <li> the destination database is using write-ahead-log journaling 8566 ** and the destination and source page sizes differ, or 8567 ** <li> the destination database is an in-memory database and the 8568 ** destination and source page sizes differ. 8569 ** </ol>)^ 8570 ** 8571 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8572 ** the [sqlite3_busy_handler | busy-handler function] 8573 ** is invoked (if one is specified). ^If the 8574 ** busy-handler returns non-zero before the lock is available, then 8575 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8576 ** sqlite3_backup_step() can be retried later. ^If the source 8577 ** [database connection] 8578 ** is being used to write to the source database when sqlite3_backup_step() 8579 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8580 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8581 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8582 ** [SQLITE_READONLY] is returned, then 8583 ** there is no point in retrying the call to sqlite3_backup_step(). These 8584 ** errors are considered fatal.)^ The application must accept 8585 ** that the backup operation has failed and pass the backup operation handle 8586 ** to the sqlite3_backup_finish() to release associated resources. 8587 ** 8588 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8589 ** on the destination file. ^The exclusive lock is not released until either 8590 ** sqlite3_backup_finish() is called or the backup operation is complete 8591 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8592 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8593 ** lasts for the duration of the sqlite3_backup_step() call. 8594 ** ^Because the source database is not locked between calls to 8595 ** sqlite3_backup_step(), the source database may be modified mid-way 8596 ** through the backup process. ^If the source database is modified by an 8597 ** external process or via a database connection other than the one being 8598 ** used by the backup operation, then the backup will be automatically 8599 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8600 ** database is modified by the using the same database connection as is used 8601 ** by the backup operation, then the backup database is automatically 8602 ** updated at the same time. 8603 ** 8604 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8605 ** 8606 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8607 ** application wishes to abandon the backup operation, the application 8608 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8609 ** ^The sqlite3_backup_finish() interfaces releases all 8610 ** resources associated with the [sqlite3_backup] object. 8611 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8612 ** active write-transaction on the destination database is rolled back. 8613 ** The [sqlite3_backup] object is invalid 8614 ** and may not be used following a call to sqlite3_backup_finish(). 8615 ** 8616 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8617 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8618 ** sqlite3_backup_step() completed. 8619 ** ^If an out-of-memory condition or IO error occurred during any prior 8620 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8621 ** sqlite3_backup_finish() returns the corresponding [error code]. 8622 ** 8623 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8624 ** is not a permanent error and does not affect the return value of 8625 ** sqlite3_backup_finish(). 8626 ** 8627 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8628 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8629 ** 8630 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8631 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8632 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8633 ** in the source database at the conclusion of the most recent 8634 ** sqlite3_backup_step(). 8635 ** ^(The values returned by these functions are only updated by 8636 ** sqlite3_backup_step(). If the source database is modified in a way that 8637 ** changes the size of the source database or the number of pages remaining, 8638 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8639 ** and sqlite3_backup_remaining() until after the next 8640 ** sqlite3_backup_step().)^ 8641 ** 8642 ** <b>Concurrent Usage of Database Handles</b> 8643 ** 8644 ** ^The source [database connection] may be used by the application for other 8645 ** purposes while a backup operation is underway or being initialized. 8646 ** ^If SQLite is compiled and configured to support threadsafe database 8647 ** connections, then the source database connection may be used concurrently 8648 ** from within other threads. 8649 ** 8650 ** However, the application must guarantee that the destination 8651 ** [database connection] is not passed to any other API (by any thread) after 8652 ** sqlite3_backup_init() is called and before the corresponding call to 8653 ** sqlite3_backup_finish(). SQLite does not currently check to see 8654 ** if the application incorrectly accesses the destination [database connection] 8655 ** and so no error code is reported, but the operations may malfunction 8656 ** nevertheless. Use of the destination database connection while a 8657 ** backup is in progress might also also cause a mutex deadlock. 8658 ** 8659 ** If running in [shared cache mode], the application must 8660 ** guarantee that the shared cache used by the destination database 8661 ** is not accessed while the backup is running. In practice this means 8662 ** that the application must guarantee that the disk file being 8663 ** backed up to is not accessed by any connection within the process, 8664 ** not just the specific connection that was passed to sqlite3_backup_init(). 8665 ** 8666 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8667 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8668 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8669 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8670 ** same time as another thread is invoking sqlite3_backup_step() it is 8671 ** possible that they return invalid values. 8672 */ 8673 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8674 sqlite3 *pDest, /* Destination database handle */ 8675 const char *zDestName, /* Destination database name */ 8676 sqlite3 *pSource, /* Source database handle */ 8677 const char *zSourceName /* Source database name */ 8678 ); 8679 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8680 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8681 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8682 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8683 8684 /* 8685 ** CAPI3REF: Unlock Notification 8686 ** METHOD: sqlite3 8687 ** 8688 ** ^When running in shared-cache mode, a database operation may fail with 8689 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8690 ** individual tables within the shared-cache cannot be obtained. See 8691 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8692 ** ^This API may be used to register a callback that SQLite will invoke 8693 ** when the connection currently holding the required lock relinquishes it. 8694 ** ^This API is only available if the library was compiled with the 8695 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8696 ** 8697 ** See Also: [Using the SQLite Unlock Notification Feature]. 8698 ** 8699 ** ^Shared-cache locks are released when a database connection concludes 8700 ** its current transaction, either by committing it or rolling it back. 8701 ** 8702 ** ^When a connection (known as the blocked connection) fails to obtain a 8703 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8704 ** identity of the database connection (the blocking connection) that 8705 ** has locked the required resource is stored internally. ^After an 8706 ** application receives an SQLITE_LOCKED error, it may call the 8707 ** sqlite3_unlock_notify() method with the blocked connection handle as 8708 ** the first argument to register for a callback that will be invoked 8709 ** when the blocking connections current transaction is concluded. ^The 8710 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8711 ** call that concludes the blocking connection's transaction. 8712 ** 8713 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8714 ** there is a chance that the blocking connection will have already 8715 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8716 ** If this happens, then the specified callback is invoked immediately, 8717 ** from within the call to sqlite3_unlock_notify().)^ 8718 ** 8719 ** ^If the blocked connection is attempting to obtain a write-lock on a 8720 ** shared-cache table, and more than one other connection currently holds 8721 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8722 ** the other connections to use as the blocking connection. 8723 ** 8724 ** ^(There may be at most one unlock-notify callback registered by a 8725 ** blocked connection. If sqlite3_unlock_notify() is called when the 8726 ** blocked connection already has a registered unlock-notify callback, 8727 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8728 ** called with a NULL pointer as its second argument, then any existing 8729 ** unlock-notify callback is canceled. ^The blocked connections 8730 ** unlock-notify callback may also be canceled by closing the blocked 8731 ** connection using [sqlite3_close()]. 8732 ** 8733 ** The unlock-notify callback is not reentrant. If an application invokes 8734 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8735 ** crash or deadlock may be the result. 8736 ** 8737 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8738 ** returns SQLITE_OK. 8739 ** 8740 ** <b>Callback Invocation Details</b> 8741 ** 8742 ** When an unlock-notify callback is registered, the application provides a 8743 ** single void* pointer that is passed to the callback when it is invoked. 8744 ** However, the signature of the callback function allows SQLite to pass 8745 ** it an array of void* context pointers. The first argument passed to 8746 ** an unlock-notify callback is a pointer to an array of void* pointers, 8747 ** and the second is the number of entries in the array. 8748 ** 8749 ** When a blocking connection's transaction is concluded, there may be 8750 ** more than one blocked connection that has registered for an unlock-notify 8751 ** callback. ^If two or more such blocked connections have specified the 8752 ** same callback function, then instead of invoking the callback function 8753 ** multiple times, it is invoked once with the set of void* context pointers 8754 ** specified by the blocked connections bundled together into an array. 8755 ** This gives the application an opportunity to prioritize any actions 8756 ** related to the set of unblocked database connections. 8757 ** 8758 ** <b>Deadlock Detection</b> 8759 ** 8760 ** Assuming that after registering for an unlock-notify callback a 8761 ** database waits for the callback to be issued before taking any further 8762 ** action (a reasonable assumption), then using this API may cause the 8763 ** application to deadlock. For example, if connection X is waiting for 8764 ** connection Y's transaction to be concluded, and similarly connection 8765 ** Y is waiting on connection X's transaction, then neither connection 8766 ** will proceed and the system may remain deadlocked indefinitely. 8767 ** 8768 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8769 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8770 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8771 ** unlock-notify callback is registered. The system is said to be in 8772 ** a deadlocked state if connection A has registered for an unlock-notify 8773 ** callback on the conclusion of connection B's transaction, and connection 8774 ** B has itself registered for an unlock-notify callback when connection 8775 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8776 ** the system is also considered to be deadlocked if connection B has 8777 ** registered for an unlock-notify callback on the conclusion of connection 8778 ** C's transaction, where connection C is waiting on connection A. ^Any 8779 ** number of levels of indirection are allowed. 8780 ** 8781 ** <b>The "DROP TABLE" Exception</b> 8782 ** 8783 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8784 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8785 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8786 ** SQLite checks if there are any currently executing SELECT statements 8787 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8788 ** returned. In this case there is no "blocking connection", so invoking 8789 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8790 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8791 ** or "DROP INDEX" query, an infinite loop might be the result. 8792 ** 8793 ** One way around this problem is to check the extended error code returned 8794 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8795 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8796 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8797 ** SQLITE_LOCKED.)^ 8798 */ 8799 SQLITE_API int sqlite3_unlock_notify( 8800 sqlite3 *pBlocked, /* Waiting connection */ 8801 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8802 void *pNotifyArg /* Argument to pass to xNotify */ 8803 ); 8804 8805 8806 /* 8807 ** CAPI3REF: String Comparison 8808 ** 8809 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8810 ** and extensions to compare the contents of two buffers containing UTF-8 8811 ** strings in a case-independent fashion, using the same definition of "case 8812 ** independence" that SQLite uses internally when comparing identifiers. 8813 */ 8814 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8815 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8816 8817 /* 8818 ** CAPI3REF: String Globbing 8819 * 8820 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8821 ** string X matches the [GLOB] pattern P. 8822 ** ^The definition of [GLOB] pattern matching used in 8823 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8824 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8825 ** is case sensitive. 8826 ** 8827 ** Note that this routine returns zero on a match and non-zero if the strings 8828 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8829 ** 8830 ** See also: [sqlite3_strlike()]. 8831 */ 8832 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8833 8834 /* 8835 ** CAPI3REF: String LIKE Matching 8836 * 8837 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8838 ** string X matches the [LIKE] pattern P with escape character E. 8839 ** ^The definition of [LIKE] pattern matching used in 8840 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8841 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8842 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8843 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8844 ** insensitive - equivalent upper and lower case ASCII characters match 8845 ** one another. 8846 ** 8847 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8848 ** only ASCII characters are case folded. 8849 ** 8850 ** Note that this routine returns zero on a match and non-zero if the strings 8851 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8852 ** 8853 ** See also: [sqlite3_strglob()]. 8854 */ 8855 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8856 8857 /* 8858 ** CAPI3REF: Error Logging Interface 8859 ** 8860 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8861 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8862 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8863 ** used with [sqlite3_snprintf()] to generate the final output string. 8864 ** 8865 ** The sqlite3_log() interface is intended for use by extensions such as 8866 ** virtual tables, collating functions, and SQL functions. While there is 8867 ** nothing to prevent an application from calling sqlite3_log(), doing so 8868 ** is considered bad form. 8869 ** 8870 ** The zFormat string must not be NULL. 8871 ** 8872 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8873 ** will not use dynamically allocated memory. The log message is stored in 8874 ** a fixed-length buffer on the stack. If the log message is longer than 8875 ** a few hundred characters, it will be truncated to the length of the 8876 ** buffer. 8877 */ 8878 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8879 8880 /* 8881 ** CAPI3REF: Write-Ahead Log Commit Hook 8882 ** METHOD: sqlite3 8883 ** 8884 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8885 ** is invoked each time data is committed to a database in wal mode. 8886 ** 8887 ** ^(The callback is invoked by SQLite after the commit has taken place and 8888 ** the associated write-lock on the database released)^, so the implementation 8889 ** may read, write or [checkpoint] the database as required. 8890 ** 8891 ** ^The first parameter passed to the callback function when it is invoked 8892 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8893 ** registering the callback. ^The second is a copy of the database handle. 8894 ** ^The third parameter is the name of the database that was written to - 8895 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8896 ** is the number of pages currently in the write-ahead log file, 8897 ** including those that were just committed. 8898 ** 8899 ** The callback function should normally return [SQLITE_OK]. ^If an error 8900 ** code is returned, that error will propagate back up through the 8901 ** SQLite code base to cause the statement that provoked the callback 8902 ** to report an error, though the commit will have still occurred. If the 8903 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8904 ** that does not correspond to any valid SQLite error code, the results 8905 ** are undefined. 8906 ** 8907 ** A single database handle may have at most a single write-ahead log callback 8908 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8909 ** previously registered write-ahead log callback. ^Note that the 8910 ** [sqlite3_wal_autocheckpoint()] interface and the 8911 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8912 ** overwrite any prior [sqlite3_wal_hook()] settings. 8913 */ 8914 SQLITE_API void *sqlite3_wal_hook( 8915 sqlite3*, 8916 int(*)(void *,sqlite3*,const char*,int), 8917 void* 8918 ); 8919 8920 /* 8921 ** CAPI3REF: Configure an auto-checkpoint 8922 ** METHOD: sqlite3 8923 ** 8924 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8925 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8926 ** to automatically [checkpoint] 8927 ** after committing a transaction if there are N or 8928 ** more frames in the [write-ahead log] file. ^Passing zero or 8929 ** a negative value as the nFrame parameter disables automatic 8930 ** checkpoints entirely. 8931 ** 8932 ** ^The callback registered by this function replaces any existing callback 8933 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8934 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8935 ** configured by this function. 8936 ** 8937 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8938 ** from SQL. 8939 ** 8940 ** ^Checkpoints initiated by this mechanism are 8941 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8942 ** 8943 ** ^Every new [database connection] defaults to having the auto-checkpoint 8944 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8945 ** pages. The use of this interface 8946 ** is only necessary if the default setting is found to be suboptimal 8947 ** for a particular application. 8948 */ 8949 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8950 8951 /* 8952 ** CAPI3REF: Checkpoint a database 8953 ** METHOD: sqlite3 8954 ** 8955 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8956 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8957 ** 8958 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8959 ** [write-ahead log] for database X on [database connection] D to be 8960 ** transferred into the database file and for the write-ahead log to 8961 ** be reset. See the [checkpointing] documentation for addition 8962 ** information. 8963 ** 8964 ** This interface used to be the only way to cause a checkpoint to 8965 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8966 ** interface was added. This interface is retained for backwards 8967 ** compatibility and as a convenience for applications that need to manually 8968 ** start a callback but which do not need the full power (and corresponding 8969 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8970 */ 8971 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8972 8973 /* 8974 ** CAPI3REF: Checkpoint a database 8975 ** METHOD: sqlite3 8976 ** 8977 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8978 ** operation on database X of [database connection] D in mode M. Status 8979 ** information is written back into integers pointed to by L and C.)^ 8980 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8981 ** 8982 ** <dl> 8983 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8984 ** ^Checkpoint as many frames as possible without waiting for any database 8985 ** readers or writers to finish, then sync the database file if all frames 8986 ** in the log were checkpointed. ^The [busy-handler callback] 8987 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8988 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8989 ** if there are concurrent readers or writers. 8990 ** 8991 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8992 ** ^This mode blocks (it invokes the 8993 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8994 ** database writer and all readers are reading from the most recent database 8995 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8996 ** database file. ^This mode blocks new database writers while it is pending, 8997 ** but new database readers are allowed to continue unimpeded. 8998 ** 8999 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9000 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9001 ** that after checkpointing the log file it blocks (calls the 9002 ** [busy-handler callback]) 9003 ** until all readers are reading from the database file only. ^This ensures 9004 ** that the next writer will restart the log file from the beginning. 9005 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9006 ** database writer attempts while it is pending, but does not impede readers. 9007 ** 9008 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9009 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9010 ** addition that it also truncates the log file to zero bytes just prior 9011 ** to a successful return. 9012 ** </dl> 9013 ** 9014 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9015 ** the log file or to -1 if the checkpoint could not run because 9016 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9017 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9018 ** log file (including any that were already checkpointed before the function 9019 ** was called) or to -1 if the checkpoint could not run due to an error or 9020 ** because the database is not in WAL mode. ^Note that upon successful 9021 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9022 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9023 ** 9024 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9025 ** any other process is running a checkpoint operation at the same time, the 9026 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9027 ** busy-handler configured, it will not be invoked in this case. 9028 ** 9029 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9030 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9031 ** obtained immediately, and a busy-handler is configured, it is invoked and 9032 ** the writer lock retried until either the busy-handler returns 0 or the lock 9033 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9034 ** database readers as described above. ^If the busy-handler returns 0 before 9035 ** the writer lock is obtained or while waiting for database readers, the 9036 ** checkpoint operation proceeds from that point in the same way as 9037 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9038 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9039 ** 9040 ** ^If parameter zDb is NULL or points to a zero length string, then the 9041 ** specified operation is attempted on all WAL databases [attached] to 9042 ** [database connection] db. In this case the 9043 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9044 ** an SQLITE_BUSY error is encountered when processing one or more of the 9045 ** attached WAL databases, the operation is still attempted on any remaining 9046 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9047 ** error occurs while processing an attached database, processing is abandoned 9048 ** and the error code is returned to the caller immediately. ^If no error 9049 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9050 ** databases, SQLITE_OK is returned. 9051 ** 9052 ** ^If database zDb is the name of an attached database that is not in WAL 9053 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9054 ** zDb is not NULL (or a zero length string) and is not the name of any 9055 ** attached database, SQLITE_ERROR is returned to the caller. 9056 ** 9057 ** ^Unless it returns SQLITE_MISUSE, 9058 ** the sqlite3_wal_checkpoint_v2() interface 9059 ** sets the error information that is queried by 9060 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9061 ** 9062 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9063 ** from SQL. 9064 */ 9065 SQLITE_API int sqlite3_wal_checkpoint_v2( 9066 sqlite3 *db, /* Database handle */ 9067 const char *zDb, /* Name of attached database (or NULL) */ 9068 int eMode, /* SQLITE_CHECKPOINT_* value */ 9069 int *pnLog, /* OUT: Size of WAL log in frames */ 9070 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9071 ); 9072 9073 /* 9074 ** CAPI3REF: Checkpoint Mode Values 9075 ** KEYWORDS: {checkpoint mode} 9076 ** 9077 ** These constants define all valid values for the "checkpoint mode" passed 9078 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9079 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9080 ** meaning of each of these checkpoint modes. 9081 */ 9082 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9083 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9084 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9085 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9086 9087 /* 9088 ** CAPI3REF: Virtual Table Interface Configuration 9089 ** 9090 ** This function may be called by either the [xConnect] or [xCreate] method 9091 ** of a [virtual table] implementation to configure 9092 ** various facets of the virtual table interface. 9093 ** 9094 ** If this interface is invoked outside the context of an xConnect or 9095 ** xCreate virtual table method then the behavior is undefined. 9096 ** 9097 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9098 ** [database connection] in which the virtual table is being created and 9099 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9100 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9101 ** of the [virtual table configuration options]. The presence and meaning 9102 ** of parameters after C depend on which [virtual table configuration option] 9103 ** is used. 9104 */ 9105 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9106 9107 /* 9108 ** CAPI3REF: Virtual Table Configuration Options 9109 ** KEYWORDS: {virtual table configuration options} 9110 ** KEYWORDS: {virtual table configuration option} 9111 ** 9112 ** These macros define the various options to the 9113 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9114 ** can use to customize and optimize their behavior. 9115 ** 9116 ** <dl> 9117 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9118 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9119 ** <dd>Calls of the form 9120 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9121 ** where X is an integer. If X is zero, then the [virtual table] whose 9122 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9123 ** support constraints. In this configuration (which is the default) if 9124 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9125 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9126 ** specified as part of the users SQL statement, regardless of the actual 9127 ** ON CONFLICT mode specified. 9128 ** 9129 ** If X is non-zero, then the virtual table implementation guarantees 9130 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9131 ** any modifications to internal or persistent data structures have been made. 9132 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9133 ** is able to roll back a statement or database transaction, and abandon 9134 ** or continue processing the current SQL statement as appropriate. 9135 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9136 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9137 ** had been ABORT. 9138 ** 9139 ** Virtual table implementations that are required to handle OR REPLACE 9140 ** must do so within the [xUpdate] method. If a call to the 9141 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9142 ** CONFLICT policy is REPLACE, the virtual table implementation should 9143 ** silently replace the appropriate rows within the xUpdate callback and 9144 ** return SQLITE_OK. Or, if this is not possible, it may return 9145 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9146 ** constraint handling. 9147 ** </dd> 9148 ** 9149 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9150 ** <dd>Calls of the form 9151 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9152 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9153 ** prohibits that virtual table from being used from within triggers and 9154 ** views. 9155 ** </dd> 9156 ** 9157 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9158 ** <dd>Calls of the form 9159 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9160 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9161 ** identify that virtual table as being safe to use from within triggers 9162 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9163 ** virtual table can do no serious harm even if it is controlled by a 9164 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9165 ** flag unless absolutely necessary. 9166 ** </dd> 9167 ** </dl> 9168 */ 9169 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9170 #define SQLITE_VTAB_INNOCUOUS 2 9171 #define SQLITE_VTAB_DIRECTONLY 3 9172 9173 /* 9174 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9175 ** 9176 ** This function may only be called from within a call to the [xUpdate] method 9177 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9178 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9179 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9180 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9181 ** [virtual table]. 9182 */ 9183 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9184 9185 /* 9186 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9187 ** 9188 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9189 ** method of a [virtual table], then it returns true if and only if the 9190 ** column is being fetched as part of an UPDATE operation during which the 9191 ** column value will not change. Applications might use this to substitute 9192 ** a return value that is less expensive to compute and that the corresponding 9193 ** [xUpdate] method understands as a "no-change" value. 9194 ** 9195 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9196 ** the column is not changed by the UPDATE statement, then the xColumn 9197 ** method can optionally return without setting a result, without calling 9198 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9199 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9200 ** same column in the [xUpdate] method. 9201 */ 9202 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9203 9204 /* 9205 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9206 ** 9207 ** This function may only be called from within a call to the [xBestIndex] 9208 ** method of a [virtual table]. 9209 ** 9210 ** The first argument must be the sqlite3_index_info object that is the 9211 ** first parameter to the xBestIndex() method. The second argument must be 9212 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 9213 ** structure passed to xBestIndex. This function returns a pointer to a buffer 9214 ** containing the name of the collation sequence for the corresponding 9215 ** constraint. 9216 */ 9217 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9218 9219 /* 9220 ** CAPI3REF: Conflict resolution modes 9221 ** KEYWORDS: {conflict resolution mode} 9222 ** 9223 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9224 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9225 ** is for the SQL statement being evaluated. 9226 ** 9227 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9228 ** return value from the [sqlite3_set_authorizer()] callback and that 9229 ** [SQLITE_ABORT] is also a [result code]. 9230 */ 9231 #define SQLITE_ROLLBACK 1 9232 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9233 #define SQLITE_FAIL 3 9234 /* #define SQLITE_ABORT 4 // Also an error code */ 9235 #define SQLITE_REPLACE 5 9236 9237 /* 9238 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9239 ** KEYWORDS: {scanstatus options} 9240 ** 9241 ** The following constants can be used for the T parameter to the 9242 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9243 ** different metric for sqlite3_stmt_scanstatus() to return. 9244 ** 9245 ** When the value returned to V is a string, space to hold that string is 9246 ** managed by the prepared statement S and will be automatically freed when 9247 ** S is finalized. 9248 ** 9249 ** <dl> 9250 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9251 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9252 ** set to the total number of times that the X-th loop has run.</dd> 9253 ** 9254 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9255 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9256 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9257 ** 9258 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9259 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9260 ** query planner's estimate for the average number of rows output from each 9261 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9262 ** then this value will approximate the quotient NVISIT/NLOOP and the 9263 ** product of this value for all prior loops with the same SELECTID will 9264 ** be the NLOOP value for the current loop. 9265 ** 9266 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9267 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9268 ** to a zero-terminated UTF-8 string containing the name of the index or table 9269 ** used for the X-th loop. 9270 ** 9271 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9272 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9273 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9274 ** description for the X-th loop. 9275 ** 9276 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9277 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9278 ** "select-id" for the X-th loop. The select-id identifies which query or 9279 ** subquery the loop is part of. The main query has a select-id of zero. 9280 ** The select-id is the same value as is output in the first column 9281 ** of an [EXPLAIN QUERY PLAN] query. 9282 ** </dl> 9283 */ 9284 #define SQLITE_SCANSTAT_NLOOP 0 9285 #define SQLITE_SCANSTAT_NVISIT 1 9286 #define SQLITE_SCANSTAT_EST 2 9287 #define SQLITE_SCANSTAT_NAME 3 9288 #define SQLITE_SCANSTAT_EXPLAIN 4 9289 #define SQLITE_SCANSTAT_SELECTID 5 9290 9291 /* 9292 ** CAPI3REF: Prepared Statement Scan Status 9293 ** METHOD: sqlite3_stmt 9294 ** 9295 ** This interface returns information about the predicted and measured 9296 ** performance for pStmt. Advanced applications can use this 9297 ** interface to compare the predicted and the measured performance and 9298 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9299 ** 9300 ** Since this interface is expected to be rarely used, it is only 9301 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9302 ** compile-time option. 9303 ** 9304 ** The "iScanStatusOp" parameter determines which status information to return. 9305 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9306 ** of this interface is undefined. 9307 ** ^The requested measurement is written into a variable pointed to by 9308 ** the "pOut" parameter. 9309 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 9310 ** Loops are numbered starting from zero. ^If idx is out of range - less than 9311 ** zero or greater than or equal to the total number of loops used to implement 9312 ** the statement - a non-zero value is returned and the variable that pOut 9313 ** points to is unchanged. 9314 ** 9315 ** ^Statistics might not be available for all loops in all statements. ^In cases 9316 ** where there exist loops with no available statistics, this function behaves 9317 ** as if the loop did not exist - it returns non-zero and leave the variable 9318 ** that pOut points to unchanged. 9319 ** 9320 ** See also: [sqlite3_stmt_scanstatus_reset()] 9321 */ 9322 SQLITE_API int sqlite3_stmt_scanstatus( 9323 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9324 int idx, /* Index of loop to report on */ 9325 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9326 void *pOut /* Result written here */ 9327 ); 9328 9329 /* 9330 ** CAPI3REF: Zero Scan-Status Counters 9331 ** METHOD: sqlite3_stmt 9332 ** 9333 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9334 ** 9335 ** This API is only available if the library is built with pre-processor 9336 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9337 */ 9338 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9339 9340 /* 9341 ** CAPI3REF: Flush caches to disk mid-transaction 9342 ** 9343 ** ^If a write-transaction is open on [database connection] D when the 9344 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9345 ** pages in the pager-cache that are not currently in use are written out 9346 ** to disk. A dirty page may be in use if a database cursor created by an 9347 ** active SQL statement is reading from it, or if it is page 1 of a database 9348 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9349 ** interface flushes caches for all schemas - "main", "temp", and 9350 ** any [attached] databases. 9351 ** 9352 ** ^If this function needs to obtain extra database locks before dirty pages 9353 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 9354 ** immediately and there is a busy-handler callback configured, it is invoked 9355 ** in the usual manner. ^If the required lock still cannot be obtained, then 9356 ** the database is skipped and an attempt made to flush any dirty pages 9357 ** belonging to the next (if any) database. ^If any databases are skipped 9358 ** because locks cannot be obtained, but no other error occurs, this 9359 ** function returns SQLITE_BUSY. 9360 ** 9361 ** ^If any other error occurs while flushing dirty pages to disk (for 9362 ** example an IO error or out-of-memory condition), then processing is 9363 ** abandoned and an SQLite [error code] is returned to the caller immediately. 9364 ** 9365 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9366 ** 9367 ** ^This function does not set the database handle error code or message 9368 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9369 */ 9370 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 9371 9372 /* 9373 ** CAPI3REF: The pre-update hook. 9374 ** 9375 ** ^These interfaces are only available if SQLite is compiled using the 9376 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9377 ** 9378 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9379 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9380 ** on a database table. 9381 ** ^At most one preupdate hook may be registered at a time on a single 9382 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9383 ** the previous setting. 9384 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9385 ** with a NULL pointer as the second parameter. 9386 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9387 ** the first parameter to callbacks. 9388 ** 9389 ** ^The preupdate hook only fires for changes to real database tables; the 9390 ** preupdate hook is not invoked for changes to [virtual tables] or to 9391 ** system tables like sqlite_master or sqlite_stat1. 9392 ** 9393 ** ^The second parameter to the preupdate callback is a pointer to 9394 ** the [database connection] that registered the preupdate hook. 9395 ** ^The third parameter to the preupdate callback is one of the constants 9396 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9397 ** kind of update operation that is about to occur. 9398 ** ^(The fourth parameter to the preupdate callback is the name of the 9399 ** database within the database connection that is being modified. This 9400 ** will be "main" for the main database or "temp" for TEMP tables or 9401 ** the name given after the AS keyword in the [ATTACH] statement for attached 9402 ** databases.)^ 9403 ** ^The fifth parameter to the preupdate callback is the name of the 9404 ** table that is being modified. 9405 ** 9406 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 9407 ** parameter passed to the preupdate callback is the initial [rowid] of the 9408 ** row being modified or deleted. For an INSERT operation on a rowid table, 9409 ** or any operation on a WITHOUT ROWID table, the value of the sixth 9410 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9411 ** seventh parameter is the final rowid value of the row being inserted 9412 ** or updated. The value of the seventh parameter passed to the callback 9413 ** function is not defined for operations on WITHOUT ROWID tables, or for 9414 ** INSERT operations on rowid tables. 9415 ** 9416 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9417 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9418 ** provide additional information about a preupdate event. These routines 9419 ** may only be called from within a preupdate callback. Invoking any of 9420 ** these routines from outside of a preupdate callback or with a 9421 ** [database connection] pointer that is different from the one supplied 9422 ** to the preupdate callback results in undefined and probably undesirable 9423 ** behavior. 9424 ** 9425 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9426 ** in the row that is being inserted, updated, or deleted. 9427 ** 9428 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9429 ** a [protected sqlite3_value] that contains the value of the Nth column of 9430 ** the table row before it is updated. The N parameter must be between 0 9431 ** and one less than the number of columns or the behavior will be 9432 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9433 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9434 ** behavior is undefined. The [sqlite3_value] that P points to 9435 ** will be destroyed when the preupdate callback returns. 9436 ** 9437 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9438 ** a [protected sqlite3_value] that contains the value of the Nth column of 9439 ** the table row after it is updated. The N parameter must be between 0 9440 ** and one less than the number of columns or the behavior will be 9441 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9442 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9443 ** behavior is undefined. The [sqlite3_value] that P points to 9444 ** will be destroyed when the preupdate callback returns. 9445 ** 9446 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9447 ** callback was invoked as a result of a direct insert, update, or delete 9448 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 9449 ** triggers; or 2 for changes resulting from triggers called by top-level 9450 ** triggers; and so forth. 9451 ** 9452 ** See also: [sqlite3_update_hook()] 9453 */ 9454 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9455 SQLITE_API void *sqlite3_preupdate_hook( 9456 sqlite3 *db, 9457 void(*xPreUpdate)( 9458 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9459 sqlite3 *db, /* Database handle */ 9460 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9461 char const *zDb, /* Database name */ 9462 char const *zName, /* Table name */ 9463 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9464 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9465 ), 9466 void* 9467 ); 9468 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9469 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 9470 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 9471 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9472 #endif 9473 9474 /* 9475 ** CAPI3REF: Low-level system error code 9476 ** 9477 ** ^Attempt to return the underlying operating system error code or error 9478 ** number that caused the most recent I/O error or failure to open a file. 9479 ** The return value is OS-dependent. For example, on unix systems, after 9480 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9481 ** called to get back the underlying "errno" that caused the problem, such 9482 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9483 */ 9484 SQLITE_API int sqlite3_system_errno(sqlite3*); 9485 9486 /* 9487 ** CAPI3REF: Database Snapshot 9488 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9489 ** 9490 ** An instance of the snapshot object records the state of a [WAL mode] 9491 ** database for some specific point in history. 9492 ** 9493 ** In [WAL mode], multiple [database connections] that are open on the 9494 ** same database file can each be reading a different historical version 9495 ** of the database file. When a [database connection] begins a read 9496 ** transaction, that connection sees an unchanging copy of the database 9497 ** as it existed for the point in time when the transaction first started. 9498 ** Subsequent changes to the database from other connections are not seen 9499 ** by the reader until a new read transaction is started. 9500 ** 9501 ** The sqlite3_snapshot object records state information about an historical 9502 ** version of the database file so that it is possible to later open a new read 9503 ** transaction that sees that historical version of the database rather than 9504 ** the most recent version. 9505 */ 9506 typedef struct sqlite3_snapshot { 9507 unsigned char hidden[48]; 9508 } sqlite3_snapshot; 9509 9510 /* 9511 ** CAPI3REF: Record A Database Snapshot 9512 ** CONSTRUCTOR: sqlite3_snapshot 9513 ** 9514 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9515 ** new [sqlite3_snapshot] object that records the current state of 9516 ** schema S in database connection D. ^On success, the 9517 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9518 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9519 ** If there is not already a read-transaction open on schema S when 9520 ** this function is called, one is opened automatically. 9521 ** 9522 ** The following must be true for this function to succeed. If any of 9523 ** the following statements are false when sqlite3_snapshot_get() is 9524 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9525 ** in this case. 9526 ** 9527 ** <ul> 9528 ** <li> The database handle must not be in [autocommit mode]. 9529 ** 9530 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9531 ** 9532 ** <li> There must not be a write transaction open on schema S of database 9533 ** connection D. 9534 ** 9535 ** <li> One or more transactions must have been written to the current wal 9536 ** file since it was created on disk (by any connection). This means 9537 ** that a snapshot cannot be taken on a wal mode database with no wal 9538 ** file immediately after it is first opened. At least one transaction 9539 ** must be written to it first. 9540 ** </ul> 9541 ** 9542 ** This function may also return SQLITE_NOMEM. If it is called with the 9543 ** database handle in autocommit mode but fails for some other reason, 9544 ** whether or not a read transaction is opened on schema S is undefined. 9545 ** 9546 ** The [sqlite3_snapshot] object returned from a successful call to 9547 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9548 ** to avoid a memory leak. 9549 ** 9550 ** The [sqlite3_snapshot_get()] interface is only available when the 9551 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9552 */ 9553 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9554 sqlite3 *db, 9555 const char *zSchema, 9556 sqlite3_snapshot **ppSnapshot 9557 ); 9558 9559 /* 9560 ** CAPI3REF: Start a read transaction on an historical snapshot 9561 ** METHOD: sqlite3_snapshot 9562 ** 9563 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9564 ** transaction or upgrades an existing one for schema S of 9565 ** [database connection] D such that the read transaction refers to 9566 ** historical [snapshot] P, rather than the most recent change to the 9567 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9568 ** on success or an appropriate [error code] if it fails. 9569 ** 9570 ** ^In order to succeed, the database connection must not be in 9571 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9572 ** is already a read transaction open on schema S, then the database handle 9573 ** must have no active statements (SELECT statements that have been passed 9574 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9575 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9576 ** if schema S does not exist, or if the snapshot object is invalid. 9577 ** 9578 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9579 ** snapshot has been overwritten by a [checkpoint]. In this case 9580 ** SQLITE_ERROR_SNAPSHOT is returned. 9581 ** 9582 ** If there is already a read transaction open when this function is 9583 ** invoked, then the same read transaction remains open (on the same 9584 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9585 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9586 ** SQLITE_IOERR error code - is returned, then the final state of the 9587 ** read transaction is undefined. If SQLITE_OK is returned, then the 9588 ** read transaction is now open on database snapshot P. 9589 ** 9590 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9591 ** database connection D does not know that the database file for 9592 ** schema S is in [WAL mode]. A database connection might not know 9593 ** that the database file is in [WAL mode] if there has been no prior 9594 ** I/O on that database connection, or if the database entered [WAL mode] 9595 ** after the most recent I/O on the database connection.)^ 9596 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9597 ** database connection in order to make it ready to use snapshots.) 9598 ** 9599 ** The [sqlite3_snapshot_open()] interface is only available when the 9600 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9601 */ 9602 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9603 sqlite3 *db, 9604 const char *zSchema, 9605 sqlite3_snapshot *pSnapshot 9606 ); 9607 9608 /* 9609 ** CAPI3REF: Destroy a snapshot 9610 ** DESTRUCTOR: sqlite3_snapshot 9611 ** 9612 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9613 ** The application must eventually free every [sqlite3_snapshot] object 9614 ** using this routine to avoid a memory leak. 9615 ** 9616 ** The [sqlite3_snapshot_free()] interface is only available when the 9617 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9618 */ 9619 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9620 9621 /* 9622 ** CAPI3REF: Compare the ages of two snapshot handles. 9623 ** METHOD: sqlite3_snapshot 9624 ** 9625 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9626 ** of two valid snapshot handles. 9627 ** 9628 ** If the two snapshot handles are not associated with the same database 9629 ** file, the result of the comparison is undefined. 9630 ** 9631 ** Additionally, the result of the comparison is only valid if both of the 9632 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9633 ** last time the wal file was deleted. The wal file is deleted when the 9634 ** database is changed back to rollback mode or when the number of database 9635 ** clients drops to zero. If either snapshot handle was obtained before the 9636 ** wal file was last deleted, the value returned by this function 9637 ** is undefined. 9638 ** 9639 ** Otherwise, this API returns a negative value if P1 refers to an older 9640 ** snapshot than P2, zero if the two handles refer to the same database 9641 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9642 ** 9643 ** This interface is only available if SQLite is compiled with the 9644 ** [SQLITE_ENABLE_SNAPSHOT] option. 9645 */ 9646 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9647 sqlite3_snapshot *p1, 9648 sqlite3_snapshot *p2 9649 ); 9650 9651 /* 9652 ** CAPI3REF: Recover snapshots from a wal file 9653 ** METHOD: sqlite3_snapshot 9654 ** 9655 ** If a [WAL file] remains on disk after all database connections close 9656 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9657 ** or because the last process to have the database opened exited without 9658 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9659 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9660 ** will only be able to open the last transaction added to the WAL file 9661 ** even though the WAL file contains other valid transactions. 9662 ** 9663 ** This function attempts to scan the WAL file associated with database zDb 9664 ** of database handle db and make all valid snapshots available to 9665 ** sqlite3_snapshot_open(). It is an error if there is already a read 9666 ** transaction open on the database, or if the database is not a WAL mode 9667 ** database. 9668 ** 9669 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9670 ** 9671 ** This interface is only available if SQLite is compiled with the 9672 ** [SQLITE_ENABLE_SNAPSHOT] option. 9673 */ 9674 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9675 9676 /* 9677 ** CAPI3REF: Serialize a database 9678 ** 9679 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9680 ** that is a serialization of the S database on [database connection] D. 9681 ** If P is not a NULL pointer, then the size of the database in bytes 9682 ** is written into *P. 9683 ** 9684 ** For an ordinary on-disk database file, the serialization is just a 9685 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9686 ** the serialization is the same sequence of bytes which would be written 9687 ** to disk if that database where backed up to disk. 9688 ** 9689 ** The usual case is that sqlite3_serialize() copies the serialization of 9690 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9691 ** a pointer to that memory. The caller is responsible for freeing the 9692 ** returned value to avoid a memory leak. However, if the F argument 9693 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9694 ** are made, and the sqlite3_serialize() function will return a pointer 9695 ** to the contiguous memory representation of the database that SQLite 9696 ** is currently using for that database, or NULL if the no such contiguous 9697 ** memory representation of the database exists. A contiguous memory 9698 ** representation of the database will usually only exist if there has 9699 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9700 ** values of D and S. 9701 ** The size of the database is written into *P even if the 9702 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9703 ** of the database exists. 9704 ** 9705 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9706 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9707 ** allocation error occurs. 9708 ** 9709 ** This interface is only available if SQLite is compiled with the 9710 ** [SQLITE_ENABLE_DESERIALIZE] option. 9711 */ 9712 SQLITE_API unsigned char *sqlite3_serialize( 9713 sqlite3 *db, /* The database connection */ 9714 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9715 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9716 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9717 ); 9718 9719 /* 9720 ** CAPI3REF: Flags for sqlite3_serialize 9721 ** 9722 ** Zero or more of the following constants can be OR-ed together for 9723 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9724 ** 9725 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9726 ** a pointer to contiguous in-memory database that it is currently using, 9727 ** without making a copy of the database. If SQLite is not currently using 9728 ** a contiguous in-memory database, then this option causes 9729 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9730 ** using a contiguous in-memory database if it has been initialized by a 9731 ** prior call to [sqlite3_deserialize()]. 9732 */ 9733 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9734 9735 /* 9736 ** CAPI3REF: Deserialize a database 9737 ** 9738 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9739 ** [database connection] D to disconnect from database S and then 9740 ** reopen S as an in-memory database based on the serialization contained 9741 ** in P. The serialized database P is N bytes in size. M is the size of 9742 ** the buffer P, which might be larger than N. If M is larger than N, and 9743 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9744 ** permitted to add content to the in-memory database as long as the total 9745 ** size does not exceed M bytes. 9746 ** 9747 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9748 ** invoke sqlite3_free() on the serialization buffer when the database 9749 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9750 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9751 ** if writes on the database cause it to grow larger than M bytes. 9752 ** 9753 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9754 ** database is currently in a read transaction or is involved in a backup 9755 ** operation. 9756 ** 9757 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9758 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9759 ** [sqlite3_free()] is invoked on argument P prior to returning. 9760 ** 9761 ** This interface is only available if SQLite is compiled with the 9762 ** [SQLITE_ENABLE_DESERIALIZE] option. 9763 */ 9764 SQLITE_API int sqlite3_deserialize( 9765 sqlite3 *db, /* The database connection */ 9766 const char *zSchema, /* Which DB to reopen with the deserialization */ 9767 unsigned char *pData, /* The serialized database content */ 9768 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9769 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9770 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9771 ); 9772 9773 /* 9774 ** CAPI3REF: Flags for sqlite3_deserialize() 9775 ** 9776 ** The following are allowed values for 6th argument (the F argument) to 9777 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9778 ** 9779 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9780 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9781 ** and that SQLite should take ownership of this memory and automatically 9782 ** free it when it has finished using it. Without this flag, the caller 9783 ** is responsible for freeing any dynamically allocated memory. 9784 ** 9785 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9786 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9787 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9788 ** Without this flag, the deserialized database cannot increase in size beyond 9789 ** the number of bytes specified by the M parameter. 9790 ** 9791 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9792 ** should be treated as read-only. 9793 */ 9794 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9795 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9796 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9797 9798 /* 9799 ** Undo the hack that converts floating point types to integer for 9800 ** builds on processors without floating point support. 9801 */ 9802 #ifdef SQLITE_OMIT_FLOATING_POINT 9803 # undef double 9804 #endif 9805 9806 #ifdef __cplusplus 9807 } /* End of the 'extern "C"' block */ 9808 #endif 9809 #endif /* SQLITE3_H */ 9810 9811 /******** Begin file sqlite3rtree.h *********/ 9812 /* 9813 ** 2010 August 30 9814 ** 9815 ** The author disclaims copyright to this source code. In place of 9816 ** a legal notice, here is a blessing: 9817 ** 9818 ** May you do good and not evil. 9819 ** May you find forgiveness for yourself and forgive others. 9820 ** May you share freely, never taking more than you give. 9821 ** 9822 ************************************************************************* 9823 */ 9824 9825 #ifndef _SQLITE3RTREE_H_ 9826 #define _SQLITE3RTREE_H_ 9827 9828 9829 #ifdef __cplusplus 9830 extern "C" { 9831 #endif 9832 9833 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9834 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9835 9836 /* The double-precision datatype used by RTree depends on the 9837 ** SQLITE_RTREE_INT_ONLY compile-time option. 9838 */ 9839 #ifdef SQLITE_RTREE_INT_ONLY 9840 typedef sqlite3_int64 sqlite3_rtree_dbl; 9841 #else 9842 typedef double sqlite3_rtree_dbl; 9843 #endif 9844 9845 /* 9846 ** Register a geometry callback named zGeom that can be used as part of an 9847 ** R-Tree geometry query as follows: 9848 ** 9849 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9850 */ 9851 SQLITE_API int sqlite3_rtree_geometry_callback( 9852 sqlite3 *db, 9853 const char *zGeom, 9854 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9855 void *pContext 9856 ); 9857 9858 9859 /* 9860 ** A pointer to a structure of the following type is passed as the first 9861 ** argument to callbacks registered using rtree_geometry_callback(). 9862 */ 9863 struct sqlite3_rtree_geometry { 9864 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9865 int nParam; /* Size of array aParam[] */ 9866 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9867 void *pUser; /* Callback implementation user data */ 9868 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9869 }; 9870 9871 /* 9872 ** Register a 2nd-generation geometry callback named zScore that can be 9873 ** used as part of an R-Tree geometry query as follows: 9874 ** 9875 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9876 */ 9877 SQLITE_API int sqlite3_rtree_query_callback( 9878 sqlite3 *db, 9879 const char *zQueryFunc, 9880 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9881 void *pContext, 9882 void (*xDestructor)(void*) 9883 ); 9884 9885 9886 /* 9887 ** A pointer to a structure of the following type is passed as the 9888 ** argument to scored geometry callback registered using 9889 ** sqlite3_rtree_query_callback(). 9890 ** 9891 ** Note that the first 5 fields of this structure are identical to 9892 ** sqlite3_rtree_geometry. This structure is a subclass of 9893 ** sqlite3_rtree_geometry. 9894 */ 9895 struct sqlite3_rtree_query_info { 9896 void *pContext; /* pContext from when function registered */ 9897 int nParam; /* Number of function parameters */ 9898 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9899 void *pUser; /* callback can use this, if desired */ 9900 void (*xDelUser)(void*); /* function to free pUser */ 9901 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9902 unsigned int *anQueue; /* Number of pending entries in the queue */ 9903 int nCoord; /* Number of coordinates */ 9904 int iLevel; /* Level of current node or entry */ 9905 int mxLevel; /* The largest iLevel value in the tree */ 9906 sqlite3_int64 iRowid; /* Rowid for current entry */ 9907 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9908 int eParentWithin; /* Visibility of parent node */ 9909 int eWithin; /* OUT: Visibility */ 9910 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9911 /* The following fields are only available in 3.8.11 and later */ 9912 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9913 }; 9914 9915 /* 9916 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9917 */ 9918 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9919 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9920 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9921 9922 9923 #ifdef __cplusplus 9924 } /* end of the 'extern "C"' block */ 9925 #endif 9926 9927 #endif /* ifndef _SQLITE3RTREE_H_ */ 9928 9929 /******** End of sqlite3rtree.h *********/ 9930 /******** Begin file sqlite3session.h *********/ 9931 9932 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9933 #define __SQLITESESSION_H_ 1 9934 9935 /* 9936 ** Make sure we can call this stuff from C++. 9937 */ 9938 #ifdef __cplusplus 9939 extern "C" { 9940 #endif 9941 9942 9943 /* 9944 ** CAPI3REF: Session Object Handle 9945 ** 9946 ** An instance of this object is a [session] that can be used to 9947 ** record changes to a database. 9948 */ 9949 typedef struct sqlite3_session sqlite3_session; 9950 9951 /* 9952 ** CAPI3REF: Changeset Iterator Handle 9953 ** 9954 ** An instance of this object acts as a cursor for iterating 9955 ** over the elements of a [changeset] or [patchset]. 9956 */ 9957 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9958 9959 /* 9960 ** CAPI3REF: Create A New Session Object 9961 ** CONSTRUCTOR: sqlite3_session 9962 ** 9963 ** Create a new session object attached to database handle db. If successful, 9964 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9965 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9966 ** error code (e.g. SQLITE_NOMEM) is returned. 9967 ** 9968 ** It is possible to create multiple session objects attached to a single 9969 ** database handle. 9970 ** 9971 ** Session objects created using this function should be deleted using the 9972 ** [sqlite3session_delete()] function before the database handle that they 9973 ** are attached to is itself closed. If the database handle is closed before 9974 ** the session object is deleted, then the results of calling any session 9975 ** module function, including [sqlite3session_delete()] on the session object 9976 ** are undefined. 9977 ** 9978 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9979 ** is not possible for an application to register a pre-update hook on a 9980 ** database handle that has one or more session objects attached. Nor is 9981 ** it possible to create a session object attached to a database handle for 9982 ** which a pre-update hook is already defined. The results of attempting 9983 ** either of these things are undefined. 9984 ** 9985 ** The session object will be used to create changesets for tables in 9986 ** database zDb, where zDb is either "main", or "temp", or the name of an 9987 ** attached database. It is not an error if database zDb is not attached 9988 ** to the database when the session object is created. 9989 */ 9990 SQLITE_API int sqlite3session_create( 9991 sqlite3 *db, /* Database handle */ 9992 const char *zDb, /* Name of db (e.g. "main") */ 9993 sqlite3_session **ppSession /* OUT: New session object */ 9994 ); 9995 9996 /* 9997 ** CAPI3REF: Delete A Session Object 9998 ** DESTRUCTOR: sqlite3_session 9999 ** 10000 ** Delete a session object previously allocated using 10001 ** [sqlite3session_create()]. Once a session object has been deleted, the 10002 ** results of attempting to use pSession with any other session module 10003 ** function are undefined. 10004 ** 10005 ** Session objects must be deleted before the database handle to which they 10006 ** are attached is closed. Refer to the documentation for 10007 ** [sqlite3session_create()] for details. 10008 */ 10009 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10010 10011 10012 /* 10013 ** CAPI3REF: Enable Or Disable A Session Object 10014 ** METHOD: sqlite3_session 10015 ** 10016 ** Enable or disable the recording of changes by a session object. When 10017 ** enabled, a session object records changes made to the database. When 10018 ** disabled - it does not. A newly created session object is enabled. 10019 ** Refer to the documentation for [sqlite3session_changeset()] for further 10020 ** details regarding how enabling and disabling a session object affects 10021 ** the eventual changesets. 10022 ** 10023 ** Passing zero to this function disables the session. Passing a value 10024 ** greater than zero enables it. Passing a value less than zero is a 10025 ** no-op, and may be used to query the current state of the session. 10026 ** 10027 ** The return value indicates the final state of the session object: 0 if 10028 ** the session is disabled, or 1 if it is enabled. 10029 */ 10030 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10031 10032 /* 10033 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10034 ** METHOD: sqlite3_session 10035 ** 10036 ** Each change recorded by a session object is marked as either direct or 10037 ** indirect. A change is marked as indirect if either: 10038 ** 10039 ** <ul> 10040 ** <li> The session object "indirect" flag is set when the change is 10041 ** made, or 10042 ** <li> The change is made by an SQL trigger or foreign key action 10043 ** instead of directly as a result of a users SQL statement. 10044 ** </ul> 10045 ** 10046 ** If a single row is affected by more than one operation within a session, 10047 ** then the change is considered indirect if all operations meet the criteria 10048 ** for an indirect change above, or direct otherwise. 10049 ** 10050 ** This function is used to set, clear or query the session object indirect 10051 ** flag. If the second argument passed to this function is zero, then the 10052 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10053 ** is set. Passing a value less than zero does not modify the current value 10054 ** of the indirect flag, and may be used to query the current state of the 10055 ** indirect flag for the specified session object. 10056 ** 10057 ** The return value indicates the final state of the indirect flag: 0 if 10058 ** it is clear, or 1 if it is set. 10059 */ 10060 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10061 10062 /* 10063 ** CAPI3REF: Attach A Table To A Session Object 10064 ** METHOD: sqlite3_session 10065 ** 10066 ** If argument zTab is not NULL, then it is the name of a table to attach 10067 ** to the session object passed as the first argument. All subsequent changes 10068 ** made to the table while the session object is enabled will be recorded. See 10069 ** documentation for [sqlite3session_changeset()] for further details. 10070 ** 10071 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10072 ** in the database. If additional tables are added to the database (by 10073 ** executing "CREATE TABLE" statements) after this call is made, changes for 10074 ** the new tables are also recorded. 10075 ** 10076 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10077 ** defined as part of their CREATE TABLE statement. It does not matter if the 10078 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10079 ** KEY may consist of a single column, or may be a composite key. 10080 ** 10081 ** It is not an error if the named table does not exist in the database. Nor 10082 ** is it an error if the named table does not have a PRIMARY KEY. However, 10083 ** no changes will be recorded in either of these scenarios. 10084 ** 10085 ** Changes are not recorded for individual rows that have NULL values stored 10086 ** in one or more of their PRIMARY KEY columns. 10087 ** 10088 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10089 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10090 ** 10091 ** <h3>Special sqlite_stat1 Handling</h3> 10092 ** 10093 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10094 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10095 ** <pre> 10096 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10097 ** </pre> 10098 ** 10099 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10100 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10101 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10102 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10103 ** patchset instead of a NULL value. This allows such changesets to be 10104 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10105 ** concat() and similar. 10106 ** 10107 ** The sqlite3changeset_apply() function automatically converts the 10108 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10109 ** table. However, if the application calls sqlite3changeset_new(), 10110 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10111 ** iterator directly (including on a changeset iterator passed to a 10112 ** conflict-handler callback) then the X'' value is returned. The application 10113 ** must translate X'' to NULL itself if required. 10114 ** 10115 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10116 ** changes made to the sqlite_stat1 table. Legacy versions of the 10117 ** sqlite3changeset_apply() function silently ignore any modifications to the 10118 ** sqlite_stat1 table that are part of a changeset or patchset. 10119 */ 10120 SQLITE_API int sqlite3session_attach( 10121 sqlite3_session *pSession, /* Session object */ 10122 const char *zTab /* Table name */ 10123 ); 10124 10125 /* 10126 ** CAPI3REF: Set a table filter on a Session Object. 10127 ** METHOD: sqlite3_session 10128 ** 10129 ** The second argument (xFilter) is the "filter callback". For changes to rows 10130 ** in tables that are not attached to the Session object, the filter is called 10131 ** to determine whether changes to the table's rows should be tracked or not. 10132 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10133 ** attached, xFilter will not be called again. 10134 */ 10135 SQLITE_API void sqlite3session_table_filter( 10136 sqlite3_session *pSession, /* Session object */ 10137 int(*xFilter)( 10138 void *pCtx, /* Copy of third arg to _filter_table() */ 10139 const char *zTab /* Table name */ 10140 ), 10141 void *pCtx /* First argument passed to xFilter */ 10142 ); 10143 10144 /* 10145 ** CAPI3REF: Generate A Changeset From A Session Object 10146 ** METHOD: sqlite3_session 10147 ** 10148 ** Obtain a changeset containing changes to the tables attached to the 10149 ** session object passed as the first argument. If successful, 10150 ** set *ppChangeset to point to a buffer containing the changeset 10151 ** and *pnChangeset to the size of the changeset in bytes before returning 10152 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10153 ** zero and return an SQLite error code. 10154 ** 10155 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10156 ** each representing a change to a single row of an attached table. An INSERT 10157 ** change contains the values of each field of a new database row. A DELETE 10158 ** contains the original values of each field of a deleted database row. An 10159 ** UPDATE change contains the original values of each field of an updated 10160 ** database row along with the updated values for each updated non-primary-key 10161 ** column. It is not possible for an UPDATE change to represent a change that 10162 ** modifies the values of primary key columns. If such a change is made, it 10163 ** is represented in a changeset as a DELETE followed by an INSERT. 10164 ** 10165 ** Changes are not recorded for rows that have NULL values stored in one or 10166 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10167 ** no corresponding change is present in the changesets returned by this 10168 ** function. If an existing row with one or more NULL values stored in 10169 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10170 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10171 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10172 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10173 ** DELETE change only. 10174 ** 10175 ** The contents of a changeset may be traversed using an iterator created 10176 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10177 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10178 ** API. 10179 ** 10180 ** Within a changeset generated by this function, all changes related to a 10181 ** single table are grouped together. In other words, when iterating through 10182 ** a changeset or when applying a changeset to a database, all changes related 10183 ** to a single table are processed before moving on to the next table. Tables 10184 ** are sorted in the same order in which they were attached (or auto-attached) 10185 ** to the sqlite3_session object. The order in which the changes related to 10186 ** a single table are stored is undefined. 10187 ** 10188 ** Following a successful call to this function, it is the responsibility of 10189 ** the caller to eventually free the buffer that *ppChangeset points to using 10190 ** [sqlite3_free()]. 10191 ** 10192 ** <h3>Changeset Generation</h3> 10193 ** 10194 ** Once a table has been attached to a session object, the session object 10195 ** records the primary key values of all new rows inserted into the table. 10196 ** It also records the original primary key and other column values of any 10197 ** deleted or updated rows. For each unique primary key value, data is only 10198 ** recorded once - the first time a row with said primary key is inserted, 10199 ** updated or deleted in the lifetime of the session. 10200 ** 10201 ** There is one exception to the previous paragraph: when a row is inserted, 10202 ** updated or deleted, if one or more of its primary key columns contain a 10203 ** NULL value, no record of the change is made. 10204 ** 10205 ** The session object therefore accumulates two types of records - those 10206 ** that consist of primary key values only (created when the user inserts 10207 ** a new record) and those that consist of the primary key values and the 10208 ** original values of other table columns (created when the users deletes 10209 ** or updates a record). 10210 ** 10211 ** When this function is called, the requested changeset is created using 10212 ** both the accumulated records and the current contents of the database 10213 ** file. Specifically: 10214 ** 10215 ** <ul> 10216 ** <li> For each record generated by an insert, the database is queried 10217 ** for a row with a matching primary key. If one is found, an INSERT 10218 ** change is added to the changeset. If no such row is found, no change 10219 ** is added to the changeset. 10220 ** 10221 ** <li> For each record generated by an update or delete, the database is 10222 ** queried for a row with a matching primary key. If such a row is 10223 ** found and one or more of the non-primary key fields have been 10224 ** modified from their original values, an UPDATE change is added to 10225 ** the changeset. Or, if no such row is found in the table, a DELETE 10226 ** change is added to the changeset. If there is a row with a matching 10227 ** primary key in the database, but all fields contain their original 10228 ** values, no change is added to the changeset. 10229 ** </ul> 10230 ** 10231 ** This means, amongst other things, that if a row is inserted and then later 10232 ** deleted while a session object is active, neither the insert nor the delete 10233 ** will be present in the changeset. Or if a row is deleted and then later a 10234 ** row with the same primary key values inserted while a session object is 10235 ** active, the resulting changeset will contain an UPDATE change instead of 10236 ** a DELETE and an INSERT. 10237 ** 10238 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10239 ** it does not accumulate records when rows are inserted, updated or deleted. 10240 ** This may appear to have some counter-intuitive effects if a single row 10241 ** is written to more than once during a session. For example, if a row 10242 ** is inserted while a session object is enabled, then later deleted while 10243 ** the same session object is disabled, no INSERT record will appear in the 10244 ** changeset, even though the delete took place while the session was disabled. 10245 ** Or, if one field of a row is updated while a session is disabled, and 10246 ** another field of the same row is updated while the session is enabled, the 10247 ** resulting changeset will contain an UPDATE change that updates both fields. 10248 */ 10249 SQLITE_API int sqlite3session_changeset( 10250 sqlite3_session *pSession, /* Session object */ 10251 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10252 void **ppChangeset /* OUT: Buffer containing changeset */ 10253 ); 10254 10255 /* 10256 ** CAPI3REF: Load The Difference Between Tables Into A Session 10257 ** METHOD: sqlite3_session 10258 ** 10259 ** If it is not already attached to the session object passed as the first 10260 ** argument, this function attaches table zTbl in the same manner as the 10261 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 10262 ** does not have a primary key, this function is a no-op (but does not return 10263 ** an error). 10264 ** 10265 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 10266 ** attached to the same database handle as the session object that contains 10267 ** a table compatible with the table attached to the session by this function. 10268 ** A table is considered compatible if it: 10269 ** 10270 ** <ul> 10271 ** <li> Has the same name, 10272 ** <li> Has the same set of columns declared in the same order, and 10273 ** <li> Has the same PRIMARY KEY definition. 10274 ** </ul> 10275 ** 10276 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 10277 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 10278 ** but no changes are added to the session object. As with other session 10279 ** APIs, tables without PRIMARY KEYs are simply ignored. 10280 ** 10281 ** This function adds a set of changes to the session object that could be 10282 ** used to update the table in database zFrom (call this the "from-table") 10283 ** so that its content is the same as the table attached to the session 10284 ** object (call this the "to-table"). Specifically: 10285 ** 10286 ** <ul> 10287 ** <li> For each row (primary key) that exists in the to-table but not in 10288 ** the from-table, an INSERT record is added to the session object. 10289 ** 10290 ** <li> For each row (primary key) that exists in the to-table but not in 10291 ** the from-table, a DELETE record is added to the session object. 10292 ** 10293 ** <li> For each row (primary key) that exists in both tables, but features 10294 ** different non-PK values in each, an UPDATE record is added to the 10295 ** session. 10296 ** </ul> 10297 ** 10298 ** To clarify, if this function is called and then a changeset constructed 10299 ** using [sqlite3session_changeset()], then after applying that changeset to 10300 ** database zFrom the contents of the two compatible tables would be 10301 ** identical. 10302 ** 10303 ** It an error if database zFrom does not exist or does not contain the 10304 ** required compatible table. 10305 ** 10306 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 10307 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 10308 ** may be set to point to a buffer containing an English language error 10309 ** message. It is the responsibility of the caller to free this buffer using 10310 ** sqlite3_free(). 10311 */ 10312 SQLITE_API int sqlite3session_diff( 10313 sqlite3_session *pSession, 10314 const char *zFromDb, 10315 const char *zTbl, 10316 char **pzErrMsg 10317 ); 10318 10319 10320 /* 10321 ** CAPI3REF: Generate A Patchset From A Session Object 10322 ** METHOD: sqlite3_session 10323 ** 10324 ** The differences between a patchset and a changeset are that: 10325 ** 10326 ** <ul> 10327 ** <li> DELETE records consist of the primary key fields only. The 10328 ** original values of other fields are omitted. 10329 ** <li> The original values of any modified fields are omitted from 10330 ** UPDATE records. 10331 ** </ul> 10332 ** 10333 ** A patchset blob may be used with up to date versions of all 10334 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 10335 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 10336 ** attempting to use a patchset blob with old versions of the 10337 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 10338 ** 10339 ** Because the non-primary key "old.*" fields are omitted, no 10340 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 10341 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 10342 ** in the same way as for changesets. 10343 ** 10344 ** Changes within a patchset are ordered in the same way as for changesets 10345 ** generated by the sqlite3session_changeset() function (i.e. all changes for 10346 ** a single table are grouped together, tables appear in the order in which 10347 ** they were attached to the session object). 10348 */ 10349 SQLITE_API int sqlite3session_patchset( 10350 sqlite3_session *pSession, /* Session object */ 10351 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 10352 void **ppPatchset /* OUT: Buffer containing patchset */ 10353 ); 10354 10355 /* 10356 ** CAPI3REF: Test if a changeset has recorded any changes. 10357 ** 10358 ** Return non-zero if no changes to attached tables have been recorded by 10359 ** the session object passed as the first argument. Otherwise, if one or 10360 ** more changes have been recorded, return zero. 10361 ** 10362 ** Even if this function returns zero, it is possible that calling 10363 ** [sqlite3session_changeset()] on the session handle may still return a 10364 ** changeset that contains no changes. This can happen when a row in 10365 ** an attached table is modified and then later on the original values 10366 ** are restored. However, if this function returns non-zero, then it is 10367 ** guaranteed that a call to sqlite3session_changeset() will return a 10368 ** changeset containing zero changes. 10369 */ 10370 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 10371 10372 /* 10373 ** CAPI3REF: Create An Iterator To Traverse A Changeset 10374 ** CONSTRUCTOR: sqlite3_changeset_iter 10375 ** 10376 ** Create an iterator used to iterate through the contents of a changeset. 10377 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 10378 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 10379 ** SQLite error code is returned. 10380 ** 10381 ** The following functions can be used to advance and query a changeset 10382 ** iterator created by this function: 10383 ** 10384 ** <ul> 10385 ** <li> [sqlite3changeset_next()] 10386 ** <li> [sqlite3changeset_op()] 10387 ** <li> [sqlite3changeset_new()] 10388 ** <li> [sqlite3changeset_old()] 10389 ** </ul> 10390 ** 10391 ** It is the responsibility of the caller to eventually destroy the iterator 10392 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 10393 ** changeset (pChangeset) must remain valid until after the iterator is 10394 ** destroyed. 10395 ** 10396 ** Assuming the changeset blob was created by one of the 10397 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 10398 ** [sqlite3changeset_invert()] functions, all changes within the changeset 10399 ** that apply to a single table are grouped together. This means that when 10400 ** an application iterates through a changeset using an iterator created by 10401 ** this function, all changes that relate to a single table are visited 10402 ** consecutively. There is no chance that the iterator will visit a change 10403 ** the applies to table X, then one for table Y, and then later on visit 10404 ** another change for table X. 10405 ** 10406 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 10407 ** may be modified by passing a combination of 10408 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 10409 ** 10410 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 10411 ** and therefore subject to change. 10412 */ 10413 SQLITE_API int sqlite3changeset_start( 10414 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10415 int nChangeset, /* Size of changeset blob in bytes */ 10416 void *pChangeset /* Pointer to blob containing changeset */ 10417 ); 10418 SQLITE_API int sqlite3changeset_start_v2( 10419 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 10420 int nChangeset, /* Size of changeset blob in bytes */ 10421 void *pChangeset, /* Pointer to blob containing changeset */ 10422 int flags /* SESSION_CHANGESETSTART_* flags */ 10423 ); 10424 10425 /* 10426 ** CAPI3REF: Flags for sqlite3changeset_start_v2 10427 ** 10428 ** The following flags may passed via the 4th parameter to 10429 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 10430 ** 10431 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10432 ** Invert the changeset while iterating through it. This is equivalent to 10433 ** inverting a changeset using sqlite3changeset_invert() before applying it. 10434 ** It is an error to specify this flag with a patchset. 10435 */ 10436 #define SQLITE_CHANGESETSTART_INVERT 0x0002 10437 10438 10439 /* 10440 ** CAPI3REF: Advance A Changeset Iterator 10441 ** METHOD: sqlite3_changeset_iter 10442 ** 10443 ** This function may only be used with iterators created by the function 10444 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 10445 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 10446 ** is returned and the call has no effect. 10447 ** 10448 ** Immediately after an iterator is created by sqlite3changeset_start(), it 10449 ** does not point to any change in the changeset. Assuming the changeset 10450 ** is not empty, the first call to this function advances the iterator to 10451 ** point to the first change in the changeset. Each subsequent call advances 10452 ** the iterator to point to the next change in the changeset (if any). If 10453 ** no error occurs and the iterator points to a valid change after a call 10454 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 10455 ** Otherwise, if all changes in the changeset have already been visited, 10456 ** SQLITE_DONE is returned. 10457 ** 10458 ** If an error occurs, an SQLite error code is returned. Possible error 10459 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 10460 ** SQLITE_NOMEM. 10461 */ 10462 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 10463 10464 /* 10465 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 10466 ** METHOD: sqlite3_changeset_iter 10467 ** 10468 ** The pIter argument passed to this function may either be an iterator 10469 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10470 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10471 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 10472 ** is not the case, this function returns [SQLITE_MISUSE]. 10473 ** 10474 ** If argument pzTab is not NULL, then *pzTab is set to point to a 10475 ** nul-terminated utf-8 encoded string containing the name of the table 10476 ** affected by the current change. The buffer remains valid until either 10477 ** sqlite3changeset_next() is called on the iterator or until the 10478 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 10479 ** set to the number of columns in the table affected by the change. If 10480 ** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 10481 ** is an indirect change, or false (0) otherwise. See the documentation for 10482 ** [sqlite3session_indirect()] for a description of direct and indirect 10483 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10484 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10485 ** type of change that the iterator currently points to. 10486 ** 10487 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10488 ** SQLite error code is returned. The values of the output variables may not 10489 ** be trusted in this case. 10490 */ 10491 SQLITE_API int sqlite3changeset_op( 10492 sqlite3_changeset_iter *pIter, /* Iterator object */ 10493 const char **pzTab, /* OUT: Pointer to table name */ 10494 int *pnCol, /* OUT: Number of columns in table */ 10495 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10496 int *pbIndirect /* OUT: True for an 'indirect' change */ 10497 ); 10498 10499 /* 10500 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10501 ** METHOD: sqlite3_changeset_iter 10502 ** 10503 ** For each modified table, a changeset includes the following: 10504 ** 10505 ** <ul> 10506 ** <li> The number of columns in the table, and 10507 ** <li> Which of those columns make up the tables PRIMARY KEY. 10508 ** </ul> 10509 ** 10510 ** This function is used to find which columns comprise the PRIMARY KEY of 10511 ** the table modified by the change that iterator pIter currently points to. 10512 ** If successful, *pabPK is set to point to an array of nCol entries, where 10513 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10514 ** 0x01 if the corresponding column is part of the tables primary key, or 10515 ** 0x00 if it is not. 10516 ** 10517 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10518 ** in the table. 10519 ** 10520 ** If this function is called when the iterator does not point to a valid 10521 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10522 ** SQLITE_OK is returned and the output variables populated as described 10523 ** above. 10524 */ 10525 SQLITE_API int sqlite3changeset_pk( 10526 sqlite3_changeset_iter *pIter, /* Iterator object */ 10527 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10528 int *pnCol /* OUT: Number of entries in output array */ 10529 ); 10530 10531 /* 10532 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10533 ** METHOD: sqlite3_changeset_iter 10534 ** 10535 ** The pIter argument passed to this function may either be an iterator 10536 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10537 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10538 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10539 ** Furthermore, it may only be called if the type of change that the iterator 10540 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10541 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10542 ** 10543 ** Argument iVal must be greater than or equal to 0, and less than the number 10544 ** of columns in the table affected by the current change. Otherwise, 10545 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10546 ** 10547 ** If successful, this function sets *ppValue to point to a protected 10548 ** sqlite3_value object containing the iVal'th value from the vector of 10549 ** original row values stored as part of the UPDATE or DELETE change and 10550 ** returns SQLITE_OK. The name of the function comes from the fact that this 10551 ** is similar to the "old.*" columns available to update or delete triggers. 10552 ** 10553 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10554 ** is returned and *ppValue is set to NULL. 10555 */ 10556 SQLITE_API int sqlite3changeset_old( 10557 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10558 int iVal, /* Column number */ 10559 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10560 ); 10561 10562 /* 10563 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10564 ** METHOD: sqlite3_changeset_iter 10565 ** 10566 ** The pIter argument passed to this function may either be an iterator 10567 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10568 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10569 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10570 ** Furthermore, it may only be called if the type of change that the iterator 10571 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10572 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10573 ** 10574 ** Argument iVal must be greater than or equal to 0, and less than the number 10575 ** of columns in the table affected by the current change. Otherwise, 10576 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10577 ** 10578 ** If successful, this function sets *ppValue to point to a protected 10579 ** sqlite3_value object containing the iVal'th value from the vector of 10580 ** new row values stored as part of the UPDATE or INSERT change and 10581 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10582 ** a new value for the requested column, *ppValue is set to NULL and 10583 ** SQLITE_OK returned. The name of the function comes from the fact that 10584 ** this is similar to the "new.*" columns available to update or delete 10585 ** triggers. 10586 ** 10587 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10588 ** is returned and *ppValue is set to NULL. 10589 */ 10590 SQLITE_API int sqlite3changeset_new( 10591 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10592 int iVal, /* Column number */ 10593 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10594 ); 10595 10596 /* 10597 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10598 ** METHOD: sqlite3_changeset_iter 10599 ** 10600 ** This function should only be used with iterator objects passed to a 10601 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10602 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10603 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10604 ** is set to NULL. 10605 ** 10606 ** Argument iVal must be greater than or equal to 0, and less than the number 10607 ** of columns in the table affected by the current change. Otherwise, 10608 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10609 ** 10610 ** If successful, this function sets *ppValue to point to a protected 10611 ** sqlite3_value object containing the iVal'th value from the 10612 ** "conflicting row" associated with the current conflict-handler callback 10613 ** and returns SQLITE_OK. 10614 ** 10615 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10616 ** is returned and *ppValue is set to NULL. 10617 */ 10618 SQLITE_API int sqlite3changeset_conflict( 10619 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10620 int iVal, /* Column number */ 10621 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10622 ); 10623 10624 /* 10625 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10626 ** METHOD: sqlite3_changeset_iter 10627 ** 10628 ** This function may only be called with an iterator passed to an 10629 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10630 ** it sets the output variable to the total number of known foreign key 10631 ** violations in the destination database and returns SQLITE_OK. 10632 ** 10633 ** In all other cases this function returns SQLITE_MISUSE. 10634 */ 10635 SQLITE_API int sqlite3changeset_fk_conflicts( 10636 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10637 int *pnOut /* OUT: Number of FK violations */ 10638 ); 10639 10640 10641 /* 10642 ** CAPI3REF: Finalize A Changeset Iterator 10643 ** METHOD: sqlite3_changeset_iter 10644 ** 10645 ** This function is used to finalize an iterator allocated with 10646 ** [sqlite3changeset_start()]. 10647 ** 10648 ** This function should only be called on iterators created using the 10649 ** [sqlite3changeset_start()] function. If an application calls this 10650 ** function with an iterator passed to a conflict-handler by 10651 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10652 ** call has no effect. 10653 ** 10654 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10655 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10656 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10657 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10658 ** returned. This is to allow the following pattern (pseudo-code): 10659 ** 10660 ** <pre> 10661 ** sqlite3changeset_start(); 10662 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10663 ** // Do something with change. 10664 ** } 10665 ** rc = sqlite3changeset_finalize(); 10666 ** if( rc!=SQLITE_OK ){ 10667 ** // An error has occurred 10668 ** } 10669 ** </pre> 10670 */ 10671 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10672 10673 /* 10674 ** CAPI3REF: Invert A Changeset 10675 ** 10676 ** This function is used to "invert" a changeset object. Applying an inverted 10677 ** changeset to a database reverses the effects of applying the uninverted 10678 ** changeset. Specifically: 10679 ** 10680 ** <ul> 10681 ** <li> Each DELETE change is changed to an INSERT, and 10682 ** <li> Each INSERT change is changed to a DELETE, and 10683 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10684 ** </ul> 10685 ** 10686 ** This function does not change the order in which changes appear within 10687 ** the changeset. It merely reverses the sense of each individual change. 10688 ** 10689 ** If successful, a pointer to a buffer containing the inverted changeset 10690 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10691 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10692 ** zeroed and an SQLite error code returned. 10693 ** 10694 ** It is the responsibility of the caller to eventually call sqlite3_free() 10695 ** on the *ppOut pointer to free the buffer allocation following a successful 10696 ** call to this function. 10697 ** 10698 ** WARNING/TODO: This function currently assumes that the input is a valid 10699 ** changeset. If it is not, the results are undefined. 10700 */ 10701 SQLITE_API int sqlite3changeset_invert( 10702 int nIn, const void *pIn, /* Input changeset */ 10703 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10704 ); 10705 10706 /* 10707 ** CAPI3REF: Concatenate Two Changeset Objects 10708 ** 10709 ** This function is used to concatenate two changesets, A and B, into a 10710 ** single changeset. The result is a changeset equivalent to applying 10711 ** changeset A followed by changeset B. 10712 ** 10713 ** This function combines the two input changesets using an 10714 ** sqlite3_changegroup object. Calling it produces similar results as the 10715 ** following code fragment: 10716 ** 10717 ** <pre> 10718 ** sqlite3_changegroup *pGrp; 10719 ** rc = sqlite3_changegroup_new(&pGrp); 10720 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10721 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10722 ** if( rc==SQLITE_OK ){ 10723 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10724 ** }else{ 10725 ** *ppOut = 0; 10726 ** *pnOut = 0; 10727 ** } 10728 ** </pre> 10729 ** 10730 ** Refer to the sqlite3_changegroup documentation below for details. 10731 */ 10732 SQLITE_API int sqlite3changeset_concat( 10733 int nA, /* Number of bytes in buffer pA */ 10734 void *pA, /* Pointer to buffer containing changeset A */ 10735 int nB, /* Number of bytes in buffer pB */ 10736 void *pB, /* Pointer to buffer containing changeset B */ 10737 int *pnOut, /* OUT: Number of bytes in output changeset */ 10738 void **ppOut /* OUT: Buffer containing output changeset */ 10739 ); 10740 10741 10742 /* 10743 ** CAPI3REF: Changegroup Handle 10744 ** 10745 ** A changegroup is an object used to combine two or more 10746 ** [changesets] or [patchsets] 10747 */ 10748 typedef struct sqlite3_changegroup sqlite3_changegroup; 10749 10750 /* 10751 ** CAPI3REF: Create A New Changegroup Object 10752 ** CONSTRUCTOR: sqlite3_changegroup 10753 ** 10754 ** An sqlite3_changegroup object is used to combine two or more changesets 10755 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10756 ** object may combine changesets or patchsets, but not both. The output is 10757 ** always in the same format as the input. 10758 ** 10759 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10760 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10761 ** should eventually free the returned object using a call to 10762 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10763 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10764 ** 10765 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10766 ** 10767 ** <ul> 10768 ** <li> It is created using a call to sqlite3changegroup_new(). 10769 ** 10770 ** <li> Zero or more changesets (or patchsets) are added to the object 10771 ** by calling sqlite3changegroup_add(). 10772 ** 10773 ** <li> The result of combining all input changesets together is obtained 10774 ** by the application via a call to sqlite3changegroup_output(). 10775 ** 10776 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10777 ** </ul> 10778 ** 10779 ** Any number of calls to add() and output() may be made between the calls to 10780 ** new() and delete(), and in any order. 10781 ** 10782 ** As well as the regular sqlite3changegroup_add() and 10783 ** sqlite3changegroup_output() functions, also available are the streaming 10784 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10785 */ 10786 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10787 10788 /* 10789 ** CAPI3REF: Add A Changeset To A Changegroup 10790 ** METHOD: sqlite3_changegroup 10791 ** 10792 ** Add all changes within the changeset (or patchset) in buffer pData (size 10793 ** nData bytes) to the changegroup. 10794 ** 10795 ** If the buffer contains a patchset, then all prior calls to this function 10796 ** on the same changegroup object must also have specified patchsets. Or, if 10797 ** the buffer contains a changeset, so must have the earlier calls to this 10798 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10799 ** to the changegroup. 10800 ** 10801 ** Rows within the changeset and changegroup are identified by the values in 10802 ** their PRIMARY KEY columns. A change in the changeset is considered to 10803 ** apply to the same row as a change already present in the changegroup if 10804 ** the two rows have the same primary key. 10805 ** 10806 ** Changes to rows that do not already appear in the changegroup are 10807 ** simply copied into it. Or, if both the new changeset and the changegroup 10808 ** contain changes that apply to a single row, the final contents of the 10809 ** changegroup depends on the type of each change, as follows: 10810 ** 10811 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10812 ** <tr><th style="white-space:pre">Existing Change </th> 10813 ** <th style="white-space:pre">New Change </th> 10814 ** <th>Output Change 10815 ** <tr><td>INSERT <td>INSERT <td> 10816 ** The new change is ignored. This case does not occur if the new 10817 ** changeset was recorded immediately after the changesets already 10818 ** added to the changegroup. 10819 ** <tr><td>INSERT <td>UPDATE <td> 10820 ** The INSERT change remains in the changegroup. The values in the 10821 ** INSERT change are modified as if the row was inserted by the 10822 ** existing change and then updated according to the new change. 10823 ** <tr><td>INSERT <td>DELETE <td> 10824 ** The existing INSERT is removed from the changegroup. The DELETE is 10825 ** not added. 10826 ** <tr><td>UPDATE <td>INSERT <td> 10827 ** The new change is ignored. This case does not occur if the new 10828 ** changeset was recorded immediately after the changesets already 10829 ** added to the changegroup. 10830 ** <tr><td>UPDATE <td>UPDATE <td> 10831 ** The existing UPDATE remains within the changegroup. It is amended 10832 ** so that the accompanying values are as if the row was updated once 10833 ** by the existing change and then again by the new change. 10834 ** <tr><td>UPDATE <td>DELETE <td> 10835 ** The existing UPDATE is replaced by the new DELETE within the 10836 ** changegroup. 10837 ** <tr><td>DELETE <td>INSERT <td> 10838 ** If one or more of the column values in the row inserted by the 10839 ** new change differ from those in the row deleted by the existing 10840 ** change, the existing DELETE is replaced by an UPDATE within the 10841 ** changegroup. Otherwise, if the inserted row is exactly the same 10842 ** as the deleted row, the existing DELETE is simply discarded. 10843 ** <tr><td>DELETE <td>UPDATE <td> 10844 ** The new change is ignored. This case does not occur if the new 10845 ** changeset was recorded immediately after the changesets already 10846 ** added to the changegroup. 10847 ** <tr><td>DELETE <td>DELETE <td> 10848 ** The new change is ignored. This case does not occur if the new 10849 ** changeset was recorded immediately after the changesets already 10850 ** added to the changegroup. 10851 ** </table> 10852 ** 10853 ** If the new changeset contains changes to a table that is already present 10854 ** in the changegroup, then the number of columns and the position of the 10855 ** primary key columns for the table must be consistent. If this is not the 10856 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10857 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10858 ** returned. Or, if an out-of-memory condition occurs during processing, this 10859 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 10860 ** of the final contents of the changegroup is undefined. 10861 ** 10862 ** If no error occurs, SQLITE_OK is returned. 10863 */ 10864 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10865 10866 /* 10867 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10868 ** METHOD: sqlite3_changegroup 10869 ** 10870 ** Obtain a buffer containing a changeset (or patchset) representing the 10871 ** current contents of the changegroup. If the inputs to the changegroup 10872 ** were themselves changesets, the output is a changeset. Or, if the 10873 ** inputs were patchsets, the output is also a patchset. 10874 ** 10875 ** As with the output of the sqlite3session_changeset() and 10876 ** sqlite3session_patchset() functions, all changes related to a single 10877 ** table are grouped together in the output of this function. Tables appear 10878 ** in the same order as for the very first changeset added to the changegroup. 10879 ** If the second or subsequent changesets added to the changegroup contain 10880 ** changes for tables that do not appear in the first changeset, they are 10881 ** appended onto the end of the output changeset, again in the order in 10882 ** which they are first encountered. 10883 ** 10884 ** If an error occurs, an SQLite error code is returned and the output 10885 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10886 ** is returned and the output variables are set to the size of and a 10887 ** pointer to the output buffer, respectively. In this case it is the 10888 ** responsibility of the caller to eventually free the buffer using a 10889 ** call to sqlite3_free(). 10890 */ 10891 SQLITE_API int sqlite3changegroup_output( 10892 sqlite3_changegroup*, 10893 int *pnData, /* OUT: Size of output buffer in bytes */ 10894 void **ppData /* OUT: Pointer to output buffer */ 10895 ); 10896 10897 /* 10898 ** CAPI3REF: Delete A Changegroup Object 10899 ** DESTRUCTOR: sqlite3_changegroup 10900 */ 10901 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10902 10903 /* 10904 ** CAPI3REF: Apply A Changeset To A Database 10905 ** 10906 ** Apply a changeset or patchset to a database. These functions attempt to 10907 ** update the "main" database attached to handle db with the changes found in 10908 ** the changeset passed via the second and third arguments. 10909 ** 10910 ** The fourth argument (xFilter) passed to these functions is the "filter 10911 ** callback". If it is not NULL, then for each table affected by at least one 10912 ** change in the changeset, the filter callback is invoked with 10913 ** the table name as the second argument, and a copy of the context pointer 10914 ** passed as the sixth argument as the first. If the "filter callback" 10915 ** returns zero, then no attempt is made to apply any changes to the table. 10916 ** Otherwise, if the return value is non-zero or the xFilter argument to 10917 ** is NULL, all changes related to the table are attempted. 10918 ** 10919 ** For each table that is not excluded by the filter callback, this function 10920 ** tests that the target database contains a compatible table. A table is 10921 ** considered compatible if all of the following are true: 10922 ** 10923 ** <ul> 10924 ** <li> The table has the same name as the name recorded in the 10925 ** changeset, and 10926 ** <li> The table has at least as many columns as recorded in the 10927 ** changeset, and 10928 ** <li> The table has primary key columns in the same position as 10929 ** recorded in the changeset. 10930 ** </ul> 10931 ** 10932 ** If there is no compatible table, it is not an error, but none of the 10933 ** changes associated with the table are applied. A warning message is issued 10934 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10935 ** one such warning is issued for each table in the changeset. 10936 ** 10937 ** For each change for which there is a compatible table, an attempt is made 10938 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10939 ** change. If a change cannot be applied cleanly, the conflict handler 10940 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10941 ** invoked. A description of exactly when the conflict handler is invoked for 10942 ** each type of change is below. 10943 ** 10944 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10945 ** of passing anything other than a valid function pointer as the xConflict 10946 ** argument are undefined. 10947 ** 10948 ** Each time the conflict handler function is invoked, it must return one 10949 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10950 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10951 ** if the second argument passed to the conflict handler is either 10952 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10953 ** returns an illegal value, any changes already made are rolled back and 10954 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10955 ** actions are taken by sqlite3changeset_apply() depending on the value 10956 ** returned by each invocation of the conflict-handler function. Refer to 10957 ** the documentation for the three 10958 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10959 ** 10960 ** <dl> 10961 ** <dt>DELETE Changes<dd> 10962 ** For each DELETE change, the function checks if the target database 10963 ** contains a row with the same primary key value (or values) as the 10964 ** original row values stored in the changeset. If it does, and the values 10965 ** stored in all non-primary key columns also match the values stored in 10966 ** the changeset the row is deleted from the target database. 10967 ** 10968 ** If a row with matching primary key values is found, but one or more of 10969 ** the non-primary key fields contains a value different from the original 10970 ** row value stored in the changeset, the conflict-handler function is 10971 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10972 ** database table has more columns than are recorded in the changeset, 10973 ** only the values of those non-primary key fields are compared against 10974 ** the current database contents - any trailing database table columns 10975 ** are ignored. 10976 ** 10977 ** If no row with matching primary key values is found in the database, 10978 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10979 ** passed as the second argument. 10980 ** 10981 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10982 ** (which can only happen if a foreign key constraint is violated), the 10983 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10984 ** passed as the second argument. This includes the case where the DELETE 10985 ** operation is attempted because an earlier call to the conflict handler 10986 ** function returned [SQLITE_CHANGESET_REPLACE]. 10987 ** 10988 ** <dt>INSERT Changes<dd> 10989 ** For each INSERT change, an attempt is made to insert the new row into 10990 ** the database. If the changeset row contains fewer fields than the 10991 ** database table, the trailing fields are populated with their default 10992 ** values. 10993 ** 10994 ** If the attempt to insert the row fails because the database already 10995 ** contains a row with the same primary key values, the conflict handler 10996 ** function is invoked with the second argument set to 10997 ** [SQLITE_CHANGESET_CONFLICT]. 10998 ** 10999 ** If the attempt to insert the row fails because of some other constraint 11000 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11001 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11002 ** This includes the case where the INSERT operation is re-attempted because 11003 ** an earlier call to the conflict handler function returned 11004 ** [SQLITE_CHANGESET_REPLACE]. 11005 ** 11006 ** <dt>UPDATE Changes<dd> 11007 ** For each UPDATE change, the function checks if the target database 11008 ** contains a row with the same primary key value (or values) as the 11009 ** original row values stored in the changeset. If it does, and the values 11010 ** stored in all modified non-primary key columns also match the values 11011 ** stored in the changeset the row is updated within the target database. 11012 ** 11013 ** If a row with matching primary key values is found, but one or more of 11014 ** the modified non-primary key fields contains a value different from an 11015 ** original row value stored in the changeset, the conflict-handler function 11016 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11017 ** UPDATE changes only contain values for non-primary key fields that are 11018 ** to be modified, only those fields need to match the original values to 11019 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11020 ** 11021 ** If no row with matching primary key values is found in the database, 11022 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11023 ** passed as the second argument. 11024 ** 11025 ** If the UPDATE operation is attempted, but SQLite returns 11026 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11027 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11028 ** This includes the case where the UPDATE operation is attempted after 11029 ** an earlier call to the conflict handler function returned 11030 ** [SQLITE_CHANGESET_REPLACE]. 11031 ** </dl> 11032 ** 11033 ** It is safe to execute SQL statements, including those that write to the 11034 ** table that the callback related to, from within the xConflict callback. 11035 ** This can be used to further customize the application's conflict 11036 ** resolution strategy. 11037 ** 11038 ** All changes made by these functions are enclosed in a savepoint transaction. 11039 ** If any other error (aside from a constraint failure when attempting to 11040 ** write to the target database) occurs, then the savepoint transaction is 11041 ** rolled back, restoring the target database to its original state, and an 11042 ** SQLite error code returned. 11043 ** 11044 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11045 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11046 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11047 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11048 ** is set to the size of the buffer in bytes. It is the responsibility of the 11049 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11050 ** is only allocated and populated if one or more conflicts were encountered 11051 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11052 ** APIs for further details. 11053 ** 11054 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11055 ** may be modified by passing a combination of 11056 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11057 ** 11058 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11059 ** and therefore subject to change. 11060 */ 11061 SQLITE_API int sqlite3changeset_apply( 11062 sqlite3 *db, /* Apply change to "main" db of this handle */ 11063 int nChangeset, /* Size of changeset in bytes */ 11064 void *pChangeset, /* Changeset blob */ 11065 int(*xFilter)( 11066 void *pCtx, /* Copy of sixth arg to _apply() */ 11067 const char *zTab /* Table name */ 11068 ), 11069 int(*xConflict)( 11070 void *pCtx, /* Copy of sixth arg to _apply() */ 11071 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11072 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11073 ), 11074 void *pCtx /* First argument passed to xConflict */ 11075 ); 11076 SQLITE_API int sqlite3changeset_apply_v2( 11077 sqlite3 *db, /* Apply change to "main" db of this handle */ 11078 int nChangeset, /* Size of changeset in bytes */ 11079 void *pChangeset, /* Changeset blob */ 11080 int(*xFilter)( 11081 void *pCtx, /* Copy of sixth arg to _apply() */ 11082 const char *zTab /* Table name */ 11083 ), 11084 int(*xConflict)( 11085 void *pCtx, /* Copy of sixth arg to _apply() */ 11086 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11087 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11088 ), 11089 void *pCtx, /* First argument passed to xConflict */ 11090 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11091 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11092 ); 11093 11094 /* 11095 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11096 ** 11097 ** The following flags may passed via the 9th parameter to 11098 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11099 ** 11100 ** <dl> 11101 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11102 ** Usually, the sessions module encloses all operations performed by 11103 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11104 ** SAVEPOINT is committed if the changeset or patchset is successfully 11105 ** applied, or rolled back if an error occurs. Specifying this flag 11106 ** causes the sessions module to omit this savepoint. In this case, if the 11107 ** caller has an open transaction or savepoint when apply_v2() is called, 11108 ** it may revert the partially applied changeset by rolling it back. 11109 ** 11110 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11111 ** Invert the changeset before applying it. This is equivalent to inverting 11112 ** a changeset using sqlite3changeset_invert() before applying it. It is 11113 ** an error to specify this flag with a patchset. 11114 */ 11115 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11116 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11117 11118 /* 11119 ** CAPI3REF: Constants Passed To The Conflict Handler 11120 ** 11121 ** Values that may be passed as the second argument to a conflict-handler. 11122 ** 11123 ** <dl> 11124 ** <dt>SQLITE_CHANGESET_DATA<dd> 11125 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11126 ** when processing a DELETE or UPDATE change if a row with the required 11127 ** PRIMARY KEY fields is present in the database, but one or more other 11128 ** (non primary-key) fields modified by the update do not contain the 11129 ** expected "before" values. 11130 ** 11131 ** The conflicting row, in this case, is the database row with the matching 11132 ** primary key. 11133 ** 11134 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11135 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11136 ** argument when processing a DELETE or UPDATE change if a row with the 11137 ** required PRIMARY KEY fields is not present in the database. 11138 ** 11139 ** There is no conflicting row in this case. The results of invoking the 11140 ** sqlite3changeset_conflict() API are undefined. 11141 ** 11142 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11143 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11144 ** handler while processing an INSERT change if the operation would result 11145 ** in duplicate primary key values. 11146 ** 11147 ** The conflicting row in this case is the database row with the matching 11148 ** primary key. 11149 ** 11150 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11151 ** If foreign key handling is enabled, and applying a changeset leaves the 11152 ** database in a state containing foreign key violations, the conflict 11153 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11154 ** exactly once before the changeset is committed. If the conflict handler 11155 ** returns CHANGESET_OMIT, the changes, including those that caused the 11156 ** foreign key constraint violation, are committed. Or, if it returns 11157 ** CHANGESET_ABORT, the changeset is rolled back. 11158 ** 11159 ** No current or conflicting row information is provided. The only function 11160 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11161 ** is sqlite3changeset_fk_conflicts(). 11162 ** 11163 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11164 ** If any other constraint violation occurs while applying a change (i.e. 11165 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11166 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11167 ** 11168 ** There is no conflicting row in this case. The results of invoking the 11169 ** sqlite3changeset_conflict() API are undefined. 11170 ** 11171 ** </dl> 11172 */ 11173 #define SQLITE_CHANGESET_DATA 1 11174 #define SQLITE_CHANGESET_NOTFOUND 2 11175 #define SQLITE_CHANGESET_CONFLICT 3 11176 #define SQLITE_CHANGESET_CONSTRAINT 4 11177 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11178 11179 /* 11180 ** CAPI3REF: Constants Returned By The Conflict Handler 11181 ** 11182 ** A conflict handler callback must return one of the following three values. 11183 ** 11184 ** <dl> 11185 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11186 ** If a conflict handler returns this value no special action is taken. The 11187 ** change that caused the conflict is not applied. The session module 11188 ** continues to the next change in the changeset. 11189 ** 11190 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11191 ** This value may only be returned if the second argument to the conflict 11192 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11193 ** is not the case, any changes applied so far are rolled back and the 11194 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11195 ** 11196 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11197 ** handler, then the conflicting row is either updated or deleted, depending 11198 ** on the type of change. 11199 ** 11200 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11201 ** handler, then the conflicting row is removed from the database and a 11202 ** second attempt to apply the change is made. If this second attempt fails, 11203 ** the original row is restored to the database before continuing. 11204 ** 11205 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11206 ** If this value is returned, any changes applied so far are rolled back 11207 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11208 ** </dl> 11209 */ 11210 #define SQLITE_CHANGESET_OMIT 0 11211 #define SQLITE_CHANGESET_REPLACE 1 11212 #define SQLITE_CHANGESET_ABORT 2 11213 11214 /* 11215 ** CAPI3REF: Rebasing changesets 11216 ** EXPERIMENTAL 11217 ** 11218 ** Suppose there is a site hosting a database in state S0. And that 11219 ** modifications are made that move that database to state S1 and a 11220 ** changeset recorded (the "local" changeset). Then, a changeset based 11221 ** on S0 is received from another site (the "remote" changeset) and 11222 ** applied to the database. The database is then in state 11223 ** (S1+"remote"), where the exact state depends on any conflict 11224 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 11225 ** Rebasing a changeset is to update it to take those conflict 11226 ** resolution decisions into account, so that the same conflicts 11227 ** do not have to be resolved elsewhere in the network. 11228 ** 11229 ** For example, if both the local and remote changesets contain an 11230 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 11231 ** 11232 ** local: INSERT INTO t1 VALUES(1, 'v1'); 11233 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 11234 ** 11235 ** and the conflict resolution is REPLACE, then the INSERT change is 11236 ** removed from the local changeset (it was overridden). Or, if the 11237 ** conflict resolution was "OMIT", then the local changeset is modified 11238 ** to instead contain: 11239 ** 11240 ** UPDATE t1 SET b = 'v2' WHERE a=1; 11241 ** 11242 ** Changes within the local changeset are rebased as follows: 11243 ** 11244 ** <dl> 11245 ** <dt>Local INSERT<dd> 11246 ** This may only conflict with a remote INSERT. If the conflict 11247 ** resolution was OMIT, then add an UPDATE change to the rebased 11248 ** changeset. Or, if the conflict resolution was REPLACE, add 11249 ** nothing to the rebased changeset. 11250 ** 11251 ** <dt>Local DELETE<dd> 11252 ** This may conflict with a remote UPDATE or DELETE. In both cases the 11253 ** only possible resolution is OMIT. If the remote operation was a 11254 ** DELETE, then add no change to the rebased changeset. If the remote 11255 ** operation was an UPDATE, then the old.* fields of change are updated 11256 ** to reflect the new.* values in the UPDATE. 11257 ** 11258 ** <dt>Local UPDATE<dd> 11259 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 11260 ** with a DELETE, and the conflict resolution was OMIT, then the update 11261 ** is changed into an INSERT. Any undefined values in the new.* record 11262 ** from the update change are filled in using the old.* values from 11263 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 11264 ** the UPDATE change is simply omitted from the rebased changeset. 11265 ** 11266 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 11267 ** the old.* values are rebased using the new.* values in the remote 11268 ** change. Or, if the resolution is REPLACE, then the change is copied 11269 ** into the rebased changeset with updates to columns also updated by 11270 ** the conflicting remote UPDATE removed. If this means no columns would 11271 ** be updated, the change is omitted. 11272 ** </dl> 11273 ** 11274 ** A local change may be rebased against multiple remote changes 11275 ** simultaneously. If a single key is modified by multiple remote 11276 ** changesets, they are combined as follows before the local changeset 11277 ** is rebased: 11278 ** 11279 ** <ul> 11280 ** <li> If there has been one or more REPLACE resolutions on a 11281 ** key, it is rebased according to a REPLACE. 11282 ** 11283 ** <li> If there have been no REPLACE resolutions on a key, then 11284 ** the local changeset is rebased according to the most recent 11285 ** of the OMIT resolutions. 11286 ** </ul> 11287 ** 11288 ** Note that conflict resolutions from multiple remote changesets are 11289 ** combined on a per-field basis, not per-row. This means that in the 11290 ** case of multiple remote UPDATE operations, some fields of a single 11291 ** local change may be rebased for REPLACE while others are rebased for 11292 ** OMIT. 11293 ** 11294 ** In order to rebase a local changeset, the remote changeset must first 11295 ** be applied to the local database using sqlite3changeset_apply_v2() and 11296 ** the buffer of rebase information captured. Then: 11297 ** 11298 ** <ol> 11299 ** <li> An sqlite3_rebaser object is created by calling 11300 ** sqlite3rebaser_create(). 11301 ** <li> The new object is configured with the rebase buffer obtained from 11302 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 11303 ** If the local changeset is to be rebased against multiple remote 11304 ** changesets, then sqlite3rebaser_configure() should be called 11305 ** multiple times, in the same order that the multiple 11306 ** sqlite3changeset_apply_v2() calls were made. 11307 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 11308 ** <li> The sqlite3_rebaser object is deleted by calling 11309 ** sqlite3rebaser_delete(). 11310 ** </ol> 11311 */ 11312 typedef struct sqlite3_rebaser sqlite3_rebaser; 11313 11314 /* 11315 ** CAPI3REF: Create a changeset rebaser object. 11316 ** EXPERIMENTAL 11317 ** 11318 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 11319 ** point to the new object and return SQLITE_OK. Otherwise, if an error 11320 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 11321 ** to NULL. 11322 */ 11323 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 11324 11325 /* 11326 ** CAPI3REF: Configure a changeset rebaser object. 11327 ** EXPERIMENTAL 11328 ** 11329 ** Configure the changeset rebaser object to rebase changesets according 11330 ** to the conflict resolutions described by buffer pRebase (size nRebase 11331 ** bytes), which must have been obtained from a previous call to 11332 ** sqlite3changeset_apply_v2(). 11333 */ 11334 SQLITE_API int sqlite3rebaser_configure( 11335 sqlite3_rebaser*, 11336 int nRebase, const void *pRebase 11337 ); 11338 11339 /* 11340 ** CAPI3REF: Rebase a changeset 11341 ** EXPERIMENTAL 11342 ** 11343 ** Argument pIn must point to a buffer containing a changeset nIn bytes 11344 ** in size. This function allocates and populates a buffer with a copy 11345 ** of the changeset rebased according to the configuration of the 11346 ** rebaser object passed as the first argument. If successful, (*ppOut) 11347 ** is set to point to the new buffer containing the rebased changeset and 11348 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 11349 ** responsibility of the caller to eventually free the new buffer using 11350 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 11351 ** are set to zero and an SQLite error code returned. 11352 */ 11353 SQLITE_API int sqlite3rebaser_rebase( 11354 sqlite3_rebaser*, 11355 int nIn, const void *pIn, 11356 int *pnOut, void **ppOut 11357 ); 11358 11359 /* 11360 ** CAPI3REF: Delete a changeset rebaser object. 11361 ** EXPERIMENTAL 11362 ** 11363 ** Delete the changeset rebaser object and all associated resources. There 11364 ** should be one call to this function for each successful invocation 11365 ** of sqlite3rebaser_create(). 11366 */ 11367 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 11368 11369 /* 11370 ** CAPI3REF: Streaming Versions of API functions. 11371 ** 11372 ** The six streaming API xxx_strm() functions serve similar purposes to the 11373 ** corresponding non-streaming API functions: 11374 ** 11375 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11376 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 11377 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 11378 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 11379 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 11380 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 11381 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 11382 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 11383 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 11384 ** </table> 11385 ** 11386 ** Non-streaming functions that accept changesets (or patchsets) as input 11387 ** require that the entire changeset be stored in a single buffer in memory. 11388 ** Similarly, those that return a changeset or patchset do so by returning 11389 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 11390 ** Normally this is convenient. However, if an application running in a 11391 ** low-memory environment is required to handle very large changesets, the 11392 ** large contiguous memory allocations required can become onerous. 11393 ** 11394 ** In order to avoid this problem, instead of a single large buffer, input 11395 ** is passed to a streaming API functions by way of a callback function that 11396 ** the sessions module invokes to incrementally request input data as it is 11397 ** required. In all cases, a pair of API function parameters such as 11398 ** 11399 ** <pre> 11400 ** int nChangeset, 11401 ** void *pChangeset, 11402 ** </pre> 11403 ** 11404 ** Is replaced by: 11405 ** 11406 ** <pre> 11407 ** int (*xInput)(void *pIn, void *pData, int *pnData), 11408 ** void *pIn, 11409 ** </pre> 11410 ** 11411 ** Each time the xInput callback is invoked by the sessions module, the first 11412 ** argument passed is a copy of the supplied pIn context pointer. The second 11413 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 11414 ** error occurs the xInput method should copy up to (*pnData) bytes of data 11415 ** into the buffer and set (*pnData) to the actual number of bytes copied 11416 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 11417 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 11418 ** error code should be returned. In all cases, if an xInput callback returns 11419 ** an error, all processing is abandoned and the streaming API function 11420 ** returns a copy of the error code to the caller. 11421 ** 11422 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 11423 ** invoked by the sessions module at any point during the lifetime of the 11424 ** iterator. If such an xInput callback returns an error, the iterator enters 11425 ** an error state, whereby all subsequent calls to iterator functions 11426 ** immediately fail with the same error code as returned by xInput. 11427 ** 11428 ** Similarly, streaming API functions that return changesets (or patchsets) 11429 ** return them in chunks by way of a callback function instead of via a 11430 ** pointer to a single large buffer. In this case, a pair of parameters such 11431 ** as: 11432 ** 11433 ** <pre> 11434 ** int *pnChangeset, 11435 ** void **ppChangeset, 11436 ** </pre> 11437 ** 11438 ** Is replaced by: 11439 ** 11440 ** <pre> 11441 ** int (*xOutput)(void *pOut, const void *pData, int nData), 11442 ** void *pOut 11443 ** </pre> 11444 ** 11445 ** The xOutput callback is invoked zero or more times to return data to 11446 ** the application. The first parameter passed to each call is a copy of the 11447 ** pOut pointer supplied by the application. The second parameter, pData, 11448 ** points to a buffer nData bytes in size containing the chunk of output 11449 ** data being returned. If the xOutput callback successfully processes the 11450 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 11451 ** it should return some other SQLite error code. In this case processing 11452 ** is immediately abandoned and the streaming API function returns a copy 11453 ** of the xOutput error code to the application. 11454 ** 11455 ** The sessions module never invokes an xOutput callback with the third 11456 ** parameter set to a value less than or equal to zero. Other than this, 11457 ** no guarantees are made as to the size of the chunks of data returned. 11458 */ 11459 SQLITE_API int sqlite3changeset_apply_strm( 11460 sqlite3 *db, /* Apply change to "main" db of this handle */ 11461 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11462 void *pIn, /* First arg for xInput */ 11463 int(*xFilter)( 11464 void *pCtx, /* Copy of sixth arg to _apply() */ 11465 const char *zTab /* Table name */ 11466 ), 11467 int(*xConflict)( 11468 void *pCtx, /* Copy of sixth arg to _apply() */ 11469 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11470 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11471 ), 11472 void *pCtx /* First argument passed to xConflict */ 11473 ); 11474 SQLITE_API int sqlite3changeset_apply_v2_strm( 11475 sqlite3 *db, /* Apply change to "main" db of this handle */ 11476 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 11477 void *pIn, /* First arg for xInput */ 11478 int(*xFilter)( 11479 void *pCtx, /* Copy of sixth arg to _apply() */ 11480 const char *zTab /* Table name */ 11481 ), 11482 int(*xConflict)( 11483 void *pCtx, /* Copy of sixth arg to _apply() */ 11484 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11485 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11486 ), 11487 void *pCtx, /* First argument passed to xConflict */ 11488 void **ppRebase, int *pnRebase, 11489 int flags 11490 ); 11491 SQLITE_API int sqlite3changeset_concat_strm( 11492 int (*xInputA)(void *pIn, void *pData, int *pnData), 11493 void *pInA, 11494 int (*xInputB)(void *pIn, void *pData, int *pnData), 11495 void *pInB, 11496 int (*xOutput)(void *pOut, const void *pData, int nData), 11497 void *pOut 11498 ); 11499 SQLITE_API int sqlite3changeset_invert_strm( 11500 int (*xInput)(void *pIn, void *pData, int *pnData), 11501 void *pIn, 11502 int (*xOutput)(void *pOut, const void *pData, int nData), 11503 void *pOut 11504 ); 11505 SQLITE_API int sqlite3changeset_start_strm( 11506 sqlite3_changeset_iter **pp, 11507 int (*xInput)(void *pIn, void *pData, int *pnData), 11508 void *pIn 11509 ); 11510 SQLITE_API int sqlite3changeset_start_v2_strm( 11511 sqlite3_changeset_iter **pp, 11512 int (*xInput)(void *pIn, void *pData, int *pnData), 11513 void *pIn, 11514 int flags 11515 ); 11516 SQLITE_API int sqlite3session_changeset_strm( 11517 sqlite3_session *pSession, 11518 int (*xOutput)(void *pOut, const void *pData, int nData), 11519 void *pOut 11520 ); 11521 SQLITE_API int sqlite3session_patchset_strm( 11522 sqlite3_session *pSession, 11523 int (*xOutput)(void *pOut, const void *pData, int nData), 11524 void *pOut 11525 ); 11526 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11527 int (*xInput)(void *pIn, void *pData, int *pnData), 11528 void *pIn 11529 ); 11530 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11531 int (*xOutput)(void *pOut, const void *pData, int nData), 11532 void *pOut 11533 ); 11534 SQLITE_API int sqlite3rebaser_rebase_strm( 11535 sqlite3_rebaser *pRebaser, 11536 int (*xInput)(void *pIn, void *pData, int *pnData), 11537 void *pIn, 11538 int (*xOutput)(void *pOut, const void *pData, int nData), 11539 void *pOut 11540 ); 11541 11542 /* 11543 ** CAPI3REF: Configure global parameters 11544 ** 11545 ** The sqlite3session_config() interface is used to make global configuration 11546 ** changes to the sessions module in order to tune it to the specific needs 11547 ** of the application. 11548 ** 11549 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11550 ** while any other thread is inside any other sessions method then the 11551 ** results are undefined. Furthermore, if it is invoked after any sessions 11552 ** related objects have been created, the results are also undefined. 11553 ** 11554 ** The first argument to the sqlite3session_config() function must be one 11555 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11556 ** interpretation of the (void*) value passed as the second parameter and 11557 ** the effect of calling this function depends on the value of the first 11558 ** parameter. 11559 ** 11560 ** <dl> 11561 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11562 ** By default, the sessions module streaming interfaces attempt to input 11563 ** and output data in approximately 1 KiB chunks. This operand may be used 11564 ** to set and query the value of this configuration setting. The pointer 11565 ** passed as the second argument must point to a value of type (int). 11566 ** If this value is greater than 0, it is used as the new streaming data 11567 ** chunk size for both input and output. Before returning, the (int) value 11568 ** pointed to by pArg is set to the final value of the streaming interface 11569 ** chunk size. 11570 ** </dl> 11571 ** 11572 ** This function returns SQLITE_OK if successful, or an SQLite error code 11573 ** otherwise. 11574 */ 11575 SQLITE_API int sqlite3session_config(int op, void *pArg); 11576 11577 /* 11578 ** CAPI3REF: Values for sqlite3session_config(). 11579 */ 11580 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11581 11582 /* 11583 ** Make sure we can call this stuff from C++. 11584 */ 11585 #ifdef __cplusplus 11586 } 11587 #endif 11588 11589 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11590 11591 /******** End of sqlite3session.h *********/ 11592 /******** Begin file fts5.h *********/ 11593 /* 11594 ** 2014 May 31 11595 ** 11596 ** The author disclaims copyright to this source code. In place of 11597 ** a legal notice, here is a blessing: 11598 ** 11599 ** May you do good and not evil. 11600 ** May you find forgiveness for yourself and forgive others. 11601 ** May you share freely, never taking more than you give. 11602 ** 11603 ****************************************************************************** 11604 ** 11605 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11606 ** FTS5 may be extended with: 11607 ** 11608 ** * custom tokenizers, and 11609 ** * custom auxiliary functions. 11610 */ 11611 11612 11613 #ifndef _FTS5_H 11614 #define _FTS5_H 11615 11616 11617 #ifdef __cplusplus 11618 extern "C" { 11619 #endif 11620 11621 /************************************************************************* 11622 ** CUSTOM AUXILIARY FUNCTIONS 11623 ** 11624 ** Virtual table implementations may overload SQL functions by implementing 11625 ** the sqlite3_module.xFindFunction() method. 11626 */ 11627 11628 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11629 typedef struct Fts5Context Fts5Context; 11630 typedef struct Fts5PhraseIter Fts5PhraseIter; 11631 11632 typedef void (*fts5_extension_function)( 11633 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11634 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11635 sqlite3_context *pCtx, /* Context for returning result/error */ 11636 int nVal, /* Number of values in apVal[] array */ 11637 sqlite3_value **apVal /* Array of trailing arguments */ 11638 ); 11639 11640 struct Fts5PhraseIter { 11641 const unsigned char *a; 11642 const unsigned char *b; 11643 }; 11644 11645 /* 11646 ** EXTENSION API FUNCTIONS 11647 ** 11648 ** xUserData(pFts): 11649 ** Return a copy of the context pointer the extension function was 11650 ** registered with. 11651 ** 11652 ** xColumnTotalSize(pFts, iCol, pnToken): 11653 ** If parameter iCol is less than zero, set output variable *pnToken 11654 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11655 ** non-negative but less than the number of columns in the table, return 11656 ** the total number of tokens in column iCol, considering all rows in 11657 ** the FTS5 table. 11658 ** 11659 ** If parameter iCol is greater than or equal to the number of columns 11660 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11661 ** an OOM condition or IO error), an appropriate SQLite error code is 11662 ** returned. 11663 ** 11664 ** xColumnCount(pFts): 11665 ** Return the number of columns in the table. 11666 ** 11667 ** xColumnSize(pFts, iCol, pnToken): 11668 ** If parameter iCol is less than zero, set output variable *pnToken 11669 ** to the total number of tokens in the current row. Or, if iCol is 11670 ** non-negative but less than the number of columns in the table, set 11671 ** *pnToken to the number of tokens in column iCol of the current row. 11672 ** 11673 ** If parameter iCol is greater than or equal to the number of columns 11674 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11675 ** an OOM condition or IO error), an appropriate SQLite error code is 11676 ** returned. 11677 ** 11678 ** This function may be quite inefficient if used with an FTS5 table 11679 ** created with the "columnsize=0" option. 11680 ** 11681 ** xColumnText: 11682 ** This function attempts to retrieve the text of column iCol of the 11683 ** current document. If successful, (*pz) is set to point to a buffer 11684 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11685 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11686 ** if an error occurs, an SQLite error code is returned and the final values 11687 ** of (*pz) and (*pn) are undefined. 11688 ** 11689 ** xPhraseCount: 11690 ** Returns the number of phrases in the current query expression. 11691 ** 11692 ** xPhraseSize: 11693 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11694 ** are numbered starting from zero. 11695 ** 11696 ** xInstCount: 11697 ** Set *pnInst to the total number of occurrences of all phrases within 11698 ** the query within the current row. Return SQLITE_OK if successful, or 11699 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11700 ** 11701 ** This API can be quite slow if used with an FTS5 table created with the 11702 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11703 ** with either "detail=none" or "detail=column" and "content=" option 11704 ** (i.e. if it is a contentless table), then this API always returns 0. 11705 ** 11706 ** xInst: 11707 ** Query for the details of phrase match iIdx within the current row. 11708 ** Phrase matches are numbered starting from zero, so the iIdx argument 11709 ** should be greater than or equal to zero and smaller than the value 11710 ** output by xInstCount(). 11711 ** 11712 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11713 ** to the column in which it occurs and *piOff the token offset of the 11714 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 11715 ** code (i.e. SQLITE_NOMEM) if an error occurs. 11716 ** 11717 ** This API can be quite slow if used with an FTS5 table created with the 11718 ** "detail=none" or "detail=column" option. 11719 ** 11720 ** xRowid: 11721 ** Returns the rowid of the current row. 11722 ** 11723 ** xTokenize: 11724 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11725 ** 11726 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11727 ** This API function is used to query the FTS table for phrase iPhrase 11728 ** of the current query. Specifically, a query equivalent to: 11729 ** 11730 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11731 ** 11732 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11733 ** current query is executed. Any column filter that applies to 11734 ** phrase iPhrase of the current query is included in $p. For each 11735 ** row visited, the callback function passed as the fourth argument 11736 ** is invoked. The context and API objects passed to the callback 11737 ** function may be used to access the properties of each matched row. 11738 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11739 ** the third argument to pUserData. 11740 ** 11741 ** If the callback function returns any value other than SQLITE_OK, the 11742 ** query is abandoned and the xQueryPhrase function returns immediately. 11743 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11744 ** Otherwise, the error code is propagated upwards. 11745 ** 11746 ** If the query runs to completion without incident, SQLITE_OK is returned. 11747 ** Or, if some error occurs before the query completes or is aborted by 11748 ** the callback, an SQLite error code is returned. 11749 ** 11750 ** 11751 ** xSetAuxdata(pFts5, pAux, xDelete) 11752 ** 11753 ** Save the pointer passed as the second argument as the extension function's 11754 ** "auxiliary data". The pointer may then be retrieved by the current or any 11755 ** future invocation of the same fts5 extension function made as part of 11756 ** the same MATCH query using the xGetAuxdata() API. 11757 ** 11758 ** Each extension function is allocated a single auxiliary data slot for 11759 ** each FTS query (MATCH expression). If the extension function is invoked 11760 ** more than once for a single FTS query, then all invocations share a 11761 ** single auxiliary data context. 11762 ** 11763 ** If there is already an auxiliary data pointer when this function is 11764 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11765 ** was specified along with the original pointer, it is invoked at this 11766 ** point. 11767 ** 11768 ** The xDelete callback, if one is specified, is also invoked on the 11769 ** auxiliary data pointer after the FTS5 query has finished. 11770 ** 11771 ** If an error (e.g. an OOM condition) occurs within this function, 11772 ** the auxiliary data is set to NULL and an error code returned. If the 11773 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11774 ** pointer before returning. 11775 ** 11776 ** 11777 ** xGetAuxdata(pFts5, bClear) 11778 ** 11779 ** Returns the current auxiliary data pointer for the fts5 extension 11780 ** function. See the xSetAuxdata() method for details. 11781 ** 11782 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11783 ** (set to NULL) before this function returns. In this case the xDelete, 11784 ** if any, is not invoked. 11785 ** 11786 ** 11787 ** xRowCount(pFts5, pnRow) 11788 ** 11789 ** This function is used to retrieve the total number of rows in the table. 11790 ** In other words, the same value that would be returned by: 11791 ** 11792 ** SELECT count(*) FROM ftstable; 11793 ** 11794 ** xPhraseFirst() 11795 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11796 ** method, to iterate through all instances of a single query phrase within 11797 ** the current row. This is the same information as is accessible via the 11798 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11799 ** to use, this API may be faster under some circumstances. To iterate 11800 ** through instances of phrase iPhrase, use the following code: 11801 ** 11802 ** Fts5PhraseIter iter; 11803 ** int iCol, iOff; 11804 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11805 ** iCol>=0; 11806 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11807 ** ){ 11808 ** // An instance of phrase iPhrase at offset iOff of column iCol 11809 ** } 11810 ** 11811 ** The Fts5PhraseIter structure is defined above. Applications should not 11812 ** modify this structure directly - it should only be used as shown above 11813 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11814 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11815 ** 11816 ** This API can be quite slow if used with an FTS5 table created with the 11817 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11818 ** with either "detail=none" or "detail=column" and "content=" option 11819 ** (i.e. if it is a contentless table), then this API always iterates 11820 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11821 ** 11822 ** xPhraseNext() 11823 ** See xPhraseFirst above. 11824 ** 11825 ** xPhraseFirstColumn() 11826 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11827 ** and xPhraseNext() APIs described above. The difference is that instead 11828 ** of iterating through all instances of a phrase in the current row, these 11829 ** APIs are used to iterate through the set of columns in the current row 11830 ** that contain one or more instances of a specified phrase. For example: 11831 ** 11832 ** Fts5PhraseIter iter; 11833 ** int iCol; 11834 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11835 ** iCol>=0; 11836 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11837 ** ){ 11838 ** // Column iCol contains at least one instance of phrase iPhrase 11839 ** } 11840 ** 11841 ** This API can be quite slow if used with an FTS5 table created with the 11842 ** "detail=none" option. If the FTS5 table is created with either 11843 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11844 ** then this API always iterates through an empty set (all calls to 11845 ** xPhraseFirstColumn() set iCol to -1). 11846 ** 11847 ** The information accessed using this API and its companion 11848 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11849 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11850 ** significantly more efficient than those alternatives when used with 11851 ** "detail=column" tables. 11852 ** 11853 ** xPhraseNextColumn() 11854 ** See xPhraseFirstColumn above. 11855 */ 11856 struct Fts5ExtensionApi { 11857 int iVersion; /* Currently always set to 3 */ 11858 11859 void *(*xUserData)(Fts5Context*); 11860 11861 int (*xColumnCount)(Fts5Context*); 11862 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11863 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11864 11865 int (*xTokenize)(Fts5Context*, 11866 const char *pText, int nText, /* Text to tokenize */ 11867 void *pCtx, /* Context passed to xToken() */ 11868 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11869 ); 11870 11871 int (*xPhraseCount)(Fts5Context*); 11872 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11873 11874 int (*xInstCount)(Fts5Context*, int *pnInst); 11875 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11876 11877 sqlite3_int64 (*xRowid)(Fts5Context*); 11878 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11879 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11880 11881 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11882 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11883 ); 11884 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11885 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11886 11887 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11888 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11889 11890 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11891 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11892 }; 11893 11894 /* 11895 ** CUSTOM AUXILIARY FUNCTIONS 11896 *************************************************************************/ 11897 11898 /************************************************************************* 11899 ** CUSTOM TOKENIZERS 11900 ** 11901 ** Applications may also register custom tokenizer types. A tokenizer 11902 ** is registered by providing fts5 with a populated instance of the 11903 ** following structure. All structure methods must be defined, setting 11904 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11905 ** behaviour. The structure methods are expected to function as follows: 11906 ** 11907 ** xCreate: 11908 ** This function is used to allocate and initialize a tokenizer instance. 11909 ** A tokenizer instance is required to actually tokenize text. 11910 ** 11911 ** The first argument passed to this function is a copy of the (void*) 11912 ** pointer provided by the application when the fts5_tokenizer object 11913 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11914 ** The second and third arguments are an array of nul-terminated strings 11915 ** containing the tokenizer arguments, if any, specified following the 11916 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11917 ** to create the FTS5 table. 11918 ** 11919 ** The final argument is an output variable. If successful, (*ppOut) 11920 ** should be set to point to the new tokenizer handle and SQLITE_OK 11921 ** returned. If an error occurs, some value other than SQLITE_OK should 11922 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11923 ** is undefined. 11924 ** 11925 ** xDelete: 11926 ** This function is invoked to delete a tokenizer handle previously 11927 ** allocated using xCreate(). Fts5 guarantees that this function will 11928 ** be invoked exactly once for each successful call to xCreate(). 11929 ** 11930 ** xTokenize: 11931 ** This function is expected to tokenize the nText byte string indicated 11932 ** by argument pText. pText may or may not be nul-terminated. The first 11933 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11934 ** returned by an earlier call to xCreate(). 11935 ** 11936 ** The second argument indicates the reason that FTS5 is requesting 11937 ** tokenization of the supplied text. This is always one of the following 11938 ** four values: 11939 ** 11940 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11941 ** or removed from the FTS table. The tokenizer is being invoked to 11942 ** determine the set of tokens to add to (or delete from) the 11943 ** FTS index. 11944 ** 11945 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11946 ** against the FTS index. The tokenizer is being called to tokenize 11947 ** a bareword or quoted string specified as part of the query. 11948 ** 11949 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11950 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11951 ** followed by a "*" character, indicating that the last token 11952 ** returned by the tokenizer will be treated as a token prefix. 11953 ** 11954 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11955 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11956 ** function. Or an fts5_api.xColumnSize() request made by the same 11957 ** on a columnsize=0 database. 11958 ** </ul> 11959 ** 11960 ** For each token in the input string, the supplied callback xToken() must 11961 ** be invoked. The first argument to it should be a copy of the pointer 11962 ** passed as the second argument to xTokenize(). The third and fourth 11963 ** arguments are a pointer to a buffer containing the token text, and the 11964 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11965 ** of the first byte of and first byte immediately following the text from 11966 ** which the token is derived within the input. 11967 ** 11968 ** The second argument passed to the xToken() callback ("tflags") should 11969 ** normally be set to 0. The exception is if the tokenizer supports 11970 ** synonyms. In this case see the discussion below for details. 11971 ** 11972 ** FTS5 assumes the xToken() callback is invoked for each token in the 11973 ** order that they occur within the input text. 11974 ** 11975 ** If an xToken() callback returns any value other than SQLITE_OK, then 11976 ** the tokenization should be abandoned and the xTokenize() method should 11977 ** immediately return a copy of the xToken() return value. Or, if the 11978 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11979 ** if an error occurs with the xTokenize() implementation itself, it 11980 ** may abandon the tokenization and return any error code other than 11981 ** SQLITE_OK or SQLITE_DONE. 11982 ** 11983 ** SYNONYM SUPPORT 11984 ** 11985 ** Custom tokenizers may also support synonyms. Consider a case in which a 11986 ** user wishes to query for a phrase such as "first place". Using the 11987 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11988 ** of "first place" within the document set, but not alternative forms 11989 ** such as "1st place". In some applications, it would be better to match 11990 ** all instances of "first place" or "1st place" regardless of which form 11991 ** the user specified in the MATCH query text. 11992 ** 11993 ** There are several ways to approach this in FTS5: 11994 ** 11995 ** <ol><li> By mapping all synonyms to a single token. In this case, using 11996 ** the above example, this means that the tokenizer returns the 11997 ** same token for inputs "first" and "1st". Say that token is in 11998 ** fact "first", so that when the user inserts the document "I won 11999 ** 1st place" entries are added to the index for tokens "i", "won", 12000 ** "first" and "place". If the user then queries for '1st + place', 12001 ** the tokenizer substitutes "first" for "1st" and the query works 12002 ** as expected. 12003 ** 12004 ** <li> By querying the index for all synonyms of each query term 12005 ** separately. In this case, when tokenizing query text, the 12006 ** tokenizer may provide multiple synonyms for a single term 12007 ** within the document. FTS5 then queries the index for each 12008 ** synonym individually. For example, faced with the query: 12009 ** 12010 ** <codeblock> 12011 ** ... MATCH 'first place'</codeblock> 12012 ** 12013 ** the tokenizer offers both "1st" and "first" as synonyms for the 12014 ** first token in the MATCH query and FTS5 effectively runs a query 12015 ** similar to: 12016 ** 12017 ** <codeblock> 12018 ** ... MATCH '(first OR 1st) place'</codeblock> 12019 ** 12020 ** except that, for the purposes of auxiliary functions, the query 12021 ** still appears to contain just two phrases - "(first OR 1st)" 12022 ** being treated as a single phrase. 12023 ** 12024 ** <li> By adding multiple synonyms for a single term to the FTS index. 12025 ** Using this method, when tokenizing document text, the tokenizer 12026 ** provides multiple synonyms for each token. So that when a 12027 ** document such as "I won first place" is tokenized, entries are 12028 ** added to the FTS index for "i", "won", "first", "1st" and 12029 ** "place". 12030 ** 12031 ** This way, even if the tokenizer does not provide synonyms 12032 ** when tokenizing query text (it should not - to do so would be 12033 ** inefficient), it doesn't matter if the user queries for 12034 ** 'first + place' or '1st + place', as there are entries in the 12035 ** FTS index corresponding to both forms of the first token. 12036 ** </ol> 12037 ** 12038 ** Whether it is parsing document or query text, any call to xToken that 12039 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12040 ** is considered to supply a synonym for the previous token. For example, 12041 ** when parsing the document "I won first place", a tokenizer that supports 12042 ** synonyms would call xToken() 5 times, as follows: 12043 ** 12044 ** <codeblock> 12045 ** xToken(pCtx, 0, "i", 1, 0, 1); 12046 ** xToken(pCtx, 0, "won", 3, 2, 5); 12047 ** xToken(pCtx, 0, "first", 5, 6, 11); 12048 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12049 ** xToken(pCtx, 0, "place", 5, 12, 17); 12050 **</codeblock> 12051 ** 12052 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12053 ** xToken() is called. Multiple synonyms may be specified for a single token 12054 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12055 ** There is no limit to the number of synonyms that may be provided for a 12056 ** single token. 12057 ** 12058 ** In many cases, method (1) above is the best approach. It does not add 12059 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12060 ** so it is efficient in terms of disk space and query speed. However, it 12061 ** does not support prefix queries very well. If, as suggested above, the 12062 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12063 ** 12064 ** <codeblock> 12065 ** ... MATCH '1s*'</codeblock> 12066 ** 12067 ** will not match documents that contain the token "1st" (as the tokenizer 12068 ** will probably not map "1s" to any prefix of "first"). 12069 ** 12070 ** For full prefix support, method (3) may be preferred. In this case, 12071 ** because the index contains entries for both "first" and "1st", prefix 12072 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12073 ** extra entries are added to the FTS index, this method uses more space 12074 ** within the database. 12075 ** 12076 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12077 ** a query such as '1s*' will match documents that contain the literal 12078 ** token "1st", but not "first" (assuming the tokenizer is not able to 12079 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12080 ** will match against "1st" and "first". This method does not require 12081 ** extra disk space, as no extra entries are added to the FTS index. 12082 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12083 ** as separate queries of the FTS index are required for each synonym. 12084 ** 12085 ** When using methods (2) or (3), it is important that the tokenizer only 12086 ** provide synonyms when tokenizing document text (method (2)) or query 12087 ** text (method (3)), not both. Doing so will not cause any errors, but is 12088 ** inefficient. 12089 */ 12090 typedef struct Fts5Tokenizer Fts5Tokenizer; 12091 typedef struct fts5_tokenizer fts5_tokenizer; 12092 struct fts5_tokenizer { 12093 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12094 void (*xDelete)(Fts5Tokenizer*); 12095 int (*xTokenize)(Fts5Tokenizer*, 12096 void *pCtx, 12097 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12098 const char *pText, int nText, 12099 int (*xToken)( 12100 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12101 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12102 const char *pToken, /* Pointer to buffer containing token */ 12103 int nToken, /* Size of token in bytes */ 12104 int iStart, /* Byte offset of token within input text */ 12105 int iEnd /* Byte offset of end of token within input text */ 12106 ) 12107 ); 12108 }; 12109 12110 /* Flags that may be passed as the third argument to xTokenize() */ 12111 #define FTS5_TOKENIZE_QUERY 0x0001 12112 #define FTS5_TOKENIZE_PREFIX 0x0002 12113 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12114 #define FTS5_TOKENIZE_AUX 0x0008 12115 12116 /* Flags that may be passed by the tokenizer implementation back to FTS5 12117 ** as the third argument to the supplied xToken callback. */ 12118 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12119 12120 /* 12121 ** END OF CUSTOM TOKENIZERS 12122 *************************************************************************/ 12123 12124 /************************************************************************* 12125 ** FTS5 EXTENSION REGISTRATION API 12126 */ 12127 typedef struct fts5_api fts5_api; 12128 struct fts5_api { 12129 int iVersion; /* Currently always set to 2 */ 12130 12131 /* Create a new tokenizer */ 12132 int (*xCreateTokenizer)( 12133 fts5_api *pApi, 12134 const char *zName, 12135 void *pContext, 12136 fts5_tokenizer *pTokenizer, 12137 void (*xDestroy)(void*) 12138 ); 12139 12140 /* Find an existing tokenizer */ 12141 int (*xFindTokenizer)( 12142 fts5_api *pApi, 12143 const char *zName, 12144 void **ppContext, 12145 fts5_tokenizer *pTokenizer 12146 ); 12147 12148 /* Create a new auxiliary function */ 12149 int (*xCreateFunction)( 12150 fts5_api *pApi, 12151 const char *zName, 12152 void *pContext, 12153 fts5_extension_function xFunction, 12154 void (*xDestroy)(void*) 12155 ); 12156 }; 12157 12158 /* 12159 ** END OF REGISTRATION API 12160 *************************************************************************/ 12161 12162 #ifdef __cplusplus 12163 } /* end of the 'extern "C"' block */ 12164 #endif 12165 12166 #endif /* _FTS5_H */ 12167 12168 /******** End of fts5.h *********/ 12169