1 /* 2 ** 2001 September 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 suppose 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 ** Add the ability to override 'extern' 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 52 #ifndef SQLITE_API 53 # define SQLITE_API 54 #endif 55 56 57 /* 58 ** These no-op macros are used in front of interfaces to mark those 59 ** interfaces as either deprecated or experimental. New applications 60 ** should not use deprecated interfaces - they are support for backwards 61 ** compatibility only. Application writers should be aware that 62 ** experimental interfaces are subject to change in point releases. 63 ** 64 ** These macros used to resolve to various kinds of compiler magic that 65 ** would generate warning messages when they were used. But that 66 ** compiler magic ended up generating such a flurry of bug reports 67 ** that we have taken it all out and gone back to using simple 68 ** noop macros. 69 */ 70 #define SQLITE_DEPRECATED 71 #define SQLITE_EXPERIMENTAL 72 73 /* 74 ** Ensure these symbols were not defined by some previous header file. 75 */ 76 #ifdef SQLITE_VERSION 77 # undef SQLITE_VERSION 78 #endif 79 #ifdef SQLITE_VERSION_NUMBER 80 # undef SQLITE_VERSION_NUMBER 81 #endif 82 83 /* 84 ** CAPI3REF: Compile-Time Library Version Numbers 85 ** 86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 87 ** evaluates to a string literal that is the SQLite version in the 88 ** format "X.Y.Z" where X is the major version number (always 3 for 89 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 92 ** numbers used in [SQLITE_VERSION].)^ 93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 94 ** be larger than the release from which it is derived. Either Y will 95 ** be held constant and Z will be incremented or else Y will be incremented 96 ** and Z will be reset to zero. 97 ** 98 ** Since version 3.6.18, SQLite source code has been stored in the 99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 101 ** a string which identifies a particular check-in of SQLite 102 ** within its configuration management system. ^The SQLITE_SOURCE_ID 103 ** string contains the date and time of the check-in (UTC) and an SHA1 104 ** hash of the entire source tree. 105 ** 106 ** See also: [sqlite3_libversion()], 107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 108 ** [sqlite_version()] and [sqlite_source_id()]. 109 */ 110 #define SQLITE_VERSION "3.8.3.1" 111 #define SQLITE_VERSION_NUMBER 3008003 112 #define SQLITE_SOURCE_ID "2014-02-11 14:52:19 ea3317a4803d71d88183b29f1d3086f46d68a00e" 113 114 /* 115 ** CAPI3REF: Run-Time Library Version Numbers 116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid 117 ** 118 ** These interfaces provide the same information as the [SQLITE_VERSION], 119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 120 ** but are associated with the library instead of the header file. ^(Cautious 121 ** programmers might include assert() statements in their application to 122 ** verify that values returned by these interfaces match the macros in 123 ** the header, and thus insure that the application is 124 ** compiled with matching library and header files. 125 ** 126 ** <blockquote><pre> 127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 130 ** </pre></blockquote>)^ 131 ** 132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 133 ** macro. ^The sqlite3_libversion() function returns a pointer to the 134 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 135 ** function is provided for use in DLLs since DLL users usually do not have 136 ** direct access to string constants within the DLL. ^The 137 ** sqlite3_libversion_number() function returns an integer equal to 138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 139 ** a pointer to a string constant whose value is the same as the 140 ** [SQLITE_SOURCE_ID] C preprocessor macro. 141 ** 142 ** See also: [sqlite_version()] and [sqlite_source_id()]. 143 */ 144 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 145 SQLITE_API const char *sqlite3_libversion(void); 146 SQLITE_API const char *sqlite3_sourceid(void); 147 SQLITE_API int sqlite3_libversion_number(void); 148 149 /* 150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 151 ** 152 ** ^The sqlite3_compileoption_used() function returns 0 or 1 153 ** indicating whether the specified option was defined at 154 ** compile time. ^The SQLITE_ prefix may be omitted from the 155 ** option name passed to sqlite3_compileoption_used(). 156 ** 157 ** ^The sqlite3_compileoption_get() function allows iterating 158 ** over the list of options that were defined at compile time by 159 ** returning the N-th compile time option string. ^If N is out of range, 160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 161 ** prefix is omitted from any strings returned by 162 ** sqlite3_compileoption_get(). 163 ** 164 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 165 ** and sqlite3_compileoption_get() may be omitted by specifying the 166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 167 ** 168 ** See also: SQL functions [sqlite_compileoption_used()] and 169 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 170 */ 171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 173 SQLITE_API const char *sqlite3_compileoption_get(int N); 174 #endif 175 176 /* 177 ** CAPI3REF: Test To See If The Library Is Threadsafe 178 ** 179 ** ^The sqlite3_threadsafe() function returns zero if and only if 180 ** SQLite was compiled with mutexing code omitted due to the 181 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 182 ** 183 ** SQLite can be compiled with or without mutexes. When 184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 185 ** are enabled and SQLite is threadsafe. When the 186 ** [SQLITE_THREADSAFE] macro is 0, 187 ** the mutexes are omitted. Without the mutexes, it is not safe 188 ** to use SQLite concurrently from more than one thread. 189 ** 190 ** Enabling mutexes incurs a measurable performance penalty. 191 ** So if speed is of utmost importance, it makes sense to disable 192 ** the mutexes. But for maximum safety, mutexes should be enabled. 193 ** ^The default behavior is for mutexes to be enabled. 194 ** 195 ** This interface can be used by an application to make sure that the 196 ** version of SQLite that it is linking against was compiled with 197 ** the desired setting of the [SQLITE_THREADSAFE] macro. 198 ** 199 ** This interface only reports on the compile-time mutex setting 200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 202 ** can be fully or partially disabled using a call to [sqlite3_config()] 203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 205 ** sqlite3_threadsafe() function shows only the compile-time setting of 206 ** thread safety, not any run-time changes to that setting made by 207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 208 ** is unchanged by calls to sqlite3_config().)^ 209 ** 210 ** See the [threading mode] documentation for additional information. 211 */ 212 SQLITE_API int sqlite3_threadsafe(void); 213 214 /* 215 ** CAPI3REF: Database Connection Handle 216 ** KEYWORDS: {database connection} {database connections} 217 ** 218 ** Each open SQLite database is represented by a pointer to an instance of 219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 222 ** and [sqlite3_close_v2()] are its destructors. There are many other 223 ** interfaces (such as 224 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 225 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 226 ** sqlite3 object. 227 */ 228 typedef struct sqlite3 sqlite3; 229 230 /* 231 ** CAPI3REF: 64-Bit Integer Types 232 ** KEYWORDS: sqlite_int64 sqlite_uint64 233 ** 234 ** Because there is no cross-platform way to specify 64-bit integer types 235 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 236 ** 237 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 238 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 239 ** compatibility only. 240 ** 241 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 242 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 243 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 244 ** between 0 and +18446744073709551615 inclusive. 245 */ 246 #ifdef SQLITE_INT64_TYPE 247 typedef SQLITE_INT64_TYPE sqlite_int64; 248 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 249 #elif defined(_MSC_VER) || defined(__BORLANDC__) 250 typedef __int64 sqlite_int64; 251 typedef unsigned __int64 sqlite_uint64; 252 #else 253 typedef long long int sqlite_int64; 254 typedef unsigned long long int sqlite_uint64; 255 #endif 256 typedef sqlite_int64 sqlite3_int64; 257 typedef sqlite_uint64 sqlite3_uint64; 258 259 /* 260 ** If compiling for a processor that lacks floating point support, 261 ** substitute integer for floating-point. 262 */ 263 #ifdef SQLITE_OMIT_FLOATING_POINT 264 # define double sqlite3_int64 265 #endif 266 267 /* 268 ** CAPI3REF: Closing A Database Connection 269 ** 270 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 271 ** for the [sqlite3] object. 272 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if 273 ** the [sqlite3] object is successfully destroyed and all associated 274 ** resources are deallocated. 275 ** 276 ** ^If the database connection is associated with unfinalized prepared 277 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 278 ** will leave the database connection open and return [SQLITE_BUSY]. 279 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 280 ** and unfinished sqlite3_backups, then the database connection becomes 281 ** an unusable "zombie" which will automatically be deallocated when the 282 ** last prepared statement is finalized or the last sqlite3_backup is 283 ** finished. The sqlite3_close_v2() interface is intended for use with 284 ** host languages that are garbage collected, and where the order in which 285 ** destructors are called is arbitrary. 286 ** 287 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 288 ** [sqlite3_blob_close | close] all [BLOB handles], and 289 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 290 ** with the [sqlite3] object prior to attempting to close the object. ^If 291 ** sqlite3_close_v2() is called on a [database connection] that still has 292 ** outstanding [prepared statements], [BLOB handles], and/or 293 ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation 294 ** of resources is deferred until all [prepared statements], [BLOB handles], 295 ** and [sqlite3_backup] objects are also destroyed. 296 ** 297 ** ^If an [sqlite3] object is destroyed while a transaction is open, 298 ** the transaction is automatically rolled back. 299 ** 300 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 301 ** must be either a NULL 302 ** pointer or an [sqlite3] object pointer obtained 303 ** from [sqlite3_open()], [sqlite3_open16()], or 304 ** [sqlite3_open_v2()], and not previously closed. 305 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 306 ** argument is a harmless no-op. 307 */ 308 SQLITE_API int sqlite3_close(sqlite3*); 309 SQLITE_API int sqlite3_close_v2(sqlite3*); 310 311 /* 312 ** The type for a callback function. 313 ** This is legacy and deprecated. It is included for historical 314 ** compatibility and is not documented. 315 */ 316 typedef int (*sqlite3_callback)(void*,int,char**, char**); 317 318 /* 319 ** CAPI3REF: One-Step Query Execution Interface 320 ** 321 ** The sqlite3_exec() interface is a convenience wrapper around 322 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 323 ** that allows an application to run multiple statements of SQL 324 ** without having to use a lot of C code. 325 ** 326 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 327 ** semicolon-separate SQL statements passed into its 2nd argument, 328 ** in the context of the [database connection] passed in as its 1st 329 ** argument. ^If the callback function of the 3rd argument to 330 ** sqlite3_exec() is not NULL, then it is invoked for each result row 331 ** coming out of the evaluated SQL statements. ^The 4th argument to 332 ** sqlite3_exec() is relayed through to the 1st argument of each 333 ** callback invocation. ^If the callback pointer to sqlite3_exec() 334 ** is NULL, then no callback is ever invoked and result rows are 335 ** ignored. 336 ** 337 ** ^If an error occurs while evaluating the SQL statements passed into 338 ** sqlite3_exec(), then execution of the current statement stops and 339 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 340 ** is not NULL then any error message is written into memory obtained 341 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 342 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 343 ** on error message strings returned through the 5th parameter of 344 ** of sqlite3_exec() after the error message string is no longer needed. 345 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 346 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 347 ** NULL before returning. 348 ** 349 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 350 ** routine returns SQLITE_ABORT without invoking the callback again and 351 ** without running any subsequent SQL statements. 352 ** 353 ** ^The 2nd argument to the sqlite3_exec() callback function is the 354 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 355 ** callback is an array of pointers to strings obtained as if from 356 ** [sqlite3_column_text()], one for each column. ^If an element of a 357 ** result row is NULL then the corresponding string pointer for the 358 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 359 ** sqlite3_exec() callback is an array of pointers to strings where each 360 ** entry represents the name of corresponding result column as obtained 361 ** from [sqlite3_column_name()]. 362 ** 363 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 364 ** to an empty string, or a pointer that contains only whitespace and/or 365 ** SQL comments, then no SQL statements are evaluated and the database 366 ** is not changed. 367 ** 368 ** Restrictions: 369 ** 370 ** <ul> 371 ** <li> The application must insure that the 1st parameter to sqlite3_exec() 372 ** is a valid and open [database connection]. 373 ** <li> The application must not close the [database connection] specified by 374 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 375 ** <li> The application must not modify the SQL statement text passed into 376 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 377 ** </ul> 378 */ 379 SQLITE_API int sqlite3_exec( 380 sqlite3*, /* An open database */ 381 const char *sql, /* SQL to be evaluated */ 382 int (*callback)(void*,int,char**,char**), /* Callback function */ 383 void *, /* 1st argument to callback */ 384 char **errmsg /* Error msg written here */ 385 ); 386 387 /* 388 ** CAPI3REF: Result Codes 389 ** KEYWORDS: SQLITE_OK {error code} {error codes} 390 ** KEYWORDS: {result code} {result codes} 391 ** 392 ** Many SQLite functions return an integer result code from the set shown 393 ** here in order to indicate success or failure. 394 ** 395 ** New error codes may be added in future versions of SQLite. 396 ** 397 ** See also: [SQLITE_IOERR_READ | extended result codes], 398 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. 399 */ 400 #define SQLITE_OK 0 /* Successful result */ 401 /* beginning-of-error-codes */ 402 #define SQLITE_ERROR 1 /* SQL error or missing database */ 403 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 404 #define SQLITE_PERM 3 /* Access permission denied */ 405 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 406 #define SQLITE_BUSY 5 /* The database file is locked */ 407 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 408 #define SQLITE_NOMEM 7 /* A malloc() failed */ 409 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 410 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 411 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 412 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 413 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 414 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 415 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 416 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 417 #define SQLITE_EMPTY 16 /* Database is empty */ 418 #define SQLITE_SCHEMA 17 /* The database schema changed */ 419 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 420 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 421 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 422 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 423 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 424 #define SQLITE_AUTH 23 /* Authorization denied */ 425 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ 426 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 427 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 428 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 429 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 430 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 431 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 432 /* end-of-error-codes */ 433 434 /* 435 ** CAPI3REF: Extended Result Codes 436 ** KEYWORDS: {extended error code} {extended error codes} 437 ** KEYWORDS: {extended result code} {extended result codes} 438 ** 439 ** In its default configuration, SQLite API routines return one of 26 integer 440 ** [SQLITE_OK | result codes]. However, experience has shown that many of 441 ** these result codes are too coarse-grained. They do not provide as 442 ** much information about problems as programmers might like. In an effort to 443 ** address this, newer versions of SQLite (version 3.3.8 and later) include 444 ** support for additional result codes that provide more detailed information 445 ** about errors. The extended result codes are enabled or disabled 446 ** on a per database connection basis using the 447 ** [sqlite3_extended_result_codes()] API. 448 ** 449 ** Some of the available extended result codes are listed here. 450 ** One may expect the number of extended result codes will increase 451 ** over time. Software that uses extended result codes should expect 452 ** to see new result codes in future releases of SQLite. 453 ** 454 ** The SQLITE_OK result code will never be extended. It will always 455 ** be exactly zero. 456 */ 457 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 458 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 459 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 460 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 461 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 462 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 463 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 464 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 465 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 466 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 467 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 468 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 469 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 470 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 471 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 472 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 473 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 474 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 475 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 476 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 477 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 478 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 479 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 480 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 481 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 482 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 483 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 484 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 485 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 486 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 487 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 488 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 489 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 490 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 491 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 492 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 493 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 494 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 495 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 496 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 497 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 498 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 499 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 500 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 501 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 502 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 503 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 504 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 505 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 506 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 507 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 508 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 509 510 /* 511 ** CAPI3REF: Flags For File Open Operations 512 ** 513 ** These bit values are intended for use in the 514 ** 3rd parameter to the [sqlite3_open_v2()] interface and 515 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 516 */ 517 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 518 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 519 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 520 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 521 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 522 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 523 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 524 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 525 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 526 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 527 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 528 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 529 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 530 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 531 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 532 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 533 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 534 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 535 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 536 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 537 538 /* Reserved: 0x00F00000 */ 539 540 /* 541 ** CAPI3REF: Device Characteristics 542 ** 543 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 544 ** object returns an integer which is a vector of these 545 ** bit values expressing I/O characteristics of the mass storage 546 ** device that holds the file that the [sqlite3_io_methods] 547 ** refers to. 548 ** 549 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 550 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 551 ** mean that writes of blocks that are nnn bytes in size and 552 ** are aligned to an address which is an integer multiple of 553 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 554 ** that when data is appended to a file, the data is appended 555 ** first then the size of the file is extended, never the other 556 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 557 ** information is written to disk in the same order as calls 558 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 559 ** after reboot following a crash or power loss, the only bytes in a 560 ** file that were written at the application level might have changed 561 ** and that adjacent bytes, even bytes within the same sector are 562 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 563 ** flag indicate that a file cannot be deleted when open. 564 */ 565 #define SQLITE_IOCAP_ATOMIC 0x00000001 566 #define SQLITE_IOCAP_ATOMIC512 0x00000002 567 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 568 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 569 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 570 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 571 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 572 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 573 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 574 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 575 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 576 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 577 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 578 579 /* 580 ** CAPI3REF: File Locking Levels 581 ** 582 ** SQLite uses one of these integer values as the second 583 ** argument to calls it makes to the xLock() and xUnlock() methods 584 ** of an [sqlite3_io_methods] object. 585 */ 586 #define SQLITE_LOCK_NONE 0 587 #define SQLITE_LOCK_SHARED 1 588 #define SQLITE_LOCK_RESERVED 2 589 #define SQLITE_LOCK_PENDING 3 590 #define SQLITE_LOCK_EXCLUSIVE 4 591 592 /* 593 ** CAPI3REF: Synchronization Type Flags 594 ** 595 ** When SQLite invokes the xSync() method of an 596 ** [sqlite3_io_methods] object it uses a combination of 597 ** these integer values as the second argument. 598 ** 599 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 600 ** sync operation only needs to flush data to mass storage. Inode 601 ** information need not be flushed. If the lower four bits of the flag 602 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 603 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 604 ** to use Mac OS X style fullsync instead of fsync(). 605 ** 606 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 607 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 608 ** settings. The [synchronous pragma] determines when calls to the 609 ** xSync VFS method occur and applies uniformly across all platforms. 610 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 611 ** energetic or rigorous or forceful the sync operations are and 612 ** only make a difference on Mac OSX for the default SQLite code. 613 ** (Third-party VFS implementations might also make the distinction 614 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 615 ** operating systems natively supported by SQLite, only Mac OSX 616 ** cares about the difference.) 617 */ 618 #define SQLITE_SYNC_NORMAL 0x00002 619 #define SQLITE_SYNC_FULL 0x00003 620 #define SQLITE_SYNC_DATAONLY 0x00010 621 622 /* 623 ** CAPI3REF: OS Interface Open File Handle 624 ** 625 ** An [sqlite3_file] object represents an open file in the 626 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 627 ** implementations will 628 ** want to subclass this object by appending additional fields 629 ** for their own use. The pMethods entry is a pointer to an 630 ** [sqlite3_io_methods] object that defines methods for performing 631 ** I/O operations on the open file. 632 */ 633 typedef struct sqlite3_file sqlite3_file; 634 struct sqlite3_file { 635 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 636 }; 637 638 /* 639 ** CAPI3REF: OS Interface File Virtual Methods Object 640 ** 641 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 642 ** [sqlite3_file] object (or, more commonly, a subclass of the 643 ** [sqlite3_file] object) with a pointer to an instance of this object. 644 ** This object defines the methods used to perform various operations 645 ** against the open file represented by the [sqlite3_file] object. 646 ** 647 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 648 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 649 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 650 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 651 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 652 ** to NULL. 653 ** 654 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 655 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 656 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 657 ** flag may be ORed in to indicate that only the data of the file 658 ** and not its inode needs to be synced. 659 ** 660 ** The integer values to xLock() and xUnlock() are one of 661 ** <ul> 662 ** <li> [SQLITE_LOCK_NONE], 663 ** <li> [SQLITE_LOCK_SHARED], 664 ** <li> [SQLITE_LOCK_RESERVED], 665 ** <li> [SQLITE_LOCK_PENDING], or 666 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 667 ** </ul> 668 ** xLock() increases the lock. xUnlock() decreases the lock. 669 ** The xCheckReservedLock() method checks whether any database connection, 670 ** either in this process or in some other process, is holding a RESERVED, 671 ** PENDING, or EXCLUSIVE lock on the file. It returns true 672 ** if such a lock exists and false otherwise. 673 ** 674 ** The xFileControl() method is a generic interface that allows custom 675 ** VFS implementations to directly control an open file using the 676 ** [sqlite3_file_control()] interface. The second "op" argument is an 677 ** integer opcode. The third argument is a generic pointer intended to 678 ** point to a structure that may contain arguments or space in which to 679 ** write return values. Potential uses for xFileControl() might be 680 ** functions to enable blocking locks with timeouts, to change the 681 ** locking strategy (for example to use dot-file locks), to inquire 682 ** about the status of a lock, or to break stale locks. The SQLite 683 ** core reserves all opcodes less than 100 for its own use. 684 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 685 ** Applications that define a custom xFileControl method should use opcodes 686 ** greater than 100 to avoid conflicts. VFS implementations should 687 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 688 ** recognize. 689 ** 690 ** The xSectorSize() method returns the sector size of the 691 ** device that underlies the file. The sector size is the 692 ** minimum write that can be performed without disturbing 693 ** other bytes in the file. The xDeviceCharacteristics() 694 ** method returns a bit vector describing behaviors of the 695 ** underlying device: 696 ** 697 ** <ul> 698 ** <li> [SQLITE_IOCAP_ATOMIC] 699 ** <li> [SQLITE_IOCAP_ATOMIC512] 700 ** <li> [SQLITE_IOCAP_ATOMIC1K] 701 ** <li> [SQLITE_IOCAP_ATOMIC2K] 702 ** <li> [SQLITE_IOCAP_ATOMIC4K] 703 ** <li> [SQLITE_IOCAP_ATOMIC8K] 704 ** <li> [SQLITE_IOCAP_ATOMIC16K] 705 ** <li> [SQLITE_IOCAP_ATOMIC32K] 706 ** <li> [SQLITE_IOCAP_ATOMIC64K] 707 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 708 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 709 ** </ul> 710 ** 711 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 712 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 713 ** mean that writes of blocks that are nnn bytes in size and 714 ** are aligned to an address which is an integer multiple of 715 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 716 ** that when data is appended to a file, the data is appended 717 ** first then the size of the file is extended, never the other 718 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 719 ** information is written to disk in the same order as calls 720 ** to xWrite(). 721 ** 722 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 723 ** in the unread portions of the buffer with zeros. A VFS that 724 ** fails to zero-fill short reads might seem to work. However, 725 ** failure to zero-fill short reads will eventually lead to 726 ** database corruption. 727 */ 728 typedef struct sqlite3_io_methods sqlite3_io_methods; 729 struct sqlite3_io_methods { 730 int iVersion; 731 int (*xClose)(sqlite3_file*); 732 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 733 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 734 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 735 int (*xSync)(sqlite3_file*, int flags); 736 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 737 int (*xLock)(sqlite3_file*, int); 738 int (*xUnlock)(sqlite3_file*, int); 739 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 740 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 741 int (*xSectorSize)(sqlite3_file*); 742 int (*xDeviceCharacteristics)(sqlite3_file*); 743 /* Methods above are valid for version 1 */ 744 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 745 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 746 void (*xShmBarrier)(sqlite3_file*); 747 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 748 /* Methods above are valid for version 2 */ 749 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 750 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 751 /* Methods above are valid for version 3 */ 752 /* Additional methods may be added in future releases */ 753 }; 754 755 /* 756 ** CAPI3REF: Standard File Control Opcodes 757 ** 758 ** These integer constants are opcodes for the xFileControl method 759 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 760 ** interface. 761 ** 762 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 763 ** opcode causes the xFileControl method to write the current state of 764 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 765 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 766 ** into an integer that the pArg argument points to. This capability 767 ** is used during testing and only needs to be supported when SQLITE_TEST 768 ** is defined. 769 ** <ul> 770 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 771 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 772 ** layer a hint of how large the database file will grow to be during the 773 ** current transaction. This hint is not guaranteed to be accurate but it 774 ** is often close. The underlying VFS might choose to preallocate database 775 ** file space based on this hint in order to help writes to the database 776 ** file run faster. 777 ** 778 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 779 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 780 ** extends and truncates the database file in chunks of a size specified 781 ** by the user. The fourth argument to [sqlite3_file_control()] should 782 ** point to an integer (type int) containing the new chunk-size to use 783 ** for the nominated database. Allocating database file space in large 784 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 785 ** improve performance on some systems. 786 ** 787 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 788 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 789 ** to the [sqlite3_file] object associated with a particular database 790 ** connection. See the [sqlite3_file_control()] documentation for 791 ** additional information. 792 ** 793 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 794 ** No longer in use. 795 ** 796 ** <li>[[SQLITE_FCNTL_SYNC]] 797 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 798 ** sent to the VFS immediately before the xSync method is invoked on a 799 ** database file descriptor. Or, if the xSync method is not invoked 800 ** because the user has configured SQLite with 801 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 802 ** of the xSync method. In most cases, the pointer argument passed with 803 ** this file-control is NULL. However, if the database file is being synced 804 ** as part of a multi-database commit, the argument points to a nul-terminated 805 ** string containing the transactions master-journal file name. VFSes that 806 ** do not need this signal should silently ignore this opcode. Applications 807 ** should not call [sqlite3_file_control()] with this opcode as doing so may 808 ** disrupt the operation of the specialized VFSes that do require it. 809 ** 810 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 811 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 812 ** and sent to the VFS after a transaction has been committed immediately 813 ** but before the database is unlocked. VFSes that do not need this signal 814 ** should silently ignore this opcode. Applications should not call 815 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 816 ** operation of the specialized VFSes that do require it. 817 ** 818 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 819 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 820 ** retry counts and intervals for certain disk I/O operations for the 821 ** windows [VFS] in order to provide robustness in the presence of 822 ** anti-virus programs. By default, the windows VFS will retry file read, 823 ** file write, and file delete operations up to 10 times, with a delay 824 ** of 25 milliseconds before the first retry and with the delay increasing 825 ** by an additional 25 milliseconds with each subsequent retry. This 826 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 827 ** to be adjusted. The values are changed for all database connections 828 ** within the same process. The argument is a pointer to an array of two 829 ** integers where the first integer i the new retry count and the second 830 ** integer is the delay. If either integer is negative, then the setting 831 ** is not changed but instead the prior value of that setting is written 832 ** into the array entry, allowing the current retry settings to be 833 ** interrogated. The zDbName parameter is ignored. 834 ** 835 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 836 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 837 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 838 ** write ahead log and shared memory files used for transaction control 839 ** are automatically deleted when the latest connection to the database 840 ** closes. Setting persistent WAL mode causes those files to persist after 841 ** close. Persisting the files is useful when other processes that do not 842 ** have write permission on the directory containing the database file want 843 ** to read the database file, as the WAL and shared memory files must exist 844 ** in order for the database to be readable. The fourth parameter to 845 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 846 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 847 ** WAL mode. If the integer is -1, then it is overwritten with the current 848 ** WAL persistence setting. 849 ** 850 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 851 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 852 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 853 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 854 ** xDeviceCharacteristics methods. The fourth parameter to 855 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 856 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 857 ** mode. If the integer is -1, then it is overwritten with the current 858 ** zero-damage mode setting. 859 ** 860 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 861 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 862 ** a write transaction to indicate that, unless it is rolled back for some 863 ** reason, the entire database file will be overwritten by the current 864 ** transaction. This is used by VACUUM operations. 865 ** 866 ** <li>[[SQLITE_FCNTL_VFSNAME]] 867 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 868 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 869 ** final bottom-level VFS are written into memory obtained from 870 ** [sqlite3_malloc()] and the result is stored in the char* variable 871 ** that the fourth parameter of [sqlite3_file_control()] points to. 872 ** The caller is responsible for freeing the memory when done. As with 873 ** all file-control actions, there is no guarantee that this will actually 874 ** do anything. Callers should initialize the char* variable to a NULL 875 ** pointer in case this file-control is not implemented. This file-control 876 ** is intended for diagnostic use only. 877 ** 878 ** <li>[[SQLITE_FCNTL_PRAGMA]] 879 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 880 ** file control is sent to the open [sqlite3_file] object corresponding 881 ** to the database file to which the pragma statement refers. ^The argument 882 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 883 ** pointers to strings (char**) in which the second element of the array 884 ** is the name of the pragma and the third element is the argument to the 885 ** pragma or NULL if the pragma has no argument. ^The handler for an 886 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 887 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 888 ** or the equivalent and that string will become the result of the pragma or 889 ** the error message if the pragma fails. ^If the 890 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 891 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 892 ** file control returns [SQLITE_OK], then the parser assumes that the 893 ** VFS has handled the PRAGMA itself and the parser generates a no-op 894 ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 895 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 896 ** that the VFS encountered an error while handling the [PRAGMA] and the 897 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 898 ** file control occurs at the beginning of pragma statement analysis and so 899 ** it is able to override built-in [PRAGMA] statements. 900 ** 901 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 902 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 903 ** file-control may be invoked by SQLite on the database file handle 904 ** shortly after it is opened in order to provide a custom VFS with access 905 ** to the connections busy-handler callback. The argument is of type (void **) 906 ** - an array of two (void *) values. The first (void *) actually points 907 ** to a function of type (int (*)(void *)). In order to invoke the connections 908 ** busy-handler, this function should be invoked with the second (void *) in 909 ** the array as the only argument. If it returns non-zero, then the operation 910 ** should be retried. If it returns zero, the custom VFS should abandon the 911 ** current operation. 912 ** 913 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 914 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 915 ** to have SQLite generate a 916 ** temporary filename using the same algorithm that is followed to generate 917 ** temporary filenames for TEMP tables and other internal uses. The 918 ** argument should be a char** which will be filled with the filename 919 ** written into memory obtained from [sqlite3_malloc()]. The caller should 920 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 921 ** 922 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 923 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 924 ** maximum number of bytes that will be used for memory-mapped I/O. 925 ** The argument is a pointer to a value of type sqlite3_int64 that 926 ** is an advisory maximum number of bytes in the file to memory map. The 927 ** pointer is overwritten with the old value. The limit is not changed if 928 ** the value originally pointed to is negative, and so the current limit 929 ** can be queried by passing in a pointer to a negative number. This 930 ** file-control is used internally to implement [PRAGMA mmap_size]. 931 ** 932 ** <li>[[SQLITE_FCNTL_TRACE]] 933 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 934 ** to the VFS about what the higher layers of the SQLite stack are doing. 935 ** This file control is used by some VFS activity tracing [shims]. 936 ** The argument is a zero-terminated string. Higher layers in the 937 ** SQLite stack may generate instances of this file control if 938 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 939 ** 940 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 941 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 942 ** pointer to an integer and it writes a boolean into that integer depending 943 ** on whether or not the file has been renamed, moved, or deleted since it 944 ** was first opened. 945 ** 946 ** </ul> 947 */ 948 #define SQLITE_FCNTL_LOCKSTATE 1 949 #define SQLITE_GET_LOCKPROXYFILE 2 950 #define SQLITE_SET_LOCKPROXYFILE 3 951 #define SQLITE_LAST_ERRNO 4 952 #define SQLITE_FCNTL_SIZE_HINT 5 953 #define SQLITE_FCNTL_CHUNK_SIZE 6 954 #define SQLITE_FCNTL_FILE_POINTER 7 955 #define SQLITE_FCNTL_SYNC_OMITTED 8 956 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 957 #define SQLITE_FCNTL_PERSIST_WAL 10 958 #define SQLITE_FCNTL_OVERWRITE 11 959 #define SQLITE_FCNTL_VFSNAME 12 960 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 961 #define SQLITE_FCNTL_PRAGMA 14 962 #define SQLITE_FCNTL_BUSYHANDLER 15 963 #define SQLITE_FCNTL_TEMPFILENAME 16 964 #define SQLITE_FCNTL_MMAP_SIZE 18 965 #define SQLITE_FCNTL_TRACE 19 966 #define SQLITE_FCNTL_HAS_MOVED 20 967 #define SQLITE_FCNTL_SYNC 21 968 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 969 970 /* 971 ** CAPI3REF: Mutex Handle 972 ** 973 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 974 ** abstract type for a mutex object. The SQLite core never looks 975 ** at the internal representation of an [sqlite3_mutex]. It only 976 ** deals with pointers to the [sqlite3_mutex] object. 977 ** 978 ** Mutexes are created using [sqlite3_mutex_alloc()]. 979 */ 980 typedef struct sqlite3_mutex sqlite3_mutex; 981 982 /* 983 ** CAPI3REF: OS Interface Object 984 ** 985 ** An instance of the sqlite3_vfs object defines the interface between 986 ** the SQLite core and the underlying operating system. The "vfs" 987 ** in the name of the object stands for "virtual file system". See 988 ** the [VFS | VFS documentation] for further information. 989 ** 990 ** The value of the iVersion field is initially 1 but may be larger in 991 ** future versions of SQLite. Additional fields may be appended to this 992 ** object when the iVersion value is increased. Note that the structure 993 ** of the sqlite3_vfs object changes in the transaction between 994 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 995 ** modified. 996 ** 997 ** The szOsFile field is the size of the subclassed [sqlite3_file] 998 ** structure used by this VFS. mxPathname is the maximum length of 999 ** a pathname in this VFS. 1000 ** 1001 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1002 ** the pNext pointer. The [sqlite3_vfs_register()] 1003 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1004 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1005 ** searches the list. Neither the application code nor the VFS 1006 ** implementation should use the pNext pointer. 1007 ** 1008 ** The pNext field is the only field in the sqlite3_vfs 1009 ** structure that SQLite will ever modify. SQLite will only access 1010 ** or modify this field while holding a particular static mutex. 1011 ** The application should never modify anything within the sqlite3_vfs 1012 ** object once the object has been registered. 1013 ** 1014 ** The zName field holds the name of the VFS module. The name must 1015 ** be unique across all VFS modules. 1016 ** 1017 ** [[sqlite3_vfs.xOpen]] 1018 ** ^SQLite guarantees that the zFilename parameter to xOpen 1019 ** is either a NULL pointer or string obtained 1020 ** from xFullPathname() with an optional suffix added. 1021 ** ^If a suffix is added to the zFilename parameter, it will 1022 ** consist of a single "-" character followed by no more than 1023 ** 11 alphanumeric and/or "-" characters. 1024 ** ^SQLite further guarantees that 1025 ** the string will be valid and unchanged until xClose() is 1026 ** called. Because of the previous sentence, 1027 ** the [sqlite3_file] can safely store a pointer to the 1028 ** filename if it needs to remember the filename for some reason. 1029 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1030 ** must invent its own temporary name for the file. ^Whenever the 1031 ** xFilename parameter is NULL it will also be the case that the 1032 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1033 ** 1034 ** The flags argument to xOpen() includes all bits set in 1035 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1036 ** or [sqlite3_open16()] is used, then flags includes at least 1037 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1038 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1039 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1040 ** 1041 ** ^(SQLite will also add one of the following flags to the xOpen() 1042 ** call, depending on the object being opened: 1043 ** 1044 ** <ul> 1045 ** <li> [SQLITE_OPEN_MAIN_DB] 1046 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1047 ** <li> [SQLITE_OPEN_TEMP_DB] 1048 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1049 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1050 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1051 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1052 ** <li> [SQLITE_OPEN_WAL] 1053 ** </ul>)^ 1054 ** 1055 ** The file I/O implementation can use the object type flags to 1056 ** change the way it deals with files. For example, an application 1057 ** that does not care about crash recovery or rollback might make 1058 ** the open of a journal file a no-op. Writes to this journal would 1059 ** also be no-ops, and any attempt to read the journal would return 1060 ** SQLITE_IOERR. Or the implementation might recognize that a database 1061 ** file will be doing page-aligned sector reads and writes in a random 1062 ** order and set up its I/O subsystem accordingly. 1063 ** 1064 ** SQLite might also add one of the following flags to the xOpen method: 1065 ** 1066 ** <ul> 1067 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1068 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1069 ** </ul> 1070 ** 1071 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1072 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1073 ** will be set for TEMP databases and their journals, transient 1074 ** databases, and subjournals. 1075 ** 1076 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1077 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1078 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1079 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1080 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1081 ** be created, and that it is an error if it already exists. 1082 ** It is <i>not</i> used to indicate the file should be opened 1083 ** for exclusive access. 1084 ** 1085 ** ^At least szOsFile bytes of memory are allocated by SQLite 1086 ** to hold the [sqlite3_file] structure passed as the third 1087 ** argument to xOpen. The xOpen method does not have to 1088 ** allocate the structure; it should just fill it in. Note that 1089 ** the xOpen method must set the sqlite3_file.pMethods to either 1090 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1091 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1092 ** element will be valid after xOpen returns regardless of the success 1093 ** or failure of the xOpen call. 1094 ** 1095 ** [[sqlite3_vfs.xAccess]] 1096 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1097 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1098 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1099 ** to test whether a file is at least readable. The file can be a 1100 ** directory. 1101 ** 1102 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1103 ** output buffer xFullPathname. The exact size of the output buffer 1104 ** is also passed as a parameter to both methods. If the output buffer 1105 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1106 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1107 ** to prevent this by setting mxPathname to a sufficiently large value. 1108 ** 1109 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1110 ** interfaces are not strictly a part of the filesystem, but they are 1111 ** included in the VFS structure for completeness. 1112 ** The xRandomness() function attempts to return nBytes bytes 1113 ** of good-quality randomness into zOut. The return value is 1114 ** the actual number of bytes of randomness obtained. 1115 ** The xSleep() method causes the calling thread to sleep for at 1116 ** least the number of microseconds given. ^The xCurrentTime() 1117 ** method returns a Julian Day Number for the current date and time as 1118 ** a floating point value. 1119 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1120 ** Day Number multiplied by 86400000 (the number of milliseconds in 1121 ** a 24-hour day). 1122 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1123 ** date and time if that method is available (if iVersion is 2 or 1124 ** greater and the function pointer is not NULL) and will fall back 1125 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1126 ** 1127 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1128 ** are not used by the SQLite core. These optional interfaces are provided 1129 ** by some VFSes to facilitate testing of the VFS code. By overriding 1130 ** system calls with functions under its control, a test program can 1131 ** simulate faults and error conditions that would otherwise be difficult 1132 ** or impossible to induce. The set of system calls that can be overridden 1133 ** varies from one VFS to another, and from one version of the same VFS to the 1134 ** next. Applications that use these interfaces must be prepared for any 1135 ** or all of these interfaces to be NULL or for their behavior to change 1136 ** from one release to the next. Applications must not attempt to access 1137 ** any of these methods if the iVersion of the VFS is less than 3. 1138 */ 1139 typedef struct sqlite3_vfs sqlite3_vfs; 1140 typedef void (*sqlite3_syscall_ptr)(void); 1141 struct sqlite3_vfs { 1142 int iVersion; /* Structure version number (currently 3) */ 1143 int szOsFile; /* Size of subclassed sqlite3_file */ 1144 int mxPathname; /* Maximum file pathname length */ 1145 sqlite3_vfs *pNext; /* Next registered VFS */ 1146 const char *zName; /* Name of this virtual file system */ 1147 void *pAppData; /* Pointer to application-specific data */ 1148 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1149 int flags, int *pOutFlags); 1150 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1151 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1152 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1153 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1154 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1155 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1156 void (*xDlClose)(sqlite3_vfs*, void*); 1157 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1158 int (*xSleep)(sqlite3_vfs*, int microseconds); 1159 int (*xCurrentTime)(sqlite3_vfs*, double*); 1160 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1161 /* 1162 ** The methods above are in version 1 of the sqlite_vfs object 1163 ** definition. Those that follow are added in version 2 or later 1164 */ 1165 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1166 /* 1167 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1168 ** Those below are for version 3 and greater. 1169 */ 1170 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1171 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1172 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1173 /* 1174 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1175 ** New fields may be appended in figure versions. The iVersion 1176 ** value will increment whenever this happens. 1177 */ 1178 }; 1179 1180 /* 1181 ** CAPI3REF: Flags for the xAccess VFS method 1182 ** 1183 ** These integer constants can be used as the third parameter to 1184 ** the xAccess method of an [sqlite3_vfs] object. They determine 1185 ** what kind of permissions the xAccess method is looking for. 1186 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1187 ** simply checks whether the file exists. 1188 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1189 ** checks whether the named directory is both readable and writable 1190 ** (in other words, if files can be added, removed, and renamed within 1191 ** the directory). 1192 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1193 ** [temp_store_directory pragma], though this could change in a future 1194 ** release of SQLite. 1195 ** With SQLITE_ACCESS_READ, the xAccess method 1196 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1197 ** currently unused, though it might be used in a future release of 1198 ** SQLite. 1199 */ 1200 #define SQLITE_ACCESS_EXISTS 0 1201 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1202 #define SQLITE_ACCESS_READ 2 /* Unused */ 1203 1204 /* 1205 ** CAPI3REF: Flags for the xShmLock VFS method 1206 ** 1207 ** These integer constants define the various locking operations 1208 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1209 ** following are the only legal combinations of flags to the 1210 ** xShmLock method: 1211 ** 1212 ** <ul> 1213 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1214 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1215 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1216 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1217 ** </ul> 1218 ** 1219 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1220 ** was given no the corresponding lock. 1221 ** 1222 ** The xShmLock method can transition between unlocked and SHARED or 1223 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1224 ** and EXCLUSIVE. 1225 */ 1226 #define SQLITE_SHM_UNLOCK 1 1227 #define SQLITE_SHM_LOCK 2 1228 #define SQLITE_SHM_SHARED 4 1229 #define SQLITE_SHM_EXCLUSIVE 8 1230 1231 /* 1232 ** CAPI3REF: Maximum xShmLock index 1233 ** 1234 ** The xShmLock method on [sqlite3_io_methods] may use values 1235 ** between 0 and this upper bound as its "offset" argument. 1236 ** The SQLite core will never attempt to acquire or release a 1237 ** lock outside of this range 1238 */ 1239 #define SQLITE_SHM_NLOCK 8 1240 1241 1242 /* 1243 ** CAPI3REF: Initialize The SQLite Library 1244 ** 1245 ** ^The sqlite3_initialize() routine initializes the 1246 ** SQLite library. ^The sqlite3_shutdown() routine 1247 ** deallocates any resources that were allocated by sqlite3_initialize(). 1248 ** These routines are designed to aid in process initialization and 1249 ** shutdown on embedded systems. Workstation applications using 1250 ** SQLite normally do not need to invoke either of these routines. 1251 ** 1252 ** A call to sqlite3_initialize() is an "effective" call if it is 1253 ** the first time sqlite3_initialize() is invoked during the lifetime of 1254 ** the process, or if it is the first time sqlite3_initialize() is invoked 1255 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1256 ** of sqlite3_initialize() does any initialization. All other calls 1257 ** are harmless no-ops.)^ 1258 ** 1259 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1260 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1261 ** an effective call to sqlite3_shutdown() does any deinitialization. 1262 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1263 ** 1264 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1265 ** is not. The sqlite3_shutdown() interface must only be called from a 1266 ** single thread. All open [database connections] must be closed and all 1267 ** other SQLite resources must be deallocated prior to invoking 1268 ** sqlite3_shutdown(). 1269 ** 1270 ** Among other things, ^sqlite3_initialize() will invoke 1271 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1272 ** will invoke sqlite3_os_end(). 1273 ** 1274 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1275 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1276 ** the library (perhaps it is unable to allocate a needed resource such 1277 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1278 ** 1279 ** ^The sqlite3_initialize() routine is called internally by many other 1280 ** SQLite interfaces so that an application usually does not need to 1281 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1282 ** calls sqlite3_initialize() so the SQLite library will be automatically 1283 ** initialized when [sqlite3_open()] is called if it has not be initialized 1284 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1285 ** compile-time option, then the automatic calls to sqlite3_initialize() 1286 ** are omitted and the application must call sqlite3_initialize() directly 1287 ** prior to using any other SQLite interface. For maximum portability, 1288 ** it is recommended that applications always invoke sqlite3_initialize() 1289 ** directly prior to using any other SQLite interface. Future releases 1290 ** of SQLite may require this. In other words, the behavior exhibited 1291 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1292 ** default behavior in some future release of SQLite. 1293 ** 1294 ** The sqlite3_os_init() routine does operating-system specific 1295 ** initialization of the SQLite library. The sqlite3_os_end() 1296 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1297 ** performed by these routines include allocation or deallocation 1298 ** of static resources, initialization of global variables, 1299 ** setting up a default [sqlite3_vfs] module, or setting up 1300 ** a default configuration using [sqlite3_config()]. 1301 ** 1302 ** The application should never invoke either sqlite3_os_init() 1303 ** or sqlite3_os_end() directly. The application should only invoke 1304 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1305 ** interface is called automatically by sqlite3_initialize() and 1306 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1307 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1308 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1309 ** When [custom builds | built for other platforms] 1310 ** (using the [SQLITE_OS_OTHER=1] compile-time 1311 ** option) the application must supply a suitable implementation for 1312 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1313 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1314 ** must return [SQLITE_OK] on success and some other [error code] upon 1315 ** failure. 1316 */ 1317 SQLITE_API int sqlite3_initialize(void); 1318 SQLITE_API int sqlite3_shutdown(void); 1319 SQLITE_API int sqlite3_os_init(void); 1320 SQLITE_API int sqlite3_os_end(void); 1321 1322 /* 1323 ** CAPI3REF: Configuring The SQLite Library 1324 ** 1325 ** The sqlite3_config() interface is used to make global configuration 1326 ** changes to SQLite in order to tune SQLite to the specific needs of 1327 ** the application. The default configuration is recommended for most 1328 ** applications and so this routine is usually not necessary. It is 1329 ** provided to support rare applications with unusual needs. 1330 ** 1331 ** The sqlite3_config() interface is not threadsafe. The application 1332 ** must insure that no other SQLite interfaces are invoked by other 1333 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1334 ** may only be invoked prior to library initialization using 1335 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1336 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1337 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1338 ** Note, however, that ^sqlite3_config() can be called as part of the 1339 ** implementation of an application-defined [sqlite3_os_init()]. 1340 ** 1341 ** The first argument to sqlite3_config() is an integer 1342 ** [configuration option] that determines 1343 ** what property of SQLite is to be configured. Subsequent arguments 1344 ** vary depending on the [configuration option] 1345 ** in the first argument. 1346 ** 1347 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1348 ** ^If the option is unknown or SQLite is unable to set the option 1349 ** then this routine returns a non-zero [error code]. 1350 */ 1351 SQLITE_API int sqlite3_config(int, ...); 1352 1353 /* 1354 ** CAPI3REF: Configure database connections 1355 ** 1356 ** The sqlite3_db_config() interface is used to make configuration 1357 ** changes to a [database connection]. The interface is similar to 1358 ** [sqlite3_config()] except that the changes apply to a single 1359 ** [database connection] (specified in the first argument). 1360 ** 1361 ** The second argument to sqlite3_db_config(D,V,...) is the 1362 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1363 ** that indicates what aspect of the [database connection] is being configured. 1364 ** Subsequent arguments vary depending on the configuration verb. 1365 ** 1366 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1367 ** the call is considered successful. 1368 */ 1369 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1370 1371 /* 1372 ** CAPI3REF: Memory Allocation Routines 1373 ** 1374 ** An instance of this object defines the interface between SQLite 1375 ** and low-level memory allocation routines. 1376 ** 1377 ** This object is used in only one place in the SQLite interface. 1378 ** A pointer to an instance of this object is the argument to 1379 ** [sqlite3_config()] when the configuration option is 1380 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1381 ** By creating an instance of this object 1382 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1383 ** during configuration, an application can specify an alternative 1384 ** memory allocation subsystem for SQLite to use for all of its 1385 ** dynamic memory needs. 1386 ** 1387 ** Note that SQLite comes with several [built-in memory allocators] 1388 ** that are perfectly adequate for the overwhelming majority of applications 1389 ** and that this object is only useful to a tiny minority of applications 1390 ** with specialized memory allocation requirements. This object is 1391 ** also used during testing of SQLite in order to specify an alternative 1392 ** memory allocator that simulates memory out-of-memory conditions in 1393 ** order to verify that SQLite recovers gracefully from such 1394 ** conditions. 1395 ** 1396 ** The xMalloc, xRealloc, and xFree methods must work like the 1397 ** malloc(), realloc() and free() functions from the standard C library. 1398 ** ^SQLite guarantees that the second argument to 1399 ** xRealloc is always a value returned by a prior call to xRoundup. 1400 ** 1401 ** xSize should return the allocated size of a memory allocation 1402 ** previously obtained from xMalloc or xRealloc. The allocated size 1403 ** is always at least as big as the requested size but may be larger. 1404 ** 1405 ** The xRoundup method returns what would be the allocated size of 1406 ** a memory allocation given a particular requested size. Most memory 1407 ** allocators round up memory allocations at least to the next multiple 1408 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1409 ** Every memory allocation request coming in through [sqlite3_malloc()] 1410 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1411 ** that causes the corresponding memory allocation to fail. 1412 ** 1413 ** The xInit method initializes the memory allocator. For example, 1414 ** it might allocate any require mutexes or initialize internal data 1415 ** structures. The xShutdown method is invoked (indirectly) by 1416 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1417 ** by xInit. The pAppData pointer is used as the only parameter to 1418 ** xInit and xShutdown. 1419 ** 1420 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1421 ** the xInit method, so the xInit method need not be threadsafe. The 1422 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1423 ** not need to be threadsafe either. For all other methods, SQLite 1424 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1425 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1426 ** it is by default) and so the methods are automatically serialized. 1427 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1428 ** methods must be threadsafe or else make their own arrangements for 1429 ** serialization. 1430 ** 1431 ** SQLite will never invoke xInit() more than once without an intervening 1432 ** call to xShutdown(). 1433 */ 1434 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1435 struct sqlite3_mem_methods { 1436 void *(*xMalloc)(int); /* Memory allocation function */ 1437 void (*xFree)(void*); /* Free a prior allocation */ 1438 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1439 int (*xSize)(void*); /* Return the size of an allocation */ 1440 int (*xRoundup)(int); /* Round up request size to allocation size */ 1441 int (*xInit)(void*); /* Initialize the memory allocator */ 1442 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1443 void *pAppData; /* Argument to xInit() and xShutdown() */ 1444 }; 1445 1446 /* 1447 ** CAPI3REF: Configuration Options 1448 ** KEYWORDS: {configuration option} 1449 ** 1450 ** These constants are the available integer configuration options that 1451 ** can be passed as the first argument to the [sqlite3_config()] interface. 1452 ** 1453 ** New configuration options may be added in future releases of SQLite. 1454 ** Existing configuration options might be discontinued. Applications 1455 ** should check the return code from [sqlite3_config()] to make sure that 1456 ** the call worked. The [sqlite3_config()] interface will return a 1457 ** non-zero [error code] if a discontinued or unsupported configuration option 1458 ** is invoked. 1459 ** 1460 ** <dl> 1461 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1462 ** <dd>There are no arguments to this option. ^This option sets the 1463 ** [threading mode] to Single-thread. In other words, it disables 1464 ** all mutexing and puts SQLite into a mode where it can only be used 1465 ** by a single thread. ^If SQLite is compiled with 1466 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1467 ** it is not possible to change the [threading mode] from its default 1468 ** value of Single-thread and so [sqlite3_config()] will return 1469 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1470 ** configuration option.</dd> 1471 ** 1472 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1473 ** <dd>There are no arguments to this option. ^This option sets the 1474 ** [threading mode] to Multi-thread. In other words, it disables 1475 ** mutexing on [database connection] and [prepared statement] objects. 1476 ** The application is responsible for serializing access to 1477 ** [database connections] and [prepared statements]. But other mutexes 1478 ** are enabled so that SQLite will be safe to use in a multi-threaded 1479 ** environment as long as no two threads attempt to use the same 1480 ** [database connection] at the same time. ^If SQLite is compiled with 1481 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1482 ** it is not possible to set the Multi-thread [threading mode] and 1483 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1484 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1485 ** 1486 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1487 ** <dd>There are no arguments to this option. ^This option sets the 1488 ** [threading mode] to Serialized. In other words, this option enables 1489 ** all mutexes including the recursive 1490 ** mutexes on [database connection] and [prepared statement] objects. 1491 ** In this mode (which is the default when SQLite is compiled with 1492 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1493 ** to [database connections] and [prepared statements] so that the 1494 ** application is free to use the same [database connection] or the 1495 ** same [prepared statement] in different threads at the same time. 1496 ** ^If SQLite is compiled with 1497 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1498 ** it is not possible to set the Serialized [threading mode] and 1499 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1500 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1501 ** 1502 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1503 ** <dd> ^(This option takes a single argument which is a pointer to an 1504 ** instance of the [sqlite3_mem_methods] structure. The argument specifies 1505 ** alternative low-level memory allocation routines to be used in place of 1506 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1507 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1508 ** before the [sqlite3_config()] call returns.</dd> 1509 ** 1510 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1511 ** <dd> ^(This option takes a single argument which is a pointer to an 1512 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1513 ** structure is filled with the currently defined memory allocation routines.)^ 1514 ** This option can be used to overload the default memory allocation 1515 ** routines with a wrapper that simulations memory allocation failure or 1516 ** tracks memory usage, for example. </dd> 1517 ** 1518 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1519 ** <dd> ^This option takes single argument of type int, interpreted as a 1520 ** boolean, which enables or disables the collection of memory allocation 1521 ** statistics. ^(When memory allocation statistics are disabled, the 1522 ** following SQLite interfaces become non-operational: 1523 ** <ul> 1524 ** <li> [sqlite3_memory_used()] 1525 ** <li> [sqlite3_memory_highwater()] 1526 ** <li> [sqlite3_soft_heap_limit64()] 1527 ** <li> [sqlite3_status()] 1528 ** </ul>)^ 1529 ** ^Memory allocation statistics are enabled by default unless SQLite is 1530 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1531 ** allocation statistics are disabled by default. 1532 ** </dd> 1533 ** 1534 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1535 ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1536 ** scratch memory. There are three arguments: A pointer an 8-byte 1537 ** aligned memory buffer from which the scratch allocations will be 1538 ** drawn, the size of each scratch allocation (sz), 1539 ** and the maximum number of scratch allocations (N). The sz 1540 ** argument must be a multiple of 16. 1541 ** The first argument must be a pointer to an 8-byte aligned buffer 1542 ** of at least sz*N bytes of memory. 1543 ** ^SQLite will use no more than two scratch buffers per thread. So 1544 ** N should be set to twice the expected maximum number of threads. 1545 ** ^SQLite will never require a scratch buffer that is more than 6 1546 ** times the database page size. ^If SQLite needs needs additional 1547 ** scratch memory beyond what is provided by this configuration option, then 1548 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1549 ** 1550 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1551 ** <dd> ^This option specifies a static memory buffer that SQLite can use for 1552 ** the database page cache with the default page cache implementation. 1553 ** This configuration should not be used if an application-define page 1554 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1555 ** There are three arguments to this option: A pointer to 8-byte aligned 1556 ** memory, the size of each page buffer (sz), and the number of pages (N). 1557 ** The sz argument should be the size of the largest database page 1558 ** (a power of two between 512 and 32768) plus a little extra for each 1559 ** page header. ^The page header size is 20 to 40 bytes depending on 1560 ** the host architecture. ^It is harmless, apart from the wasted memory, 1561 ** to make sz a little too large. The first 1562 ** argument should point to an allocation of at least sz*N bytes of memory. 1563 ** ^SQLite will use the memory provided by the first argument to satisfy its 1564 ** memory needs for the first N pages that it adds to cache. ^If additional 1565 ** page cache memory is needed beyond what is provided by this option, then 1566 ** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1567 ** The pointer in the first argument must 1568 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1569 ** will be undefined.</dd> 1570 ** 1571 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1572 ** <dd> ^This option specifies a static memory buffer that SQLite will use 1573 ** for all of its dynamic memory allocation needs beyond those provided 1574 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1575 ** There are three arguments: An 8-byte aligned pointer to the memory, 1576 ** the number of bytes in the memory buffer, and the minimum allocation size. 1577 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1578 ** to using its default memory allocator (the system malloc() implementation), 1579 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1580 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1581 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1582 ** allocator is engaged to handle all of SQLites memory allocation needs. 1583 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1584 ** boundary or subsequent behavior of SQLite will be undefined. 1585 ** The minimum allocation size is capped at 2**12. Reasonable values 1586 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1587 ** 1588 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1589 ** <dd> ^(This option takes a single argument which is a pointer to an 1590 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1591 ** alternative low-level mutex routines to be used in place 1592 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1593 ** content of the [sqlite3_mutex_methods] structure before the call to 1594 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1595 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1596 ** the entire mutexing subsystem is omitted from the build and hence calls to 1597 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1598 ** return [SQLITE_ERROR].</dd> 1599 ** 1600 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1601 ** <dd> ^(This option takes a single argument which is a pointer to an 1602 ** instance of the [sqlite3_mutex_methods] structure. The 1603 ** [sqlite3_mutex_methods] 1604 ** structure is filled with the currently defined mutex routines.)^ 1605 ** This option can be used to overload the default mutex allocation 1606 ** routines with a wrapper used to track mutex usage for performance 1607 ** profiling or testing, for example. ^If SQLite is compiled with 1608 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1609 ** the entire mutexing subsystem is omitted from the build and hence calls to 1610 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1611 ** return [SQLITE_ERROR].</dd> 1612 ** 1613 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1614 ** <dd> ^(This option takes two arguments that determine the default 1615 ** memory allocation for the lookaside memory allocator on each 1616 ** [database connection]. The first argument is the 1617 ** size of each lookaside buffer slot and the second is the number of 1618 ** slots allocated to each database connection.)^ ^(This option sets the 1619 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1620 ** verb to [sqlite3_db_config()] can be used to change the lookaside 1621 ** configuration on individual connections.)^ </dd> 1622 ** 1623 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1624 ** <dd> ^(This option takes a single argument which is a pointer to 1625 ** an [sqlite3_pcache_methods2] object. This object specifies the interface 1626 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1627 ** object and uses it for page cache memory allocations.</dd> 1628 ** 1629 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1630 ** <dd> ^(This option takes a single argument which is a pointer to an 1631 ** [sqlite3_pcache_methods2] object. SQLite copies of the current 1632 ** page cache implementation into that object.)^ </dd> 1633 ** 1634 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1635 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1636 ** global [error log]. 1637 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1638 ** function with a call signature of void(*)(void*,int,const char*), 1639 ** and a pointer to void. ^If the function pointer is not NULL, it is 1640 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1641 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1642 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1643 ** passed through as the first parameter to the application-defined logger 1644 ** function whenever that function is invoked. ^The second parameter to 1645 ** the logger function is a copy of the first parameter to the corresponding 1646 ** [sqlite3_log()] call and is intended to be a [result code] or an 1647 ** [extended result code]. ^The third parameter passed to the logger is 1648 ** log message after formatting via [sqlite3_snprintf()]. 1649 ** The SQLite logging interface is not reentrant; the logger function 1650 ** supplied by the application must not invoke any SQLite interface. 1651 ** In a multi-threaded application, the application-defined logger 1652 ** function must be threadsafe. </dd> 1653 ** 1654 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1655 ** <dd>^(This option takes a single argument of type int. If non-zero, then 1656 ** URI handling is globally enabled. If the parameter is zero, then URI handling 1657 ** is globally disabled.)^ ^If URI handling is globally enabled, all filenames 1658 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1659 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1660 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1661 ** connection is opened. ^If it is globally disabled, filenames are 1662 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1663 ** database connection is opened. ^(By default, URI handling is globally 1664 ** disabled. The default value may be changed by compiling with the 1665 ** [SQLITE_USE_URI] symbol defined.)^ 1666 ** 1667 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1668 ** <dd>^This option takes a single integer argument which is interpreted as 1669 ** a boolean in order to enable or disable the use of covering indices for 1670 ** full table scans in the query optimizer. ^The default setting is determined 1671 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1672 ** if that compile-time option is omitted. 1673 ** The ability to disable the use of covering indices for full table scans 1674 ** is because some incorrectly coded legacy applications might malfunction 1675 ** when the optimization is enabled. Providing the ability to 1676 ** disable the optimization allows the older, buggy application code to work 1677 ** without change even with newer versions of SQLite. 1678 ** 1679 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1680 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1681 ** <dd> These options are obsolete and should not be used by new code. 1682 ** They are retained for backwards compatibility but are now no-ops. 1683 ** </dd> 1684 ** 1685 ** [[SQLITE_CONFIG_SQLLOG]] 1686 ** <dt>SQLITE_CONFIG_SQLLOG 1687 ** <dd>This option is only available if sqlite is compiled with the 1688 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1689 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1690 ** The second should be of type (void*). The callback is invoked by the library 1691 ** in three separate circumstances, identified by the value passed as the 1692 ** fourth parameter. If the fourth parameter is 0, then the database connection 1693 ** passed as the second argument has just been opened. The third argument 1694 ** points to a buffer containing the name of the main database file. If the 1695 ** fourth parameter is 1, then the SQL statement that the third parameter 1696 ** points to has just been executed. Or, if the fourth parameter is 2, then 1697 ** the connection being passed as the second parameter is being closed. The 1698 ** third parameter is passed NULL In this case. An example of using this 1699 ** configuration option can be seen in the "test_sqllog.c" source file in 1700 ** the canonical SQLite source tree.</dd> 1701 ** 1702 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1703 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1704 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1705 ** that are the default mmap size limit (the default setting for 1706 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1707 ** ^The default setting can be overridden by each database connection using 1708 ** either the [PRAGMA mmap_size] command, or by using the 1709 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1710 ** cannot be changed at run-time. Nor may the maximum allowed mmap size 1711 ** exceed the compile-time maximum mmap size set by the 1712 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1713 ** ^If either argument to this option is negative, then that argument is 1714 ** changed to its compile-time default. 1715 ** 1716 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1717 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1718 ** <dd>^This option is only available if SQLite is compiled for Windows 1719 ** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. 1720 ** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1721 ** that specifies the maximum size of the created heap. 1722 ** </dl> 1723 */ 1724 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1725 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1726 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1727 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1728 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1729 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1730 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1731 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1732 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1733 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1734 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1735 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1736 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1737 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1738 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1739 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1740 #define SQLITE_CONFIG_URI 17 /* int */ 1741 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1742 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1743 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1744 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1745 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1746 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1747 1748 /* 1749 ** CAPI3REF: Database Connection Configuration Options 1750 ** 1751 ** These constants are the available integer configuration options that 1752 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1753 ** 1754 ** New configuration options may be added in future releases of SQLite. 1755 ** Existing configuration options might be discontinued. Applications 1756 ** should check the return code from [sqlite3_db_config()] to make sure that 1757 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1758 ** non-zero [error code] if a discontinued or unsupported configuration option 1759 ** is invoked. 1760 ** 1761 ** <dl> 1762 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1763 ** <dd> ^This option takes three additional arguments that determine the 1764 ** [lookaside memory allocator] configuration for the [database connection]. 1765 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1766 ** pointer to a memory buffer to use for lookaside memory. 1767 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1768 ** may be NULL in which case SQLite will allocate the 1769 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1770 ** size of each lookaside buffer slot. ^The third argument is the number of 1771 ** slots. The size of the buffer in the first argument must be greater than 1772 ** or equal to the product of the second and third arguments. The buffer 1773 ** must be aligned to an 8-byte boundary. ^If the second argument to 1774 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1775 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1776 ** configuration for a database connection can only be changed when that 1777 ** connection is not currently using lookaside memory, or in other words 1778 ** when the "current value" returned by 1779 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1780 ** Any attempt to change the lookaside memory configuration when lookaside 1781 ** memory is in use leaves the configuration unchanged and returns 1782 ** [SQLITE_BUSY].)^</dd> 1783 ** 1784 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1785 ** <dd> ^This option is used to enable or disable the enforcement of 1786 ** [foreign key constraints]. There should be two additional arguments. 1787 ** The first argument is an integer which is 0 to disable FK enforcement, 1788 ** positive to enable FK enforcement or negative to leave FK enforcement 1789 ** unchanged. The second parameter is a pointer to an integer into which 1790 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1791 ** following this call. The second parameter may be a NULL pointer, in 1792 ** which case the FK enforcement setting is not reported back. </dd> 1793 ** 1794 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1795 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1796 ** There should be two additional arguments. 1797 ** The first argument is an integer which is 0 to disable triggers, 1798 ** positive to enable triggers or negative to leave the setting unchanged. 1799 ** The second parameter is a pointer to an integer into which 1800 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 1801 ** following this call. The second parameter may be a NULL pointer, in 1802 ** which case the trigger setting is not reported back. </dd> 1803 ** 1804 ** </dl> 1805 */ 1806 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1807 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1808 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1809 1810 1811 /* 1812 ** CAPI3REF: Enable Or Disable Extended Result Codes 1813 ** 1814 ** ^The sqlite3_extended_result_codes() routine enables or disables the 1815 ** [extended result codes] feature of SQLite. ^The extended result 1816 ** codes are disabled by default for historical compatibility. 1817 */ 1818 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1819 1820 /* 1821 ** CAPI3REF: Last Insert Rowid 1822 ** 1823 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1824 ** has a unique 64-bit signed 1825 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1826 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1827 ** names are not also used by explicitly declared columns. ^If 1828 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 1829 ** is another alias for the rowid. 1830 ** 1831 ** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1832 ** most recent successful [INSERT] into a rowid table or [virtual table] 1833 ** on database connection D. 1834 ** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1835 ** ^If no successful [INSERT]s into rowid tables 1836 ** have ever occurred on the database connection D, 1837 ** then sqlite3_last_insert_rowid(D) returns zero. 1838 ** 1839 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1840 ** method, then this routine will return the [rowid] of the inserted 1841 ** row as long as the trigger or virtual table method is running. 1842 ** But once the trigger or virtual table method ends, the value returned 1843 ** by this routine reverts to what it was before the trigger or virtual 1844 ** table method began.)^ 1845 ** 1846 ** ^An [INSERT] that fails due to a constraint violation is not a 1847 ** successful [INSERT] and does not change the value returned by this 1848 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1849 ** and INSERT OR ABORT make no changes to the return value of this 1850 ** routine when their insertion fails. ^(When INSERT OR REPLACE 1851 ** encounters a constraint violation, it does not fail. The 1852 ** INSERT continues to completion after deleting rows that caused 1853 ** the constraint problem so INSERT OR REPLACE will always change 1854 ** the return value of this interface.)^ 1855 ** 1856 ** ^For the purposes of this routine, an [INSERT] is considered to 1857 ** be successful even if it is subsequently rolled back. 1858 ** 1859 ** This function is accessible to SQL statements via the 1860 ** [last_insert_rowid() SQL function]. 1861 ** 1862 ** If a separate thread performs a new [INSERT] on the same 1863 ** database connection while the [sqlite3_last_insert_rowid()] 1864 ** function is running and thus changes the last insert [rowid], 1865 ** then the value returned by [sqlite3_last_insert_rowid()] is 1866 ** unpredictable and might not equal either the old or the new 1867 ** last insert [rowid]. 1868 */ 1869 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1870 1871 /* 1872 ** CAPI3REF: Count The Number Of Rows Modified 1873 ** 1874 ** ^This function returns the number of database rows that were changed 1875 ** or inserted or deleted by the most recently completed SQL statement 1876 ** on the [database connection] specified by the first parameter. 1877 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1878 ** or [DELETE] statement are counted. Auxiliary changes caused by 1879 ** triggers or [foreign key actions] are not counted.)^ Use the 1880 ** [sqlite3_total_changes()] function to find the total number of changes 1881 ** including changes caused by triggers and foreign key actions. 1882 ** 1883 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 1884 ** are not counted. Only real table changes are counted. 1885 ** 1886 ** ^(A "row change" is a change to a single row of a single table 1887 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that 1888 ** are changed as side effects of [REPLACE] constraint resolution, 1889 ** rollback, ABORT processing, [DROP TABLE], or by any other 1890 ** mechanisms do not count as direct row changes.)^ 1891 ** 1892 ** A "trigger context" is a scope of execution that begins and 1893 ** ends with the script of a [CREATE TRIGGER | trigger]. 1894 ** Most SQL statements are 1895 ** evaluated outside of any trigger. This is the "top level" 1896 ** trigger context. If a trigger fires from the top level, a 1897 ** new trigger context is entered for the duration of that one 1898 ** trigger. Subtriggers create subcontexts for their duration. 1899 ** 1900 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 1901 ** not create a new trigger context. 1902 ** 1903 ** ^This function returns the number of direct row changes in the 1904 ** most recent INSERT, UPDATE, or DELETE statement within the same 1905 ** trigger context. 1906 ** 1907 ** ^Thus, when called from the top level, this function returns the 1908 ** number of changes in the most recent INSERT, UPDATE, or DELETE 1909 ** that also occurred at the top level. ^(Within the body of a trigger, 1910 ** the sqlite3_changes() interface can be called to find the number of 1911 ** changes in the most recently completed INSERT, UPDATE, or DELETE 1912 ** statement within the body of the same trigger. 1913 ** However, the number returned does not include changes 1914 ** caused by subtriggers since those have their own context.)^ 1915 ** 1916 ** See also the [sqlite3_total_changes()] interface, the 1917 ** [count_changes pragma], and the [changes() SQL function]. 1918 ** 1919 ** If a separate thread makes changes on the same database connection 1920 ** while [sqlite3_changes()] is running then the value returned 1921 ** is unpredictable and not meaningful. 1922 */ 1923 SQLITE_API int sqlite3_changes(sqlite3*); 1924 1925 /* 1926 ** CAPI3REF: Total Number Of Rows Modified 1927 ** 1928 ** ^This function returns the number of row changes caused by [INSERT], 1929 ** [UPDATE] or [DELETE] statements since the [database connection] was opened. 1930 ** ^(The count returned by sqlite3_total_changes() includes all changes 1931 ** from all [CREATE TRIGGER | trigger] contexts and changes made by 1932 ** [foreign key actions]. However, 1933 ** the count does not include changes used to implement [REPLACE] constraints, 1934 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 1935 ** count does not include rows of views that fire an [INSTEAD OF trigger], 1936 ** though if the INSTEAD OF trigger makes changes of its own, those changes 1937 ** are counted.)^ 1938 ** ^The sqlite3_total_changes() function counts the changes as soon as 1939 ** the statement that makes them is completed (when the statement handle 1940 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 1941 ** 1942 ** See also the [sqlite3_changes()] interface, the 1943 ** [count_changes pragma], and the [total_changes() SQL function]. 1944 ** 1945 ** If a separate thread makes changes on the same database connection 1946 ** while [sqlite3_total_changes()] is running then the value 1947 ** returned is unpredictable and not meaningful. 1948 */ 1949 SQLITE_API int sqlite3_total_changes(sqlite3*); 1950 1951 /* 1952 ** CAPI3REF: Interrupt A Long-Running Query 1953 ** 1954 ** ^This function causes any pending database operation to abort and 1955 ** return at its earliest opportunity. This routine is typically 1956 ** called in response to a user action such as pressing "Cancel" 1957 ** or Ctrl-C where the user wants a long query operation to halt 1958 ** immediately. 1959 ** 1960 ** ^It is safe to call this routine from a thread different from the 1961 ** thread that is currently running the database operation. But it 1962 ** is not safe to call this routine with a [database connection] that 1963 ** is closed or might close before sqlite3_interrupt() returns. 1964 ** 1965 ** ^If an SQL operation is very nearly finished at the time when 1966 ** sqlite3_interrupt() is called, then it might not have an opportunity 1967 ** to be interrupted and might continue to completion. 1968 ** 1969 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 1970 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 1971 ** that is inside an explicit transaction, then the entire transaction 1972 ** will be rolled back automatically. 1973 ** 1974 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 1975 ** SQL statements on [database connection] D complete. ^Any new SQL statements 1976 ** that are started after the sqlite3_interrupt() call and before the 1977 ** running statements reaches zero are interrupted as if they had been 1978 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 1979 ** that are started after the running statement count reaches zero are 1980 ** not effected by the sqlite3_interrupt(). 1981 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 1982 ** SQL statements is a no-op and has no effect on SQL statements 1983 ** that are started after the sqlite3_interrupt() call returns. 1984 ** 1985 ** If the database connection closes while [sqlite3_interrupt()] 1986 ** is running then bad things will likely happen. 1987 */ 1988 SQLITE_API void sqlite3_interrupt(sqlite3*); 1989 1990 /* 1991 ** CAPI3REF: Determine If An SQL Statement Is Complete 1992 ** 1993 ** These routines are useful during command-line input to determine if the 1994 ** currently entered text seems to form a complete SQL statement or 1995 ** if additional input is needed before sending the text into 1996 ** SQLite for parsing. ^These routines return 1 if the input string 1997 ** appears to be a complete SQL statement. ^A statement is judged to be 1998 ** complete if it ends with a semicolon token and is not a prefix of a 1999 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2000 ** string literals or quoted identifier names or comments are not 2001 ** independent tokens (they are part of the token in which they are 2002 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2003 ** and comments that follow the final semicolon are ignored. 2004 ** 2005 ** ^These routines return 0 if the statement is incomplete. ^If a 2006 ** memory allocation fails, then SQLITE_NOMEM is returned. 2007 ** 2008 ** ^These routines do not parse the SQL statements thus 2009 ** will not detect syntactically incorrect SQL. 2010 ** 2011 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2012 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2013 ** automatically by sqlite3_complete16(). If that initialization fails, 2014 ** then the return value from sqlite3_complete16() will be non-zero 2015 ** regardless of whether or not the input SQL is complete.)^ 2016 ** 2017 ** The input to [sqlite3_complete()] must be a zero-terminated 2018 ** UTF-8 string. 2019 ** 2020 ** The input to [sqlite3_complete16()] must be a zero-terminated 2021 ** UTF-16 string in native byte order. 2022 */ 2023 SQLITE_API int sqlite3_complete(const char *sql); 2024 SQLITE_API int sqlite3_complete16(const void *sql); 2025 2026 /* 2027 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2028 ** 2029 ** ^This routine sets a callback function that might be invoked whenever 2030 ** an attempt is made to open a database table that another thread 2031 ** or process has locked. 2032 ** 2033 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] 2034 ** is returned immediately upon encountering the lock. ^If the busy callback 2035 ** is not NULL, then the callback might be invoked with two arguments. 2036 ** 2037 ** ^The first argument to the busy handler is a copy of the void* pointer which 2038 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2039 ** the busy handler callback is the number of times that the busy handler has 2040 ** been invoked for this locking event. ^If the 2041 ** busy callback returns 0, then no additional attempts are made to 2042 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 2043 ** ^If the callback returns non-zero, then another attempt 2044 ** is made to open the database for reading and the cycle repeats. 2045 ** 2046 ** The presence of a busy handler does not guarantee that it will be invoked 2047 ** when there is lock contention. ^If SQLite determines that invoking the busy 2048 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2049 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. 2050 ** Consider a scenario where one process is holding a read lock that 2051 ** it is trying to promote to a reserved lock and 2052 ** a second process is holding a reserved lock that it is trying 2053 ** to promote to an exclusive lock. The first process cannot proceed 2054 ** because it is blocked by the second and the second process cannot 2055 ** proceed because it is blocked by the first. If both processes 2056 ** invoke the busy handlers, neither will make any progress. Therefore, 2057 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2058 ** will induce the first process to release its read lock and allow 2059 ** the second process to proceed. 2060 ** 2061 ** ^The default busy callback is NULL. 2062 ** 2063 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 2064 ** when SQLite is in the middle of a large transaction where all the 2065 ** changes will not fit into the in-memory cache. SQLite will 2066 ** already hold a RESERVED lock on the database file, but it needs 2067 ** to promote this lock to EXCLUSIVE so that it can spill cache 2068 ** pages into the database file without harm to concurrent 2069 ** readers. ^If it is unable to promote the lock, then the in-memory 2070 ** cache will be left in an inconsistent state and so the error 2071 ** code is promoted from the relatively benign [SQLITE_BUSY] to 2072 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion 2073 ** forces an automatic rollback of the changes. See the 2074 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> 2075 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why 2076 ** this is important. 2077 ** 2078 ** ^(There can only be a single busy handler defined for each 2079 ** [database connection]. Setting a new busy handler clears any 2080 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2081 ** will also set or clear the busy handler. 2082 ** 2083 ** The busy callback should not take any actions which modify the 2084 ** database connection that invoked the busy handler. Any such actions 2085 ** result in undefined behavior. 2086 ** 2087 ** A busy handler must not close the database connection 2088 ** or [prepared statement] that invoked the busy handler. 2089 */ 2090 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2091 2092 /* 2093 ** CAPI3REF: Set A Busy Timeout 2094 ** 2095 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2096 ** for a specified amount of time when a table is locked. ^The handler 2097 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2098 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2099 ** the handler returns 0 which causes [sqlite3_step()] to return 2100 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 2101 ** 2102 ** ^Calling this routine with an argument less than or equal to zero 2103 ** turns off all busy handlers. 2104 ** 2105 ** ^(There can only be a single busy handler for a particular 2106 ** [database connection] any any given moment. If another busy handler 2107 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2108 ** this routine, that other busy handler is cleared.)^ 2109 */ 2110 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2111 2112 /* 2113 ** CAPI3REF: Convenience Routines For Running Queries 2114 ** 2115 ** This is a legacy interface that is preserved for backwards compatibility. 2116 ** Use of this interface is not recommended. 2117 ** 2118 ** Definition: A <b>result table</b> is memory data structure created by the 2119 ** [sqlite3_get_table()] interface. A result table records the 2120 ** complete query results from one or more queries. 2121 ** 2122 ** The table conceptually has a number of rows and columns. But 2123 ** these numbers are not part of the result table itself. These 2124 ** numbers are obtained separately. Let N be the number of rows 2125 ** and M be the number of columns. 2126 ** 2127 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2128 ** There are (N+1)*M elements in the array. The first M pointers point 2129 ** to zero-terminated strings that contain the names of the columns. 2130 ** The remaining entries all point to query results. NULL values result 2131 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2132 ** string representation as returned by [sqlite3_column_text()]. 2133 ** 2134 ** A result table might consist of one or more memory allocations. 2135 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2136 ** A result table should be deallocated using [sqlite3_free_table()]. 2137 ** 2138 ** ^(As an example of the result table format, suppose a query result 2139 ** is as follows: 2140 ** 2141 ** <blockquote><pre> 2142 ** Name | Age 2143 ** ----------------------- 2144 ** Alice | 43 2145 ** Bob | 28 2146 ** Cindy | 21 2147 ** </pre></blockquote> 2148 ** 2149 ** There are two column (M==2) and three rows (N==3). Thus the 2150 ** result table has 8 entries. Suppose the result table is stored 2151 ** in an array names azResult. Then azResult holds this content: 2152 ** 2153 ** <blockquote><pre> 2154 ** azResult[0] = "Name"; 2155 ** azResult[1] = "Age"; 2156 ** azResult[2] = "Alice"; 2157 ** azResult[3] = "43"; 2158 ** azResult[4] = "Bob"; 2159 ** azResult[5] = "28"; 2160 ** azResult[6] = "Cindy"; 2161 ** azResult[7] = "21"; 2162 ** </pre></blockquote>)^ 2163 ** 2164 ** ^The sqlite3_get_table() function evaluates one or more 2165 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2166 ** string of its 2nd parameter and returns a result table to the 2167 ** pointer given in its 3rd parameter. 2168 ** 2169 ** After the application has finished with the result from sqlite3_get_table(), 2170 ** it must pass the result table pointer to sqlite3_free_table() in order to 2171 ** release the memory that was malloced. Because of the way the 2172 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2173 ** function must not try to call [sqlite3_free()] directly. Only 2174 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2175 ** 2176 ** The sqlite3_get_table() interface is implemented as a wrapper around 2177 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2178 ** to any internal data structures of SQLite. It uses only the public 2179 ** interface defined here. As a consequence, errors that occur in the 2180 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2181 ** reflected in subsequent calls to [sqlite3_errcode()] or 2182 ** [sqlite3_errmsg()]. 2183 */ 2184 SQLITE_API int sqlite3_get_table( 2185 sqlite3 *db, /* An open database */ 2186 const char *zSql, /* SQL to be evaluated */ 2187 char ***pazResult, /* Results of the query */ 2188 int *pnRow, /* Number of result rows written here */ 2189 int *pnColumn, /* Number of result columns written here */ 2190 char **pzErrmsg /* Error msg written here */ 2191 ); 2192 SQLITE_API void sqlite3_free_table(char **result); 2193 2194 /* 2195 ** CAPI3REF: Formatted String Printing Functions 2196 ** 2197 ** These routines are work-alikes of the "printf()" family of functions 2198 ** from the standard C library. 2199 ** 2200 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2201 ** results into memory obtained from [sqlite3_malloc()]. 2202 ** The strings returned by these two routines should be 2203 ** released by [sqlite3_free()]. ^Both routines return a 2204 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2205 ** memory to hold the resulting string. 2206 ** 2207 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2208 ** the standard C library. The result is written into the 2209 ** buffer supplied as the second parameter whose size is given by 2210 ** the first parameter. Note that the order of the 2211 ** first two parameters is reversed from snprintf().)^ This is an 2212 ** historical accident that cannot be fixed without breaking 2213 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2214 ** returns a pointer to its buffer instead of the number of 2215 ** characters actually written into the buffer.)^ We admit that 2216 ** the number of characters written would be a more useful return 2217 ** value but we cannot change the implementation of sqlite3_snprintf() 2218 ** now without breaking compatibility. 2219 ** 2220 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2221 ** guarantees that the buffer is always zero-terminated. ^The first 2222 ** parameter "n" is the total size of the buffer, including space for 2223 ** the zero terminator. So the longest string that can be completely 2224 ** written will be n-1 characters. 2225 ** 2226 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2227 ** 2228 ** These routines all implement some additional formatting 2229 ** options that are useful for constructing SQL statements. 2230 ** All of the usual printf() formatting options apply. In addition, there 2231 ** is are "%q", "%Q", and "%z" options. 2232 ** 2233 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2234 ** string from the argument list. But %q also doubles every '\'' character. 2235 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2236 ** character it escapes that character and allows it to be inserted into 2237 ** the string. 2238 ** 2239 ** For example, assume the string variable zText contains text as follows: 2240 ** 2241 ** <blockquote><pre> 2242 ** char *zText = "It's a happy day!"; 2243 ** </pre></blockquote> 2244 ** 2245 ** One can use this text in an SQL statement as follows: 2246 ** 2247 ** <blockquote><pre> 2248 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2249 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2250 ** sqlite3_free(zSQL); 2251 ** </pre></blockquote> 2252 ** 2253 ** Because the %q format string is used, the '\'' character in zText 2254 ** is escaped and the SQL generated is as follows: 2255 ** 2256 ** <blockquote><pre> 2257 ** INSERT INTO table1 VALUES('It''s a happy day!') 2258 ** </pre></blockquote> 2259 ** 2260 ** This is correct. Had we used %s instead of %q, the generated SQL 2261 ** would have looked like this: 2262 ** 2263 ** <blockquote><pre> 2264 ** INSERT INTO table1 VALUES('It's a happy day!'); 2265 ** </pre></blockquote> 2266 ** 2267 ** This second example is an SQL syntax error. As a general rule you should 2268 ** always use %q instead of %s when inserting text into a string literal. 2269 ** 2270 ** ^(The %Q option works like %q except it also adds single quotes around 2271 ** the outside of the total string. Additionally, if the parameter in the 2272 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2273 ** single quotes).)^ So, for example, one could say: 2274 ** 2275 ** <blockquote><pre> 2276 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2277 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2278 ** sqlite3_free(zSQL); 2279 ** </pre></blockquote> 2280 ** 2281 ** The code above will render a correct SQL statement in the zSQL 2282 ** variable even if the zText variable is a NULL pointer. 2283 ** 2284 ** ^(The "%z" formatting option works like "%s" but with the 2285 ** addition that after the string has been read and copied into 2286 ** the result, [sqlite3_free()] is called on the input string.)^ 2287 */ 2288 SQLITE_API char *sqlite3_mprintf(const char*,...); 2289 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2290 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2291 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2292 2293 /* 2294 ** CAPI3REF: Memory Allocation Subsystem 2295 ** 2296 ** The SQLite core uses these three routines for all of its own 2297 ** internal memory allocation needs. "Core" in the previous sentence 2298 ** does not include operating-system specific VFS implementation. The 2299 ** Windows VFS uses native malloc() and free() for some operations. 2300 ** 2301 ** ^The sqlite3_malloc() routine returns a pointer to a block 2302 ** of memory at least N bytes in length, where N is the parameter. 2303 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2304 ** memory, it returns a NULL pointer. ^If the parameter N to 2305 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2306 ** a NULL pointer. 2307 ** 2308 ** ^Calling sqlite3_free() with a pointer previously returned 2309 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2310 ** that it might be reused. ^The sqlite3_free() routine is 2311 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2312 ** to sqlite3_free() is harmless. After being freed, memory 2313 ** should neither be read nor written. Even reading previously freed 2314 ** memory might result in a segmentation fault or other severe error. 2315 ** Memory corruption, a segmentation fault, or other severe error 2316 ** might result if sqlite3_free() is called with a non-NULL pointer that 2317 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2318 ** 2319 ** ^(The sqlite3_realloc() interface attempts to resize a 2320 ** prior memory allocation to be at least N bytes, where N is the 2321 ** second parameter. The memory allocation to be resized is the first 2322 ** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2323 ** is a NULL pointer then its behavior is identical to calling 2324 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2325 ** ^If the second parameter to sqlite3_realloc() is zero or 2326 ** negative then the behavior is exactly the same as calling 2327 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2328 ** ^sqlite3_realloc() returns a pointer to a memory allocation 2329 ** of at least N bytes in size or NULL if sufficient memory is unavailable. 2330 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2331 ** of the prior allocation are copied into the beginning of buffer returned 2332 ** by sqlite3_realloc() and the prior allocation is freed. 2333 ** ^If sqlite3_realloc() returns NULL, then the prior allocation 2334 ** is not freed. 2335 ** 2336 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2337 ** is always aligned to at least an 8 byte boundary, or to a 2338 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2339 ** option is used. 2340 ** 2341 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2342 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2343 ** implementation of these routines to be omitted. That capability 2344 ** is no longer provided. Only built-in memory allocators can be used. 2345 ** 2346 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2347 ** the system malloc() and free() directly when converting 2348 ** filenames between the UTF-8 encoding used by SQLite 2349 ** and whatever filename encoding is used by the particular Windows 2350 ** installation. Memory allocation errors were detected, but 2351 ** they were reported back as [SQLITE_CANTOPEN] or 2352 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2353 ** 2354 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2355 ** must be either NULL or else pointers obtained from a prior 2356 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2357 ** not yet been released. 2358 ** 2359 ** The application must not read or write any part of 2360 ** a block of memory after it has been released using 2361 ** [sqlite3_free()] or [sqlite3_realloc()]. 2362 */ 2363 SQLITE_API void *sqlite3_malloc(int); 2364 SQLITE_API void *sqlite3_realloc(void*, int); 2365 SQLITE_API void sqlite3_free(void*); 2366 2367 /* 2368 ** CAPI3REF: Memory Allocator Statistics 2369 ** 2370 ** SQLite provides these two interfaces for reporting on the status 2371 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2372 ** routines, which form the built-in memory allocation subsystem. 2373 ** 2374 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2375 ** of memory currently outstanding (malloced but not freed). 2376 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2377 ** value of [sqlite3_memory_used()] since the high-water mark 2378 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2379 ** [sqlite3_memory_highwater()] include any overhead 2380 ** added by SQLite in its implementation of [sqlite3_malloc()], 2381 ** but not overhead added by the any underlying system library 2382 ** routines that [sqlite3_malloc()] may call. 2383 ** 2384 ** ^The memory high-water mark is reset to the current value of 2385 ** [sqlite3_memory_used()] if and only if the parameter to 2386 ** [sqlite3_memory_highwater()] is true. ^The value returned 2387 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2388 ** prior to the reset. 2389 */ 2390 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2391 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2392 2393 /* 2394 ** CAPI3REF: Pseudo-Random Number Generator 2395 ** 2396 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2397 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2398 ** already uses the largest possible [ROWID]. The PRNG is also used for 2399 ** the build-in random() and randomblob() SQL functions. This interface allows 2400 ** applications to access the same PRNG for other purposes. 2401 ** 2402 ** ^A call to this routine stores N bytes of randomness into buffer P. 2403 ** ^If N is less than one, then P can be a NULL pointer. 2404 ** 2405 ** ^If this routine has not been previously called or if the previous 2406 ** call had N less than one, then the PRNG is seeded using randomness 2407 ** obtained from the xRandomness method of the default [sqlite3_vfs] object. 2408 ** ^If the previous call to this routine had an N of 1 or more then 2409 ** the pseudo-randomness is generated 2410 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2411 ** method. 2412 */ 2413 SQLITE_API void sqlite3_randomness(int N, void *P); 2414 2415 /* 2416 ** CAPI3REF: Compile-Time Authorization Callbacks 2417 ** 2418 ** ^This routine registers an authorizer callback with a particular 2419 ** [database connection], supplied in the first argument. 2420 ** ^The authorizer callback is invoked as SQL statements are being compiled 2421 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2422 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2423 ** points during the compilation process, as logic is being created 2424 ** to perform various actions, the authorizer callback is invoked to 2425 ** see if those actions are allowed. ^The authorizer callback should 2426 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2427 ** specific action but allow the SQL statement to continue to be 2428 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2429 ** rejected with an error. ^If the authorizer callback returns 2430 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2431 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2432 ** the authorizer will fail with an error message. 2433 ** 2434 ** When the callback returns [SQLITE_OK], that means the operation 2435 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2436 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2437 ** authorizer will fail with an error message explaining that 2438 ** access is denied. 2439 ** 2440 ** ^The first parameter to the authorizer callback is a copy of the third 2441 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2442 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2443 ** the particular action to be authorized. ^The third through sixth parameters 2444 ** to the callback are zero-terminated strings that contain additional 2445 ** details about the action to be authorized. 2446 ** 2447 ** ^If the action code is [SQLITE_READ] 2448 ** and the callback returns [SQLITE_IGNORE] then the 2449 ** [prepared statement] statement is constructed to substitute 2450 ** a NULL value in place of the table column that would have 2451 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2452 ** return can be used to deny an untrusted user access to individual 2453 ** columns of a table. 2454 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2455 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2456 ** [truncate optimization] is disabled and all rows are deleted individually. 2457 ** 2458 ** An authorizer is used when [sqlite3_prepare | preparing] 2459 ** SQL statements from an untrusted source, to ensure that the SQL statements 2460 ** do not try to access data they are not allowed to see, or that they do not 2461 ** try to execute malicious statements that damage the database. For 2462 ** example, an application may allow a user to enter arbitrary 2463 ** SQL queries for evaluation by a database. But the application does 2464 ** not want the user to be able to make arbitrary changes to the 2465 ** database. An authorizer could then be put in place while the 2466 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2467 ** disallows everything except [SELECT] statements. 2468 ** 2469 ** Applications that need to process SQL from untrusted sources 2470 ** might also consider lowering resource limits using [sqlite3_limit()] 2471 ** and limiting database size using the [max_page_count] [PRAGMA] 2472 ** in addition to using an authorizer. 2473 ** 2474 ** ^(Only a single authorizer can be in place on a database connection 2475 ** at a time. Each call to sqlite3_set_authorizer overrides the 2476 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2477 ** The authorizer is disabled by default. 2478 ** 2479 ** The authorizer callback must not do anything that will modify 2480 ** the database connection that invoked the authorizer callback. 2481 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2482 ** database connections for the meaning of "modify" in this paragraph. 2483 ** 2484 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2485 ** statement might be re-prepared during [sqlite3_step()] due to a 2486 ** schema change. Hence, the application should ensure that the 2487 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2488 ** 2489 ** ^Note that the authorizer callback is invoked only during 2490 ** [sqlite3_prepare()] or its variants. Authorization is not 2491 ** performed during statement evaluation in [sqlite3_step()], unless 2492 ** as stated in the previous paragraph, sqlite3_step() invokes 2493 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2494 */ 2495 SQLITE_API int sqlite3_set_authorizer( 2496 sqlite3*, 2497 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2498 void *pUserData 2499 ); 2500 2501 /* 2502 ** CAPI3REF: Authorizer Return Codes 2503 ** 2504 ** The [sqlite3_set_authorizer | authorizer callback function] must 2505 ** return either [SQLITE_OK] or one of these two constants in order 2506 ** to signal SQLite whether or not the action is permitted. See the 2507 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2508 ** information. 2509 ** 2510 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] 2511 ** from the [sqlite3_vtab_on_conflict()] interface. 2512 */ 2513 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2514 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2515 2516 /* 2517 ** CAPI3REF: Authorizer Action Codes 2518 ** 2519 ** The [sqlite3_set_authorizer()] interface registers a callback function 2520 ** that is invoked to authorize certain SQL statement actions. The 2521 ** second parameter to the callback is an integer code that specifies 2522 ** what action is being authorized. These are the integer action codes that 2523 ** the authorizer callback may be passed. 2524 ** 2525 ** These action code values signify what kind of operation is to be 2526 ** authorized. The 3rd and 4th parameters to the authorization 2527 ** callback function will be parameters or NULL depending on which of these 2528 ** codes is used as the second parameter. ^(The 5th parameter to the 2529 ** authorizer callback is the name of the database ("main", "temp", 2530 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2531 ** is the name of the inner-most trigger or view that is responsible for 2532 ** the access attempt or NULL if this access attempt is directly from 2533 ** top-level SQL code. 2534 */ 2535 /******************************************* 3rd ************ 4th ***********/ 2536 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2537 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2538 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2539 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2540 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2541 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2542 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2543 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2544 #define SQLITE_DELETE 9 /* Table Name NULL */ 2545 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2546 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2547 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2548 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2549 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2550 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2551 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2552 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2553 #define SQLITE_INSERT 18 /* Table Name NULL */ 2554 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2555 #define SQLITE_READ 20 /* Table Name Column Name */ 2556 #define SQLITE_SELECT 21 /* NULL NULL */ 2557 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2558 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2559 #define SQLITE_ATTACH 24 /* Filename NULL */ 2560 #define SQLITE_DETACH 25 /* Database Name NULL */ 2561 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2562 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2563 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2564 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2565 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2566 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2567 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2568 #define SQLITE_COPY 0 /* No longer used */ 2569 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2570 2571 /* 2572 ** CAPI3REF: Tracing And Profiling Functions 2573 ** 2574 ** These routines register callback functions that can be used for 2575 ** tracing and profiling the execution of SQL statements. 2576 ** 2577 ** ^The callback function registered by sqlite3_trace() is invoked at 2578 ** various times when an SQL statement is being run by [sqlite3_step()]. 2579 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2580 ** SQL statement text as the statement first begins executing. 2581 ** ^(Additional sqlite3_trace() callbacks might occur 2582 ** as each triggered subprogram is entered. The callbacks for triggers 2583 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2584 ** 2585 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2586 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2587 ** 2588 ** ^The callback function registered by sqlite3_profile() is invoked 2589 ** as each SQL statement finishes. ^The profile callback contains 2590 ** the original statement text and an estimate of wall-clock time 2591 ** of how long that statement took to run. ^The profile callback 2592 ** time is in units of nanoseconds, however the current implementation 2593 ** is only capable of millisecond resolution so the six least significant 2594 ** digits in the time are meaningless. Future versions of SQLite 2595 ** might provide greater resolution on the profiler callback. The 2596 ** sqlite3_profile() function is considered experimental and is 2597 ** subject to change in future versions of SQLite. 2598 */ 2599 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2600 SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2601 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2602 2603 /* 2604 ** CAPI3REF: Query Progress Callbacks 2605 ** 2606 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2607 ** function X to be invoked periodically during long running calls to 2608 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2609 ** database connection D. An example use for this 2610 ** interface is to keep a GUI updated during a large query. 2611 ** 2612 ** ^The parameter P is passed through as the only parameter to the 2613 ** callback function X. ^The parameter N is the approximate number of 2614 ** [virtual machine instructions] that are evaluated between successive 2615 ** invocations of the callback X. ^If N is less than one then the progress 2616 ** handler is disabled. 2617 ** 2618 ** ^Only a single progress handler may be defined at one time per 2619 ** [database connection]; setting a new progress handler cancels the 2620 ** old one. ^Setting parameter X to NULL disables the progress handler. 2621 ** ^The progress handler is also disabled by setting N to a value less 2622 ** than 1. 2623 ** 2624 ** ^If the progress callback returns non-zero, the operation is 2625 ** interrupted. This feature can be used to implement a 2626 ** "Cancel" button on a GUI progress dialog box. 2627 ** 2628 ** The progress handler callback must not do anything that will modify 2629 ** the database connection that invoked the progress handler. 2630 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2631 ** database connections for the meaning of "modify" in this paragraph. 2632 ** 2633 */ 2634 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2635 2636 /* 2637 ** CAPI3REF: Opening A New Database Connection 2638 ** 2639 ** ^These routines open an SQLite database file as specified by the 2640 ** filename argument. ^The filename argument is interpreted as UTF-8 for 2641 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2642 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 2643 ** returned in *ppDb, even if an error occurs. The only exception is that 2644 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2645 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2646 ** object.)^ ^(If the database is opened (and/or created) successfully, then 2647 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2648 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2649 ** an English language description of the error following a failure of any 2650 ** of the sqlite3_open() routines. 2651 ** 2652 ** ^The default encoding for the database will be UTF-8 if 2653 ** sqlite3_open() or sqlite3_open_v2() is called and 2654 ** UTF-16 in the native byte order if sqlite3_open16() is used. 2655 ** 2656 ** Whether or not an error occurs when it is opened, resources 2657 ** associated with the [database connection] handle should be released by 2658 ** passing it to [sqlite3_close()] when it is no longer required. 2659 ** 2660 ** The sqlite3_open_v2() interface works like sqlite3_open() 2661 ** except that it accepts two additional parameters for additional control 2662 ** over the new database connection. ^(The flags parameter to 2663 ** sqlite3_open_v2() can take one of 2664 ** the following three values, optionally combined with the 2665 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2666 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2667 ** 2668 ** <dl> 2669 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2670 ** <dd>The database is opened in read-only mode. If the database does not 2671 ** already exist, an error is returned.</dd>)^ 2672 ** 2673 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2674 ** <dd>The database is opened for reading and writing if possible, or reading 2675 ** only if the file is write protected by the operating system. In either 2676 ** case the database must already exist, otherwise an error is returned.</dd>)^ 2677 ** 2678 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2679 ** <dd>The database is opened for reading and writing, and is created if 2680 ** it does not already exist. This is the behavior that is always used for 2681 ** sqlite3_open() and sqlite3_open16().</dd>)^ 2682 ** </dl> 2683 ** 2684 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 2685 ** combinations shown above optionally combined with other 2686 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2687 ** then the behavior is undefined. 2688 ** 2689 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2690 ** opens in the multi-thread [threading mode] as long as the single-thread 2691 ** mode has not been set at compile-time or start-time. ^If the 2692 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2693 ** in the serialized [threading mode] unless single-thread was 2694 ** previously selected at compile-time or start-time. 2695 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2696 ** eligible to use [shared cache mode], regardless of whether or not shared 2697 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2698 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2699 ** participate in [shared cache mode] even if it is enabled. 2700 ** 2701 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 2702 ** [sqlite3_vfs] object that defines the operating system interface that 2703 ** the new database connection should use. ^If the fourth parameter is 2704 ** a NULL pointer then the default [sqlite3_vfs] object is used. 2705 ** 2706 ** ^If the filename is ":memory:", then a private, temporary in-memory database 2707 ** is created for the connection. ^This in-memory database will vanish when 2708 ** the database connection is closed. Future versions of SQLite might 2709 ** make use of additional special filenames that begin with the ":" character. 2710 ** It is recommended that when a database filename actually does begin with 2711 ** a ":" character you should prefix the filename with a pathname such as 2712 ** "./" to avoid ambiguity. 2713 ** 2714 ** ^If the filename is an empty string, then a private, temporary 2715 ** on-disk database will be created. ^This private database will be 2716 ** automatically deleted as soon as the database connection is closed. 2717 ** 2718 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2719 ** 2720 ** ^If [URI filename] interpretation is enabled, and the filename argument 2721 ** begins with "file:", then the filename is interpreted as a URI. ^URI 2722 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2723 ** set in the fourth argument to sqlite3_open_v2(), or if it has 2724 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2725 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2726 ** As of SQLite version 3.7.7, URI filename interpretation is turned off 2727 ** by default, but future releases of SQLite might enable URI filename 2728 ** interpretation by default. See "[URI filenames]" for additional 2729 ** information. 2730 ** 2731 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2732 ** authority, then it must be either an empty string or the string 2733 ** "localhost". ^If the authority is not an empty string or "localhost", an 2734 ** error is returned to the caller. ^The fragment component of a URI, if 2735 ** present, is ignored. 2736 ** 2737 ** ^SQLite uses the path component of the URI as the name of the disk file 2738 ** which contains the database. ^If the path begins with a '/' character, 2739 ** then it is interpreted as an absolute path. ^If the path does not begin 2740 ** with a '/' (meaning that the authority section is omitted from the URI) 2741 ** then the path is interpreted as a relative path. 2742 ** ^On windows, the first component of an absolute path 2743 ** is a drive specification (e.g. "C:"). 2744 ** 2745 ** [[core URI query parameters]] 2746 ** The query component of a URI may contain parameters that are interpreted 2747 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2748 ** SQLite interprets the following three query parameters: 2749 ** 2750 ** <ul> 2751 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2752 ** a VFS object that provides the operating system interface that should 2753 ** be used to access the database file on disk. ^If this option is set to 2754 ** an empty string the default VFS object is used. ^Specifying an unknown 2755 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2756 ** present, then the VFS specified by the option takes precedence over 2757 ** the value passed as the fourth parameter to sqlite3_open_v2(). 2758 ** 2759 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2760 ** "rwc", or "memory". Attempting to set it to any other value is 2761 ** an error)^. 2762 ** ^If "ro" is specified, then the database is opened for read-only 2763 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2764 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 2765 ** "rw", then the database is opened for read-write (but not create) 2766 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2767 ** been set. ^Value "rwc" is equivalent to setting both 2768 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2769 ** set to "memory" then a pure [in-memory database] that never reads 2770 ** or writes from disk is used. ^It is an error to specify a value for 2771 ** the mode parameter that is less restrictive than that specified by 2772 ** the flags passed in the third parameter to sqlite3_open_v2(). 2773 ** 2774 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2775 ** "private". ^Setting it to "shared" is equivalent to setting the 2776 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2777 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2778 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2779 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2780 ** a URI filename, its value overrides any behavior requested by setting 2781 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2782 ** </ul> 2783 ** 2784 ** ^Specifying an unknown parameter in the query component of a URI is not an 2785 ** error. Future versions of SQLite might understand additional query 2786 ** parameters. See "[query parameters with special meaning to SQLite]" for 2787 ** additional information. 2788 ** 2789 ** [[URI filename examples]] <h3>URI filename examples</h3> 2790 ** 2791 ** <table border="1" align=center cellpadding=5> 2792 ** <tr><th> URI filenames <th> Results 2793 ** <tr><td> file:data.db <td> 2794 ** Open the file "data.db" in the current directory. 2795 ** <tr><td> file:/home/fred/data.db<br> 2796 ** file:///home/fred/data.db <br> 2797 ** file://localhost/home/fred/data.db <br> <td> 2798 ** Open the database file "/home/fred/data.db". 2799 ** <tr><td> file://darkstar/home/fred/data.db <td> 2800 ** An error. "darkstar" is not a recognized authority. 2801 ** <tr><td style="white-space:nowrap"> 2802 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2803 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2804 ** C:. Note that the %20 escaping in this example is not strictly 2805 ** necessary - space characters can be used literally 2806 ** in URI filenames. 2807 ** <tr><td> file:data.db?mode=ro&cache=private <td> 2808 ** Open file "data.db" in the current directory for read-only access. 2809 ** Regardless of whether or not shared-cache mode is enabled by 2810 ** default, use a private cache. 2811 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> 2812 ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". 2813 ** <tr><td> file:data.db?mode=readonly <td> 2814 ** An error. "readonly" is not a valid option for the "mode" parameter. 2815 ** </table> 2816 ** 2817 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2818 ** query components of a URI. A hexadecimal escape sequence consists of a 2819 ** percent sign - "%" - followed by exactly two hexadecimal digits 2820 ** specifying an octet value. ^Before the path or query components of a 2821 ** URI filename are interpreted, they are encoded using UTF-8 and all 2822 ** hexadecimal escape sequences replaced by a single byte containing the 2823 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 2824 ** the results are undefined. 2825 ** 2826 ** <b>Note to Windows users:</b> The encoding used for the filename argument 2827 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2828 ** codepage is currently defined. Filenames containing international 2829 ** characters must be converted to UTF-8 prior to passing them into 2830 ** sqlite3_open() or sqlite3_open_v2(). 2831 ** 2832 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2833 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2834 ** features that require the use of temporary files may fail. 2835 ** 2836 ** See also: [sqlite3_temp_directory] 2837 */ 2838 SQLITE_API int sqlite3_open( 2839 const char *filename, /* Database filename (UTF-8) */ 2840 sqlite3 **ppDb /* OUT: SQLite db handle */ 2841 ); 2842 SQLITE_API int sqlite3_open16( 2843 const void *filename, /* Database filename (UTF-16) */ 2844 sqlite3 **ppDb /* OUT: SQLite db handle */ 2845 ); 2846 SQLITE_API int sqlite3_open_v2( 2847 const char *filename, /* Database filename (UTF-8) */ 2848 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2849 int flags, /* Flags */ 2850 const char *zVfs /* Name of VFS module to use */ 2851 ); 2852 2853 /* 2854 ** CAPI3REF: Obtain Values For URI Parameters 2855 ** 2856 ** These are utility routines, useful to VFS implementations, that check 2857 ** to see if a database file was a URI that contained a specific query 2858 ** parameter, and if so obtains the value of that query parameter. 2859 ** 2860 ** If F is the database filename pointer passed into the xOpen() method of 2861 ** a VFS implementation when the flags parameter to xOpen() has one or 2862 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 2863 ** P is the name of the query parameter, then 2864 ** sqlite3_uri_parameter(F,P) returns the value of the P 2865 ** parameter if it exists or a NULL pointer if P does not appear as a 2866 ** query parameter on F. If P is a query parameter of F 2867 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 2868 ** a pointer to an empty string. 2869 ** 2870 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 2871 ** parameter and returns true (1) or false (0) according to the value 2872 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 2873 ** value of query parameter P is one of "yes", "true", or "on" in any 2874 ** case or if the value begins with a non-zero number. The 2875 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 2876 ** query parameter P is one of "no", "false", or "off" in any case or 2877 ** if the value begins with a numeric zero. If P is not a query 2878 ** parameter on F or if the value of P is does not match any of the 2879 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 2880 ** 2881 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 2882 ** 64-bit signed integer and returns that integer, or D if P does not 2883 ** exist. If the value of P is something other than an integer, then 2884 ** zero is returned. 2885 ** 2886 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 2887 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 2888 ** is not a database file pathname pointer that SQLite passed into the xOpen 2889 ** VFS method, then the behavior of this routine is undefined and probably 2890 ** undesirable. 2891 */ 2892 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 2893 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 2894 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 2895 2896 2897 /* 2898 ** CAPI3REF: Error Codes And Messages 2899 ** 2900 ** ^The sqlite3_errcode() interface returns the numeric [result code] or 2901 ** [extended result code] for the most recent failed sqlite3_* API call 2902 ** associated with a [database connection]. If a prior API call failed 2903 ** but the most recent API call succeeded, the return value from 2904 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 2905 ** interface is the same except that it always returns the 2906 ** [extended result code] even when extended result codes are 2907 ** disabled. 2908 ** 2909 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 2910 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 2911 ** ^(Memory to hold the error message string is managed internally. 2912 ** The application does not need to worry about freeing the result. 2913 ** However, the error string might be overwritten or deallocated by 2914 ** subsequent calls to other SQLite interface functions.)^ 2915 ** 2916 ** ^The sqlite3_errstr() interface returns the English-language text 2917 ** that describes the [result code], as UTF-8. 2918 ** ^(Memory to hold the error message string is managed internally 2919 ** and must not be freed by the application)^. 2920 ** 2921 ** When the serialized [threading mode] is in use, it might be the 2922 ** case that a second error occurs on a separate thread in between 2923 ** the time of the first error and the call to these interfaces. 2924 ** When that happens, the second error will be reported since these 2925 ** interfaces always report the most recent result. To avoid 2926 ** this, each thread can obtain exclusive use of the [database connection] D 2927 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 2928 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 2929 ** all calls to the interfaces listed here are completed. 2930 ** 2931 ** If an interface fails with SQLITE_MISUSE, that means the interface 2932 ** was invoked incorrectly by the application. In that case, the 2933 ** error code and message may or may not be set. 2934 */ 2935 SQLITE_API int sqlite3_errcode(sqlite3 *db); 2936 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 2937 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 2938 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 2939 SQLITE_API const char *sqlite3_errstr(int); 2940 2941 /* 2942 ** CAPI3REF: SQL Statement Object 2943 ** KEYWORDS: {prepared statement} {prepared statements} 2944 ** 2945 ** An instance of this object represents a single SQL statement. 2946 ** This object is variously known as a "prepared statement" or a 2947 ** "compiled SQL statement" or simply as a "statement". 2948 ** 2949 ** The life of a statement object goes something like this: 2950 ** 2951 ** <ol> 2952 ** <li> Create the object using [sqlite3_prepare_v2()] or a related 2953 ** function. 2954 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() 2955 ** interfaces. 2956 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 2957 ** <li> Reset the statement using [sqlite3_reset()] then go back 2958 ** to step 2. Do this zero or more times. 2959 ** <li> Destroy the object using [sqlite3_finalize()]. 2960 ** </ol> 2961 ** 2962 ** Refer to documentation on individual methods above for additional 2963 ** information. 2964 */ 2965 typedef struct sqlite3_stmt sqlite3_stmt; 2966 2967 /* 2968 ** CAPI3REF: Run-time Limits 2969 ** 2970 ** ^(This interface allows the size of various constructs to be limited 2971 ** on a connection by connection basis. The first parameter is the 2972 ** [database connection] whose limit is to be set or queried. The 2973 ** second parameter is one of the [limit categories] that define a 2974 ** class of constructs to be size limited. The third parameter is the 2975 ** new limit for that construct.)^ 2976 ** 2977 ** ^If the new limit is a negative number, the limit is unchanged. 2978 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 2979 ** [limits | hard upper bound] 2980 ** set at compile-time by a C preprocessor macro called 2981 ** [limits | SQLITE_MAX_<i>NAME</i>]. 2982 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 2983 ** ^Attempts to increase a limit above its hard upper bound are 2984 ** silently truncated to the hard upper bound. 2985 ** 2986 ** ^Regardless of whether or not the limit was changed, the 2987 ** [sqlite3_limit()] interface returns the prior value of the limit. 2988 ** ^Hence, to find the current value of a limit without changing it, 2989 ** simply invoke this interface with the third parameter set to -1. 2990 ** 2991 ** Run-time limits are intended for use in applications that manage 2992 ** both their own internal database and also databases that are controlled 2993 ** by untrusted external sources. An example application might be a 2994 ** web browser that has its own databases for storing history and 2995 ** separate databases controlled by JavaScript applications downloaded 2996 ** off the Internet. The internal databases can be given the 2997 ** large, default limits. Databases managed by external sources can 2998 ** be given much smaller limits designed to prevent a denial of service 2999 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3000 ** interface to further control untrusted SQL. The size of the database 3001 ** created by an untrusted script can be contained using the 3002 ** [max_page_count] [PRAGMA]. 3003 ** 3004 ** New run-time limit categories may be added in future releases. 3005 */ 3006 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3007 3008 /* 3009 ** CAPI3REF: Run-Time Limit Categories 3010 ** KEYWORDS: {limit category} {*limit categories} 3011 ** 3012 ** These constants define various performance limits 3013 ** that can be lowered at run-time using [sqlite3_limit()]. 3014 ** The synopsis of the meanings of the various limits is shown below. 3015 ** Additional information is available at [limits | Limits in SQLite]. 3016 ** 3017 ** <dl> 3018 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3019 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3020 ** 3021 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3022 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3023 ** 3024 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3025 ** <dd>The maximum number of columns in a table definition or in the 3026 ** result set of a [SELECT] or the maximum number of columns in an index 3027 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3028 ** 3029 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3030 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3031 ** 3032 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3033 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3034 ** 3035 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3036 ** <dd>The maximum number of instructions in a virtual machine program 3037 ** used to implement an SQL statement. This limit is not currently 3038 ** enforced, though that might be added in some future release of 3039 ** SQLite.</dd>)^ 3040 ** 3041 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3042 ** <dd>The maximum number of arguments on a function.</dd>)^ 3043 ** 3044 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3045 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3046 ** 3047 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3048 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3049 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3050 ** [GLOB] operators.</dd>)^ 3051 ** 3052 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3053 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3054 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3055 ** 3056 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3057 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3058 ** </dl> 3059 */ 3060 #define SQLITE_LIMIT_LENGTH 0 3061 #define SQLITE_LIMIT_SQL_LENGTH 1 3062 #define SQLITE_LIMIT_COLUMN 2 3063 #define SQLITE_LIMIT_EXPR_DEPTH 3 3064 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3065 #define SQLITE_LIMIT_VDBE_OP 5 3066 #define SQLITE_LIMIT_FUNCTION_ARG 6 3067 #define SQLITE_LIMIT_ATTACHED 7 3068 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3069 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3070 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3071 3072 /* 3073 ** CAPI3REF: Compiling An SQL Statement 3074 ** KEYWORDS: {SQL statement compiler} 3075 ** 3076 ** To execute an SQL query, it must first be compiled into a byte-code 3077 ** program using one of these routines. 3078 ** 3079 ** The first argument, "db", is a [database connection] obtained from a 3080 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3081 ** [sqlite3_open16()]. The database connection must not have been closed. 3082 ** 3083 ** The second argument, "zSql", is the statement to be compiled, encoded 3084 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3085 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3086 ** use UTF-16. 3087 ** 3088 ** ^If the nByte argument is less than zero, then zSql is read up to the 3089 ** first zero terminator. ^If nByte is non-negative, then it is the maximum 3090 ** number of bytes read from zSql. ^When nByte is non-negative, the 3091 ** zSql string ends at either the first '\000' or '\u0000' character or 3092 ** the nByte-th byte, whichever comes first. If the caller knows 3093 ** that the supplied string is nul-terminated, then there is a small 3094 ** performance advantage to be gained by passing an nByte parameter that 3095 ** is equal to the number of bytes in the input string <i>including</i> 3096 ** the nul-terminator bytes as this saves SQLite from having to 3097 ** make a copy of the input string. 3098 ** 3099 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3100 ** past the end of the first SQL statement in zSql. These routines only 3101 ** compile the first statement in zSql, so *pzTail is left pointing to 3102 ** what remains uncompiled. 3103 ** 3104 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3105 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3106 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3107 ** string or a comment) then *ppStmt is set to NULL. 3108 ** The calling procedure is responsible for deleting the compiled 3109 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3110 ** ppStmt may not be NULL. 3111 ** 3112 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3113 ** otherwise an [error code] is returned. 3114 ** 3115 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3116 ** recommended for all new programs. The two older interfaces are retained 3117 ** for backwards compatibility, but their use is discouraged. 3118 ** ^In the "v2" interfaces, the prepared statement 3119 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3120 ** original SQL text. This causes the [sqlite3_step()] interface to 3121 ** behave differently in three ways: 3122 ** 3123 ** <ol> 3124 ** <li> 3125 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3126 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3127 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3128 ** retries will occur before sqlite3_step() gives up and returns an error. 3129 ** </li> 3130 ** 3131 ** <li> 3132 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3133 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3134 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3135 ** and the application would have to make a second call to [sqlite3_reset()] 3136 ** in order to find the underlying cause of the problem. With the "v2" prepare 3137 ** interfaces, the underlying reason for the error is returned immediately. 3138 ** </li> 3139 ** 3140 ** <li> 3141 ** ^If the specific value bound to [parameter | host parameter] in the 3142 ** WHERE clause might influence the choice of query plan for a statement, 3143 ** then the statement will be automatically recompiled, as if there had been 3144 ** a schema change, on the first [sqlite3_step()] call following any change 3145 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3146 ** ^The specific value of WHERE-clause [parameter] might influence the 3147 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3148 ** or [GLOB] operator or if the parameter is compared to an indexed column 3149 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3150 ** </li> 3151 ** </ol> 3152 */ 3153 SQLITE_API int sqlite3_prepare( 3154 sqlite3 *db, /* Database handle */ 3155 const char *zSql, /* SQL statement, UTF-8 encoded */ 3156 int nByte, /* Maximum length of zSql in bytes. */ 3157 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3158 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3159 ); 3160 SQLITE_API int sqlite3_prepare_v2( 3161 sqlite3 *db, /* Database handle */ 3162 const char *zSql, /* SQL statement, UTF-8 encoded */ 3163 int nByte, /* Maximum length of zSql in bytes. */ 3164 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3165 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3166 ); 3167 SQLITE_API int sqlite3_prepare16( 3168 sqlite3 *db, /* Database handle */ 3169 const void *zSql, /* SQL statement, UTF-16 encoded */ 3170 int nByte, /* Maximum length of zSql in bytes. */ 3171 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3172 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3173 ); 3174 SQLITE_API int sqlite3_prepare16_v2( 3175 sqlite3 *db, /* Database handle */ 3176 const void *zSql, /* SQL statement, UTF-16 encoded */ 3177 int nByte, /* Maximum length of zSql in bytes. */ 3178 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3179 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3180 ); 3181 3182 /* 3183 ** CAPI3REF: Retrieving Statement SQL 3184 ** 3185 ** ^This interface can be used to retrieve a saved copy of the original 3186 ** SQL text used to create a [prepared statement] if that statement was 3187 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3188 */ 3189 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3190 3191 /* 3192 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3193 ** 3194 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3195 ** and only if the [prepared statement] X makes no direct changes to 3196 ** the content of the database file. 3197 ** 3198 ** Note that [application-defined SQL functions] or 3199 ** [virtual tables] might change the database indirectly as a side effect. 3200 ** ^(For example, if an application defines a function "eval()" that 3201 ** calls [sqlite3_exec()], then the following SQL statement would 3202 ** change the database file through side-effects: 3203 ** 3204 ** <blockquote><pre> 3205 ** SELECT eval('DELETE FROM t1') FROM t2; 3206 ** </pre></blockquote> 3207 ** 3208 ** But because the [SELECT] statement does not change the database file 3209 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3210 ** 3211 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3212 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3213 ** since the statements themselves do not actually modify the database but 3214 ** rather they control the timing of when other statements modify the 3215 ** database. ^The [ATTACH] and [DETACH] statements also cause 3216 ** sqlite3_stmt_readonly() to return true since, while those statements 3217 ** change the configuration of a database connection, they do not make 3218 ** changes to the content of the database files on disk. 3219 */ 3220 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3221 3222 /* 3223 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3224 ** 3225 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3226 ** [prepared statement] S has been stepped at least once using 3227 ** [sqlite3_step(S)] but has not run to completion and/or has not 3228 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3229 ** interface returns false if S is a NULL pointer. If S is not a 3230 ** NULL pointer and is not a pointer to a valid [prepared statement] 3231 ** object, then the behavior is undefined and probably undesirable. 3232 ** 3233 ** This interface can be used in combination [sqlite3_next_stmt()] 3234 ** to locate all prepared statements associated with a database 3235 ** connection that are in need of being reset. This can be used, 3236 ** for example, in diagnostic routines to search for prepared 3237 ** statements that are holding a transaction open. 3238 */ 3239 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3240 3241 /* 3242 ** CAPI3REF: Dynamically Typed Value Object 3243 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3244 ** 3245 ** SQLite uses the sqlite3_value object to represent all values 3246 ** that can be stored in a database table. SQLite uses dynamic typing 3247 ** for the values it stores. ^Values stored in sqlite3_value objects 3248 ** can be integers, floating point values, strings, BLOBs, or NULL. 3249 ** 3250 ** An sqlite3_value object may be either "protected" or "unprotected". 3251 ** Some interfaces require a protected sqlite3_value. Other interfaces 3252 ** will accept either a protected or an unprotected sqlite3_value. 3253 ** Every interface that accepts sqlite3_value arguments specifies 3254 ** whether or not it requires a protected sqlite3_value. 3255 ** 3256 ** The terms "protected" and "unprotected" refer to whether or not 3257 ** a mutex is held. An internal mutex is held for a protected 3258 ** sqlite3_value object but no mutex is held for an unprotected 3259 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3260 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3261 ** or if SQLite is run in one of reduced mutex modes 3262 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3263 ** then there is no distinction between protected and unprotected 3264 ** sqlite3_value objects and they can be used interchangeably. However, 3265 ** for maximum code portability it is recommended that applications 3266 ** still make the distinction between protected and unprotected 3267 ** sqlite3_value objects even when not strictly required. 3268 ** 3269 ** ^The sqlite3_value objects that are passed as parameters into the 3270 ** implementation of [application-defined SQL functions] are protected. 3271 ** ^The sqlite3_value object returned by 3272 ** [sqlite3_column_value()] is unprotected. 3273 ** Unprotected sqlite3_value objects may only be used with 3274 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3275 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3276 ** interfaces require protected sqlite3_value objects. 3277 */ 3278 typedef struct Mem sqlite3_value; 3279 3280 /* 3281 ** CAPI3REF: SQL Function Context Object 3282 ** 3283 ** The context in which an SQL function executes is stored in an 3284 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3285 ** is always first parameter to [application-defined SQL functions]. 3286 ** The application-defined SQL function implementation will pass this 3287 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3288 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3289 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3290 ** and/or [sqlite3_set_auxdata()]. 3291 */ 3292 typedef struct sqlite3_context sqlite3_context; 3293 3294 /* 3295 ** CAPI3REF: Binding Values To Prepared Statements 3296 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3297 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3298 ** 3299 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3300 ** literals may be replaced by a [parameter] that matches one of following 3301 ** templates: 3302 ** 3303 ** <ul> 3304 ** <li> ? 3305 ** <li> ?NNN 3306 ** <li> :VVV 3307 ** <li> @VVV 3308 ** <li> $VVV 3309 ** </ul> 3310 ** 3311 ** In the templates above, NNN represents an integer literal, 3312 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3313 ** parameters (also called "host parameter names" or "SQL parameters") 3314 ** can be set using the sqlite3_bind_*() routines defined here. 3315 ** 3316 ** ^The first argument to the sqlite3_bind_*() routines is always 3317 ** a pointer to the [sqlite3_stmt] object returned from 3318 ** [sqlite3_prepare_v2()] or its variants. 3319 ** 3320 ** ^The second argument is the index of the SQL parameter to be set. 3321 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3322 ** SQL parameter is used more than once, second and subsequent 3323 ** occurrences have the same index as the first occurrence. 3324 ** ^The index for named parameters can be looked up using the 3325 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3326 ** for "?NNN" parameters is the value of NNN. 3327 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3328 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3329 ** 3330 ** ^The third argument is the value to bind to the parameter. 3331 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3332 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3333 ** is ignored and the end result is the same as sqlite3_bind_null(). 3334 ** 3335 ** ^(In those routines that have a fourth argument, its value is the 3336 ** number of bytes in the parameter. To be clear: the value is the 3337 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3338 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3339 ** is negative, then the length of the string is 3340 ** the number of bytes up to the first zero terminator. 3341 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3342 ** the behavior is undefined. 3343 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3344 ** or sqlite3_bind_text16() then that parameter must be the byte offset 3345 ** where the NUL terminator would occur assuming the string were NUL 3346 ** terminated. If any NUL characters occur at byte offsets less than 3347 ** the value of the fourth parameter then the resulting string value will 3348 ** contain embedded NULs. The result of expressions involving strings 3349 ** with embedded NULs is undefined. 3350 ** 3351 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3352 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3353 ** string after SQLite has finished with it. ^The destructor is called 3354 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3355 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3356 ** ^If the fifth argument is 3357 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3358 ** information is in static, unmanaged space and does not need to be freed. 3359 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3360 ** SQLite makes its own private copy of the data immediately, before 3361 ** the sqlite3_bind_*() routine returns. 3362 ** 3363 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3364 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3365 ** (just an integer to hold its size) while it is being processed. 3366 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3367 ** content is later written using 3368 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3369 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3370 ** 3371 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3372 ** for the [prepared statement] or with a prepared statement for which 3373 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3374 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3375 ** routine is passed a [prepared statement] that has been finalized, the 3376 ** result is undefined and probably harmful. 3377 ** 3378 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3379 ** ^Unbound parameters are interpreted as NULL. 3380 ** 3381 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3382 ** [error code] if anything goes wrong. 3383 ** ^[SQLITE_RANGE] is returned if the parameter 3384 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3385 ** 3386 ** See also: [sqlite3_bind_parameter_count()], 3387 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3388 */ 3389 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3390 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3391 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3392 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3393 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3394 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3395 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3396 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3397 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3398 3399 /* 3400 ** CAPI3REF: Number Of SQL Parameters 3401 ** 3402 ** ^This routine can be used to find the number of [SQL parameters] 3403 ** in a [prepared statement]. SQL parameters are tokens of the 3404 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3405 ** placeholders for values that are [sqlite3_bind_blob | bound] 3406 ** to the parameters at a later time. 3407 ** 3408 ** ^(This routine actually returns the index of the largest (rightmost) 3409 ** parameter. For all forms except ?NNN, this will correspond to the 3410 ** number of unique parameters. If parameters of the ?NNN form are used, 3411 ** there may be gaps in the list.)^ 3412 ** 3413 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3414 ** [sqlite3_bind_parameter_name()], and 3415 ** [sqlite3_bind_parameter_index()]. 3416 */ 3417 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3418 3419 /* 3420 ** CAPI3REF: Name Of A Host Parameter 3421 ** 3422 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 3423 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 3424 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3425 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3426 ** respectively. 3427 ** In other words, the initial ":" or "$" or "@" or "?" 3428 ** is included as part of the name.)^ 3429 ** ^Parameters of the form "?" without a following integer have no name 3430 ** and are referred to as "nameless" or "anonymous parameters". 3431 ** 3432 ** ^The first host parameter has an index of 1, not 0. 3433 ** 3434 ** ^If the value N is out of range or if the N-th parameter is 3435 ** nameless, then NULL is returned. ^The returned string is 3436 ** always in UTF-8 encoding even if the named parameter was 3437 ** originally specified as UTF-16 in [sqlite3_prepare16()] or 3438 ** [sqlite3_prepare16_v2()]. 3439 ** 3440 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3441 ** [sqlite3_bind_parameter_count()], and 3442 ** [sqlite3_bind_parameter_index()]. 3443 */ 3444 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3445 3446 /* 3447 ** CAPI3REF: Index Of A Parameter With A Given Name 3448 ** 3449 ** ^Return the index of an SQL parameter given its name. ^The 3450 ** index value returned is suitable for use as the second 3451 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3452 ** is returned if no matching parameter is found. ^The parameter 3453 ** name must be given in UTF-8 even if the original statement 3454 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3455 ** 3456 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3457 ** [sqlite3_bind_parameter_count()], and 3458 ** [sqlite3_bind_parameter_index()]. 3459 */ 3460 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3461 3462 /* 3463 ** CAPI3REF: Reset All Bindings On A Prepared Statement 3464 ** 3465 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3466 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3467 ** ^Use this routine to reset all host parameters to NULL. 3468 */ 3469 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3470 3471 /* 3472 ** CAPI3REF: Number Of Columns In A Result Set 3473 ** 3474 ** ^Return the number of columns in the result set returned by the 3475 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3476 ** statement that does not return data (for example an [UPDATE]). 3477 ** 3478 ** See also: [sqlite3_data_count()] 3479 */ 3480 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3481 3482 /* 3483 ** CAPI3REF: Column Names In A Result Set 3484 ** 3485 ** ^These routines return the name assigned to a particular column 3486 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3487 ** interface returns a pointer to a zero-terminated UTF-8 string 3488 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 3489 ** UTF-16 string. ^The first parameter is the [prepared statement] 3490 ** that implements the [SELECT] statement. ^The second parameter is the 3491 ** column number. ^The leftmost column is number 0. 3492 ** 3493 ** ^The returned string pointer is valid until either the [prepared statement] 3494 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3495 ** reprepared by the first call to [sqlite3_step()] for a particular run 3496 ** or until the next call to 3497 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3498 ** 3499 ** ^If sqlite3_malloc() fails during the processing of either routine 3500 ** (for example during a conversion from UTF-8 to UTF-16) then a 3501 ** NULL pointer is returned. 3502 ** 3503 ** ^The name of a result column is the value of the "AS" clause for 3504 ** that column, if there is an AS clause. If there is no AS clause 3505 ** then the name of the column is unspecified and may change from 3506 ** one release of SQLite to the next. 3507 */ 3508 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3509 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3510 3511 /* 3512 ** CAPI3REF: Source Of Data In A Query Result 3513 ** 3514 ** ^These routines provide a means to determine the database, table, and 3515 ** table column that is the origin of a particular result column in 3516 ** [SELECT] statement. 3517 ** ^The name of the database or table or column can be returned as 3518 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3519 ** the database name, the _table_ routines return the table name, and 3520 ** the origin_ routines return the column name. 3521 ** ^The returned string is valid until the [prepared statement] is destroyed 3522 ** using [sqlite3_finalize()] or until the statement is automatically 3523 ** reprepared by the first call to [sqlite3_step()] for a particular run 3524 ** or until the same information is requested 3525 ** again in a different encoding. 3526 ** 3527 ** ^The names returned are the original un-aliased names of the 3528 ** database, table, and column. 3529 ** 3530 ** ^The first argument to these interfaces is a [prepared statement]. 3531 ** ^These functions return information about the Nth result column returned by 3532 ** the statement, where N is the second function argument. 3533 ** ^The left-most column is column 0 for these routines. 3534 ** 3535 ** ^If the Nth column returned by the statement is an expression or 3536 ** subquery and is not a column value, then all of these functions return 3537 ** NULL. ^These routine might also return NULL if a memory allocation error 3538 ** occurs. ^Otherwise, they return the name of the attached database, table, 3539 ** or column that query result column was extracted from. 3540 ** 3541 ** ^As with all other SQLite APIs, those whose names end with "16" return 3542 ** UTF-16 encoded strings and the other functions return UTF-8. 3543 ** 3544 ** ^These APIs are only available if the library was compiled with the 3545 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3546 ** 3547 ** If two or more threads call one or more of these routines against the same 3548 ** prepared statement and column at the same time then the results are 3549 ** undefined. 3550 ** 3551 ** If two or more threads call one or more 3552 ** [sqlite3_column_database_name | column metadata interfaces] 3553 ** for the same [prepared statement] and result column 3554 ** at the same time then the results are undefined. 3555 */ 3556 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3557 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3558 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3559 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3560 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3561 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3562 3563 /* 3564 ** CAPI3REF: Declared Datatype Of A Query Result 3565 ** 3566 ** ^(The first parameter is a [prepared statement]. 3567 ** If this statement is a [SELECT] statement and the Nth column of the 3568 ** returned result set of that [SELECT] is a table column (not an 3569 ** expression or subquery) then the declared type of the table 3570 ** column is returned.)^ ^If the Nth column of the result set is an 3571 ** expression or subquery, then a NULL pointer is returned. 3572 ** ^The returned string is always UTF-8 encoded. 3573 ** 3574 ** ^(For example, given the database schema: 3575 ** 3576 ** CREATE TABLE t1(c1 VARIANT); 3577 ** 3578 ** and the following statement to be compiled: 3579 ** 3580 ** SELECT c1 + 1, c1 FROM t1; 3581 ** 3582 ** this routine would return the string "VARIANT" for the second result 3583 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3584 ** 3585 ** ^SQLite uses dynamic run-time typing. ^So just because a column 3586 ** is declared to contain a particular type does not mean that the 3587 ** data stored in that column is of the declared type. SQLite is 3588 ** strongly typed, but the typing is dynamic not static. ^Type 3589 ** is associated with individual values, not with the containers 3590 ** used to hold those values. 3591 */ 3592 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3593 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3594 3595 /* 3596 ** CAPI3REF: Evaluate An SQL Statement 3597 ** 3598 ** After a [prepared statement] has been prepared using either 3599 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3600 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3601 ** must be called one or more times to evaluate the statement. 3602 ** 3603 ** The details of the behavior of the sqlite3_step() interface depend 3604 ** on whether the statement was prepared using the newer "v2" interface 3605 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3606 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3607 ** new "v2" interface is recommended for new applications but the legacy 3608 ** interface will continue to be supported. 3609 ** 3610 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3611 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3612 ** ^With the "v2" interface, any of the other [result codes] or 3613 ** [extended result codes] might be returned as well. 3614 ** 3615 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3616 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 3617 ** or occurs outside of an explicit transaction, then you can retry the 3618 ** statement. If the statement is not a [COMMIT] and occurs within an 3619 ** explicit transaction then you should rollback the transaction before 3620 ** continuing. 3621 ** 3622 ** ^[SQLITE_DONE] means that the statement has finished executing 3623 ** successfully. sqlite3_step() should not be called again on this virtual 3624 ** machine without first calling [sqlite3_reset()] to reset the virtual 3625 ** machine back to its initial state. 3626 ** 3627 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3628 ** is returned each time a new row of data is ready for processing by the 3629 ** caller. The values may be accessed using the [column access functions]. 3630 ** sqlite3_step() is called again to retrieve the next row of data. 3631 ** 3632 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3633 ** violation) has occurred. sqlite3_step() should not be called again on 3634 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 3635 ** ^With the legacy interface, a more specific error code (for example, 3636 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3637 ** can be obtained by calling [sqlite3_reset()] on the 3638 ** [prepared statement]. ^In the "v2" interface, 3639 ** the more specific error code is returned directly by sqlite3_step(). 3640 ** 3641 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3642 ** Perhaps it was called on a [prepared statement] that has 3643 ** already been [sqlite3_finalize | finalized] or on one that had 3644 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3645 ** be the case that the same database connection is being used by two or 3646 ** more threads at the same moment in time. 3647 ** 3648 ** For all versions of SQLite up to and including 3.6.23.1, a call to 3649 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 3650 ** other than [SQLITE_ROW] before any subsequent invocation of 3651 ** sqlite3_step(). Failure to reset the prepared statement using 3652 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3653 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3654 ** calling [sqlite3_reset()] automatically in this circumstance rather 3655 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3656 ** break because any application that ever receives an SQLITE_MISUSE error 3657 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3658 ** can be used to restore the legacy behavior. 3659 ** 3660 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3661 ** API always returns a generic error code, [SQLITE_ERROR], following any 3662 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3663 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3664 ** specific [error codes] that better describes the error. 3665 ** We admit that this is a goofy design. The problem has been fixed 3666 ** with the "v2" interface. If you prepare all of your SQL statements 3667 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3668 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3669 ** then the more specific [error codes] are returned directly 3670 ** by sqlite3_step(). The use of the "v2" interface is recommended. 3671 */ 3672 SQLITE_API int sqlite3_step(sqlite3_stmt*); 3673 3674 /* 3675 ** CAPI3REF: Number of columns in a result set 3676 ** 3677 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 3678 ** current row of the result set of [prepared statement] P. 3679 ** ^If prepared statement P does not have results ready to return 3680 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3681 ** interfaces) then sqlite3_data_count(P) returns 0. 3682 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3683 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3684 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3685 ** will return non-zero if previous call to [sqlite3_step](P) returned 3686 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3687 ** where it always returns zero since each step of that multi-step 3688 ** pragma returns 0 columns of data. 3689 ** 3690 ** See also: [sqlite3_column_count()] 3691 */ 3692 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3693 3694 /* 3695 ** CAPI3REF: Fundamental Datatypes 3696 ** KEYWORDS: SQLITE_TEXT 3697 ** 3698 ** ^(Every value in SQLite has one of five fundamental datatypes: 3699 ** 3700 ** <ul> 3701 ** <li> 64-bit signed integer 3702 ** <li> 64-bit IEEE floating point number 3703 ** <li> string 3704 ** <li> BLOB 3705 ** <li> NULL 3706 ** </ul>)^ 3707 ** 3708 ** These constants are codes for each of those types. 3709 ** 3710 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3711 ** for a completely different meaning. Software that links against both 3712 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3713 ** SQLITE_TEXT. 3714 */ 3715 #define SQLITE_INTEGER 1 3716 #define SQLITE_FLOAT 2 3717 #define SQLITE_BLOB 4 3718 #define SQLITE_NULL 5 3719 #ifdef SQLITE_TEXT 3720 # undef SQLITE_TEXT 3721 #else 3722 # define SQLITE_TEXT 3 3723 #endif 3724 #define SQLITE3_TEXT 3 3725 3726 /* 3727 ** CAPI3REF: Result Values From A Query 3728 ** KEYWORDS: {column access functions} 3729 ** 3730 ** These routines form the "result set" interface. 3731 ** 3732 ** ^These routines return information about a single column of the current 3733 ** result row of a query. ^In every case the first argument is a pointer 3734 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3735 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3736 ** and the second argument is the index of the column for which information 3737 ** should be returned. ^The leftmost column of the result set has the index 0. 3738 ** ^The number of columns in the result can be determined using 3739 ** [sqlite3_column_count()]. 3740 ** 3741 ** If the SQL statement does not currently point to a valid row, or if the 3742 ** column index is out of range, the result is undefined. 3743 ** These routines may only be called when the most recent call to 3744 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3745 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3746 ** If any of these routines are called after [sqlite3_reset()] or 3747 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3748 ** something other than [SQLITE_ROW], the results are undefined. 3749 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3750 ** are called from a different thread while any of these routines 3751 ** are pending, then the results are undefined. 3752 ** 3753 ** ^The sqlite3_column_type() routine returns the 3754 ** [SQLITE_INTEGER | datatype code] for the initial data type 3755 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3756 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3757 ** returned by sqlite3_column_type() is only meaningful if no type 3758 ** conversions have occurred as described below. After a type conversion, 3759 ** the value returned by sqlite3_column_type() is undefined. Future 3760 ** versions of SQLite may change the behavior of sqlite3_column_type() 3761 ** following a type conversion. 3762 ** 3763 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3764 ** routine returns the number of bytes in that BLOB or string. 3765 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3766 ** the string to UTF-8 and then returns the number of bytes. 3767 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 3768 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3769 ** the number of bytes in that string. 3770 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3771 ** 3772 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3773 ** routine returns the number of bytes in that BLOB or string. 3774 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3775 ** the string to UTF-16 and then returns the number of bytes. 3776 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3777 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3778 ** the number of bytes in that string. 3779 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3780 ** 3781 ** ^The values returned by [sqlite3_column_bytes()] and 3782 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3783 ** of the string. ^For clarity: the values returned by 3784 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3785 ** bytes in the string, not the number of characters. 3786 ** 3787 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3788 ** even empty strings, are always zero-terminated. ^The return 3789 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3790 ** 3791 ** ^The object returned by [sqlite3_column_value()] is an 3792 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3793 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3794 ** If the [unprotected sqlite3_value] object returned by 3795 ** [sqlite3_column_value()] is used in any other way, including calls 3796 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3797 ** or [sqlite3_value_bytes()], then the behavior is undefined. 3798 ** 3799 ** These routines attempt to convert the value where appropriate. ^For 3800 ** example, if the internal representation is FLOAT and a text result 3801 ** is requested, [sqlite3_snprintf()] is used internally to perform the 3802 ** conversion automatically. ^(The following table details the conversions 3803 ** that are applied: 3804 ** 3805 ** <blockquote> 3806 ** <table border="1"> 3807 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3808 ** 3809 ** <tr><td> NULL <td> INTEGER <td> Result is 0 3810 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3811 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3812 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3813 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3814 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3815 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3816 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3817 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3818 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3819 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3820 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3821 ** <tr><td> TEXT <td> BLOB <td> No change 3822 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3823 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3824 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3825 ** </table> 3826 ** </blockquote>)^ 3827 ** 3828 ** The table above makes reference to standard C library functions atoi() 3829 ** and atof(). SQLite does not really use these functions. It has its 3830 ** own equivalent internal routines. The atoi() and atof() names are 3831 ** used in the table for brevity and because they are familiar to most 3832 ** C programmers. 3833 ** 3834 ** Note that when type conversions occur, pointers returned by prior 3835 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3836 ** sqlite3_column_text16() may be invalidated. 3837 ** Type conversions and pointer invalidations might occur 3838 ** in the following cases: 3839 ** 3840 ** <ul> 3841 ** <li> The initial content is a BLOB and sqlite3_column_text() or 3842 ** sqlite3_column_text16() is called. A zero-terminator might 3843 ** need to be added to the string.</li> 3844 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3845 ** sqlite3_column_text16() is called. The content must be converted 3846 ** to UTF-16.</li> 3847 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3848 ** sqlite3_column_text() is called. The content must be converted 3849 ** to UTF-8.</li> 3850 ** </ul> 3851 ** 3852 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3853 ** not invalidate a prior pointer, though of course the content of the buffer 3854 ** that the prior pointer references will have been modified. Other kinds 3855 ** of conversion are done in place when it is possible, but sometimes they 3856 ** are not possible and in those cases prior pointers are invalidated. 3857 ** 3858 ** The safest and easiest to remember policy is to invoke these routines 3859 ** in one of the following ways: 3860 ** 3861 ** <ul> 3862 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 3863 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 3864 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 3865 ** </ul> 3866 ** 3867 ** In other words, you should call sqlite3_column_text(), 3868 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 3869 ** into the desired format, then invoke sqlite3_column_bytes() or 3870 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 3871 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 3872 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 3873 ** with calls to sqlite3_column_bytes(). 3874 ** 3875 ** ^The pointers returned are valid until a type conversion occurs as 3876 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 3877 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 3878 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 3879 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 3880 ** [sqlite3_free()]. 3881 ** 3882 ** ^(If a memory allocation error occurs during the evaluation of any 3883 ** of these routines, a default value is returned. The default value 3884 ** is either the integer 0, the floating point number 0.0, or a NULL 3885 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 3886 ** [SQLITE_NOMEM].)^ 3887 */ 3888 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 3889 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 3890 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 3891 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 3892 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 3893 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 3894 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 3895 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 3896 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 3897 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 3898 3899 /* 3900 ** CAPI3REF: Destroy A Prepared Statement Object 3901 ** 3902 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 3903 ** ^If the most recent evaluation of the statement encountered no errors 3904 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 3905 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 3906 ** sqlite3_finalize(S) returns the appropriate [error code] or 3907 ** [extended error code]. 3908 ** 3909 ** ^The sqlite3_finalize(S) routine can be called at any point during 3910 ** the life cycle of [prepared statement] S: 3911 ** before statement S is ever evaluated, after 3912 ** one or more calls to [sqlite3_reset()], or after any call 3913 ** to [sqlite3_step()] regardless of whether or not the statement has 3914 ** completed execution. 3915 ** 3916 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 3917 ** 3918 ** The application must finalize every [prepared statement] in order to avoid 3919 ** resource leaks. It is a grievous error for the application to try to use 3920 ** a prepared statement after it has been finalized. Any use of a prepared 3921 ** statement after it has been finalized can result in undefined and 3922 ** undesirable behavior such as segfaults and heap corruption. 3923 */ 3924 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 3925 3926 /* 3927 ** CAPI3REF: Reset A Prepared Statement Object 3928 ** 3929 ** The sqlite3_reset() function is called to reset a [prepared statement] 3930 ** object back to its initial state, ready to be re-executed. 3931 ** ^Any SQL statement variables that had values bound to them using 3932 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 3933 ** Use [sqlite3_clear_bindings()] to reset the bindings. 3934 ** 3935 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 3936 ** back to the beginning of its program. 3937 ** 3938 ** ^If the most recent call to [sqlite3_step(S)] for the 3939 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 3940 ** or if [sqlite3_step(S)] has never before been called on S, 3941 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 3942 ** 3943 ** ^If the most recent call to [sqlite3_step(S)] for the 3944 ** [prepared statement] S indicated an error, then 3945 ** [sqlite3_reset(S)] returns an appropriate [error code]. 3946 ** 3947 ** ^The [sqlite3_reset(S)] interface does not change the values 3948 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 3949 */ 3950 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 3951 3952 /* 3953 ** CAPI3REF: Create Or Redefine SQL Functions 3954 ** KEYWORDS: {function creation routines} 3955 ** KEYWORDS: {application-defined SQL function} 3956 ** KEYWORDS: {application-defined SQL functions} 3957 ** 3958 ** ^These functions (collectively known as "function creation routines") 3959 ** are used to add SQL functions or aggregates or to redefine the behavior 3960 ** of existing SQL functions or aggregates. The only differences between 3961 ** these routines are the text encoding expected for 3962 ** the second parameter (the name of the function being created) 3963 ** and the presence or absence of a destructor callback for 3964 ** the application data pointer. 3965 ** 3966 ** ^The first parameter is the [database connection] to which the SQL 3967 ** function is to be added. ^If an application uses more than one database 3968 ** connection then application-defined SQL functions must be added 3969 ** to each database connection separately. 3970 ** 3971 ** ^The second parameter is the name of the SQL function to be created or 3972 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 3973 ** representation, exclusive of the zero-terminator. ^Note that the name 3974 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 3975 ** ^Any attempt to create a function with a longer name 3976 ** will result in [SQLITE_MISUSE] being returned. 3977 ** 3978 ** ^The third parameter (nArg) 3979 ** is the number of arguments that the SQL function or 3980 ** aggregate takes. ^If this parameter is -1, then the SQL function or 3981 ** aggregate may take any number of arguments between 0 and the limit 3982 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 3983 ** parameter is less than -1 or greater than 127 then the behavior is 3984 ** undefined. 3985 ** 3986 ** ^The fourth parameter, eTextRep, specifies what 3987 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 3988 ** its parameters. The application should set this parameter to 3989 ** [SQLITE_UTF16LE] if the function implementation invokes 3990 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 3991 ** implementation invokes [sqlite3_value_text16be()] on an input, or 3992 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 3993 ** otherwise. ^The same SQL function may be registered multiple times using 3994 ** different preferred text encodings, with different implementations for 3995 ** each encoding. 3996 ** ^When multiple implementations of the same function are available, SQLite 3997 ** will pick the one that involves the least amount of data conversion. 3998 ** 3999 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4000 ** to signal that the function will always return the same result given 4001 ** the same inputs within a single SQL statement. Most SQL functions are 4002 ** deterministic. The built-in [random()] SQL function is an example of a 4003 ** function that is not deterministic. The SQLite query planner is able to 4004 ** perform additional optimizations on deterministic functions, so use 4005 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4006 ** 4007 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4008 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4009 ** 4010 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4011 ** pointers to C-language functions that implement the SQL function or 4012 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4013 ** callback only; NULL pointers must be passed as the xStep and xFinal 4014 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4015 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4016 ** SQL function or aggregate, pass NULL pointers for all three function 4017 ** callbacks. 4018 ** 4019 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4020 ** then it is destructor for the application data pointer. 4021 ** The destructor is invoked when the function is deleted, either by being 4022 ** overloaded or when the database connection closes.)^ 4023 ** ^The destructor is also invoked if the call to 4024 ** sqlite3_create_function_v2() fails. 4025 ** ^When the destructor callback of the tenth parameter is invoked, it 4026 ** is passed a single argument which is a copy of the application data 4027 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4028 ** 4029 ** ^It is permitted to register multiple implementations of the same 4030 ** functions with the same name but with either differing numbers of 4031 ** arguments or differing preferred text encodings. ^SQLite will use 4032 ** the implementation that most closely matches the way in which the 4033 ** SQL function is used. ^A function implementation with a non-negative 4034 ** nArg parameter is a better match than a function implementation with 4035 ** a negative nArg. ^A function where the preferred text encoding 4036 ** matches the database encoding is a better 4037 ** match than a function where the encoding is different. 4038 ** ^A function where the encoding difference is between UTF16le and UTF16be 4039 ** is a closer match than a function where the encoding difference is 4040 ** between UTF8 and UTF16. 4041 ** 4042 ** ^Built-in functions may be overloaded by new application-defined functions. 4043 ** 4044 ** ^An application-defined function is permitted to call other 4045 ** SQLite interfaces. However, such calls must not 4046 ** close the database connection nor finalize or reset the prepared 4047 ** statement in which the function is running. 4048 */ 4049 SQLITE_API int sqlite3_create_function( 4050 sqlite3 *db, 4051 const char *zFunctionName, 4052 int nArg, 4053 int eTextRep, 4054 void *pApp, 4055 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4056 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4057 void (*xFinal)(sqlite3_context*) 4058 ); 4059 SQLITE_API int sqlite3_create_function16( 4060 sqlite3 *db, 4061 const void *zFunctionName, 4062 int nArg, 4063 int eTextRep, 4064 void *pApp, 4065 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4066 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4067 void (*xFinal)(sqlite3_context*) 4068 ); 4069 SQLITE_API int sqlite3_create_function_v2( 4070 sqlite3 *db, 4071 const char *zFunctionName, 4072 int nArg, 4073 int eTextRep, 4074 void *pApp, 4075 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4076 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4077 void (*xFinal)(sqlite3_context*), 4078 void(*xDestroy)(void*) 4079 ); 4080 4081 /* 4082 ** CAPI3REF: Text Encodings 4083 ** 4084 ** These constant define integer codes that represent the various 4085 ** text encodings supported by SQLite. 4086 */ 4087 #define SQLITE_UTF8 1 4088 #define SQLITE_UTF16LE 2 4089 #define SQLITE_UTF16BE 3 4090 #define SQLITE_UTF16 4 /* Use native byte order */ 4091 #define SQLITE_ANY 5 /* Deprecated */ 4092 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4093 4094 /* 4095 ** CAPI3REF: Function Flags 4096 ** 4097 ** These constants may be ORed together with the 4098 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4099 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4100 ** [sqlite3_create_function_v2()]. 4101 */ 4102 #define SQLITE_DETERMINISTIC 0x800 4103 4104 /* 4105 ** CAPI3REF: Deprecated Functions 4106 ** DEPRECATED 4107 ** 4108 ** These functions are [deprecated]. In order to maintain 4109 ** backwards compatibility with older code, these functions continue 4110 ** to be supported. However, new applications should avoid 4111 ** the use of these functions. To help encourage people to avoid 4112 ** using these functions, we are not going to tell you what they do. 4113 */ 4114 #ifndef SQLITE_OMIT_DEPRECATED 4115 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4116 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4117 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4118 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4119 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4120 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4121 void*,sqlite3_int64); 4122 #endif 4123 4124 /* 4125 ** CAPI3REF: Obtaining SQL Function Parameter Values 4126 ** 4127 ** The C-language implementation of SQL functions and aggregates uses 4128 ** this set of interface routines to access the parameter values on 4129 ** the function or aggregate. 4130 ** 4131 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4132 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4133 ** define callbacks that implement the SQL functions and aggregates. 4134 ** The 3rd parameter to these callbacks is an array of pointers to 4135 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4136 ** each parameter to the SQL function. These routines are used to 4137 ** extract values from the [sqlite3_value] objects. 4138 ** 4139 ** These routines work only with [protected sqlite3_value] objects. 4140 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4141 ** object results in undefined behavior. 4142 ** 4143 ** ^These routines work just like the corresponding [column access functions] 4144 ** except that these routines take a single [protected sqlite3_value] object 4145 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4146 ** 4147 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4148 ** in the native byte-order of the host machine. ^The 4149 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4150 ** extract UTF-16 strings as big-endian and little-endian respectively. 4151 ** 4152 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4153 ** numeric affinity to the value. This means that an attempt is 4154 ** made to convert the value to an integer or floating point. If 4155 ** such a conversion is possible without loss of information (in other 4156 ** words, if the value is a string that looks like a number) 4157 ** then the conversion is performed. Otherwise no conversion occurs. 4158 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4159 ** 4160 ** Please pay particular attention to the fact that the pointer returned 4161 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4162 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4163 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4164 ** or [sqlite3_value_text16()]. 4165 ** 4166 ** These routines must be called from the same thread as 4167 ** the SQL function that supplied the [sqlite3_value*] parameters. 4168 */ 4169 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4170 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4171 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4172 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4173 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4174 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4175 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4176 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4177 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4178 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4179 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4180 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4181 4182 /* 4183 ** CAPI3REF: Obtain Aggregate Function Context 4184 ** 4185 ** Implementations of aggregate SQL functions use this 4186 ** routine to allocate memory for storing their state. 4187 ** 4188 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4189 ** for a particular aggregate function, SQLite 4190 ** allocates N of memory, zeroes out that memory, and returns a pointer 4191 ** to the new memory. ^On second and subsequent calls to 4192 ** sqlite3_aggregate_context() for the same aggregate function instance, 4193 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4194 ** called once for each invocation of the xStep callback and then one 4195 ** last time when the xFinal callback is invoked. ^(When no rows match 4196 ** an aggregate query, the xStep() callback of the aggregate function 4197 ** implementation is never called and xFinal() is called exactly once. 4198 ** In those cases, sqlite3_aggregate_context() might be called for the 4199 ** first time from within xFinal().)^ 4200 ** 4201 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4202 ** when first called if N is less than or equal to zero or if a memory 4203 ** allocate error occurs. 4204 ** 4205 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4206 ** determined by the N parameter on first successful call. Changing the 4207 ** value of N in subsequent call to sqlite3_aggregate_context() within 4208 ** the same aggregate function instance will not resize the memory 4209 ** allocation.)^ Within the xFinal callback, it is customary to set 4210 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4211 ** pointless memory allocations occur. 4212 ** 4213 ** ^SQLite automatically frees the memory allocated by 4214 ** sqlite3_aggregate_context() when the aggregate query concludes. 4215 ** 4216 ** The first parameter must be a copy of the 4217 ** [sqlite3_context | SQL function context] that is the first parameter 4218 ** to the xStep or xFinal callback routine that implements the aggregate 4219 ** function. 4220 ** 4221 ** This routine must be called from the same thread in which 4222 ** the aggregate SQL function is running. 4223 */ 4224 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4225 4226 /* 4227 ** CAPI3REF: User Data For Functions 4228 ** 4229 ** ^The sqlite3_user_data() interface returns a copy of 4230 ** the pointer that was the pUserData parameter (the 5th parameter) 4231 ** of the [sqlite3_create_function()] 4232 ** and [sqlite3_create_function16()] routines that originally 4233 ** registered the application defined function. 4234 ** 4235 ** This routine must be called from the same thread in which 4236 ** the application-defined function is running. 4237 */ 4238 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4239 4240 /* 4241 ** CAPI3REF: Database Connection For Functions 4242 ** 4243 ** ^The sqlite3_context_db_handle() interface returns a copy of 4244 ** the pointer to the [database connection] (the 1st parameter) 4245 ** of the [sqlite3_create_function()] 4246 ** and [sqlite3_create_function16()] routines that originally 4247 ** registered the application defined function. 4248 */ 4249 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4250 4251 /* 4252 ** CAPI3REF: Function Auxiliary Data 4253 ** 4254 ** These functions may be used by (non-aggregate) SQL functions to 4255 ** associate metadata with argument values. If the same value is passed to 4256 ** multiple invocations of the same SQL function during query execution, under 4257 ** some circumstances the associated metadata may be preserved. An example 4258 ** of where this might be useful is in a regular-expression matching 4259 ** function. The compiled version of the regular expression can be stored as 4260 ** metadata associated with the pattern string. 4261 ** Then as long as the pattern string remains the same, 4262 ** the compiled regular expression can be reused on multiple 4263 ** invocations of the same function. 4264 ** 4265 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4266 ** associated by the sqlite3_set_auxdata() function with the Nth argument 4267 ** value to the application-defined function. ^If there is no metadata 4268 ** associated with the function argument, this sqlite3_get_auxdata() interface 4269 ** returns a NULL pointer. 4270 ** 4271 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4272 ** argument of the application-defined function. ^Subsequent 4273 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4274 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4275 ** NULL if the metadata has been discarded. 4276 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4277 ** SQLite will invoke the destructor function X with parameter P exactly 4278 ** once, when the metadata is discarded. 4279 ** SQLite is free to discard the metadata at any time, including: <ul> 4280 ** <li> when the corresponding function parameter changes, or 4281 ** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4282 ** SQL statement, or 4283 ** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4284 ** <li> during the original sqlite3_set_auxdata() call when a memory 4285 ** allocation error occurs. </ul>)^ 4286 ** 4287 ** Note the last bullet in particular. The destructor X in 4288 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4289 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4290 ** should be called near the end of the function implementation and the 4291 ** function implementation should not make any use of P after 4292 ** sqlite3_set_auxdata() has been called. 4293 ** 4294 ** ^(In practice, metadata is preserved between function calls for 4295 ** function parameters that are compile-time constants, including literal 4296 ** values and [parameters] and expressions composed from the same.)^ 4297 ** 4298 ** These routines must be called from the same thread in which 4299 ** the SQL function is running. 4300 */ 4301 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4302 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4303 4304 4305 /* 4306 ** CAPI3REF: Constants Defining Special Destructor Behavior 4307 ** 4308 ** These are special values for the destructor that is passed in as the 4309 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4310 ** argument is SQLITE_STATIC, it means that the content pointer is constant 4311 ** and will never change. It does not need to be destroyed. ^The 4312 ** SQLITE_TRANSIENT value means that the content will likely change in 4313 ** the near future and that SQLite should make its own private copy of 4314 ** the content before returning. 4315 ** 4316 ** The typedef is necessary to work around problems in certain 4317 ** C++ compilers. 4318 */ 4319 typedef void (*sqlite3_destructor_type)(void*); 4320 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 4321 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4322 4323 /* 4324 ** CAPI3REF: Setting The Result Of An SQL Function 4325 ** 4326 ** These routines are used by the xFunc or xFinal callbacks that 4327 ** implement SQL functions and aggregates. See 4328 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 4329 ** for additional information. 4330 ** 4331 ** These functions work very much like the [parameter binding] family of 4332 ** functions used to bind values to host parameters in prepared statements. 4333 ** Refer to the [SQL parameter] documentation for additional information. 4334 ** 4335 ** ^The sqlite3_result_blob() interface sets the result from 4336 ** an application-defined function to be the BLOB whose content is pointed 4337 ** to by the second parameter and which is N bytes long where N is the 4338 ** third parameter. 4339 ** 4340 ** ^The sqlite3_result_zeroblob() interfaces set the result of 4341 ** the application-defined function to be a BLOB containing all zero 4342 ** bytes and N bytes in size, where N is the value of the 2nd parameter. 4343 ** 4344 ** ^The sqlite3_result_double() interface sets the result from 4345 ** an application-defined function to be a floating point value specified 4346 ** by its 2nd argument. 4347 ** 4348 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4349 ** cause the implemented SQL function to throw an exception. 4350 ** ^SQLite uses the string pointed to by the 4351 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4352 ** as the text of an error message. ^SQLite interprets the error 4353 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 4354 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 4355 ** byte order. ^If the third parameter to sqlite3_result_error() 4356 ** or sqlite3_result_error16() is negative then SQLite takes as the error 4357 ** message all text up through the first zero character. 4358 ** ^If the third parameter to sqlite3_result_error() or 4359 ** sqlite3_result_error16() is non-negative then SQLite takes that many 4360 ** bytes (not characters) from the 2nd parameter as the error message. 4361 ** ^The sqlite3_result_error() and sqlite3_result_error16() 4362 ** routines make a private copy of the error message text before 4363 ** they return. Hence, the calling function can deallocate or 4364 ** modify the text after they return without harm. 4365 ** ^The sqlite3_result_error_code() function changes the error code 4366 ** returned by SQLite as a result of an error in a function. ^By default, 4367 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4368 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4369 ** 4370 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4371 ** error indicating that a string or BLOB is too long to represent. 4372 ** 4373 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4374 ** error indicating that a memory allocation failed. 4375 ** 4376 ** ^The sqlite3_result_int() interface sets the return value 4377 ** of the application-defined function to be the 32-bit signed integer 4378 ** value given in the 2nd argument. 4379 ** ^The sqlite3_result_int64() interface sets the return value 4380 ** of the application-defined function to be the 64-bit signed integer 4381 ** value given in the 2nd argument. 4382 ** 4383 ** ^The sqlite3_result_null() interface sets the return value 4384 ** of the application-defined function to be NULL. 4385 ** 4386 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 4387 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4388 ** set the return value of the application-defined function to be 4389 ** a text string which is represented as UTF-8, UTF-16 native byte order, 4390 ** UTF-16 little endian, or UTF-16 big endian, respectively. 4391 ** ^SQLite takes the text result from the application from 4392 ** the 2nd parameter of the sqlite3_result_text* interfaces. 4393 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4394 ** is negative, then SQLite takes result text from the 2nd parameter 4395 ** through the first zero character. 4396 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4397 ** is non-negative, then as many bytes (not characters) of the text 4398 ** pointed to by the 2nd parameter are taken as the application-defined 4399 ** function result. If the 3rd parameter is non-negative, then it 4400 ** must be the byte offset into the string where the NUL terminator would 4401 ** appear if the string where NUL terminated. If any NUL characters occur 4402 ** in the string at a byte offset that is less than the value of the 3rd 4403 ** parameter, then the resulting string will contain embedded NULs and the 4404 ** result of expressions operating on strings with embedded NULs is undefined. 4405 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4406 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4407 ** function as the destructor on the text or BLOB result when it has 4408 ** finished using that result. 4409 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4410 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4411 ** assumes that the text or BLOB result is in constant space and does not 4412 ** copy the content of the parameter nor call a destructor on the content 4413 ** when it has finished using that result. 4414 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 4415 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4416 ** then SQLite makes a copy of the result into space obtained from 4417 ** from [sqlite3_malloc()] before it returns. 4418 ** 4419 ** ^The sqlite3_result_value() interface sets the result of 4420 ** the application-defined function to be a copy the 4421 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4422 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4423 ** so that the [sqlite3_value] specified in the parameter may change or 4424 ** be deallocated after sqlite3_result_value() returns without harm. 4425 ** ^A [protected sqlite3_value] object may always be used where an 4426 ** [unprotected sqlite3_value] object is required, so either 4427 ** kind of [sqlite3_value] object can be used with this interface. 4428 ** 4429 ** If these routines are called from within the different thread 4430 ** than the one containing the application-defined function that received 4431 ** the [sqlite3_context] pointer, the results are undefined. 4432 */ 4433 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4434 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4435 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4436 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4437 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4438 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4439 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4440 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4441 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4442 SQLITE_API void sqlite3_result_null(sqlite3_context*); 4443 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4444 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4445 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4446 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4447 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4448 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4449 4450 /* 4451 ** CAPI3REF: Define New Collating Sequences 4452 ** 4453 ** ^These functions add, remove, or modify a [collation] associated 4454 ** with the [database connection] specified as the first argument. 4455 ** 4456 ** ^The name of the collation is a UTF-8 string 4457 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4458 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4459 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4460 ** considered to be the same name. 4461 ** 4462 ** ^(The third argument (eTextRep) must be one of the constants: 4463 ** <ul> 4464 ** <li> [SQLITE_UTF8], 4465 ** <li> [SQLITE_UTF16LE], 4466 ** <li> [SQLITE_UTF16BE], 4467 ** <li> [SQLITE_UTF16], or 4468 ** <li> [SQLITE_UTF16_ALIGNED]. 4469 ** </ul>)^ 4470 ** ^The eTextRep argument determines the encoding of strings passed 4471 ** to the collating function callback, xCallback. 4472 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4473 ** force strings to be UTF16 with native byte order. 4474 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4475 ** on an even byte address. 4476 ** 4477 ** ^The fourth argument, pArg, is an application data pointer that is passed 4478 ** through as the first argument to the collating function callback. 4479 ** 4480 ** ^The fifth argument, xCallback, is a pointer to the collating function. 4481 ** ^Multiple collating functions can be registered using the same name but 4482 ** with different eTextRep parameters and SQLite will use whichever 4483 ** function requires the least amount of data transformation. 4484 ** ^If the xCallback argument is NULL then the collating function is 4485 ** deleted. ^When all collating functions having the same name are deleted, 4486 ** that collation is no longer usable. 4487 ** 4488 ** ^The collating function callback is invoked with a copy of the pArg 4489 ** application data pointer and with two strings in the encoding specified 4490 ** by the eTextRep argument. The collating function must return an 4491 ** integer that is negative, zero, or positive 4492 ** if the first string is less than, equal to, or greater than the second, 4493 ** respectively. A collating function must always return the same answer 4494 ** given the same inputs. If two or more collating functions are registered 4495 ** to the same collation name (using different eTextRep values) then all 4496 ** must give an equivalent answer when invoked with equivalent strings. 4497 ** The collating function must obey the following properties for all 4498 ** strings A, B, and C: 4499 ** 4500 ** <ol> 4501 ** <li> If A==B then B==A. 4502 ** <li> If A==B and B==C then A==C. 4503 ** <li> If A<B THEN B>A. 4504 ** <li> If A<B and B<C then A<C. 4505 ** </ol> 4506 ** 4507 ** If a collating function fails any of the above constraints and that 4508 ** collating function is registered and used, then the behavior of SQLite 4509 ** is undefined. 4510 ** 4511 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4512 ** with the addition that the xDestroy callback is invoked on pArg when 4513 ** the collating function is deleted. 4514 ** ^Collating functions are deleted when they are overridden by later 4515 ** calls to the collation creation functions or when the 4516 ** [database connection] is closed using [sqlite3_close()]. 4517 ** 4518 ** ^The xDestroy callback is <u>not</u> called if the 4519 ** sqlite3_create_collation_v2() function fails. Applications that invoke 4520 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4521 ** check the return code and dispose of the application data pointer 4522 ** themselves rather than expecting SQLite to deal with it for them. 4523 ** This is different from every other SQLite interface. The inconsistency 4524 ** is unfortunate but cannot be changed without breaking backwards 4525 ** compatibility. 4526 ** 4527 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4528 */ 4529 SQLITE_API int sqlite3_create_collation( 4530 sqlite3*, 4531 const char *zName, 4532 int eTextRep, 4533 void *pArg, 4534 int(*xCompare)(void*,int,const void*,int,const void*) 4535 ); 4536 SQLITE_API int sqlite3_create_collation_v2( 4537 sqlite3*, 4538 const char *zName, 4539 int eTextRep, 4540 void *pArg, 4541 int(*xCompare)(void*,int,const void*,int,const void*), 4542 void(*xDestroy)(void*) 4543 ); 4544 SQLITE_API int sqlite3_create_collation16( 4545 sqlite3*, 4546 const void *zName, 4547 int eTextRep, 4548 void *pArg, 4549 int(*xCompare)(void*,int,const void*,int,const void*) 4550 ); 4551 4552 /* 4553 ** CAPI3REF: Collation Needed Callbacks 4554 ** 4555 ** ^To avoid having to register all collation sequences before a database 4556 ** can be used, a single callback function may be registered with the 4557 ** [database connection] to be invoked whenever an undefined collation 4558 ** sequence is required. 4559 ** 4560 ** ^If the function is registered using the sqlite3_collation_needed() API, 4561 ** then it is passed the names of undefined collation sequences as strings 4562 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4563 ** the names are passed as UTF-16 in machine native byte order. 4564 ** ^A call to either function replaces the existing collation-needed callback. 4565 ** 4566 ** ^(When the callback is invoked, the first argument passed is a copy 4567 ** of the second argument to sqlite3_collation_needed() or 4568 ** sqlite3_collation_needed16(). The second argument is the database 4569 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4570 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4571 ** sequence function required. The fourth parameter is the name of the 4572 ** required collation sequence.)^ 4573 ** 4574 ** The callback function should register the desired collation using 4575 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4576 ** [sqlite3_create_collation_v2()]. 4577 */ 4578 SQLITE_API int sqlite3_collation_needed( 4579 sqlite3*, 4580 void*, 4581 void(*)(void*,sqlite3*,int eTextRep,const char*) 4582 ); 4583 SQLITE_API int sqlite3_collation_needed16( 4584 sqlite3*, 4585 void*, 4586 void(*)(void*,sqlite3*,int eTextRep,const void*) 4587 ); 4588 4589 #ifdef SQLITE_HAS_CODEC 4590 /* 4591 ** Specify the key for an encrypted database. This routine should be 4592 ** called right after sqlite3_open(). 4593 ** 4594 ** The code to implement this API is not available in the public release 4595 ** of SQLite. 4596 */ 4597 SQLITE_API int sqlite3_key( 4598 sqlite3 *db, /* Database to be rekeyed */ 4599 const void *pKey, int nKey /* The key */ 4600 ); 4601 SQLITE_API int sqlite3_key_v2( 4602 sqlite3 *db, /* Database to be rekeyed */ 4603 const char *zDbName, /* Name of the database */ 4604 const void *pKey, int nKey /* The key */ 4605 ); 4606 4607 /* 4608 ** Change the key on an open database. If the current database is not 4609 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4610 ** database is decrypted. 4611 ** 4612 ** The code to implement this API is not available in the public release 4613 ** of SQLite. 4614 */ 4615 SQLITE_API int sqlite3_rekey( 4616 sqlite3 *db, /* Database to be rekeyed */ 4617 const void *pKey, int nKey /* The new key */ 4618 ); 4619 SQLITE_API int sqlite3_rekey_v2( 4620 sqlite3 *db, /* Database to be rekeyed */ 4621 const char *zDbName, /* Name of the database */ 4622 const void *pKey, int nKey /* The new key */ 4623 ); 4624 4625 /* 4626 ** Specify the activation key for a SEE database. Unless 4627 ** activated, none of the SEE routines will work. 4628 */ 4629 SQLITE_API void sqlite3_activate_see( 4630 const char *zPassPhrase /* Activation phrase */ 4631 ); 4632 #endif 4633 4634 #ifdef SQLITE_ENABLE_CEROD 4635 /* 4636 ** Specify the activation key for a CEROD database. Unless 4637 ** activated, none of the CEROD routines will work. 4638 */ 4639 SQLITE_API void sqlite3_activate_cerod( 4640 const char *zPassPhrase /* Activation phrase */ 4641 ); 4642 #endif 4643 4644 /* 4645 ** CAPI3REF: Suspend Execution For A Short Time 4646 ** 4647 ** The sqlite3_sleep() function causes the current thread to suspend execution 4648 ** for at least a number of milliseconds specified in its parameter. 4649 ** 4650 ** If the operating system does not support sleep requests with 4651 ** millisecond time resolution, then the time will be rounded up to 4652 ** the nearest second. The number of milliseconds of sleep actually 4653 ** requested from the operating system is returned. 4654 ** 4655 ** ^SQLite implements this interface by calling the xSleep() 4656 ** method of the default [sqlite3_vfs] object. If the xSleep() method 4657 ** of the default VFS is not implemented correctly, or not implemented at 4658 ** all, then the behavior of sqlite3_sleep() may deviate from the description 4659 ** in the previous paragraphs. 4660 */ 4661 SQLITE_API int sqlite3_sleep(int); 4662 4663 /* 4664 ** CAPI3REF: Name Of The Folder Holding Temporary Files 4665 ** 4666 ** ^(If this global variable is made to point to a string which is 4667 ** the name of a folder (a.k.a. directory), then all temporary files 4668 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4669 ** will be placed in that directory.)^ ^If this variable 4670 ** is a NULL pointer, then SQLite performs a search for an appropriate 4671 ** temporary file directory. 4672 ** 4673 ** It is not safe to read or modify this variable in more than one 4674 ** thread at a time. It is not safe to read or modify this variable 4675 ** if a [database connection] is being used at the same time in a separate 4676 ** thread. 4677 ** It is intended that this variable be set once 4678 ** as part of process initialization and before any SQLite interface 4679 ** routines have been called and that this variable remain unchanged 4680 ** thereafter. 4681 ** 4682 ** ^The [temp_store_directory pragma] may modify this variable and cause 4683 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4684 ** the [temp_store_directory pragma] always assumes that any string 4685 ** that this variable points to is held in memory obtained from 4686 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4687 ** using [sqlite3_free]. 4688 ** Hence, if this variable is modified directly, either it should be 4689 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4690 ** or else the use of the [temp_store_directory pragma] should be avoided. 4691 ** 4692 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4693 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4694 ** features that require the use of temporary files may fail. Here is an 4695 ** example of how to do this using C++ with the Windows Runtime: 4696 ** 4697 ** <blockquote><pre> 4698 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4699 ** TemporaryFolder->Path->Data(); 4700 ** char zPathBuf[MAX_PATH + 1]; 4701 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 4702 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4703 ** NULL, NULL); 4704 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4705 ** </pre></blockquote> 4706 */ 4707 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 4708 4709 /* 4710 ** CAPI3REF: Name Of The Folder Holding Database Files 4711 ** 4712 ** ^(If this global variable is made to point to a string which is 4713 ** the name of a folder (a.k.a. directory), then all database files 4714 ** specified with a relative pathname and created or accessed by 4715 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4716 ** to be relative to that directory.)^ ^If this variable is a NULL 4717 ** pointer, then SQLite assumes that all database files specified 4718 ** with a relative pathname are relative to the current directory 4719 ** for the process. Only the windows VFS makes use of this global 4720 ** variable; it is ignored by the unix VFS. 4721 ** 4722 ** Changing the value of this variable while a database connection is 4723 ** open can result in a corrupt database. 4724 ** 4725 ** It is not safe to read or modify this variable in more than one 4726 ** thread at a time. It is not safe to read or modify this variable 4727 ** if a [database connection] is being used at the same time in a separate 4728 ** thread. 4729 ** It is intended that this variable be set once 4730 ** as part of process initialization and before any SQLite interface 4731 ** routines have been called and that this variable remain unchanged 4732 ** thereafter. 4733 ** 4734 ** ^The [data_store_directory pragma] may modify this variable and cause 4735 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4736 ** the [data_store_directory pragma] always assumes that any string 4737 ** that this variable points to is held in memory obtained from 4738 ** [sqlite3_malloc] and the pragma may attempt to free that memory 4739 ** using [sqlite3_free]. 4740 ** Hence, if this variable is modified directly, either it should be 4741 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 4742 ** or else the use of the [data_store_directory pragma] should be avoided. 4743 */ 4744 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 4745 4746 /* 4747 ** CAPI3REF: Test For Auto-Commit Mode 4748 ** KEYWORDS: {autocommit mode} 4749 ** 4750 ** ^The sqlite3_get_autocommit() interface returns non-zero or 4751 ** zero if the given database connection is or is not in autocommit mode, 4752 ** respectively. ^Autocommit mode is on by default. 4753 ** ^Autocommit mode is disabled by a [BEGIN] statement. 4754 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4755 ** 4756 ** If certain kinds of errors occur on a statement within a multi-statement 4757 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4758 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4759 ** transaction might be rolled back automatically. The only way to 4760 ** find out whether SQLite automatically rolled back the transaction after 4761 ** an error is to use this function. 4762 ** 4763 ** If another thread changes the autocommit status of the database 4764 ** connection while this routine is running, then the return value 4765 ** is undefined. 4766 */ 4767 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4768 4769 /* 4770 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 4771 ** 4772 ** ^The sqlite3_db_handle interface returns the [database connection] handle 4773 ** to which a [prepared statement] belongs. ^The [database connection] 4774 ** returned by sqlite3_db_handle is the same [database connection] 4775 ** that was the first argument 4776 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4777 ** create the statement in the first place. 4778 */ 4779 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4780 4781 /* 4782 ** CAPI3REF: Return The Filename For A Database Connection 4783 ** 4784 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4785 ** associated with database N of connection D. ^The main database file 4786 ** has the name "main". If there is no attached database N on the database 4787 ** connection D, or if database N is a temporary or in-memory database, then 4788 ** a NULL pointer is returned. 4789 ** 4790 ** ^The filename returned by this function is the output of the 4791 ** xFullPathname method of the [VFS]. ^In other words, the filename 4792 ** will be an absolute pathname, even if the filename used 4793 ** to open the database originally was a URI or relative pathname. 4794 */ 4795 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4796 4797 /* 4798 ** CAPI3REF: Determine if a database is read-only 4799 ** 4800 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4801 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4802 ** the name of a database on connection D. 4803 */ 4804 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4805 4806 /* 4807 ** CAPI3REF: Find the next prepared statement 4808 ** 4809 ** ^This interface returns a pointer to the next [prepared statement] after 4810 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4811 ** then this interface returns a pointer to the first prepared statement 4812 ** associated with the database connection pDb. ^If no prepared statement 4813 ** satisfies the conditions of this routine, it returns NULL. 4814 ** 4815 ** The [database connection] pointer D in a call to 4816 ** [sqlite3_next_stmt(D,S)] must refer to an open database 4817 ** connection and in particular must not be a NULL pointer. 4818 */ 4819 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4820 4821 /* 4822 ** CAPI3REF: Commit And Rollback Notification Callbacks 4823 ** 4824 ** ^The sqlite3_commit_hook() interface registers a callback 4825 ** function to be invoked whenever a transaction is [COMMIT | committed]. 4826 ** ^Any callback set by a previous call to sqlite3_commit_hook() 4827 ** for the same database connection is overridden. 4828 ** ^The sqlite3_rollback_hook() interface registers a callback 4829 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4830 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 4831 ** for the same database connection is overridden. 4832 ** ^The pArg argument is passed through to the callback. 4833 ** ^If the callback on a commit hook function returns non-zero, 4834 ** then the commit is converted into a rollback. 4835 ** 4836 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4837 ** return the P argument from the previous call of the same function 4838 ** on the same [database connection] D, or NULL for 4839 ** the first call for each function on D. 4840 ** 4841 ** The commit and rollback hook callbacks are not reentrant. 4842 ** The callback implementation must not do anything that will modify 4843 ** the database connection that invoked the callback. Any actions 4844 ** to modify the database connection must be deferred until after the 4845 ** completion of the [sqlite3_step()] call that triggered the commit 4846 ** or rollback hook in the first place. 4847 ** Note that running any other SQL statements, including SELECT statements, 4848 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4849 ** the database connections for the meaning of "modify" in this paragraph. 4850 ** 4851 ** ^Registering a NULL function disables the callback. 4852 ** 4853 ** ^When the commit hook callback routine returns zero, the [COMMIT] 4854 ** operation is allowed to continue normally. ^If the commit hook 4855 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 4856 ** ^The rollback hook is invoked on a rollback that results from a commit 4857 ** hook returning non-zero, just as it would be with any other rollback. 4858 ** 4859 ** ^For the purposes of this API, a transaction is said to have been 4860 ** rolled back if an explicit "ROLLBACK" statement is executed, or 4861 ** an error or constraint causes an implicit rollback to occur. 4862 ** ^The rollback callback is not invoked if a transaction is 4863 ** automatically rolled back because the database connection is closed. 4864 ** 4865 ** See also the [sqlite3_update_hook()] interface. 4866 */ 4867 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 4868 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 4869 4870 /* 4871 ** CAPI3REF: Data Change Notification Callbacks 4872 ** 4873 ** ^The sqlite3_update_hook() interface registers a callback function 4874 ** with the [database connection] identified by the first argument 4875 ** to be invoked whenever a row is updated, inserted or deleted in 4876 ** a rowid table. 4877 ** ^Any callback set by a previous call to this function 4878 ** for the same database connection is overridden. 4879 ** 4880 ** ^The second argument is a pointer to the function to invoke when a 4881 ** row is updated, inserted or deleted in a rowid table. 4882 ** ^The first argument to the callback is a copy of the third argument 4883 ** to sqlite3_update_hook(). 4884 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 4885 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 4886 ** to be invoked. 4887 ** ^The third and fourth arguments to the callback contain pointers to the 4888 ** database and table name containing the affected row. 4889 ** ^The final callback parameter is the [rowid] of the row. 4890 ** ^In the case of an update, this is the [rowid] after the update takes place. 4891 ** 4892 ** ^(The update hook is not invoked when internal system tables are 4893 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 4894 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 4895 ** 4896 ** ^In the current implementation, the update hook 4897 ** is not invoked when duplication rows are deleted because of an 4898 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 4899 ** invoked when rows are deleted using the [truncate optimization]. 4900 ** The exceptions defined in this paragraph might change in a future 4901 ** release of SQLite. 4902 ** 4903 ** The update hook implementation must not do anything that will modify 4904 ** the database connection that invoked the update hook. Any actions 4905 ** to modify the database connection must be deferred until after the 4906 ** completion of the [sqlite3_step()] call that triggered the update hook. 4907 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 4908 ** database connections for the meaning of "modify" in this paragraph. 4909 ** 4910 ** ^The sqlite3_update_hook(D,C,P) function 4911 ** returns the P argument from the previous call 4912 ** on the same [database connection] D, or NULL for 4913 ** the first call on D. 4914 ** 4915 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 4916 ** interfaces. 4917 */ 4918 SQLITE_API void *sqlite3_update_hook( 4919 sqlite3*, 4920 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 4921 void* 4922 ); 4923 4924 /* 4925 ** CAPI3REF: Enable Or Disable Shared Pager Cache 4926 ** 4927 ** ^(This routine enables or disables the sharing of the database cache 4928 ** and schema data structures between [database connection | connections] 4929 ** to the same database. Sharing is enabled if the argument is true 4930 ** and disabled if the argument is false.)^ 4931 ** 4932 ** ^Cache sharing is enabled and disabled for an entire process. 4933 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 4934 ** sharing was enabled or disabled for each thread separately. 4935 ** 4936 ** ^(The cache sharing mode set by this interface effects all subsequent 4937 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 4938 ** Existing database connections continue use the sharing mode 4939 ** that was in effect at the time they were opened.)^ 4940 ** 4941 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 4942 ** successfully. An [error code] is returned otherwise.)^ 4943 ** 4944 ** ^Shared cache is disabled by default. But this might change in 4945 ** future releases of SQLite. Applications that care about shared 4946 ** cache setting should set it explicitly. 4947 ** 4948 ** This interface is threadsafe on processors where writing a 4949 ** 32-bit integer is atomic. 4950 ** 4951 ** See Also: [SQLite Shared-Cache Mode] 4952 */ 4953 SQLITE_API int sqlite3_enable_shared_cache(int); 4954 4955 /* 4956 ** CAPI3REF: Attempt To Free Heap Memory 4957 ** 4958 ** ^The sqlite3_release_memory() interface attempts to free N bytes 4959 ** of heap memory by deallocating non-essential memory allocations 4960 ** held by the database library. Memory used to cache database 4961 ** pages to improve performance is an example of non-essential memory. 4962 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 4963 ** which might be more or less than the amount requested. 4964 ** ^The sqlite3_release_memory() routine is a no-op returning zero 4965 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 4966 ** 4967 ** See also: [sqlite3_db_release_memory()] 4968 */ 4969 SQLITE_API int sqlite3_release_memory(int); 4970 4971 /* 4972 ** CAPI3REF: Free Memory Used By A Database Connection 4973 ** 4974 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 4975 ** memory as possible from database connection D. Unlike the 4976 ** [sqlite3_release_memory()] interface, this interface is in effect even 4977 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 4978 ** omitted. 4979 ** 4980 ** See also: [sqlite3_release_memory()] 4981 */ 4982 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 4983 4984 /* 4985 ** CAPI3REF: Impose A Limit On Heap Size 4986 ** 4987 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 4988 ** soft limit on the amount of heap memory that may be allocated by SQLite. 4989 ** ^SQLite strives to keep heap memory utilization below the soft heap 4990 ** limit by reducing the number of pages held in the page cache 4991 ** as heap memory usages approaches the limit. 4992 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 4993 ** below the limit, it will exceed the limit rather than generate 4994 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 4995 ** is advisory only. 4996 ** 4997 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 4998 ** the soft heap limit prior to the call, or negative in the case of an 4999 ** error. ^If the argument N is negative 5000 ** then no change is made to the soft heap limit. Hence, the current 5001 ** size of the soft heap limit can be determined by invoking 5002 ** sqlite3_soft_heap_limit64() with a negative argument. 5003 ** 5004 ** ^If the argument N is zero then the soft heap limit is disabled. 5005 ** 5006 ** ^(The soft heap limit is not enforced in the current implementation 5007 ** if one or more of following conditions are true: 5008 ** 5009 ** <ul> 5010 ** <li> The soft heap limit is set to zero. 5011 ** <li> Memory accounting is disabled using a combination of the 5012 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5013 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5014 ** <li> An alternative page cache implementation is specified using 5015 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5016 ** <li> The page cache allocates from its own memory pool supplied 5017 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5018 ** from the heap. 5019 ** </ul>)^ 5020 ** 5021 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5022 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5023 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5024 ** the soft heap limit is enforced on every memory allocation. Without 5025 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5026 ** when memory is allocated by the page cache. Testing suggests that because 5027 ** the page cache is the predominate memory user in SQLite, most 5028 ** applications will achieve adequate soft heap limit enforcement without 5029 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5030 ** 5031 ** The circumstances under which SQLite will enforce the soft heap limit may 5032 ** changes in future releases of SQLite. 5033 */ 5034 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5035 5036 /* 5037 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5038 ** DEPRECATED 5039 ** 5040 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5041 ** interface. This routine is provided for historical compatibility 5042 ** only. All new applications should use the 5043 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5044 */ 5045 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5046 5047 5048 /* 5049 ** CAPI3REF: Extract Metadata About A Column Of A Table 5050 ** 5051 ** ^This routine returns metadata about a specific column of a specific 5052 ** database table accessible using the [database connection] handle 5053 ** passed as the first function argument. 5054 ** 5055 ** ^The column is identified by the second, third and fourth parameters to 5056 ** this function. ^The second parameter is either the name of the database 5057 ** (i.e. "main", "temp", or an attached database) containing the specified 5058 ** table or NULL. ^If it is NULL, then all attached databases are searched 5059 ** for the table using the same algorithm used by the database engine to 5060 ** resolve unqualified table references. 5061 ** 5062 ** ^The third and fourth parameters to this function are the table and column 5063 ** name of the desired column, respectively. Neither of these parameters 5064 ** may be NULL. 5065 ** 5066 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5067 ** and subsequent parameters to this function. ^Any of these arguments may be 5068 ** NULL, in which case the corresponding element of metadata is omitted. 5069 ** 5070 ** ^(<blockquote> 5071 ** <table border="1"> 5072 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5073 ** 5074 ** <tr><td> 5th <td> const char* <td> Data type 5075 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5076 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5077 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5078 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5079 ** </table> 5080 ** </blockquote>)^ 5081 ** 5082 ** ^The memory pointed to by the character pointers returned for the 5083 ** declaration type and collation sequence is valid only until the next 5084 ** call to any SQLite API function. 5085 ** 5086 ** ^If the specified table is actually a view, an [error code] is returned. 5087 ** 5088 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an 5089 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5090 ** parameters are set for the explicitly declared column. ^(If there is no 5091 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5092 ** parameters are set as follows: 5093 ** 5094 ** <pre> 5095 ** data type: "INTEGER" 5096 ** collation sequence: "BINARY" 5097 ** not null: 0 5098 ** primary key: 1 5099 ** auto increment: 0 5100 ** </pre>)^ 5101 ** 5102 ** ^(This function may load one or more schemas from database files. If an 5103 ** error occurs during this process, or if the requested table or column 5104 ** cannot be found, an [error code] is returned and an error message left 5105 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5106 ** 5107 ** ^This API is only available if the library was compiled with the 5108 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5109 */ 5110 SQLITE_API int sqlite3_table_column_metadata( 5111 sqlite3 *db, /* Connection handle */ 5112 const char *zDbName, /* Database name or NULL */ 5113 const char *zTableName, /* Table name */ 5114 const char *zColumnName, /* Column name */ 5115 char const **pzDataType, /* OUTPUT: Declared data type */ 5116 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5117 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5118 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5119 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5120 ); 5121 5122 /* 5123 ** CAPI3REF: Load An Extension 5124 ** 5125 ** ^This interface loads an SQLite extension library from the named file. 5126 ** 5127 ** ^The sqlite3_load_extension() interface attempts to load an 5128 ** [SQLite extension] library contained in the file zFile. If 5129 ** the file cannot be loaded directly, attempts are made to load 5130 ** with various operating-system specific extensions added. 5131 ** So for example, if "samplelib" cannot be loaded, then names like 5132 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5133 ** be tried also. 5134 ** 5135 ** ^The entry point is zProc. 5136 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5137 ** entry point name on its own. It first tries "sqlite3_extension_init". 5138 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5139 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5140 ** characters in the filename from the last "/" to the first following 5141 ** "." and omitting any initial "lib".)^ 5142 ** ^The sqlite3_load_extension() interface returns 5143 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5144 ** ^If an error occurs and pzErrMsg is not 0, then the 5145 ** [sqlite3_load_extension()] interface shall attempt to 5146 ** fill *pzErrMsg with error message text stored in memory 5147 ** obtained from [sqlite3_malloc()]. The calling function 5148 ** should free this memory by calling [sqlite3_free()]. 5149 ** 5150 ** ^Extension loading must be enabled using 5151 ** [sqlite3_enable_load_extension()] prior to calling this API, 5152 ** otherwise an error will be returned. 5153 ** 5154 ** See also the [load_extension() SQL function]. 5155 */ 5156 SQLITE_API int sqlite3_load_extension( 5157 sqlite3 *db, /* Load the extension into this database connection */ 5158 const char *zFile, /* Name of the shared library containing extension */ 5159 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5160 char **pzErrMsg /* Put error message here if not 0 */ 5161 ); 5162 5163 /* 5164 ** CAPI3REF: Enable Or Disable Extension Loading 5165 ** 5166 ** ^So as not to open security holes in older applications that are 5167 ** unprepared to deal with [extension loading], and as a means of disabling 5168 ** [extension loading] while evaluating user-entered SQL, the following API 5169 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5170 ** 5171 ** ^Extension loading is off by default. 5172 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5173 ** to turn extension loading on and call it with onoff==0 to turn 5174 ** it back off again. 5175 */ 5176 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5177 5178 /* 5179 ** CAPI3REF: Automatically Load Statically Linked Extensions 5180 ** 5181 ** ^This interface causes the xEntryPoint() function to be invoked for 5182 ** each new [database connection] that is created. The idea here is that 5183 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5184 ** that is to be automatically loaded into all new database connections. 5185 ** 5186 ** ^(Even though the function prototype shows that xEntryPoint() takes 5187 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5188 ** arguments and expects and integer result as if the signature of the 5189 ** entry point where as follows: 5190 ** 5191 ** <blockquote><pre> 5192 ** int xEntryPoint( 5193 ** sqlite3 *db, 5194 ** const char **pzErrMsg, 5195 ** const struct sqlite3_api_routines *pThunk 5196 ** ); 5197 ** </pre></blockquote>)^ 5198 ** 5199 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5200 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5201 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5202 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5203 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5204 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5205 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5206 ** 5207 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5208 ** on the list of automatic extensions is a harmless no-op. ^No entry point 5209 ** will be called more than once for each database connection that is opened. 5210 ** 5211 ** See also: [sqlite3_reset_auto_extension()] 5212 ** and [sqlite3_cancel_auto_extension()] 5213 */ 5214 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5215 5216 /* 5217 ** CAPI3REF: Cancel Automatic Extension Loading 5218 ** 5219 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5220 ** initialization routine X that was registered using a prior call to 5221 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5222 ** routine returns 1 if initialization routine X was successfully 5223 ** unregistered and it returns 0 if X was not on the list of initialization 5224 ** routines. 5225 */ 5226 SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5227 5228 /* 5229 ** CAPI3REF: Reset Automatic Extension Loading 5230 ** 5231 ** ^This interface disables all automatic extensions previously 5232 ** registered using [sqlite3_auto_extension()]. 5233 */ 5234 SQLITE_API void sqlite3_reset_auto_extension(void); 5235 5236 /* 5237 ** The interface to the virtual-table mechanism is currently considered 5238 ** to be experimental. The interface might change in incompatible ways. 5239 ** If this is a problem for you, do not use the interface at this time. 5240 ** 5241 ** When the virtual-table mechanism stabilizes, we will declare the 5242 ** interface fixed, support it indefinitely, and remove this comment. 5243 */ 5244 5245 /* 5246 ** Structures used by the virtual table interface 5247 */ 5248 typedef struct sqlite3_vtab sqlite3_vtab; 5249 typedef struct sqlite3_index_info sqlite3_index_info; 5250 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5251 typedef struct sqlite3_module sqlite3_module; 5252 5253 /* 5254 ** CAPI3REF: Virtual Table Object 5255 ** KEYWORDS: sqlite3_module {virtual table module} 5256 ** 5257 ** This structure, sometimes called a "virtual table module", 5258 ** defines the implementation of a [virtual tables]. 5259 ** This structure consists mostly of methods for the module. 5260 ** 5261 ** ^A virtual table module is created by filling in a persistent 5262 ** instance of this structure and passing a pointer to that instance 5263 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5264 ** ^The registration remains valid until it is replaced by a different 5265 ** module or until the [database connection] closes. The content 5266 ** of this structure must not change while it is registered with 5267 ** any database connection. 5268 */ 5269 struct sqlite3_module { 5270 int iVersion; 5271 int (*xCreate)(sqlite3*, void *pAux, 5272 int argc, const char *const*argv, 5273 sqlite3_vtab **ppVTab, char**); 5274 int (*xConnect)(sqlite3*, void *pAux, 5275 int argc, const char *const*argv, 5276 sqlite3_vtab **ppVTab, char**); 5277 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5278 int (*xDisconnect)(sqlite3_vtab *pVTab); 5279 int (*xDestroy)(sqlite3_vtab *pVTab); 5280 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5281 int (*xClose)(sqlite3_vtab_cursor*); 5282 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5283 int argc, sqlite3_value **argv); 5284 int (*xNext)(sqlite3_vtab_cursor*); 5285 int (*xEof)(sqlite3_vtab_cursor*); 5286 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5287 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5288 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5289 int (*xBegin)(sqlite3_vtab *pVTab); 5290 int (*xSync)(sqlite3_vtab *pVTab); 5291 int (*xCommit)(sqlite3_vtab *pVTab); 5292 int (*xRollback)(sqlite3_vtab *pVTab); 5293 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5294 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5295 void **ppArg); 5296 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5297 /* The methods above are in version 1 of the sqlite_module object. Those 5298 ** below are for version 2 and greater. */ 5299 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5300 int (*xRelease)(sqlite3_vtab *pVTab, int); 5301 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5302 }; 5303 5304 /* 5305 ** CAPI3REF: Virtual Table Indexing Information 5306 ** KEYWORDS: sqlite3_index_info 5307 ** 5308 ** The sqlite3_index_info structure and its substructures is used as part 5309 ** of the [virtual table] interface to 5310 ** pass information into and receive the reply from the [xBestIndex] 5311 ** method of a [virtual table module]. The fields under **Inputs** are the 5312 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 5313 ** results into the **Outputs** fields. 5314 ** 5315 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 5316 ** 5317 ** <blockquote>column OP expr</blockquote> 5318 ** 5319 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5320 ** stored in aConstraint[].op using one of the 5321 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5322 ** ^(The index of the column is stored in 5323 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5324 ** expr on the right-hand side can be evaluated (and thus the constraint 5325 ** is usable) and false if it cannot.)^ 5326 ** 5327 ** ^The optimizer automatically inverts terms of the form "expr OP column" 5328 ** and makes other simplifications to the WHERE clause in an attempt to 5329 ** get as many WHERE clause terms into the form shown above as possible. 5330 ** ^The aConstraint[] array only reports WHERE clause terms that are 5331 ** relevant to the particular virtual table being queried. 5332 ** 5333 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5334 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 5335 ** 5336 ** The [xBestIndex] method must fill aConstraintUsage[] with information 5337 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 5338 ** the right-hand side of the corresponding aConstraint[] is evaluated 5339 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5340 ** is true, then the constraint is assumed to be fully handled by the 5341 ** virtual table and is not checked again by SQLite.)^ 5342 ** 5343 ** ^The idxNum and idxPtr values are recorded and passed into the 5344 ** [xFilter] method. 5345 ** ^[sqlite3_free()] is used to free idxPtr if and only if 5346 ** needToFreeIdxPtr is true. 5347 ** 5348 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5349 ** the correct order to satisfy the ORDER BY clause so that no separate 5350 ** sorting step is required. 5351 ** 5352 ** ^The estimatedCost value is an estimate of the cost of a particular 5353 ** strategy. A cost of N indicates that the cost of the strategy is similar 5354 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 5355 ** indicates that the expense of the operation is similar to that of a 5356 ** binary search on a unique indexed field of an SQLite table with N rows. 5357 ** 5358 ** ^The estimatedRows value is an estimate of the number of rows that 5359 ** will be returned by the strategy. 5360 ** 5361 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5362 ** structure for SQLite version 3.8.2. If a virtual table extension is 5363 ** used with an SQLite version earlier than 3.8.2, the results of attempting 5364 ** to read or write the estimatedRows field are undefined (but are likely 5365 ** to included crashing the application). The estimatedRows field should 5366 ** therefore only be used if [sqlite3_libversion_number()] returns a 5367 ** value greater than or equal to 3008002. 5368 */ 5369 struct sqlite3_index_info { 5370 /* Inputs */ 5371 int nConstraint; /* Number of entries in aConstraint */ 5372 struct sqlite3_index_constraint { 5373 int iColumn; /* Column on left-hand side of constraint */ 5374 unsigned char op; /* Constraint operator */ 5375 unsigned char usable; /* True if this constraint is usable */ 5376 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5377 } *aConstraint; /* Table of WHERE clause constraints */ 5378 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5379 struct sqlite3_index_orderby { 5380 int iColumn; /* Column number */ 5381 unsigned char desc; /* True for DESC. False for ASC. */ 5382 } *aOrderBy; /* The ORDER BY clause */ 5383 /* Outputs */ 5384 struct sqlite3_index_constraint_usage { 5385 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5386 unsigned char omit; /* Do not code a test for this constraint */ 5387 } *aConstraintUsage; 5388 int idxNum; /* Number used to identify the index */ 5389 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5390 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5391 int orderByConsumed; /* True if output is already ordered */ 5392 double estimatedCost; /* Estimated cost of using this index */ 5393 /* Fields below are only available in SQLite 3.8.2 and later */ 5394 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5395 }; 5396 5397 /* 5398 ** CAPI3REF: Virtual Table Constraint Operator Codes 5399 ** 5400 ** These macros defined the allowed values for the 5401 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 5402 ** an operator that is part of a constraint term in the wHERE clause of 5403 ** a query that uses a [virtual table]. 5404 */ 5405 #define SQLITE_INDEX_CONSTRAINT_EQ 2 5406 #define SQLITE_INDEX_CONSTRAINT_GT 4 5407 #define SQLITE_INDEX_CONSTRAINT_LE 8 5408 #define SQLITE_INDEX_CONSTRAINT_LT 16 5409 #define SQLITE_INDEX_CONSTRAINT_GE 32 5410 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 5411 5412 /* 5413 ** CAPI3REF: Register A Virtual Table Implementation 5414 ** 5415 ** ^These routines are used to register a new [virtual table module] name. 5416 ** ^Module names must be registered before 5417 ** creating a new [virtual table] using the module and before using a 5418 ** preexisting [virtual table] for the module. 5419 ** 5420 ** ^The module name is registered on the [database connection] specified 5421 ** by the first parameter. ^The name of the module is given by the 5422 ** second parameter. ^The third parameter is a pointer to 5423 ** the implementation of the [virtual table module]. ^The fourth 5424 ** parameter is an arbitrary client data pointer that is passed through 5425 ** into the [xCreate] and [xConnect] methods of the virtual table module 5426 ** when a new virtual table is be being created or reinitialized. 5427 ** 5428 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5429 ** is a pointer to a destructor for the pClientData. ^SQLite will 5430 ** invoke the destructor function (if it is not NULL) when SQLite 5431 ** no longer needs the pClientData pointer. ^The destructor will also 5432 ** be invoked if the call to sqlite3_create_module_v2() fails. 5433 ** ^The sqlite3_create_module() 5434 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 5435 ** destructor. 5436 */ 5437 SQLITE_API int sqlite3_create_module( 5438 sqlite3 *db, /* SQLite connection to register module with */ 5439 const char *zName, /* Name of the module */ 5440 const sqlite3_module *p, /* Methods for the module */ 5441 void *pClientData /* Client data for xCreate/xConnect */ 5442 ); 5443 SQLITE_API int sqlite3_create_module_v2( 5444 sqlite3 *db, /* SQLite connection to register module with */ 5445 const char *zName, /* Name of the module */ 5446 const sqlite3_module *p, /* Methods for the module */ 5447 void *pClientData, /* Client data for xCreate/xConnect */ 5448 void(*xDestroy)(void*) /* Module destructor function */ 5449 ); 5450 5451 /* 5452 ** CAPI3REF: Virtual Table Instance Object 5453 ** KEYWORDS: sqlite3_vtab 5454 ** 5455 ** Every [virtual table module] implementation uses a subclass 5456 ** of this object to describe a particular instance 5457 ** of the [virtual table]. Each subclass will 5458 ** be tailored to the specific needs of the module implementation. 5459 ** The purpose of this superclass is to define certain fields that are 5460 ** common to all module implementations. 5461 ** 5462 ** ^Virtual tables methods can set an error message by assigning a 5463 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5464 ** take care that any prior string is freed by a call to [sqlite3_free()] 5465 ** prior to assigning a new string to zErrMsg. ^After the error message 5466 ** is delivered up to the client application, the string will be automatically 5467 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5468 */ 5469 struct sqlite3_vtab { 5470 const sqlite3_module *pModule; /* The module for this virtual table */ 5471 int nRef; /* NO LONGER USED */ 5472 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5473 /* Virtual table implementations will typically add additional fields */ 5474 }; 5475 5476 /* 5477 ** CAPI3REF: Virtual Table Cursor Object 5478 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5479 ** 5480 ** Every [virtual table module] implementation uses a subclass of the 5481 ** following structure to describe cursors that point into the 5482 ** [virtual table] and are used 5483 ** to loop through the virtual table. Cursors are created using the 5484 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5485 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5486 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5487 ** of the module. Each module implementation will define 5488 ** the content of a cursor structure to suit its own needs. 5489 ** 5490 ** This superclass exists in order to define fields of the cursor that 5491 ** are common to all implementations. 5492 */ 5493 struct sqlite3_vtab_cursor { 5494 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5495 /* Virtual table implementations will typically add additional fields */ 5496 }; 5497 5498 /* 5499 ** CAPI3REF: Declare The Schema Of A Virtual Table 5500 ** 5501 ** ^The [xCreate] and [xConnect] methods of a 5502 ** [virtual table module] call this interface 5503 ** to declare the format (the names and datatypes of the columns) of 5504 ** the virtual tables they implement. 5505 */ 5506 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5507 5508 /* 5509 ** CAPI3REF: Overload A Function For A Virtual Table 5510 ** 5511 ** ^(Virtual tables can provide alternative implementations of functions 5512 ** using the [xFindFunction] method of the [virtual table module]. 5513 ** But global versions of those functions 5514 ** must exist in order to be overloaded.)^ 5515 ** 5516 ** ^(This API makes sure a global version of a function with a particular 5517 ** name and number of parameters exists. If no such function exists 5518 ** before this API is called, a new function is created.)^ ^The implementation 5519 ** of the new function always causes an exception to be thrown. So 5520 ** the new function is not good for anything by itself. Its only 5521 ** purpose is to be a placeholder function that can be overloaded 5522 ** by a [virtual table]. 5523 */ 5524 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5525 5526 /* 5527 ** The interface to the virtual-table mechanism defined above (back up 5528 ** to a comment remarkably similar to this one) is currently considered 5529 ** to be experimental. The interface might change in incompatible ways. 5530 ** If this is a problem for you, do not use the interface at this time. 5531 ** 5532 ** When the virtual-table mechanism stabilizes, we will declare the 5533 ** interface fixed, support it indefinitely, and remove this comment. 5534 */ 5535 5536 /* 5537 ** CAPI3REF: A Handle To An Open BLOB 5538 ** KEYWORDS: {BLOB handle} {BLOB handles} 5539 ** 5540 ** An instance of this object represents an open BLOB on which 5541 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5542 ** ^Objects of this type are created by [sqlite3_blob_open()] 5543 ** and destroyed by [sqlite3_blob_close()]. 5544 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5545 ** can be used to read or write small subsections of the BLOB. 5546 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5547 */ 5548 typedef struct sqlite3_blob sqlite3_blob; 5549 5550 /* 5551 ** CAPI3REF: Open A BLOB For Incremental I/O 5552 ** 5553 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5554 ** in row iRow, column zColumn, table zTable in database zDb; 5555 ** in other words, the same BLOB that would be selected by: 5556 ** 5557 ** <pre> 5558 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5559 ** </pre>)^ 5560 ** 5561 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 5562 ** and write access. ^If it is zero, the BLOB is opened for read access. 5563 ** ^It is not possible to open a column that is part of an index or primary 5564 ** key for writing. ^If [foreign key constraints] are enabled, it is 5565 ** not possible to open a column that is part of a [child key] for writing. 5566 ** 5567 ** ^Note that the database name is not the filename that contains 5568 ** the database but rather the symbolic name of the database that 5569 ** appears after the AS keyword when the database is connected using [ATTACH]. 5570 ** ^For the main database file, the database name is "main". 5571 ** ^For TEMP tables, the database name is "temp". 5572 ** 5573 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5574 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5575 ** to be a null pointer.)^ 5576 ** ^This function sets the [database connection] error code and message 5577 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5578 ** functions. ^Note that the *ppBlob variable is always initialized in a 5579 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5580 ** regardless of the success or failure of this routine. 5581 ** 5582 ** ^(If the row that a BLOB handle points to is modified by an 5583 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5584 ** then the BLOB handle is marked as "expired". 5585 ** This is true if any column of the row is changed, even a column 5586 ** other than the one the BLOB handle is open on.)^ 5587 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5588 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5589 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 5590 ** rolled back by the expiration of the BLOB. Such changes will eventually 5591 ** commit if the transaction continues to completion.)^ 5592 ** 5593 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5594 ** the opened blob. ^The size of a blob may not be changed by this 5595 ** interface. Use the [UPDATE] SQL command to change the size of a 5596 ** blob. 5597 ** 5598 ** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] 5599 ** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. 5600 ** 5601 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5602 ** and the built-in [zeroblob] SQL function can be used, if desired, 5603 ** to create an empty, zero-filled blob in which to read or write using 5604 ** this interface. 5605 ** 5606 ** To avoid a resource leak, every open [BLOB handle] should eventually 5607 ** be released by a call to [sqlite3_blob_close()]. 5608 */ 5609 SQLITE_API int sqlite3_blob_open( 5610 sqlite3*, 5611 const char *zDb, 5612 const char *zTable, 5613 const char *zColumn, 5614 sqlite3_int64 iRow, 5615 int flags, 5616 sqlite3_blob **ppBlob 5617 ); 5618 5619 /* 5620 ** CAPI3REF: Move a BLOB Handle to a New Row 5621 ** 5622 ** ^This function is used to move an existing blob handle so that it points 5623 ** to a different row of the same database table. ^The new row is identified 5624 ** by the rowid value passed as the second argument. Only the row can be 5625 ** changed. ^The database, table and column on which the blob handle is open 5626 ** remain the same. Moving an existing blob handle to a new row can be 5627 ** faster than closing the existing handle and opening a new one. 5628 ** 5629 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5630 ** it must exist and there must be either a blob or text value stored in 5631 ** the nominated column.)^ ^If the new row is not present in the table, or if 5632 ** it does not contain a blob or text value, or if another error occurs, an 5633 ** SQLite error code is returned and the blob handle is considered aborted. 5634 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5635 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5636 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5637 ** always returns zero. 5638 ** 5639 ** ^This function sets the database handle error code and message. 5640 */ 5641 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5642 5643 /* 5644 ** CAPI3REF: Close A BLOB Handle 5645 ** 5646 ** ^Closes an open [BLOB handle]. 5647 ** 5648 ** ^Closing a BLOB shall cause the current transaction to commit 5649 ** if there are no other BLOBs, no pending prepared statements, and the 5650 ** database connection is in [autocommit mode]. 5651 ** ^If any writes were made to the BLOB, they might be held in cache 5652 ** until the close operation if they will fit. 5653 ** 5654 ** ^(Closing the BLOB often forces the changes 5655 ** out to disk and so if any I/O errors occur, they will likely occur 5656 ** at the time when the BLOB is closed. Any errors that occur during 5657 ** closing are reported as a non-zero return value.)^ 5658 ** 5659 ** ^(The BLOB is closed unconditionally. Even if this routine returns 5660 ** an error code, the BLOB is still closed.)^ 5661 ** 5662 ** ^Calling this routine with a null pointer (such as would be returned 5663 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5664 */ 5665 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 5666 5667 /* 5668 ** CAPI3REF: Return The Size Of An Open BLOB 5669 ** 5670 ** ^Returns the size in bytes of the BLOB accessible via the 5671 ** successfully opened [BLOB handle] in its only argument. ^The 5672 ** incremental blob I/O routines can only read or overwriting existing 5673 ** blob content; they cannot change the size of a blob. 5674 ** 5675 ** This routine only works on a [BLOB handle] which has been created 5676 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5677 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5678 ** to this routine results in undefined and probably undesirable behavior. 5679 */ 5680 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 5681 5682 /* 5683 ** CAPI3REF: Read Data From A BLOB Incrementally 5684 ** 5685 ** ^(This function is used to read data from an open [BLOB handle] into a 5686 ** caller-supplied buffer. N bytes of data are copied into buffer Z 5687 ** from the open BLOB, starting at offset iOffset.)^ 5688 ** 5689 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5690 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5691 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 5692 ** ^The size of the blob (and hence the maximum value of N+iOffset) 5693 ** can be determined using the [sqlite3_blob_bytes()] interface. 5694 ** 5695 ** ^An attempt to read from an expired [BLOB handle] fails with an 5696 ** error code of [SQLITE_ABORT]. 5697 ** 5698 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5699 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5700 ** 5701 ** This routine only works on a [BLOB handle] which has been created 5702 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5703 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5704 ** to this routine results in undefined and probably undesirable behavior. 5705 ** 5706 ** See also: [sqlite3_blob_write()]. 5707 */ 5708 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5709 5710 /* 5711 ** CAPI3REF: Write Data Into A BLOB Incrementally 5712 ** 5713 ** ^This function is used to write data into an open [BLOB handle] from a 5714 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5715 ** into the open BLOB, starting at offset iOffset. 5716 ** 5717 ** ^If the [BLOB handle] passed as the first argument was not opened for 5718 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5719 ** this function returns [SQLITE_READONLY]. 5720 ** 5721 ** ^This function may only modify the contents of the BLOB; it is 5722 ** not possible to increase the size of a BLOB using this API. 5723 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 5724 ** [SQLITE_ERROR] is returned and no data is written. ^If N is 5725 ** less than zero [SQLITE_ERROR] is returned and no data is written. 5726 ** The size of the BLOB (and hence the maximum value of N+iOffset) 5727 ** can be determined using the [sqlite3_blob_bytes()] interface. 5728 ** 5729 ** ^An attempt to write to an expired [BLOB handle] fails with an 5730 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5731 ** before the [BLOB handle] expired are not rolled back by the 5732 ** expiration of the handle, though of course those changes might 5733 ** have been overwritten by the statement that expired the BLOB handle 5734 ** or by other independent statements. 5735 ** 5736 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5737 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 5738 ** 5739 ** This routine only works on a [BLOB handle] which has been created 5740 ** by a prior successful call to [sqlite3_blob_open()] and which has not 5741 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5742 ** to this routine results in undefined and probably undesirable behavior. 5743 ** 5744 ** See also: [sqlite3_blob_read()]. 5745 */ 5746 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5747 5748 /* 5749 ** CAPI3REF: Virtual File System Objects 5750 ** 5751 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5752 ** that SQLite uses to interact 5753 ** with the underlying operating system. Most SQLite builds come with a 5754 ** single default VFS that is appropriate for the host computer. 5755 ** New VFSes can be registered and existing VFSes can be unregistered. 5756 ** The following interfaces are provided. 5757 ** 5758 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5759 ** ^Names are case sensitive. 5760 ** ^Names are zero-terminated UTF-8 strings. 5761 ** ^If there is no match, a NULL pointer is returned. 5762 ** ^If zVfsName is NULL then the default VFS is returned. 5763 ** 5764 ** ^New VFSes are registered with sqlite3_vfs_register(). 5765 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5766 ** ^The same VFS can be registered multiple times without injury. 5767 ** ^To make an existing VFS into the default VFS, register it again 5768 ** with the makeDflt flag set. If two different VFSes with the 5769 ** same name are registered, the behavior is undefined. If a 5770 ** VFS is registered with a name that is NULL or an empty string, 5771 ** then the behavior is undefined. 5772 ** 5773 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5774 ** ^(If the default VFS is unregistered, another VFS is chosen as 5775 ** the default. The choice for the new VFS is arbitrary.)^ 5776 */ 5777 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5778 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5779 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5780 5781 /* 5782 ** CAPI3REF: Mutexes 5783 ** 5784 ** The SQLite core uses these routines for thread 5785 ** synchronization. Though they are intended for internal 5786 ** use by SQLite, code that links against SQLite is 5787 ** permitted to use any of these routines. 5788 ** 5789 ** The SQLite source code contains multiple implementations 5790 ** of these mutex routines. An appropriate implementation 5791 ** is selected automatically at compile-time. ^(The following 5792 ** implementations are available in the SQLite core: 5793 ** 5794 ** <ul> 5795 ** <li> SQLITE_MUTEX_PTHREADS 5796 ** <li> SQLITE_MUTEX_W32 5797 ** <li> SQLITE_MUTEX_NOOP 5798 ** </ul>)^ 5799 ** 5800 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5801 ** that does no real locking and is appropriate for use in 5802 ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5803 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5804 ** and Windows. 5805 ** 5806 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5807 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5808 ** implementation is included with the library. In this case the 5809 ** application must supply a custom mutex implementation using the 5810 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5811 ** before calling sqlite3_initialize() or any other public sqlite3_ 5812 ** function that calls sqlite3_initialize().)^ 5813 ** 5814 ** ^The sqlite3_mutex_alloc() routine allocates a new 5815 ** mutex and returns a pointer to it. ^If it returns NULL 5816 ** that means that a mutex could not be allocated. ^SQLite 5817 ** will unwind its stack and return an error. ^(The argument 5818 ** to sqlite3_mutex_alloc() is one of these integer constants: 5819 ** 5820 ** <ul> 5821 ** <li> SQLITE_MUTEX_FAST 5822 ** <li> SQLITE_MUTEX_RECURSIVE 5823 ** <li> SQLITE_MUTEX_STATIC_MASTER 5824 ** <li> SQLITE_MUTEX_STATIC_MEM 5825 ** <li> SQLITE_MUTEX_STATIC_MEM2 5826 ** <li> SQLITE_MUTEX_STATIC_PRNG 5827 ** <li> SQLITE_MUTEX_STATIC_LRU 5828 ** <li> SQLITE_MUTEX_STATIC_LRU2 5829 ** </ul>)^ 5830 ** 5831 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5832 ** cause sqlite3_mutex_alloc() to create 5833 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5834 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5835 ** The mutex implementation does not need to make a distinction 5836 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5837 ** not want to. ^SQLite will only request a recursive mutex in 5838 ** cases where it really needs one. ^If a faster non-recursive mutex 5839 ** implementation is available on the host platform, the mutex subsystem 5840 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 5841 ** 5842 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5843 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5844 ** a pointer to a static preexisting mutex. ^Six static mutexes are 5845 ** used by the current version of SQLite. Future versions of SQLite 5846 ** may add additional static mutexes. Static mutexes are for internal 5847 ** use by SQLite only. Applications that use SQLite mutexes should 5848 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 5849 ** SQLITE_MUTEX_RECURSIVE. 5850 ** 5851 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 5852 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 5853 ** returns a different mutex on every call. ^But for the static 5854 ** mutex types, the same mutex is returned on every call that has 5855 ** the same type number. 5856 ** 5857 ** ^The sqlite3_mutex_free() routine deallocates a previously 5858 ** allocated dynamic mutex. ^SQLite is careful to deallocate every 5859 ** dynamic mutex that it allocates. The dynamic mutexes must not be in 5860 ** use when they are deallocated. Attempting to deallocate a static 5861 ** mutex results in undefined behavior. ^SQLite never deallocates 5862 ** a static mutex. 5863 ** 5864 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 5865 ** to enter a mutex. ^If another thread is already within the mutex, 5866 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 5867 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 5868 ** upon successful entry. ^(Mutexes created using 5869 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 5870 ** In such cases the, 5871 ** mutex must be exited an equal number of times before another thread 5872 ** can enter.)^ ^(If the same thread tries to enter any other 5873 ** kind of mutex more than once, the behavior is undefined. 5874 ** SQLite will never exhibit 5875 ** such behavior in its own use of mutexes.)^ 5876 ** 5877 ** ^(Some systems (for example, Windows 95) do not support the operation 5878 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 5879 ** will always return SQLITE_BUSY. The SQLite core only ever uses 5880 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 5881 ** 5882 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 5883 ** previously entered by the same thread. ^(The behavior 5884 ** is undefined if the mutex is not currently entered by the 5885 ** calling thread or is not currently allocated. SQLite will 5886 ** never do either.)^ 5887 ** 5888 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 5889 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 5890 ** behave as no-ops. 5891 ** 5892 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 5893 */ 5894 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 5895 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 5896 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 5897 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 5898 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 5899 5900 /* 5901 ** CAPI3REF: Mutex Methods Object 5902 ** 5903 ** An instance of this structure defines the low-level routines 5904 ** used to allocate and use mutexes. 5905 ** 5906 ** Usually, the default mutex implementations provided by SQLite are 5907 ** sufficient, however the user has the option of substituting a custom 5908 ** implementation for specialized deployments or systems for which SQLite 5909 ** does not provide a suitable implementation. In this case, the user 5910 ** creates and populates an instance of this structure to pass 5911 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 5912 ** Additionally, an instance of this structure can be used as an 5913 ** output variable when querying the system for the current mutex 5914 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 5915 ** 5916 ** ^The xMutexInit method defined by this structure is invoked as 5917 ** part of system initialization by the sqlite3_initialize() function. 5918 ** ^The xMutexInit routine is called by SQLite exactly once for each 5919 ** effective call to [sqlite3_initialize()]. 5920 ** 5921 ** ^The xMutexEnd method defined by this structure is invoked as 5922 ** part of system shutdown by the sqlite3_shutdown() function. The 5923 ** implementation of this method is expected to release all outstanding 5924 ** resources obtained by the mutex methods implementation, especially 5925 ** those obtained by the xMutexInit method. ^The xMutexEnd() 5926 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 5927 ** 5928 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 5929 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 5930 ** xMutexNotheld) implement the following interfaces (respectively): 5931 ** 5932 ** <ul> 5933 ** <li> [sqlite3_mutex_alloc()] </li> 5934 ** <li> [sqlite3_mutex_free()] </li> 5935 ** <li> [sqlite3_mutex_enter()] </li> 5936 ** <li> [sqlite3_mutex_try()] </li> 5937 ** <li> [sqlite3_mutex_leave()] </li> 5938 ** <li> [sqlite3_mutex_held()] </li> 5939 ** <li> [sqlite3_mutex_notheld()] </li> 5940 ** </ul>)^ 5941 ** 5942 ** The only difference is that the public sqlite3_XXX functions enumerated 5943 ** above silently ignore any invocations that pass a NULL pointer instead 5944 ** of a valid mutex handle. The implementations of the methods defined 5945 ** by this structure are not required to handle this case, the results 5946 ** of passing a NULL pointer instead of a valid mutex handle are undefined 5947 ** (i.e. it is acceptable to provide an implementation that segfaults if 5948 ** it is passed a NULL pointer). 5949 ** 5950 ** The xMutexInit() method must be threadsafe. ^It must be harmless to 5951 ** invoke xMutexInit() multiple times within the same process and without 5952 ** intervening calls to xMutexEnd(). Second and subsequent calls to 5953 ** xMutexInit() must be no-ops. 5954 ** 5955 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 5956 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 5957 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 5958 ** memory allocation for a fast or recursive mutex. 5959 ** 5960 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 5961 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 5962 ** If xMutexInit fails in any way, it is expected to clean up after itself 5963 ** prior to returning. 5964 */ 5965 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 5966 struct sqlite3_mutex_methods { 5967 int (*xMutexInit)(void); 5968 int (*xMutexEnd)(void); 5969 sqlite3_mutex *(*xMutexAlloc)(int); 5970 void (*xMutexFree)(sqlite3_mutex *); 5971 void (*xMutexEnter)(sqlite3_mutex *); 5972 int (*xMutexTry)(sqlite3_mutex *); 5973 void (*xMutexLeave)(sqlite3_mutex *); 5974 int (*xMutexHeld)(sqlite3_mutex *); 5975 int (*xMutexNotheld)(sqlite3_mutex *); 5976 }; 5977 5978 /* 5979 ** CAPI3REF: Mutex Verification Routines 5980 ** 5981 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 5982 ** are intended for use inside assert() statements. ^The SQLite core 5983 ** never uses these routines except inside an assert() and applications 5984 ** are advised to follow the lead of the core. ^The SQLite core only 5985 ** provides implementations for these routines when it is compiled 5986 ** with the SQLITE_DEBUG flag. ^External mutex implementations 5987 ** are only required to provide these routines if SQLITE_DEBUG is 5988 ** defined and if NDEBUG is not defined. 5989 ** 5990 ** ^These routines should return true if the mutex in their argument 5991 ** is held or not held, respectively, by the calling thread. 5992 ** 5993 ** ^The implementation is not required to provide versions of these 5994 ** routines that actually work. If the implementation does not provide working 5995 ** versions of these routines, it should at least provide stubs that always 5996 ** return true so that one does not get spurious assertion failures. 5997 ** 5998 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 5999 ** the routine should return 1. This seems counter-intuitive since 6000 ** clearly the mutex cannot be held if it does not exist. But 6001 ** the reason the mutex does not exist is because the build is not 6002 ** using mutexes. And we do not want the assert() containing the 6003 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6004 ** the appropriate thing to do. ^The sqlite3_mutex_notheld() 6005 ** interface should also return 1 when given a NULL pointer. 6006 */ 6007 #ifndef NDEBUG 6008 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6009 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6010 #endif 6011 6012 /* 6013 ** CAPI3REF: Mutex Types 6014 ** 6015 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6016 ** which is one of these integer constants. 6017 ** 6018 ** The set of static mutexes may change from one SQLite release to the 6019 ** next. Applications that override the built-in mutex logic must be 6020 ** prepared to accommodate additional static mutexes. 6021 */ 6022 #define SQLITE_MUTEX_FAST 0 6023 #define SQLITE_MUTEX_RECURSIVE 1 6024 #define SQLITE_MUTEX_STATIC_MASTER 2 6025 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6026 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6027 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6028 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6029 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6030 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6031 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6032 6033 /* 6034 ** CAPI3REF: Retrieve the mutex for a database connection 6035 ** 6036 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6037 ** serializes access to the [database connection] given in the argument 6038 ** when the [threading mode] is Serialized. 6039 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6040 ** routine returns a NULL pointer. 6041 */ 6042 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6043 6044 /* 6045 ** CAPI3REF: Low-Level Control Of Database Files 6046 ** 6047 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6048 ** xFileControl method for the [sqlite3_io_methods] object associated 6049 ** with a particular database identified by the second argument. ^The 6050 ** name of the database is "main" for the main database or "temp" for the 6051 ** TEMP database, or the name that appears after the AS keyword for 6052 ** databases that are added using the [ATTACH] SQL command. 6053 ** ^A NULL pointer can be used in place of "main" to refer to the 6054 ** main database file. 6055 ** ^The third and fourth parameters to this routine 6056 ** are passed directly through to the second and third parameters of 6057 ** the xFileControl method. ^The return value of the xFileControl 6058 ** method becomes the return value of this routine. 6059 ** 6060 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6061 ** a pointer to the underlying [sqlite3_file] object to be written into 6062 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6063 ** case is a short-circuit path which does not actually invoke the 6064 ** underlying sqlite3_io_methods.xFileControl method. 6065 ** 6066 ** ^If the second parameter (zDbName) does not match the name of any 6067 ** open database file, then SQLITE_ERROR is returned. ^This error 6068 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6069 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6070 ** also return SQLITE_ERROR. There is no way to distinguish between 6071 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6072 ** xFileControl method. 6073 ** 6074 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6075 */ 6076 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6077 6078 /* 6079 ** CAPI3REF: Testing Interface 6080 ** 6081 ** ^The sqlite3_test_control() interface is used to read out internal 6082 ** state of SQLite and to inject faults into SQLite for testing 6083 ** purposes. ^The first parameter is an operation code that determines 6084 ** the number, meaning, and operation of all subsequent parameters. 6085 ** 6086 ** This interface is not for use by applications. It exists solely 6087 ** for verifying the correct operation of the SQLite library. Depending 6088 ** on how the SQLite library is compiled, this interface might not exist. 6089 ** 6090 ** The details of the operation codes, their meanings, the parameters 6091 ** they take, and what they do are all subject to change without notice. 6092 ** Unlike most of the SQLite API, this function is not guaranteed to 6093 ** operate consistently from one release to the next. 6094 */ 6095 SQLITE_API int sqlite3_test_control(int op, ...); 6096 6097 /* 6098 ** CAPI3REF: Testing Interface Operation Codes 6099 ** 6100 ** These constants are the valid operation code parameters used 6101 ** as the first argument to [sqlite3_test_control()]. 6102 ** 6103 ** These parameters and their meanings are subject to change 6104 ** without notice. These values are for testing purposes only. 6105 ** Applications should not use any of these parameters or the 6106 ** [sqlite3_test_control()] interface. 6107 */ 6108 #define SQLITE_TESTCTRL_FIRST 5 6109 #define SQLITE_TESTCTRL_PRNG_SAVE 5 6110 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 6111 #define SQLITE_TESTCTRL_PRNG_RESET 7 6112 #define SQLITE_TESTCTRL_BITVEC_TEST 8 6113 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 6114 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6115 #define SQLITE_TESTCTRL_PENDING_BYTE 11 6116 #define SQLITE_TESTCTRL_ASSERT 12 6117 #define SQLITE_TESTCTRL_ALWAYS 13 6118 #define SQLITE_TESTCTRL_RESERVE 14 6119 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6120 #define SQLITE_TESTCTRL_ISKEYWORD 16 6121 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6122 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6123 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6124 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6125 #define SQLITE_TESTCTRL_LAST 20 6126 6127 /* 6128 ** CAPI3REF: SQLite Runtime Status 6129 ** 6130 ** ^This interface is used to retrieve runtime status information 6131 ** about the performance of SQLite, and optionally to reset various 6132 ** highwater marks. ^The first argument is an integer code for 6133 ** the specific parameter to measure. ^(Recognized integer codes 6134 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 6135 ** ^The current value of the parameter is returned into *pCurrent. 6136 ** ^The highest recorded value is returned in *pHighwater. ^If the 6137 ** resetFlag is true, then the highest record value is reset after 6138 ** *pHighwater is written. ^(Some parameters do not record the highest 6139 ** value. For those parameters 6140 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6141 ** ^(Other parameters record only the highwater mark and not the current 6142 ** value. For these latter parameters nothing is written into *pCurrent.)^ 6143 ** 6144 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6145 ** non-zero [error code] on failure. 6146 ** 6147 ** This routine is threadsafe but is not atomic. This routine can be 6148 ** called while other threads are running the same or different SQLite 6149 ** interfaces. However the values returned in *pCurrent and 6150 ** *pHighwater reflect the status of SQLite at different points in time 6151 ** and it is possible that another thread might change the parameter 6152 ** in between the times when *pCurrent and *pHighwater are written. 6153 ** 6154 ** See also: [sqlite3_db_status()] 6155 */ 6156 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6157 6158 6159 /* 6160 ** CAPI3REF: Status Parameters 6161 ** KEYWORDS: {status parameters} 6162 ** 6163 ** These integer constants designate various run-time status parameters 6164 ** that can be returned by [sqlite3_status()]. 6165 ** 6166 ** <dl> 6167 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6168 ** <dd>This parameter is the current amount of memory checked out 6169 ** using [sqlite3_malloc()], either directly or indirectly. The 6170 ** figure includes calls made to [sqlite3_malloc()] by the application 6171 ** and internal memory usage by the SQLite library. Scratch memory 6172 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6173 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6174 ** this parameter. The amount returned is the sum of the allocation 6175 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6176 ** 6177 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6178 ** <dd>This parameter records the largest memory allocation request 6179 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6180 ** internal equivalents). Only the value returned in the 6181 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6182 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6183 ** 6184 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6185 ** <dd>This parameter records the number of separate memory allocations 6186 ** currently checked out.</dd>)^ 6187 ** 6188 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6189 ** <dd>This parameter returns the number of pages used out of the 6190 ** [pagecache memory allocator] that was configured using 6191 ** [SQLITE_CONFIG_PAGECACHE]. The 6192 ** value returned is in pages, not in bytes.</dd>)^ 6193 ** 6194 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6195 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6196 ** <dd>This parameter returns the number of bytes of page cache 6197 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6198 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 6199 ** returned value includes allocations that overflowed because they 6200 ** where too large (they were larger than the "sz" parameter to 6201 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6202 ** no space was left in the page cache.</dd>)^ 6203 ** 6204 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6205 ** <dd>This parameter records the largest memory allocation request 6206 ** handed to [pagecache memory allocator]. Only the value returned in the 6207 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6208 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6209 ** 6210 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6211 ** <dd>This parameter returns the number of allocations used out of the 6212 ** [scratch memory allocator] configured using 6213 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6214 ** in bytes. Since a single thread may only have one scratch allocation 6215 ** outstanding at time, this parameter also reports the number of threads 6216 ** using scratch memory at the same time.</dd>)^ 6217 ** 6218 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6219 ** <dd>This parameter returns the number of bytes of scratch memory 6220 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6221 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6222 ** returned include overflows because the requested allocation was too 6223 ** larger (that is, because the requested allocation was larger than the 6224 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6225 ** slots were available. 6226 ** </dd>)^ 6227 ** 6228 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6229 ** <dd>This parameter records the largest memory allocation request 6230 ** handed to [scratch memory allocator]. Only the value returned in the 6231 ** *pHighwater parameter to [sqlite3_status()] is of interest. 6232 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 6233 ** 6234 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6235 ** <dd>This parameter records the deepest parser stack. It is only 6236 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6237 ** </dl> 6238 ** 6239 ** New status parameters may be added from time to time. 6240 */ 6241 #define SQLITE_STATUS_MEMORY_USED 0 6242 #define SQLITE_STATUS_PAGECACHE_USED 1 6243 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6244 #define SQLITE_STATUS_SCRATCH_USED 3 6245 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6246 #define SQLITE_STATUS_MALLOC_SIZE 5 6247 #define SQLITE_STATUS_PARSER_STACK 6 6248 #define SQLITE_STATUS_PAGECACHE_SIZE 7 6249 #define SQLITE_STATUS_SCRATCH_SIZE 8 6250 #define SQLITE_STATUS_MALLOC_COUNT 9 6251 6252 /* 6253 ** CAPI3REF: Database Connection Status 6254 ** 6255 ** ^This interface is used to retrieve runtime status information 6256 ** about a single [database connection]. ^The first argument is the 6257 ** database connection object to be interrogated. ^The second argument 6258 ** is an integer constant, taken from the set of 6259 ** [SQLITE_DBSTATUS options], that 6260 ** determines the parameter to interrogate. The set of 6261 ** [SQLITE_DBSTATUS options] is likely 6262 ** to grow in future releases of SQLite. 6263 ** 6264 ** ^The current value of the requested parameter is written into *pCur 6265 ** and the highest instantaneous value is written into *pHiwtr. ^If 6266 ** the resetFlg is true, then the highest instantaneous value is 6267 ** reset back down to the current value. 6268 ** 6269 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6270 ** non-zero [error code] on failure. 6271 ** 6272 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6273 */ 6274 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6275 6276 /* 6277 ** CAPI3REF: Status Parameters for database connections 6278 ** KEYWORDS: {SQLITE_DBSTATUS options} 6279 ** 6280 ** These constants are the available integer "verbs" that can be passed as 6281 ** the second argument to the [sqlite3_db_status()] interface. 6282 ** 6283 ** New verbs may be added in future releases of SQLite. Existing verbs 6284 ** might be discontinued. Applications should check the return code from 6285 ** [sqlite3_db_status()] to make sure that the call worked. 6286 ** The [sqlite3_db_status()] interface will return a non-zero error code 6287 ** if a discontinued or unsupported verb is invoked. 6288 ** 6289 ** <dl> 6290 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6291 ** <dd>This parameter returns the number of lookaside memory slots currently 6292 ** checked out.</dd>)^ 6293 ** 6294 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6295 ** <dd>This parameter returns the number malloc attempts that were 6296 ** satisfied using lookaside memory. Only the high-water value is meaningful; 6297 ** the current value is always zero.)^ 6298 ** 6299 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6300 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6301 ** <dd>This parameter returns the number malloc attempts that might have 6302 ** been satisfied using lookaside memory but failed due to the amount of 6303 ** memory requested being larger than the lookaside slot size. 6304 ** Only the high-water value is meaningful; 6305 ** the current value is always zero.)^ 6306 ** 6307 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6308 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6309 ** <dd>This parameter returns the number malloc attempts that might have 6310 ** been satisfied using lookaside memory but failed due to all lookaside 6311 ** memory already being in use. 6312 ** Only the high-water value is meaningful; 6313 ** the current value is always zero.)^ 6314 ** 6315 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6316 ** <dd>This parameter returns the approximate number of of bytes of heap 6317 ** memory used by all pager caches associated with the database connection.)^ 6318 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6319 ** 6320 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6321 ** <dd>This parameter returns the approximate number of of bytes of heap 6322 ** memory used to store the schema for all databases associated 6323 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6324 ** ^The full amount of memory used by the schemas is reported, even if the 6325 ** schema memory is shared with other database connections due to 6326 ** [shared cache mode] being enabled. 6327 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6328 ** 6329 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6330 ** <dd>This parameter returns the approximate number of of bytes of heap 6331 ** and lookaside memory used by all prepared statements associated with 6332 ** the database connection.)^ 6333 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6334 ** </dd> 6335 ** 6336 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6337 ** <dd>This parameter returns the number of pager cache hits that have 6338 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6339 ** is always 0. 6340 ** </dd> 6341 ** 6342 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6343 ** <dd>This parameter returns the number of pager cache misses that have 6344 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6345 ** is always 0. 6346 ** </dd> 6347 ** 6348 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6349 ** <dd>This parameter returns the number of dirty cache entries that have 6350 ** been written to disk. Specifically, the number of pages written to the 6351 ** wal file in wal mode databases, or the number of pages written to the 6352 ** database file in rollback mode databases. Any pages written as part of 6353 ** transaction rollback or database recovery operations are not included. 6354 ** If an IO or other error occurs while writing a page to disk, the effect 6355 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6356 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6357 ** </dd> 6358 ** 6359 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6360 ** <dd>This parameter returns zero for the current value if and only if 6361 ** all foreign key constraints (deferred or immediate) have been 6362 ** resolved.)^ ^The highwater mark is always 0. 6363 ** </dd> 6364 ** </dl> 6365 */ 6366 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6367 #define SQLITE_DBSTATUS_CACHE_USED 1 6368 #define SQLITE_DBSTATUS_SCHEMA_USED 2 6369 #define SQLITE_DBSTATUS_STMT_USED 3 6370 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6371 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6372 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6373 #define SQLITE_DBSTATUS_CACHE_HIT 7 6374 #define SQLITE_DBSTATUS_CACHE_MISS 8 6375 #define SQLITE_DBSTATUS_CACHE_WRITE 9 6376 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 6377 #define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6378 6379 6380 /* 6381 ** CAPI3REF: Prepared Statement Status 6382 ** 6383 ** ^(Each prepared statement maintains various 6384 ** [SQLITE_STMTSTATUS counters] that measure the number 6385 ** of times it has performed specific operations.)^ These counters can 6386 ** be used to monitor the performance characteristics of the prepared 6387 ** statements. For example, if the number of table steps greatly exceeds 6388 ** the number of table searches or result rows, that would tend to indicate 6389 ** that the prepared statement is using a full table scan rather than 6390 ** an index. 6391 ** 6392 ** ^(This interface is used to retrieve and reset counter values from 6393 ** a [prepared statement]. The first argument is the prepared statement 6394 ** object to be interrogated. The second argument 6395 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6396 ** to be interrogated.)^ 6397 ** ^The current value of the requested counter is returned. 6398 ** ^If the resetFlg is true, then the counter is reset to zero after this 6399 ** interface call returns. 6400 ** 6401 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6402 */ 6403 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6404 6405 /* 6406 ** CAPI3REF: Status Parameters for prepared statements 6407 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6408 ** 6409 ** These preprocessor macros define integer codes that name counter 6410 ** values associated with the [sqlite3_stmt_status()] interface. 6411 ** The meanings of the various counters are as follows: 6412 ** 6413 ** <dl> 6414 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6415 ** <dd>^This is the number of times that SQLite has stepped forward in 6416 ** a table as part of a full table scan. Large numbers for this counter 6417 ** may indicate opportunities for performance improvement through 6418 ** careful use of indices.</dd> 6419 ** 6420 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6421 ** <dd>^This is the number of sort operations that have occurred. 6422 ** A non-zero value in this counter may indicate an opportunity to 6423 ** improvement performance through careful use of indices.</dd> 6424 ** 6425 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6426 ** <dd>^This is the number of rows inserted into transient indices that 6427 ** were created automatically in order to help joins run faster. 6428 ** A non-zero value in this counter may indicate an opportunity to 6429 ** improvement performance by adding permanent indices that do not 6430 ** need to be reinitialized each time the statement is run.</dd> 6431 ** 6432 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6433 ** <dd>^This is the number of virtual machine operations executed 6434 ** by the prepared statement if that number is less than or equal 6435 ** to 2147483647. The number of virtual machine operations can be 6436 ** used as a proxy for the total work done by the prepared statement. 6437 ** If the number of virtual machine operations exceeds 2147483647 6438 ** then the value returned by this statement status code is undefined. 6439 ** </dd> 6440 ** </dl> 6441 */ 6442 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6443 #define SQLITE_STMTSTATUS_SORT 2 6444 #define SQLITE_STMTSTATUS_AUTOINDEX 3 6445 #define SQLITE_STMTSTATUS_VM_STEP 4 6446 6447 /* 6448 ** CAPI3REF: Custom Page Cache Object 6449 ** 6450 ** The sqlite3_pcache type is opaque. It is implemented by 6451 ** the pluggable module. The SQLite core has no knowledge of 6452 ** its size or internal structure and never deals with the 6453 ** sqlite3_pcache object except by holding and passing pointers 6454 ** to the object. 6455 ** 6456 ** See [sqlite3_pcache_methods2] for additional information. 6457 */ 6458 typedef struct sqlite3_pcache sqlite3_pcache; 6459 6460 /* 6461 ** CAPI3REF: Custom Page Cache Object 6462 ** 6463 ** The sqlite3_pcache_page object represents a single page in the 6464 ** page cache. The page cache will allocate instances of this 6465 ** object. Various methods of the page cache use pointers to instances 6466 ** of this object as parameters or as their return value. 6467 ** 6468 ** See [sqlite3_pcache_methods2] for additional information. 6469 */ 6470 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6471 struct sqlite3_pcache_page { 6472 void *pBuf; /* The content of the page */ 6473 void *pExtra; /* Extra information associated with the page */ 6474 }; 6475 6476 /* 6477 ** CAPI3REF: Application Defined Page Cache. 6478 ** KEYWORDS: {page cache} 6479 ** 6480 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6481 ** register an alternative page cache implementation by passing in an 6482 ** instance of the sqlite3_pcache_methods2 structure.)^ 6483 ** In many applications, most of the heap memory allocated by 6484 ** SQLite is used for the page cache. 6485 ** By implementing a 6486 ** custom page cache using this API, an application can better control 6487 ** the amount of memory consumed by SQLite, the way in which 6488 ** that memory is allocated and released, and the policies used to 6489 ** determine exactly which parts of a database file are cached and for 6490 ** how long. 6491 ** 6492 ** The alternative page cache mechanism is an 6493 ** extreme measure that is only needed by the most demanding applications. 6494 ** The built-in page cache is recommended for most uses. 6495 ** 6496 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6497 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6498 ** the application may discard the parameter after the call to 6499 ** [sqlite3_config()] returns.)^ 6500 ** 6501 ** [[the xInit() page cache method]] 6502 ** ^(The xInit() method is called once for each effective 6503 ** call to [sqlite3_initialize()])^ 6504 ** (usually only once during the lifetime of the process). ^(The xInit() 6505 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6506 ** The intent of the xInit() method is to set up global data structures 6507 ** required by the custom page cache implementation. 6508 ** ^(If the xInit() method is NULL, then the 6509 ** built-in default page cache is used instead of the application defined 6510 ** page cache.)^ 6511 ** 6512 ** [[the xShutdown() page cache method]] 6513 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6514 ** It can be used to clean up 6515 ** any outstanding resources before process shutdown, if required. 6516 ** ^The xShutdown() method may be NULL. 6517 ** 6518 ** ^SQLite automatically serializes calls to the xInit method, 6519 ** so the xInit method need not be threadsafe. ^The 6520 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 6521 ** not need to be threadsafe either. All other methods must be threadsafe 6522 ** in multithreaded applications. 6523 ** 6524 ** ^SQLite will never invoke xInit() more than once without an intervening 6525 ** call to xShutdown(). 6526 ** 6527 ** [[the xCreate() page cache methods]] 6528 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 6529 ** SQLite will typically create one cache instance for each open database file, 6530 ** though this is not guaranteed. ^The 6531 ** first parameter, szPage, is the size in bytes of the pages that must 6532 ** be allocated by the cache. ^szPage will always a power of two. ^The 6533 ** second parameter szExtra is a number of bytes of extra storage 6534 ** associated with each page cache entry. ^The szExtra parameter will 6535 ** a number less than 250. SQLite will use the 6536 ** extra szExtra bytes on each page to store metadata about the underlying 6537 ** database page on disk. The value passed into szExtra depends 6538 ** on the SQLite version, the target platform, and how SQLite was compiled. 6539 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6540 ** created will be used to cache database pages of a file stored on disk, or 6541 ** false if it is used for an in-memory database. The cache implementation 6542 ** does not have to do anything special based with the value of bPurgeable; 6543 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6544 ** never invoke xUnpin() except to deliberately delete a page. 6545 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6546 ** false will always have the "discard" flag set to true. 6547 ** ^Hence, a cache created with bPurgeable false will 6548 ** never contain any unpinned pages. 6549 ** 6550 ** [[the xCachesize() page cache method]] 6551 ** ^(The xCachesize() method may be called at any time by SQLite to set the 6552 ** suggested maximum cache-size (number of pages stored by) the cache 6553 ** instance passed as the first argument. This is the value configured using 6554 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6555 ** parameter, the implementation is not required to do anything with this 6556 ** value; it is advisory only. 6557 ** 6558 ** [[the xPagecount() page cache methods]] 6559 ** The xPagecount() method must return the number of pages currently 6560 ** stored in the cache, both pinned and unpinned. 6561 ** 6562 ** [[the xFetch() page cache methods]] 6563 ** The xFetch() method locates a page in the cache and returns a pointer to 6564 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6565 ** The pBuf element of the returned sqlite3_pcache_page object will be a 6566 ** pointer to a buffer of szPage bytes used to store the content of a 6567 ** single database page. The pExtra element of sqlite3_pcache_page will be 6568 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 6569 ** for each entry in the page cache. 6570 ** 6571 ** The page to be fetched is determined by the key. ^The minimum key value 6572 ** is 1. After it has been retrieved using xFetch, the page is considered 6573 ** to be "pinned". 6574 ** 6575 ** If the requested page is already in the page cache, then the page cache 6576 ** implementation must return a pointer to the page buffer with its content 6577 ** intact. If the requested page is not already in the cache, then the 6578 ** cache implementation should use the value of the createFlag 6579 ** parameter to help it determined what action to take: 6580 ** 6581 ** <table border=1 width=85% align=center> 6582 ** <tr><th> createFlag <th> Behavior when page is not already in cache 6583 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6584 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6585 ** Otherwise return NULL. 6586 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6587 ** NULL if allocating a new page is effectively impossible. 6588 ** </table> 6589 ** 6590 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6591 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 6592 ** failed.)^ In between the to xFetch() calls, SQLite may 6593 ** attempt to unpin one or more cache pages by spilling the content of 6594 ** pinned pages to disk and synching the operating system disk cache. 6595 ** 6596 ** [[the xUnpin() page cache method]] 6597 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6598 ** as its second argument. If the third parameter, discard, is non-zero, 6599 ** then the page must be evicted from the cache. 6600 ** ^If the discard parameter is 6601 ** zero, then the page may be discarded or retained at the discretion of 6602 ** page cache implementation. ^The page cache implementation 6603 ** may choose to evict unpinned pages at any time. 6604 ** 6605 ** The cache must not perform any reference counting. A single 6606 ** call to xUnpin() unpins the page regardless of the number of prior calls 6607 ** to xFetch(). 6608 ** 6609 ** [[the xRekey() page cache methods]] 6610 ** The xRekey() method is used to change the key value associated with the 6611 ** page passed as the second argument. If the cache 6612 ** previously contains an entry associated with newKey, it must be 6613 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6614 ** to be pinned. 6615 ** 6616 ** When SQLite calls the xTruncate() method, the cache must discard all 6617 ** existing cache entries with page numbers (keys) greater than or equal 6618 ** to the value of the iLimit parameter passed to xTruncate(). If any 6619 ** of these pages are pinned, they are implicitly unpinned, meaning that 6620 ** they can be safely discarded. 6621 ** 6622 ** [[the xDestroy() page cache method]] 6623 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6624 ** All resources associated with the specified cache should be freed. ^After 6625 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6626 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6627 ** functions. 6628 ** 6629 ** [[the xShrink() page cache method]] 6630 ** ^SQLite invokes the xShrink() method when it wants the page cache to 6631 ** free up as much of heap memory as possible. The page cache implementation 6632 ** is not obligated to free any memory, but well-behaved implementations should 6633 ** do their best. 6634 */ 6635 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6636 struct sqlite3_pcache_methods2 { 6637 int iVersion; 6638 void *pArg; 6639 int (*xInit)(void*); 6640 void (*xShutdown)(void*); 6641 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6642 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6643 int (*xPagecount)(sqlite3_pcache*); 6644 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6645 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6646 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6647 unsigned oldKey, unsigned newKey); 6648 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6649 void (*xDestroy)(sqlite3_pcache*); 6650 void (*xShrink)(sqlite3_pcache*); 6651 }; 6652 6653 /* 6654 ** This is the obsolete pcache_methods object that has now been replaced 6655 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6656 ** retained in the header file for backwards compatibility only. 6657 */ 6658 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6659 struct sqlite3_pcache_methods { 6660 void *pArg; 6661 int (*xInit)(void*); 6662 void (*xShutdown)(void*); 6663 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6664 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6665 int (*xPagecount)(sqlite3_pcache*); 6666 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6667 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6668 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6669 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6670 void (*xDestroy)(sqlite3_pcache*); 6671 }; 6672 6673 6674 /* 6675 ** CAPI3REF: Online Backup Object 6676 ** 6677 ** The sqlite3_backup object records state information about an ongoing 6678 ** online backup operation. ^The sqlite3_backup object is created by 6679 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 6680 ** [sqlite3_backup_finish()]. 6681 ** 6682 ** See Also: [Using the SQLite Online Backup API] 6683 */ 6684 typedef struct sqlite3_backup sqlite3_backup; 6685 6686 /* 6687 ** CAPI3REF: Online Backup API. 6688 ** 6689 ** The backup API copies the content of one database into another. 6690 ** It is useful either for creating backups of databases or 6691 ** for copying in-memory databases to or from persistent files. 6692 ** 6693 ** See Also: [Using the SQLite Online Backup API] 6694 ** 6695 ** ^SQLite holds a write transaction open on the destination database file 6696 ** for the duration of the backup operation. 6697 ** ^The source database is read-locked only while it is being read; 6698 ** it is not locked continuously for the entire backup operation. 6699 ** ^Thus, the backup may be performed on a live source database without 6700 ** preventing other database connections from 6701 ** reading or writing to the source database while the backup is underway. 6702 ** 6703 ** ^(To perform a backup operation: 6704 ** <ol> 6705 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6706 ** backup, 6707 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6708 ** the data between the two databases, and finally 6709 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6710 ** associated with the backup operation. 6711 ** </ol>)^ 6712 ** There should be exactly one call to sqlite3_backup_finish() for each 6713 ** successful call to sqlite3_backup_init(). 6714 ** 6715 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6716 ** 6717 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6718 ** [database connection] associated with the destination database 6719 ** and the database name, respectively. 6720 ** ^The database name is "main" for the main database, "temp" for the 6721 ** temporary database, or the name specified after the AS keyword in 6722 ** an [ATTACH] statement for an attached database. 6723 ** ^The S and M arguments passed to 6724 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6725 ** and database name of the source database, respectively. 6726 ** ^The source and destination [database connections] (parameters S and D) 6727 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6728 ** an error. 6729 ** 6730 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6731 ** returned and an error code and error message are stored in the 6732 ** destination [database connection] D. 6733 ** ^The error code and message for the failed call to sqlite3_backup_init() 6734 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6735 ** [sqlite3_errmsg16()] functions. 6736 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 6737 ** [sqlite3_backup] object. 6738 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6739 ** sqlite3_backup_finish() functions to perform the specified backup 6740 ** operation. 6741 ** 6742 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6743 ** 6744 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6745 ** the source and destination databases specified by [sqlite3_backup] object B. 6746 ** ^If N is negative, all remaining source pages are copied. 6747 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6748 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 6749 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6750 ** from source to destination, then it returns [SQLITE_DONE]. 6751 ** ^If an error occurs while running sqlite3_backup_step(B,N), 6752 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 6753 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6754 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6755 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6756 ** 6757 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6758 ** <ol> 6759 ** <li> the destination database was opened read-only, or 6760 ** <li> the destination database is using write-ahead-log journaling 6761 ** and the destination and source page sizes differ, or 6762 ** <li> the destination database is an in-memory database and the 6763 ** destination and source page sizes differ. 6764 ** </ol>)^ 6765 ** 6766 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6767 ** the [sqlite3_busy_handler | busy-handler function] 6768 ** is invoked (if one is specified). ^If the 6769 ** busy-handler returns non-zero before the lock is available, then 6770 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6771 ** sqlite3_backup_step() can be retried later. ^If the source 6772 ** [database connection] 6773 ** is being used to write to the source database when sqlite3_backup_step() 6774 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6775 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 6776 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6777 ** [SQLITE_READONLY] is returned, then 6778 ** there is no point in retrying the call to sqlite3_backup_step(). These 6779 ** errors are considered fatal.)^ The application must accept 6780 ** that the backup operation has failed and pass the backup operation handle 6781 ** to the sqlite3_backup_finish() to release associated resources. 6782 ** 6783 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6784 ** on the destination file. ^The exclusive lock is not released until either 6785 ** sqlite3_backup_finish() is called or the backup operation is complete 6786 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6787 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 6788 ** lasts for the duration of the sqlite3_backup_step() call. 6789 ** ^Because the source database is not locked between calls to 6790 ** sqlite3_backup_step(), the source database may be modified mid-way 6791 ** through the backup process. ^If the source database is modified by an 6792 ** external process or via a database connection other than the one being 6793 ** used by the backup operation, then the backup will be automatically 6794 ** restarted by the next call to sqlite3_backup_step(). ^If the source 6795 ** database is modified by the using the same database connection as is used 6796 ** by the backup operation, then the backup database is automatically 6797 ** updated at the same time. 6798 ** 6799 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6800 ** 6801 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6802 ** application wishes to abandon the backup operation, the application 6803 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6804 ** ^The sqlite3_backup_finish() interfaces releases all 6805 ** resources associated with the [sqlite3_backup] object. 6806 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6807 ** active write-transaction on the destination database is rolled back. 6808 ** The [sqlite3_backup] object is invalid 6809 ** and may not be used following a call to sqlite3_backup_finish(). 6810 ** 6811 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6812 ** sqlite3_backup_step() errors occurred, regardless or whether or not 6813 ** sqlite3_backup_step() completed. 6814 ** ^If an out-of-memory condition or IO error occurred during any prior 6815 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6816 ** sqlite3_backup_finish() returns the corresponding [error code]. 6817 ** 6818 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6819 ** is not a permanent error and does not affect the return value of 6820 ** sqlite3_backup_finish(). 6821 ** 6822 ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6823 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6824 ** 6825 ** ^Each call to sqlite3_backup_step() sets two values inside 6826 ** the [sqlite3_backup] object: the number of pages still to be backed 6827 ** up and the total number of pages in the source database file. 6828 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6829 ** retrieve these two values, respectively. 6830 ** 6831 ** ^The values returned by these functions are only updated by 6832 ** sqlite3_backup_step(). ^If the source database is modified during a backup 6833 ** operation, then the values are not updated to account for any extra 6834 ** pages that need to be updated or the size of the source database file 6835 ** changing. 6836 ** 6837 ** <b>Concurrent Usage of Database Handles</b> 6838 ** 6839 ** ^The source [database connection] may be used by the application for other 6840 ** purposes while a backup operation is underway or being initialized. 6841 ** ^If SQLite is compiled and configured to support threadsafe database 6842 ** connections, then the source database connection may be used concurrently 6843 ** from within other threads. 6844 ** 6845 ** However, the application must guarantee that the destination 6846 ** [database connection] is not passed to any other API (by any thread) after 6847 ** sqlite3_backup_init() is called and before the corresponding call to 6848 ** sqlite3_backup_finish(). SQLite does not currently check to see 6849 ** if the application incorrectly accesses the destination [database connection] 6850 ** and so no error code is reported, but the operations may malfunction 6851 ** nevertheless. Use of the destination database connection while a 6852 ** backup is in progress might also also cause a mutex deadlock. 6853 ** 6854 ** If running in [shared cache mode], the application must 6855 ** guarantee that the shared cache used by the destination database 6856 ** is not accessed while the backup is running. In practice this means 6857 ** that the application must guarantee that the disk file being 6858 ** backed up to is not accessed by any connection within the process, 6859 ** not just the specific connection that was passed to sqlite3_backup_init(). 6860 ** 6861 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 6862 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 6863 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 6864 ** APIs are not strictly speaking threadsafe. If they are invoked at the 6865 ** same time as another thread is invoking sqlite3_backup_step() it is 6866 ** possible that they return invalid values. 6867 */ 6868 SQLITE_API sqlite3_backup *sqlite3_backup_init( 6869 sqlite3 *pDest, /* Destination database handle */ 6870 const char *zDestName, /* Destination database name */ 6871 sqlite3 *pSource, /* Source database handle */ 6872 const char *zSourceName /* Source database name */ 6873 ); 6874 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 6875 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 6876 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 6877 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 6878 6879 /* 6880 ** CAPI3REF: Unlock Notification 6881 ** 6882 ** ^When running in shared-cache mode, a database operation may fail with 6883 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 6884 ** individual tables within the shared-cache cannot be obtained. See 6885 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 6886 ** ^This API may be used to register a callback that SQLite will invoke 6887 ** when the connection currently holding the required lock relinquishes it. 6888 ** ^This API is only available if the library was compiled with the 6889 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 6890 ** 6891 ** See Also: [Using the SQLite Unlock Notification Feature]. 6892 ** 6893 ** ^Shared-cache locks are released when a database connection concludes 6894 ** its current transaction, either by committing it or rolling it back. 6895 ** 6896 ** ^When a connection (known as the blocked connection) fails to obtain a 6897 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 6898 ** identity of the database connection (the blocking connection) that 6899 ** has locked the required resource is stored internally. ^After an 6900 ** application receives an SQLITE_LOCKED error, it may call the 6901 ** sqlite3_unlock_notify() method with the blocked connection handle as 6902 ** the first argument to register for a callback that will be invoked 6903 ** when the blocking connections current transaction is concluded. ^The 6904 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 6905 ** call that concludes the blocking connections transaction. 6906 ** 6907 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 6908 ** there is a chance that the blocking connection will have already 6909 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 6910 ** If this happens, then the specified callback is invoked immediately, 6911 ** from within the call to sqlite3_unlock_notify().)^ 6912 ** 6913 ** ^If the blocked connection is attempting to obtain a write-lock on a 6914 ** shared-cache table, and more than one other connection currently holds 6915 ** a read-lock on the same table, then SQLite arbitrarily selects one of 6916 ** the other connections to use as the blocking connection. 6917 ** 6918 ** ^(There may be at most one unlock-notify callback registered by a 6919 ** blocked connection. If sqlite3_unlock_notify() is called when the 6920 ** blocked connection already has a registered unlock-notify callback, 6921 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 6922 ** called with a NULL pointer as its second argument, then any existing 6923 ** unlock-notify callback is canceled. ^The blocked connections 6924 ** unlock-notify callback may also be canceled by closing the blocked 6925 ** connection using [sqlite3_close()]. 6926 ** 6927 ** The unlock-notify callback is not reentrant. If an application invokes 6928 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 6929 ** crash or deadlock may be the result. 6930 ** 6931 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 6932 ** returns SQLITE_OK. 6933 ** 6934 ** <b>Callback Invocation Details</b> 6935 ** 6936 ** When an unlock-notify callback is registered, the application provides a 6937 ** single void* pointer that is passed to the callback when it is invoked. 6938 ** However, the signature of the callback function allows SQLite to pass 6939 ** it an array of void* context pointers. The first argument passed to 6940 ** an unlock-notify callback is a pointer to an array of void* pointers, 6941 ** and the second is the number of entries in the array. 6942 ** 6943 ** When a blocking connections transaction is concluded, there may be 6944 ** more than one blocked connection that has registered for an unlock-notify 6945 ** callback. ^If two or more such blocked connections have specified the 6946 ** same callback function, then instead of invoking the callback function 6947 ** multiple times, it is invoked once with the set of void* context pointers 6948 ** specified by the blocked connections bundled together into an array. 6949 ** This gives the application an opportunity to prioritize any actions 6950 ** related to the set of unblocked database connections. 6951 ** 6952 ** <b>Deadlock Detection</b> 6953 ** 6954 ** Assuming that after registering for an unlock-notify callback a 6955 ** database waits for the callback to be issued before taking any further 6956 ** action (a reasonable assumption), then using this API may cause the 6957 ** application to deadlock. For example, if connection X is waiting for 6958 ** connection Y's transaction to be concluded, and similarly connection 6959 ** Y is waiting on connection X's transaction, then neither connection 6960 ** will proceed and the system may remain deadlocked indefinitely. 6961 ** 6962 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 6963 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 6964 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 6965 ** unlock-notify callback is registered. The system is said to be in 6966 ** a deadlocked state if connection A has registered for an unlock-notify 6967 ** callback on the conclusion of connection B's transaction, and connection 6968 ** B has itself registered for an unlock-notify callback when connection 6969 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 6970 ** the system is also considered to be deadlocked if connection B has 6971 ** registered for an unlock-notify callback on the conclusion of connection 6972 ** C's transaction, where connection C is waiting on connection A. ^Any 6973 ** number of levels of indirection are allowed. 6974 ** 6975 ** <b>The "DROP TABLE" Exception</b> 6976 ** 6977 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 6978 ** always appropriate to call sqlite3_unlock_notify(). There is however, 6979 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 6980 ** SQLite checks if there are any currently executing SELECT statements 6981 ** that belong to the same connection. If there are, SQLITE_LOCKED is 6982 ** returned. In this case there is no "blocking connection", so invoking 6983 ** sqlite3_unlock_notify() results in the unlock-notify callback being 6984 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 6985 ** or "DROP INDEX" query, an infinite loop might be the result. 6986 ** 6987 ** One way around this problem is to check the extended error code returned 6988 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 6989 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 6990 ** the special "DROP TABLE/INDEX" case, the extended error code is just 6991 ** SQLITE_LOCKED.)^ 6992 */ 6993 SQLITE_API int sqlite3_unlock_notify( 6994 sqlite3 *pBlocked, /* Waiting connection */ 6995 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 6996 void *pNotifyArg /* Argument to pass to xNotify */ 6997 ); 6998 6999 7000 /* 7001 ** CAPI3REF: String Comparison 7002 ** 7003 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7004 ** and extensions to compare the contents of two buffers containing UTF-8 7005 ** strings in a case-independent fashion, using the same definition of "case 7006 ** independence" that SQLite uses internally when comparing identifiers. 7007 */ 7008 SQLITE_API int sqlite3_stricmp(const char *, const char *); 7009 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7010 7011 /* 7012 ** CAPI3REF: String Globbing 7013 * 7014 ** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7015 ** the glob pattern P, and it returns non-zero if string X does not match 7016 ** the glob pattern P. ^The definition of glob pattern matching used in 7017 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7018 ** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7019 ** sensitive. 7020 ** 7021 ** Note that this routine returns zero on a match and non-zero if the strings 7022 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7023 */ 7024 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7025 7026 /* 7027 ** CAPI3REF: Error Logging Interface 7028 ** 7029 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7030 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7031 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7032 ** used with [sqlite3_snprintf()] to generate the final output string. 7033 ** 7034 ** The sqlite3_log() interface is intended for use by extensions such as 7035 ** virtual tables, collating functions, and SQL functions. While there is 7036 ** nothing to prevent an application from calling sqlite3_log(), doing so 7037 ** is considered bad form. 7038 ** 7039 ** The zFormat string must not be NULL. 7040 ** 7041 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7042 ** will not use dynamically allocated memory. The log message is stored in 7043 ** a fixed-length buffer on the stack. If the log message is longer than 7044 ** a few hundred characters, it will be truncated to the length of the 7045 ** buffer. 7046 */ 7047 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7048 7049 /* 7050 ** CAPI3REF: Write-Ahead Log Commit Hook 7051 ** 7052 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 7053 ** will be invoked each time a database connection commits data to a 7054 ** [write-ahead log] (i.e. whenever a transaction is committed in 7055 ** [journal_mode | journal_mode=WAL mode]). 7056 ** 7057 ** ^The callback is invoked by SQLite after the commit has taken place and 7058 ** the associated write-lock on the database released, so the implementation 7059 ** may read, write or [checkpoint] the database as required. 7060 ** 7061 ** ^The first parameter passed to the callback function when it is invoked 7062 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 7063 ** registering the callback. ^The second is a copy of the database handle. 7064 ** ^The third parameter is the name of the database that was written to - 7065 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7066 ** is the number of pages currently in the write-ahead log file, 7067 ** including those that were just committed. 7068 ** 7069 ** The callback function should normally return [SQLITE_OK]. ^If an error 7070 ** code is returned, that error will propagate back up through the 7071 ** SQLite code base to cause the statement that provoked the callback 7072 ** to report an error, though the commit will have still occurred. If the 7073 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7074 ** that does not correspond to any valid SQLite error code, the results 7075 ** are undefined. 7076 ** 7077 ** A single database handle may have at most a single write-ahead log callback 7078 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7079 ** previously registered write-ahead log callback. ^Note that the 7080 ** [sqlite3_wal_autocheckpoint()] interface and the 7081 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7082 ** those overwrite any prior [sqlite3_wal_hook()] settings. 7083 */ 7084 SQLITE_API void *sqlite3_wal_hook( 7085 sqlite3*, 7086 int(*)(void *,sqlite3*,const char*,int), 7087 void* 7088 ); 7089 7090 /* 7091 ** CAPI3REF: Configure an auto-checkpoint 7092 ** 7093 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7094 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 7095 ** to automatically [checkpoint] 7096 ** after committing a transaction if there are N or 7097 ** more frames in the [write-ahead log] file. ^Passing zero or 7098 ** a negative value as the nFrame parameter disables automatic 7099 ** checkpoints entirely. 7100 ** 7101 ** ^The callback registered by this function replaces any existing callback 7102 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7103 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7104 ** configured by this function. 7105 ** 7106 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7107 ** from SQL. 7108 ** 7109 ** ^Every new [database connection] defaults to having the auto-checkpoint 7110 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7111 ** pages. The use of this interface 7112 ** is only necessary if the default setting is found to be suboptimal 7113 ** for a particular application. 7114 */ 7115 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7116 7117 /* 7118 ** CAPI3REF: Checkpoint a database 7119 ** 7120 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 7121 ** on [database connection] D to be [checkpointed]. ^If X is NULL or an 7122 ** empty string, then a checkpoint is run on all databases of 7123 ** connection D. ^If the database connection D is not in 7124 ** [WAL | write-ahead log mode] then this interface is a harmless no-op. 7125 ** 7126 ** ^The [wal_checkpoint pragma] can be used to invoke this interface 7127 ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 7128 ** [wal_autocheckpoint pragma] can be used to cause this interface to be 7129 ** run whenever the WAL reaches a certain size threshold. 7130 ** 7131 ** See also: [sqlite3_wal_checkpoint_v2()] 7132 */ 7133 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7134 7135 /* 7136 ** CAPI3REF: Checkpoint a database 7137 ** 7138 ** Run a checkpoint operation on WAL database zDb attached to database 7139 ** handle db. The specific operation is determined by the value of the 7140 ** eMode parameter: 7141 ** 7142 ** <dl> 7143 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7144 ** Checkpoint as many frames as possible without waiting for any database 7145 ** readers or writers to finish. Sync the db file if all frames in the log 7146 ** are checkpointed. This mode is the same as calling 7147 ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. 7148 ** 7149 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 7150 ** This mode blocks (calls the busy-handler callback) until there is no 7151 ** database writer and all readers are reading from the most recent database 7152 ** snapshot. It then checkpoints all frames in the log file and syncs the 7153 ** database file. This call blocks database writers while it is running, 7154 ** but not database readers. 7155 ** 7156 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7157 ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7158 ** checkpointing the log file it blocks (calls the busy-handler callback) 7159 ** until all readers are reading from the database file only. This ensures 7160 ** that the next client to write to the database file restarts the log file 7161 ** from the beginning. This call blocks database writers while it is running, 7162 ** but not database readers. 7163 ** </dl> 7164 ** 7165 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7166 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7167 ** the total number of checkpointed frames (including any that were already 7168 ** checkpointed when this function is called). *pnLog and *pnCkpt may be 7169 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7170 ** If no values are available because of an error, they are both set to -1 7171 ** before returning to communicate this to the caller. 7172 ** 7173 ** All calls obtain an exclusive "checkpoint" lock on the database file. If 7174 ** any other process is running a checkpoint operation at the same time, the 7175 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7176 ** busy-handler configured, it will not be invoked in this case. 7177 ** 7178 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7179 ** "writer" lock on the database file. If the writer lock cannot be obtained 7180 ** immediately, and a busy-handler is configured, it is invoked and the writer 7181 ** lock retried until either the busy-handler returns 0 or the lock is 7182 ** successfully obtained. The busy-handler is also invoked while waiting for 7183 ** database readers as described above. If the busy-handler returns 0 before 7184 ** the writer lock is obtained or while waiting for database readers, the 7185 ** checkpoint operation proceeds from that point in the same way as 7186 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7187 ** without blocking any further. SQLITE_BUSY is returned in this case. 7188 ** 7189 ** If parameter zDb is NULL or points to a zero length string, then the 7190 ** specified operation is attempted on all WAL databases. In this case the 7191 ** values written to output parameters *pnLog and *pnCkpt are undefined. If 7192 ** an SQLITE_BUSY error is encountered when processing one or more of the 7193 ** attached WAL databases, the operation is still attempted on any remaining 7194 ** attached databases and SQLITE_BUSY is returned to the caller. If any other 7195 ** error occurs while processing an attached database, processing is abandoned 7196 ** and the error code returned to the caller immediately. If no error 7197 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7198 ** databases, SQLITE_OK is returned. 7199 ** 7200 ** If database zDb is the name of an attached database that is not in WAL 7201 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7202 ** zDb is not NULL (or a zero length string) and is not the name of any 7203 ** attached database, SQLITE_ERROR is returned to the caller. 7204 */ 7205 SQLITE_API int sqlite3_wal_checkpoint_v2( 7206 sqlite3 *db, /* Database handle */ 7207 const char *zDb, /* Name of attached database (or NULL) */ 7208 int eMode, /* SQLITE_CHECKPOINT_* value */ 7209 int *pnLog, /* OUT: Size of WAL log in frames */ 7210 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7211 ); 7212 7213 /* 7214 ** CAPI3REF: Checkpoint operation parameters 7215 ** 7216 ** These constants can be used as the 3rd parameter to 7217 ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7218 ** documentation for additional information about the meaning and use of 7219 ** each of these values. 7220 */ 7221 #define SQLITE_CHECKPOINT_PASSIVE 0 7222 #define SQLITE_CHECKPOINT_FULL 1 7223 #define SQLITE_CHECKPOINT_RESTART 2 7224 7225 /* 7226 ** CAPI3REF: Virtual Table Interface Configuration 7227 ** 7228 ** This function may be called by either the [xConnect] or [xCreate] method 7229 ** of a [virtual table] implementation to configure 7230 ** various facets of the virtual table interface. 7231 ** 7232 ** If this interface is invoked outside the context of an xConnect or 7233 ** xCreate virtual table method then the behavior is undefined. 7234 ** 7235 ** At present, there is only one option that may be configured using 7236 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7237 ** may be added in the future. 7238 */ 7239 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7240 7241 /* 7242 ** CAPI3REF: Virtual Table Configuration Options 7243 ** 7244 ** These macros define the various options to the 7245 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 7246 ** can use to customize and optimize their behavior. 7247 ** 7248 ** <dl> 7249 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7250 ** <dd>Calls of the form 7251 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7252 ** where X is an integer. If X is zero, then the [virtual table] whose 7253 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7254 ** support constraints. In this configuration (which is the default) if 7255 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7256 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7257 ** specified as part of the users SQL statement, regardless of the actual 7258 ** ON CONFLICT mode specified. 7259 ** 7260 ** If X is non-zero, then the virtual table implementation guarantees 7261 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7262 ** any modifications to internal or persistent data structures have been made. 7263 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7264 ** is able to roll back a statement or database transaction, and abandon 7265 ** or continue processing the current SQL statement as appropriate. 7266 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7267 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7268 ** had been ABORT. 7269 ** 7270 ** Virtual table implementations that are required to handle OR REPLACE 7271 ** must do so within the [xUpdate] method. If a call to the 7272 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7273 ** CONFLICT policy is REPLACE, the virtual table implementation should 7274 ** silently replace the appropriate rows within the xUpdate callback and 7275 ** return SQLITE_OK. Or, if this is not possible, it may return 7276 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7277 ** constraint handling. 7278 ** </dl> 7279 */ 7280 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7281 7282 /* 7283 ** CAPI3REF: Determine The Virtual Table Conflict Policy 7284 ** 7285 ** This function may only be called from within a call to the [xUpdate] method 7286 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7287 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7288 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7289 ** of the SQL statement that triggered the call to the [xUpdate] method of the 7290 ** [virtual table]. 7291 */ 7292 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 7293 7294 /* 7295 ** CAPI3REF: Conflict resolution modes 7296 ** 7297 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 7298 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 7299 ** is for the SQL statement being evaluated. 7300 ** 7301 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 7302 ** return value from the [sqlite3_set_authorizer()] callback and that 7303 ** [SQLITE_ABORT] is also a [result code]. 7304 */ 7305 #define SQLITE_ROLLBACK 1 7306 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7307 #define SQLITE_FAIL 3 7308 /* #define SQLITE_ABORT 4 // Also an error code */ 7309 #define SQLITE_REPLACE 5 7310 7311 7312 7313 /* 7314 ** Undo the hack that converts floating point types to integer for 7315 ** builds on processors without floating point support. 7316 */ 7317 #ifdef SQLITE_OMIT_FLOATING_POINT 7318 # undef double 7319 #endif 7320 7321 #ifdef __cplusplus 7322 } /* End of the 'extern "C"' block */ 7323 #endif 7324 #endif /* _SQLITE3_H_ */ 7325 7326 /* 7327 ** 2010 August 30 7328 ** 7329 ** The author disclaims copyright to this source code. In place of 7330 ** a legal notice, here is a blessing: 7331 ** 7332 ** May you do good and not evil. 7333 ** May you find forgiveness for yourself and forgive others. 7334 ** May you share freely, never taking more than you give. 7335 ** 7336 ************************************************************************* 7337 */ 7338 7339 #ifndef _SQLITE3RTREE_H_ 7340 #define _SQLITE3RTREE_H_ 7341 7342 7343 #ifdef __cplusplus 7344 extern "C" { 7345 #endif 7346 7347 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7348 7349 /* 7350 ** Register a geometry callback named zGeom that can be used as part of an 7351 ** R-Tree geometry query as follows: 7352 ** 7353 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7354 */ 7355 SQLITE_API int sqlite3_rtree_geometry_callback( 7356 sqlite3 *db, 7357 const char *zGeom, 7358 #ifdef SQLITE_RTREE_INT_ONLY 7359 int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes), 7360 #else 7361 int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes), 7362 #endif 7363 void *pContext 7364 ); 7365 7366 7367 /* 7368 ** A pointer to a structure of the following type is passed as the first 7369 ** argument to callbacks registered using rtree_geometry_callback(). 7370 */ 7371 struct sqlite3_rtree_geometry { 7372 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7373 int nParam; /* Size of array aParam[] */ 7374 double *aParam; /* Parameters passed to SQL geom function */ 7375 void *pUser; /* Callback implementation user data */ 7376 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7377 }; 7378 7379 7380 #ifdef __cplusplus 7381 } /* end of the 'extern "C"' block */ 7382 #endif 7383 7384 #endif /* ifndef _SQLITE3RTREE_H_ */ 7385 7386