1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#else 193# define sqlite3_compileoption_used(X) 0 194# define sqlite3_compileoption_get(X) ((void*)0) 195#endif 196 197/* 198** CAPI3REF: Test To See If The Library Is Threadsafe 199** 200** ^The sqlite3_threadsafe() function returns zero if and only if 201** SQLite was compiled with mutexing code omitted due to the 202** [SQLITE_THREADSAFE] compile-time option being set to 0. 203** 204** SQLite can be compiled with or without mutexes. When 205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206** are enabled and SQLite is threadsafe. When the 207** [SQLITE_THREADSAFE] macro is 0, 208** the mutexes are omitted. Without the mutexes, it is not safe 209** to use SQLite concurrently from more than one thread. 210** 211** Enabling mutexes incurs a measurable performance penalty. 212** So if speed is of utmost importance, it makes sense to disable 213** the mutexes. But for maximum safety, mutexes should be enabled. 214** ^The default behavior is for mutexes to be enabled. 215** 216** This interface can be used by an application to make sure that the 217** version of SQLite that it is linking against was compiled with 218** the desired setting of the [SQLITE_THREADSAFE] macro. 219** 220** This interface only reports on the compile-time mutex setting 221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223** can be fully or partially disabled using a call to [sqlite3_config()] 224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226** sqlite3_threadsafe() function shows only the compile-time setting of 227** thread safety, not any run-time changes to that setting made by 228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229** is unchanged by calls to sqlite3_config().)^ 230** 231** See the [threading mode] documentation for additional information. 232*/ 233int sqlite3_threadsafe(void); 234 235/* 236** CAPI3REF: Database Connection Handle 237** KEYWORDS: {database connection} {database connections} 238** 239** Each open SQLite database is represented by a pointer to an instance of 240** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243** and [sqlite3_close_v2()] are its destructors. There are many other 244** interfaces (such as 245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246** [sqlite3_busy_timeout()] to name but three) that are methods on an 247** sqlite3 object. 248*/ 249typedef struct sqlite3 sqlite3; 250 251/* 252** CAPI3REF: 64-Bit Integer Types 253** KEYWORDS: sqlite_int64 sqlite_uint64 254** 255** Because there is no cross-platform way to specify 64-bit integer types 256** SQLite includes typedefs for 64-bit signed and unsigned integers. 257** 258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260** compatibility only. 261** 262** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264** sqlite3_uint64 and sqlite_uint64 types can store integer values 265** between 0 and +18446744073709551615 inclusive. 266*/ 267#ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269# ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271# else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273# endif 274#elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277#else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280#endif 281typedef sqlite_int64 sqlite3_int64; 282typedef sqlite_uint64 sqlite3_uint64; 283 284/* 285** If compiling for a processor that lacks floating point support, 286** substitute integer for floating-point. 287*/ 288#ifdef SQLITE_OMIT_FLOATING_POINT 289# define double sqlite3_int64 290#endif 291 292/* 293** CAPI3REF: Closing A Database Connection 294** DESTRUCTOR: sqlite3 295** 296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297** for the [sqlite3] object. 298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299** the [sqlite3] object is successfully destroyed and all associated 300** resources are deallocated. 301** 302** ^If the database connection is associated with unfinalized prepared 303** statements or unfinished sqlite3_backup objects then sqlite3_close() 304** will leave the database connection open and return [SQLITE_BUSY]. 305** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306** and/or unfinished sqlite3_backups, then the database connection becomes 307** an unusable "zombie" which will automatically be deallocated when the 308** last prepared statement is finalized or the last sqlite3_backup is 309** finished. The sqlite3_close_v2() interface is intended for use with 310** host languages that are garbage collected, and where the order in which 311** destructors are called is arbitrary. 312** 313** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314** [sqlite3_blob_close | close] all [BLOB handles], and 315** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316** with the [sqlite3] object prior to attempting to close the object. ^If 317** sqlite3_close_v2() is called on a [database connection] that still has 318** outstanding [prepared statements], [BLOB handles], and/or 319** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320** of resources is deferred until all [prepared statements], [BLOB handles], 321** and [sqlite3_backup] objects are also destroyed. 322** 323** ^If an [sqlite3] object is destroyed while a transaction is open, 324** the transaction is automatically rolled back. 325** 326** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327** must be either a NULL 328** pointer or an [sqlite3] object pointer obtained 329** from [sqlite3_open()], [sqlite3_open16()], or 330** [sqlite3_open_v2()], and not previously closed. 331** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332** argument is a harmless no-op. 333*/ 334int sqlite3_close(sqlite3*); 335int sqlite3_close_v2(sqlite3*); 336 337/* 338** The type for a callback function. 339** This is legacy and deprecated. It is included for historical 340** compatibility and is not documented. 341*/ 342typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344/* 345** CAPI3REF: One-Step Query Execution Interface 346** METHOD: sqlite3 347** 348** The sqlite3_exec() interface is a convenience wrapper around 349** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350** that allows an application to run multiple statements of SQL 351** without having to use a lot of C code. 352** 353** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354** semicolon-separate SQL statements passed into its 2nd argument, 355** in the context of the [database connection] passed in as its 1st 356** argument. ^If the callback function of the 3rd argument to 357** sqlite3_exec() is not NULL, then it is invoked for each result row 358** coming out of the evaluated SQL statements. ^The 4th argument to 359** sqlite3_exec() is relayed through to the 1st argument of each 360** callback invocation. ^If the callback pointer to sqlite3_exec() 361** is NULL, then no callback is ever invoked and result rows are 362** ignored. 363** 364** ^If an error occurs while evaluating the SQL statements passed into 365** sqlite3_exec(), then execution of the current statement stops and 366** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367** is not NULL then any error message is written into memory obtained 368** from [sqlite3_malloc()] and passed back through the 5th parameter. 369** To avoid memory leaks, the application should invoke [sqlite3_free()] 370** on error message strings returned through the 5th parameter of 371** sqlite3_exec() after the error message string is no longer needed. 372** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374** NULL before returning. 375** 376** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377** routine returns SQLITE_ABORT without invoking the callback again and 378** without running any subsequent SQL statements. 379** 380** ^The 2nd argument to the sqlite3_exec() callback function is the 381** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382** callback is an array of pointers to strings obtained as if from 383** [sqlite3_column_text()], one for each column. ^If an element of a 384** result row is NULL then the corresponding string pointer for the 385** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386** sqlite3_exec() callback is an array of pointers to strings where each 387** entry represents the name of corresponding result column as obtained 388** from [sqlite3_column_name()]. 389** 390** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391** to an empty string, or a pointer that contains only whitespace and/or 392** SQL comments, then no SQL statements are evaluated and the database 393** is not changed. 394** 395** Restrictions: 396** 397** <ul> 398** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399** is a valid and open [database connection]. 400** <li> The application must not close the [database connection] specified by 401** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402** <li> The application must not modify the SQL statement text passed into 403** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404** </ul> 405*/ 406int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412); 413 414/* 415** CAPI3REF: Result Codes 416** KEYWORDS: {result code definitions} 417** 418** Many SQLite functions return an integer result code from the set shown 419** here in order to indicate success or failure. 420** 421** New error codes may be added in future versions of SQLite. 422** 423** See also: [extended result code definitions] 424*/ 425#define SQLITE_OK 0 /* Successful result */ 426/* beginning-of-error-codes */ 427#define SQLITE_ERROR 1 /* Generic error */ 428#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429#define SQLITE_PERM 3 /* Access permission denied */ 430#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431#define SQLITE_BUSY 5 /* The database file is locked */ 432#define SQLITE_LOCKED 6 /* A table in the database is locked */ 433#define SQLITE_NOMEM 7 /* A malloc() failed */ 434#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439#define SQLITE_FULL 13 /* Insertion failed because database is full */ 440#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442#define SQLITE_EMPTY 16 /* Internal use only */ 443#define SQLITE_SCHEMA 17 /* The database schema changed */ 444#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446#define SQLITE_MISMATCH 20 /* Data type mismatch */ 447#define SQLITE_MISUSE 21 /* Library used incorrectly */ 448#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449#define SQLITE_AUTH 23 /* Authorization denied */ 450#define SQLITE_FORMAT 24 /* Not used */ 451#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457/* end-of-error-codes */ 458 459/* 460** CAPI3REF: Extended Result Codes 461** KEYWORDS: {extended result code definitions} 462** 463** In its default configuration, SQLite API routines return one of 30 integer 464** [result codes]. However, experience has shown that many of 465** these result codes are too coarse-grained. They do not provide as 466** much information about problems as programmers might like. In an effort to 467** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468** and later) include 469** support for additional result codes that provide more detailed information 470** about errors. These [extended result codes] are enabled or disabled 471** on a per database connection basis using the 472** [sqlite3_extended_result_codes()] API. Or, the extended code for 473** the most recent error can be obtained using 474** [sqlite3_extended_errcode()]. 475*/ 476#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 520#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 540#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 541#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 542#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 543#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 544#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 545#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 546 547/* 548** CAPI3REF: Flags For File Open Operations 549** 550** These bit values are intended for use in the 551** 3rd parameter to the [sqlite3_open_v2()] interface and 552** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 553*/ 554#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 557#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 558#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 559#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 560#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 561#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 562#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 563#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 564#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 565#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 566#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 567#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 568#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 569#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 570#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 571#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 572#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 573#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 574#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575 576/* Reserved: 0x00F00000 */ 577 578/* 579** CAPI3REF: Device Characteristics 580** 581** The xDeviceCharacteristics method of the [sqlite3_io_methods] 582** object returns an integer which is a vector of these 583** bit values expressing I/O characteristics of the mass storage 584** device that holds the file that the [sqlite3_io_methods] 585** refers to. 586** 587** The SQLITE_IOCAP_ATOMIC property means that all writes of 588** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 589** mean that writes of blocks that are nnn bytes in size and 590** are aligned to an address which is an integer multiple of 591** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 592** that when data is appended to a file, the data is appended 593** first then the size of the file is extended, never the other 594** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 595** information is written to disk in the same order as calls 596** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 597** after reboot following a crash or power loss, the only bytes in a 598** file that were written at the application level might have changed 599** and that adjacent bytes, even bytes within the same sector are 600** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 601** flag indicates that a file cannot be deleted when open. The 602** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 603** read-only media and cannot be changed even by processes with 604** elevated privileges. 605** 606** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 607** filesystem supports doing multiple write operations atomically when those 608** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 609** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 610*/ 611#define SQLITE_IOCAP_ATOMIC 0x00000001 612#define SQLITE_IOCAP_ATOMIC512 0x00000002 613#define SQLITE_IOCAP_ATOMIC1K 0x00000004 614#define SQLITE_IOCAP_ATOMIC2K 0x00000008 615#define SQLITE_IOCAP_ATOMIC4K 0x00000010 616#define SQLITE_IOCAP_ATOMIC8K 0x00000020 617#define SQLITE_IOCAP_ATOMIC16K 0x00000040 618#define SQLITE_IOCAP_ATOMIC32K 0x00000080 619#define SQLITE_IOCAP_ATOMIC64K 0x00000100 620#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 621#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 622#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 623#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 624#define SQLITE_IOCAP_IMMUTABLE 0x00002000 625#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 626 627/* 628** CAPI3REF: File Locking Levels 629** 630** SQLite uses one of these integer values as the second 631** argument to calls it makes to the xLock() and xUnlock() methods 632** of an [sqlite3_io_methods] object. 633*/ 634#define SQLITE_LOCK_NONE 0 635#define SQLITE_LOCK_SHARED 1 636#define SQLITE_LOCK_RESERVED 2 637#define SQLITE_LOCK_PENDING 3 638#define SQLITE_LOCK_EXCLUSIVE 4 639 640/* 641** CAPI3REF: Synchronization Type Flags 642** 643** When SQLite invokes the xSync() method of an 644** [sqlite3_io_methods] object it uses a combination of 645** these integer values as the second argument. 646** 647** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 648** sync operation only needs to flush data to mass storage. Inode 649** information need not be flushed. If the lower four bits of the flag 650** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 651** If the lower four bits equal SQLITE_SYNC_FULL, that means 652** to use Mac OS X style fullsync instead of fsync(). 653** 654** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 655** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 656** settings. The [synchronous pragma] determines when calls to the 657** xSync VFS method occur and applies uniformly across all platforms. 658** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 659** energetic or rigorous or forceful the sync operations are and 660** only make a difference on Mac OSX for the default SQLite code. 661** (Third-party VFS implementations might also make the distinction 662** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 663** operating systems natively supported by SQLite, only Mac OSX 664** cares about the difference.) 665*/ 666#define SQLITE_SYNC_NORMAL 0x00002 667#define SQLITE_SYNC_FULL 0x00003 668#define SQLITE_SYNC_DATAONLY 0x00010 669 670/* 671** CAPI3REF: OS Interface Open File Handle 672** 673** An [sqlite3_file] object represents an open file in the 674** [sqlite3_vfs | OS interface layer]. Individual OS interface 675** implementations will 676** want to subclass this object by appending additional fields 677** for their own use. The pMethods entry is a pointer to an 678** [sqlite3_io_methods] object that defines methods for performing 679** I/O operations on the open file. 680*/ 681typedef struct sqlite3_file sqlite3_file; 682struct sqlite3_file { 683 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 684}; 685 686/* 687** CAPI3REF: OS Interface File Virtual Methods Object 688** 689** Every file opened by the [sqlite3_vfs.xOpen] method populates an 690** [sqlite3_file] object (or, more commonly, a subclass of the 691** [sqlite3_file] object) with a pointer to an instance of this object. 692** This object defines the methods used to perform various operations 693** against the open file represented by the [sqlite3_file] object. 694** 695** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 696** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 697** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 698** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 699** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 700** to NULL. 701** 702** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 703** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 704** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 705** flag may be ORed in to indicate that only the data of the file 706** and not its inode needs to be synced. 707** 708** The integer values to xLock() and xUnlock() are one of 709** <ul> 710** <li> [SQLITE_LOCK_NONE], 711** <li> [SQLITE_LOCK_SHARED], 712** <li> [SQLITE_LOCK_RESERVED], 713** <li> [SQLITE_LOCK_PENDING], or 714** <li> [SQLITE_LOCK_EXCLUSIVE]. 715** </ul> 716** xLock() increases the lock. xUnlock() decreases the lock. 717** The xCheckReservedLock() method checks whether any database connection, 718** either in this process or in some other process, is holding a RESERVED, 719** PENDING, or EXCLUSIVE lock on the file. It returns true 720** if such a lock exists and false otherwise. 721** 722** The xFileControl() method is a generic interface that allows custom 723** VFS implementations to directly control an open file using the 724** [sqlite3_file_control()] interface. The second "op" argument is an 725** integer opcode. The third argument is a generic pointer intended to 726** point to a structure that may contain arguments or space in which to 727** write return values. Potential uses for xFileControl() might be 728** functions to enable blocking locks with timeouts, to change the 729** locking strategy (for example to use dot-file locks), to inquire 730** about the status of a lock, or to break stale locks. The SQLite 731** core reserves all opcodes less than 100 for its own use. 732** A [file control opcodes | list of opcodes] less than 100 is available. 733** Applications that define a custom xFileControl method should use opcodes 734** greater than 100 to avoid conflicts. VFS implementations should 735** return [SQLITE_NOTFOUND] for file control opcodes that they do not 736** recognize. 737** 738** The xSectorSize() method returns the sector size of the 739** device that underlies the file. The sector size is the 740** minimum write that can be performed without disturbing 741** other bytes in the file. The xDeviceCharacteristics() 742** method returns a bit vector describing behaviors of the 743** underlying device: 744** 745** <ul> 746** <li> [SQLITE_IOCAP_ATOMIC] 747** <li> [SQLITE_IOCAP_ATOMIC512] 748** <li> [SQLITE_IOCAP_ATOMIC1K] 749** <li> [SQLITE_IOCAP_ATOMIC2K] 750** <li> [SQLITE_IOCAP_ATOMIC4K] 751** <li> [SQLITE_IOCAP_ATOMIC8K] 752** <li> [SQLITE_IOCAP_ATOMIC16K] 753** <li> [SQLITE_IOCAP_ATOMIC32K] 754** <li> [SQLITE_IOCAP_ATOMIC64K] 755** <li> [SQLITE_IOCAP_SAFE_APPEND] 756** <li> [SQLITE_IOCAP_SEQUENTIAL] 757** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 758** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 759** <li> [SQLITE_IOCAP_IMMUTABLE] 760** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 761** </ul> 762** 763** The SQLITE_IOCAP_ATOMIC property means that all writes of 764** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 765** mean that writes of blocks that are nnn bytes in size and 766** are aligned to an address which is an integer multiple of 767** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 768** that when data is appended to a file, the data is appended 769** first then the size of the file is extended, never the other 770** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 771** information is written to disk in the same order as calls 772** to xWrite(). 773** 774** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 775** in the unread portions of the buffer with zeros. A VFS that 776** fails to zero-fill short reads might seem to work. However, 777** failure to zero-fill short reads will eventually lead to 778** database corruption. 779*/ 780typedef struct sqlite3_io_methods sqlite3_io_methods; 781struct sqlite3_io_methods { 782 int iVersion; 783 int (*xClose)(sqlite3_file*); 784 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 785 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 786 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 787 int (*xSync)(sqlite3_file*, int flags); 788 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 789 int (*xLock)(sqlite3_file*, int); 790 int (*xUnlock)(sqlite3_file*, int); 791 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 792 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 793 int (*xSectorSize)(sqlite3_file*); 794 int (*xDeviceCharacteristics)(sqlite3_file*); 795 /* Methods above are valid for version 1 */ 796 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 797 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 798 void (*xShmBarrier)(sqlite3_file*); 799 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 800 /* Methods above are valid for version 2 */ 801 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 802 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 803 /* Methods above are valid for version 3 */ 804 /* Additional methods may be added in future releases */ 805}; 806 807/* 808** CAPI3REF: Standard File Control Opcodes 809** KEYWORDS: {file control opcodes} {file control opcode} 810** 811** These integer constants are opcodes for the xFileControl method 812** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 813** interface. 814** 815** <ul> 816** <li>[[SQLITE_FCNTL_LOCKSTATE]] 817** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 818** opcode causes the xFileControl method to write the current state of 819** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 820** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 821** into an integer that the pArg argument points to. This capability 822** is used during testing and is only available when the SQLITE_TEST 823** compile-time option is used. 824** 825** <li>[[SQLITE_FCNTL_SIZE_HINT]] 826** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 827** layer a hint of how large the database file will grow to be during the 828** current transaction. This hint is not guaranteed to be accurate but it 829** is often close. The underlying VFS might choose to preallocate database 830** file space based on this hint in order to help writes to the database 831** file run faster. 832** 833** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 834** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 835** implements [sqlite3_deserialize()] to set an upper bound on the size 836** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 837** If the integer pointed to is negative, then it is filled in with the 838** current limit. Otherwise the limit is set to the larger of the value 839** of the integer pointed to and the current database size. The integer 840** pointed to is set to the new limit. 841** 842** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 843** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 844** extends and truncates the database file in chunks of a size specified 845** by the user. The fourth argument to [sqlite3_file_control()] should 846** point to an integer (type int) containing the new chunk-size to use 847** for the nominated database. Allocating database file space in large 848** chunks (say 1MB at a time), may reduce file-system fragmentation and 849** improve performance on some systems. 850** 851** <li>[[SQLITE_FCNTL_FILE_POINTER]] 852** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 853** to the [sqlite3_file] object associated with a particular database 854** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 855** 856** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 857** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 858** to the [sqlite3_file] object associated with the journal file (either 859** the [rollback journal] or the [write-ahead log]) for a particular database 860** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 861** 862** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 863** No longer in use. 864** 865** <li>[[SQLITE_FCNTL_SYNC]] 866** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 867** sent to the VFS immediately before the xSync method is invoked on a 868** database file descriptor. Or, if the xSync method is not invoked 869** because the user has configured SQLite with 870** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 871** of the xSync method. In most cases, the pointer argument passed with 872** this file-control is NULL. However, if the database file is being synced 873** as part of a multi-database commit, the argument points to a nul-terminated 874** string containing the transactions master-journal file name. VFSes that 875** do not need this signal should silently ignore this opcode. Applications 876** should not call [sqlite3_file_control()] with this opcode as doing so may 877** disrupt the operation of the specialized VFSes that do require it. 878** 879** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 880** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 881** and sent to the VFS after a transaction has been committed immediately 882** but before the database is unlocked. VFSes that do not need this signal 883** should silently ignore this opcode. Applications should not call 884** [sqlite3_file_control()] with this opcode as doing so may disrupt the 885** operation of the specialized VFSes that do require it. 886** 887** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 888** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 889** retry counts and intervals for certain disk I/O operations for the 890** windows [VFS] in order to provide robustness in the presence of 891** anti-virus programs. By default, the windows VFS will retry file read, 892** file write, and file delete operations up to 10 times, with a delay 893** of 25 milliseconds before the first retry and with the delay increasing 894** by an additional 25 milliseconds with each subsequent retry. This 895** opcode allows these two values (10 retries and 25 milliseconds of delay) 896** to be adjusted. The values are changed for all database connections 897** within the same process. The argument is a pointer to an array of two 898** integers where the first integer is the new retry count and the second 899** integer is the delay. If either integer is negative, then the setting 900** is not changed but instead the prior value of that setting is written 901** into the array entry, allowing the current retry settings to be 902** interrogated. The zDbName parameter is ignored. 903** 904** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 905** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 906** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 907** write ahead log ([WAL file]) and shared memory 908** files used for transaction control 909** are automatically deleted when the latest connection to the database 910** closes. Setting persistent WAL mode causes those files to persist after 911** close. Persisting the files is useful when other processes that do not 912** have write permission on the directory containing the database file want 913** to read the database file, as the WAL and shared memory files must exist 914** in order for the database to be readable. The fourth parameter to 915** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 916** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 917** WAL mode. If the integer is -1, then it is overwritten with the current 918** WAL persistence setting. 919** 920** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 921** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 922** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 923** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 924** xDeviceCharacteristics methods. The fourth parameter to 925** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 926** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 927** mode. If the integer is -1, then it is overwritten with the current 928** zero-damage mode setting. 929** 930** <li>[[SQLITE_FCNTL_OVERWRITE]] 931** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 932** a write transaction to indicate that, unless it is rolled back for some 933** reason, the entire database file will be overwritten by the current 934** transaction. This is used by VACUUM operations. 935** 936** <li>[[SQLITE_FCNTL_VFSNAME]] 937** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 938** all [VFSes] in the VFS stack. The names are of all VFS shims and the 939** final bottom-level VFS are written into memory obtained from 940** [sqlite3_malloc()] and the result is stored in the char* variable 941** that the fourth parameter of [sqlite3_file_control()] points to. 942** The caller is responsible for freeing the memory when done. As with 943** all file-control actions, there is no guarantee that this will actually 944** do anything. Callers should initialize the char* variable to a NULL 945** pointer in case this file-control is not implemented. This file-control 946** is intended for diagnostic use only. 947** 948** <li>[[SQLITE_FCNTL_VFS_POINTER]] 949** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 950** [VFSes] currently in use. ^(The argument X in 951** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 952** of type "[sqlite3_vfs] **". This opcodes will set *X 953** to a pointer to the top-level VFS.)^ 954** ^When there are multiple VFS shims in the stack, this opcode finds the 955** upper-most shim only. 956** 957** <li>[[SQLITE_FCNTL_PRAGMA]] 958** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 959** file control is sent to the open [sqlite3_file] object corresponding 960** to the database file to which the pragma statement refers. ^The argument 961** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 962** pointers to strings (char**) in which the second element of the array 963** is the name of the pragma and the third element is the argument to the 964** pragma or NULL if the pragma has no argument. ^The handler for an 965** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 966** of the char** argument point to a string obtained from [sqlite3_mprintf()] 967** or the equivalent and that string will become the result of the pragma or 968** the error message if the pragma fails. ^If the 969** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 970** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 971** file control returns [SQLITE_OK], then the parser assumes that the 972** VFS has handled the PRAGMA itself and the parser generates a no-op 973** prepared statement if result string is NULL, or that returns a copy 974** of the result string if the string is non-NULL. 975** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 976** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 977** that the VFS encountered an error while handling the [PRAGMA] and the 978** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 979** file control occurs at the beginning of pragma statement analysis and so 980** it is able to override built-in [PRAGMA] statements. 981** 982** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 983** ^The [SQLITE_FCNTL_BUSYHANDLER] 984** file-control may be invoked by SQLite on the database file handle 985** shortly after it is opened in order to provide a custom VFS with access 986** to the connection's busy-handler callback. The argument is of type (void**) 987** - an array of two (void *) values. The first (void *) actually points 988** to a function of type (int (*)(void *)). In order to invoke the connection's 989** busy-handler, this function should be invoked with the second (void *) in 990** the array as the only argument. If it returns non-zero, then the operation 991** should be retried. If it returns zero, the custom VFS should abandon the 992** current operation. 993** 994** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 995** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 996** to have SQLite generate a 997** temporary filename using the same algorithm that is followed to generate 998** temporary filenames for TEMP tables and other internal uses. The 999** argument should be a char** which will be filled with the filename 1000** written into memory obtained from [sqlite3_malloc()]. The caller should 1001** invoke [sqlite3_free()] on the result to avoid a memory leak. 1002** 1003** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1004** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1005** maximum number of bytes that will be used for memory-mapped I/O. 1006** The argument is a pointer to a value of type sqlite3_int64 that 1007** is an advisory maximum number of bytes in the file to memory map. The 1008** pointer is overwritten with the old value. The limit is not changed if 1009** the value originally pointed to is negative, and so the current limit 1010** can be queried by passing in a pointer to a negative number. This 1011** file-control is used internally to implement [PRAGMA mmap_size]. 1012** 1013** <li>[[SQLITE_FCNTL_TRACE]] 1014** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1015** to the VFS about what the higher layers of the SQLite stack are doing. 1016** This file control is used by some VFS activity tracing [shims]. 1017** The argument is a zero-terminated string. Higher layers in the 1018** SQLite stack may generate instances of this file control if 1019** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1020** 1021** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1022** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1023** pointer to an integer and it writes a boolean into that integer depending 1024** on whether or not the file has been renamed, moved, or deleted since it 1025** was first opened. 1026** 1027** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1028** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1029** underlying native file handle associated with a file handle. This file 1030** control interprets its argument as a pointer to a native file handle and 1031** writes the resulting value there. 1032** 1033** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1034** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1035** opcode causes the xFileControl method to swap the file handle with the one 1036** pointed to by the pArg argument. This capability is used during testing 1037** and only needs to be supported when SQLITE_TEST is defined. 1038** 1039** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1040** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1041** be advantageous to block on the next WAL lock if the lock is not immediately 1042** available. The WAL subsystem issues this signal during rare 1043** circumstances in order to fix a problem with priority inversion. 1044** Applications should <em>not</em> use this file-control. 1045** 1046** <li>[[SQLITE_FCNTL_ZIPVFS]] 1047** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1048** VFS should return SQLITE_NOTFOUND for this opcode. 1049** 1050** <li>[[SQLITE_FCNTL_RBU]] 1051** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1052** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1053** this opcode. 1054** 1055** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1056** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1057** the file descriptor is placed in "batch write mode", which 1058** means all subsequent write operations will be deferred and done 1059** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1060** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1061** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1062** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1063** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1064** no VFS interface calls on the same [sqlite3_file] file descriptor 1065** except for calls to the xWrite method and the xFileControl method 1066** with [SQLITE_FCNTL_SIZE_HINT]. 1067** 1068** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1069** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1070** operations since the previous successful call to 1071** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1072** This file control returns [SQLITE_OK] if and only if the writes were 1073** all performed successfully and have been committed to persistent storage. 1074** ^Regardless of whether or not it is successful, this file control takes 1075** the file descriptor out of batch write mode so that all subsequent 1076** write operations are independent. 1077** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1078** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1079** 1080** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1081** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1082** operations since the previous successful call to 1083** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1084** ^This file control takes the file descriptor out of batch write mode 1085** so that all subsequent write operations are independent. 1086** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1087** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1088** 1089** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1090** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1091** a file lock using the xLock or xShmLock methods of the VFS to wait 1092** for up to M milliseconds before failing, where M is the single 1093** unsigned integer parameter. 1094** 1095** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1096** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1097** a database file. The argument is a pointer to a 32-bit unsigned integer. 1098** The "data version" for the pager is written into the pointer. The 1099** "data version" changes whenever any change occurs to the corresponding 1100** database file, either through SQL statements on the same database 1101** connection or through transactions committed by separate database 1102** connections possibly in other processes. The [sqlite3_total_changes()] 1103** interface can be used to find if any database on the connection has changed, 1104** but that interface responds to changes on TEMP as well as MAIN and does 1105** not provide a mechanism to detect changes to MAIN only. Also, the 1106** [sqlite3_total_changes()] interface responds to internal changes only and 1107** omits changes made by other database connections. The 1108** [PRAGMA data_version] command provides a mechanism to detect changes to 1109** a single attached database that occur due to other database connections, 1110** but omits changes implemented by the database connection on which it is 1111** called. This file control is the only mechanism to detect changes that 1112** happen either internally or externally and that are associated with 1113** a particular attached database. 1114** 1115** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1116** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1117** in wal mode after the client has finished copying pages from the wal 1118** file to the database file, but before the *-shm file is updated to 1119** record the fact that the pages have been checkpointed. 1120** </ul> 1121*/ 1122#define SQLITE_FCNTL_LOCKSTATE 1 1123#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1124#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1125#define SQLITE_FCNTL_LAST_ERRNO 4 1126#define SQLITE_FCNTL_SIZE_HINT 5 1127#define SQLITE_FCNTL_CHUNK_SIZE 6 1128#define SQLITE_FCNTL_FILE_POINTER 7 1129#define SQLITE_FCNTL_SYNC_OMITTED 8 1130#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1131#define SQLITE_FCNTL_PERSIST_WAL 10 1132#define SQLITE_FCNTL_OVERWRITE 11 1133#define SQLITE_FCNTL_VFSNAME 12 1134#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1135#define SQLITE_FCNTL_PRAGMA 14 1136#define SQLITE_FCNTL_BUSYHANDLER 15 1137#define SQLITE_FCNTL_TEMPFILENAME 16 1138#define SQLITE_FCNTL_MMAP_SIZE 18 1139#define SQLITE_FCNTL_TRACE 19 1140#define SQLITE_FCNTL_HAS_MOVED 20 1141#define SQLITE_FCNTL_SYNC 21 1142#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1143#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1144#define SQLITE_FCNTL_WAL_BLOCK 24 1145#define SQLITE_FCNTL_ZIPVFS 25 1146#define SQLITE_FCNTL_RBU 26 1147#define SQLITE_FCNTL_VFS_POINTER 27 1148#define SQLITE_FCNTL_JOURNAL_POINTER 28 1149#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1150#define SQLITE_FCNTL_PDB 30 1151#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1152#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1153#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1154#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1155#define SQLITE_FCNTL_DATA_VERSION 35 1156#define SQLITE_FCNTL_SIZE_LIMIT 36 1157#define SQLITE_FCNTL_CKPT_DONE 37 1158 1159/* deprecated names */ 1160#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1161#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1162#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1163 1164 1165/* 1166** CAPI3REF: Mutex Handle 1167** 1168** The mutex module within SQLite defines [sqlite3_mutex] to be an 1169** abstract type for a mutex object. The SQLite core never looks 1170** at the internal representation of an [sqlite3_mutex]. It only 1171** deals with pointers to the [sqlite3_mutex] object. 1172** 1173** Mutexes are created using [sqlite3_mutex_alloc()]. 1174*/ 1175typedef struct sqlite3_mutex sqlite3_mutex; 1176 1177/* 1178** CAPI3REF: Loadable Extension Thunk 1179** 1180** A pointer to the opaque sqlite3_api_routines structure is passed as 1181** the third parameter to entry points of [loadable extensions]. This 1182** structure must be typedefed in order to work around compiler warnings 1183** on some platforms. 1184*/ 1185typedef struct sqlite3_api_routines sqlite3_api_routines; 1186 1187/* 1188** CAPI3REF: OS Interface Object 1189** 1190** An instance of the sqlite3_vfs object defines the interface between 1191** the SQLite core and the underlying operating system. The "vfs" 1192** in the name of the object stands for "virtual file system". See 1193** the [VFS | VFS documentation] for further information. 1194** 1195** The VFS interface is sometimes extended by adding new methods onto 1196** the end. Each time such an extension occurs, the iVersion field 1197** is incremented. The iVersion value started out as 1 in 1198** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1199** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1200** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1201** may be appended to the sqlite3_vfs object and the iVersion value 1202** may increase again in future versions of SQLite. 1203** Note that due to an oversight, the structure 1204** of the sqlite3_vfs object changed in the transition from 1205** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1206** and yet the iVersion field was not increased. 1207** 1208** The szOsFile field is the size of the subclassed [sqlite3_file] 1209** structure used by this VFS. mxPathname is the maximum length of 1210** a pathname in this VFS. 1211** 1212** Registered sqlite3_vfs objects are kept on a linked list formed by 1213** the pNext pointer. The [sqlite3_vfs_register()] 1214** and [sqlite3_vfs_unregister()] interfaces manage this list 1215** in a thread-safe way. The [sqlite3_vfs_find()] interface 1216** searches the list. Neither the application code nor the VFS 1217** implementation should use the pNext pointer. 1218** 1219** The pNext field is the only field in the sqlite3_vfs 1220** structure that SQLite will ever modify. SQLite will only access 1221** or modify this field while holding a particular static mutex. 1222** The application should never modify anything within the sqlite3_vfs 1223** object once the object has been registered. 1224** 1225** The zName field holds the name of the VFS module. The name must 1226** be unique across all VFS modules. 1227** 1228** [[sqlite3_vfs.xOpen]] 1229** ^SQLite guarantees that the zFilename parameter to xOpen 1230** is either a NULL pointer or string obtained 1231** from xFullPathname() with an optional suffix added. 1232** ^If a suffix is added to the zFilename parameter, it will 1233** consist of a single "-" character followed by no more than 1234** 11 alphanumeric and/or "-" characters. 1235** ^SQLite further guarantees that 1236** the string will be valid and unchanged until xClose() is 1237** called. Because of the previous sentence, 1238** the [sqlite3_file] can safely store a pointer to the 1239** filename if it needs to remember the filename for some reason. 1240** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1241** must invent its own temporary name for the file. ^Whenever the 1242** xFilename parameter is NULL it will also be the case that the 1243** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1244** 1245** The flags argument to xOpen() includes all bits set in 1246** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1247** or [sqlite3_open16()] is used, then flags includes at least 1248** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1249** If xOpen() opens a file read-only then it sets *pOutFlags to 1250** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1251** 1252** ^(SQLite will also add one of the following flags to the xOpen() 1253** call, depending on the object being opened: 1254** 1255** <ul> 1256** <li> [SQLITE_OPEN_MAIN_DB] 1257** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1258** <li> [SQLITE_OPEN_TEMP_DB] 1259** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1260** <li> [SQLITE_OPEN_TRANSIENT_DB] 1261** <li> [SQLITE_OPEN_SUBJOURNAL] 1262** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1263** <li> [SQLITE_OPEN_WAL] 1264** </ul>)^ 1265** 1266** The file I/O implementation can use the object type flags to 1267** change the way it deals with files. For example, an application 1268** that does not care about crash recovery or rollback might make 1269** the open of a journal file a no-op. Writes to this journal would 1270** also be no-ops, and any attempt to read the journal would return 1271** SQLITE_IOERR. Or the implementation might recognize that a database 1272** file will be doing page-aligned sector reads and writes in a random 1273** order and set up its I/O subsystem accordingly. 1274** 1275** SQLite might also add one of the following flags to the xOpen method: 1276** 1277** <ul> 1278** <li> [SQLITE_OPEN_DELETEONCLOSE] 1279** <li> [SQLITE_OPEN_EXCLUSIVE] 1280** </ul> 1281** 1282** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1283** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1284** will be set for TEMP databases and their journals, transient 1285** databases, and subjournals. 1286** 1287** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1288** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1289** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1290** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1291** SQLITE_OPEN_CREATE, is used to indicate that file should always 1292** be created, and that it is an error if it already exists. 1293** It is <i>not</i> used to indicate the file should be opened 1294** for exclusive access. 1295** 1296** ^At least szOsFile bytes of memory are allocated by SQLite 1297** to hold the [sqlite3_file] structure passed as the third 1298** argument to xOpen. The xOpen method does not have to 1299** allocate the structure; it should just fill it in. Note that 1300** the xOpen method must set the sqlite3_file.pMethods to either 1301** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1302** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1303** element will be valid after xOpen returns regardless of the success 1304** or failure of the xOpen call. 1305** 1306** [[sqlite3_vfs.xAccess]] 1307** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1308** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1309** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1310** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1311** flag is never actually used and is not implemented in the built-in 1312** VFSes of SQLite. The file is named by the second argument and can be a 1313** directory. The xAccess method returns [SQLITE_OK] on success or some 1314** non-zero error code if there is an I/O error or if the name of 1315** the file given in the second argument is illegal. If SQLITE_OK 1316** is returned, then non-zero or zero is written into *pResOut to indicate 1317** whether or not the file is accessible. 1318** 1319** ^SQLite will always allocate at least mxPathname+1 bytes for the 1320** output buffer xFullPathname. The exact size of the output buffer 1321** is also passed as a parameter to both methods. If the output buffer 1322** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1323** handled as a fatal error by SQLite, vfs implementations should endeavor 1324** to prevent this by setting mxPathname to a sufficiently large value. 1325** 1326** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1327** interfaces are not strictly a part of the filesystem, but they are 1328** included in the VFS structure for completeness. 1329** The xRandomness() function attempts to return nBytes bytes 1330** of good-quality randomness into zOut. The return value is 1331** the actual number of bytes of randomness obtained. 1332** The xSleep() method causes the calling thread to sleep for at 1333** least the number of microseconds given. ^The xCurrentTime() 1334** method returns a Julian Day Number for the current date and time as 1335** a floating point value. 1336** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1337** Day Number multiplied by 86400000 (the number of milliseconds in 1338** a 24-hour day). 1339** ^SQLite will use the xCurrentTimeInt64() method to get the current 1340** date and time if that method is available (if iVersion is 2 or 1341** greater and the function pointer is not NULL) and will fall back 1342** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1343** 1344** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1345** are not used by the SQLite core. These optional interfaces are provided 1346** by some VFSes to facilitate testing of the VFS code. By overriding 1347** system calls with functions under its control, a test program can 1348** simulate faults and error conditions that would otherwise be difficult 1349** or impossible to induce. The set of system calls that can be overridden 1350** varies from one VFS to another, and from one version of the same VFS to the 1351** next. Applications that use these interfaces must be prepared for any 1352** or all of these interfaces to be NULL or for their behavior to change 1353** from one release to the next. Applications must not attempt to access 1354** any of these methods if the iVersion of the VFS is less than 3. 1355*/ 1356typedef struct sqlite3_vfs sqlite3_vfs; 1357typedef void (*sqlite3_syscall_ptr)(void); 1358struct sqlite3_vfs { 1359 int iVersion; /* Structure version number (currently 3) */ 1360 int szOsFile; /* Size of subclassed sqlite3_file */ 1361 int mxPathname; /* Maximum file pathname length */ 1362 sqlite3_vfs *pNext; /* Next registered VFS */ 1363 const char *zName; /* Name of this virtual file system */ 1364 void *pAppData; /* Pointer to application-specific data */ 1365 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1366 int flags, int *pOutFlags); 1367 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1368 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1369 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1370 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1371 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1372 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1373 void (*xDlClose)(sqlite3_vfs*, void*); 1374 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1375 int (*xSleep)(sqlite3_vfs*, int microseconds); 1376 int (*xCurrentTime)(sqlite3_vfs*, double*); 1377 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1378 /* 1379 ** The methods above are in version 1 of the sqlite_vfs object 1380 ** definition. Those that follow are added in version 2 or later 1381 */ 1382 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1383 /* 1384 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1385 ** Those below are for version 3 and greater. 1386 */ 1387 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1388 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1389 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1390 /* 1391 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1392 ** New fields may be appended in future versions. The iVersion 1393 ** value will increment whenever this happens. 1394 */ 1395}; 1396 1397/* 1398** CAPI3REF: Flags for the xAccess VFS method 1399** 1400** These integer constants can be used as the third parameter to 1401** the xAccess method of an [sqlite3_vfs] object. They determine 1402** what kind of permissions the xAccess method is looking for. 1403** With SQLITE_ACCESS_EXISTS, the xAccess method 1404** simply checks whether the file exists. 1405** With SQLITE_ACCESS_READWRITE, the xAccess method 1406** checks whether the named directory is both readable and writable 1407** (in other words, if files can be added, removed, and renamed within 1408** the directory). 1409** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1410** [temp_store_directory pragma], though this could change in a future 1411** release of SQLite. 1412** With SQLITE_ACCESS_READ, the xAccess method 1413** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1414** currently unused, though it might be used in a future release of 1415** SQLite. 1416*/ 1417#define SQLITE_ACCESS_EXISTS 0 1418#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1419#define SQLITE_ACCESS_READ 2 /* Unused */ 1420 1421/* 1422** CAPI3REF: Flags for the xShmLock VFS method 1423** 1424** These integer constants define the various locking operations 1425** allowed by the xShmLock method of [sqlite3_io_methods]. The 1426** following are the only legal combinations of flags to the 1427** xShmLock method: 1428** 1429** <ul> 1430** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1431** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1432** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1433** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1434** </ul> 1435** 1436** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1437** was given on the corresponding lock. 1438** 1439** The xShmLock method can transition between unlocked and SHARED or 1440** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1441** and EXCLUSIVE. 1442*/ 1443#define SQLITE_SHM_UNLOCK 1 1444#define SQLITE_SHM_LOCK 2 1445#define SQLITE_SHM_SHARED 4 1446#define SQLITE_SHM_EXCLUSIVE 8 1447 1448/* 1449** CAPI3REF: Maximum xShmLock index 1450** 1451** The xShmLock method on [sqlite3_io_methods] may use values 1452** between 0 and this upper bound as its "offset" argument. 1453** The SQLite core will never attempt to acquire or release a 1454** lock outside of this range 1455*/ 1456#define SQLITE_SHM_NLOCK 8 1457 1458 1459/* 1460** CAPI3REF: Initialize The SQLite Library 1461** 1462** ^The sqlite3_initialize() routine initializes the 1463** SQLite library. ^The sqlite3_shutdown() routine 1464** deallocates any resources that were allocated by sqlite3_initialize(). 1465** These routines are designed to aid in process initialization and 1466** shutdown on embedded systems. Workstation applications using 1467** SQLite normally do not need to invoke either of these routines. 1468** 1469** A call to sqlite3_initialize() is an "effective" call if it is 1470** the first time sqlite3_initialize() is invoked during the lifetime of 1471** the process, or if it is the first time sqlite3_initialize() is invoked 1472** following a call to sqlite3_shutdown(). ^(Only an effective call 1473** of sqlite3_initialize() does any initialization. All other calls 1474** are harmless no-ops.)^ 1475** 1476** A call to sqlite3_shutdown() is an "effective" call if it is the first 1477** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1478** an effective call to sqlite3_shutdown() does any deinitialization. 1479** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1480** 1481** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1482** is not. The sqlite3_shutdown() interface must only be called from a 1483** single thread. All open [database connections] must be closed and all 1484** other SQLite resources must be deallocated prior to invoking 1485** sqlite3_shutdown(). 1486** 1487** Among other things, ^sqlite3_initialize() will invoke 1488** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1489** will invoke sqlite3_os_end(). 1490** 1491** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1492** ^If for some reason, sqlite3_initialize() is unable to initialize 1493** the library (perhaps it is unable to allocate a needed resource such 1494** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1495** 1496** ^The sqlite3_initialize() routine is called internally by many other 1497** SQLite interfaces so that an application usually does not need to 1498** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1499** calls sqlite3_initialize() so the SQLite library will be automatically 1500** initialized when [sqlite3_open()] is called if it has not be initialized 1501** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1502** compile-time option, then the automatic calls to sqlite3_initialize() 1503** are omitted and the application must call sqlite3_initialize() directly 1504** prior to using any other SQLite interface. For maximum portability, 1505** it is recommended that applications always invoke sqlite3_initialize() 1506** directly prior to using any other SQLite interface. Future releases 1507** of SQLite may require this. In other words, the behavior exhibited 1508** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1509** default behavior in some future release of SQLite. 1510** 1511** The sqlite3_os_init() routine does operating-system specific 1512** initialization of the SQLite library. The sqlite3_os_end() 1513** routine undoes the effect of sqlite3_os_init(). Typical tasks 1514** performed by these routines include allocation or deallocation 1515** of static resources, initialization of global variables, 1516** setting up a default [sqlite3_vfs] module, or setting up 1517** a default configuration using [sqlite3_config()]. 1518** 1519** The application should never invoke either sqlite3_os_init() 1520** or sqlite3_os_end() directly. The application should only invoke 1521** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1522** interface is called automatically by sqlite3_initialize() and 1523** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1524** implementations for sqlite3_os_init() and sqlite3_os_end() 1525** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1526** When [custom builds | built for other platforms] 1527** (using the [SQLITE_OS_OTHER=1] compile-time 1528** option) the application must supply a suitable implementation for 1529** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1530** implementation of sqlite3_os_init() or sqlite3_os_end() 1531** must return [SQLITE_OK] on success and some other [error code] upon 1532** failure. 1533*/ 1534int sqlite3_initialize(void); 1535int sqlite3_shutdown(void); 1536int sqlite3_os_init(void); 1537int sqlite3_os_end(void); 1538 1539/* 1540** CAPI3REF: Configuring The SQLite Library 1541** 1542** The sqlite3_config() interface is used to make global configuration 1543** changes to SQLite in order to tune SQLite to the specific needs of 1544** the application. The default configuration is recommended for most 1545** applications and so this routine is usually not necessary. It is 1546** provided to support rare applications with unusual needs. 1547** 1548** <b>The sqlite3_config() interface is not threadsafe. The application 1549** must ensure that no other SQLite interfaces are invoked by other 1550** threads while sqlite3_config() is running.</b> 1551** 1552** The sqlite3_config() interface 1553** may only be invoked prior to library initialization using 1554** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1555** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1556** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1557** Note, however, that ^sqlite3_config() can be called as part of the 1558** implementation of an application-defined [sqlite3_os_init()]. 1559** 1560** The first argument to sqlite3_config() is an integer 1561** [configuration option] that determines 1562** what property of SQLite is to be configured. Subsequent arguments 1563** vary depending on the [configuration option] 1564** in the first argument. 1565** 1566** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1567** ^If the option is unknown or SQLite is unable to set the option 1568** then this routine returns a non-zero [error code]. 1569*/ 1570int sqlite3_config(int, ...); 1571 1572/* 1573** CAPI3REF: Configure database connections 1574** METHOD: sqlite3 1575** 1576** The sqlite3_db_config() interface is used to make configuration 1577** changes to a [database connection]. The interface is similar to 1578** [sqlite3_config()] except that the changes apply to a single 1579** [database connection] (specified in the first argument). 1580** 1581** The second argument to sqlite3_db_config(D,V,...) is the 1582** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1583** that indicates what aspect of the [database connection] is being configured. 1584** Subsequent arguments vary depending on the configuration verb. 1585** 1586** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1587** the call is considered successful. 1588*/ 1589int sqlite3_db_config(sqlite3*, int op, ...); 1590 1591/* 1592** CAPI3REF: Memory Allocation Routines 1593** 1594** An instance of this object defines the interface between SQLite 1595** and low-level memory allocation routines. 1596** 1597** This object is used in only one place in the SQLite interface. 1598** A pointer to an instance of this object is the argument to 1599** [sqlite3_config()] when the configuration option is 1600** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1601** By creating an instance of this object 1602** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1603** during configuration, an application can specify an alternative 1604** memory allocation subsystem for SQLite to use for all of its 1605** dynamic memory needs. 1606** 1607** Note that SQLite comes with several [built-in memory allocators] 1608** that are perfectly adequate for the overwhelming majority of applications 1609** and that this object is only useful to a tiny minority of applications 1610** with specialized memory allocation requirements. This object is 1611** also used during testing of SQLite in order to specify an alternative 1612** memory allocator that simulates memory out-of-memory conditions in 1613** order to verify that SQLite recovers gracefully from such 1614** conditions. 1615** 1616** The xMalloc, xRealloc, and xFree methods must work like the 1617** malloc(), realloc() and free() functions from the standard C library. 1618** ^SQLite guarantees that the second argument to 1619** xRealloc is always a value returned by a prior call to xRoundup. 1620** 1621** xSize should return the allocated size of a memory allocation 1622** previously obtained from xMalloc or xRealloc. The allocated size 1623** is always at least as big as the requested size but may be larger. 1624** 1625** The xRoundup method returns what would be the allocated size of 1626** a memory allocation given a particular requested size. Most memory 1627** allocators round up memory allocations at least to the next multiple 1628** of 8. Some allocators round up to a larger multiple or to a power of 2. 1629** Every memory allocation request coming in through [sqlite3_malloc()] 1630** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1631** that causes the corresponding memory allocation to fail. 1632** 1633** The xInit method initializes the memory allocator. For example, 1634** it might allocate any required mutexes or initialize internal data 1635** structures. The xShutdown method is invoked (indirectly) by 1636** [sqlite3_shutdown()] and should deallocate any resources acquired 1637** by xInit. The pAppData pointer is used as the only parameter to 1638** xInit and xShutdown. 1639** 1640** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1641** the xInit method, so the xInit method need not be threadsafe. The 1642** xShutdown method is only called from [sqlite3_shutdown()] so it does 1643** not need to be threadsafe either. For all other methods, SQLite 1644** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1645** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1646** it is by default) and so the methods are automatically serialized. 1647** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1648** methods must be threadsafe or else make their own arrangements for 1649** serialization. 1650** 1651** SQLite will never invoke xInit() more than once without an intervening 1652** call to xShutdown(). 1653*/ 1654typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1655struct sqlite3_mem_methods { 1656 void *(*xMalloc)(int); /* Memory allocation function */ 1657 void (*xFree)(void*); /* Free a prior allocation */ 1658 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1659 int (*xSize)(void*); /* Return the size of an allocation */ 1660 int (*xRoundup)(int); /* Round up request size to allocation size */ 1661 int (*xInit)(void*); /* Initialize the memory allocator */ 1662 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1663 void *pAppData; /* Argument to xInit() and xShutdown() */ 1664}; 1665 1666/* 1667** CAPI3REF: Configuration Options 1668** KEYWORDS: {configuration option} 1669** 1670** These constants are the available integer configuration options that 1671** can be passed as the first argument to the [sqlite3_config()] interface. 1672** 1673** New configuration options may be added in future releases of SQLite. 1674** Existing configuration options might be discontinued. Applications 1675** should check the return code from [sqlite3_config()] to make sure that 1676** the call worked. The [sqlite3_config()] interface will return a 1677** non-zero [error code] if a discontinued or unsupported configuration option 1678** is invoked. 1679** 1680** <dl> 1681** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1682** <dd>There are no arguments to this option. ^This option sets the 1683** [threading mode] to Single-thread. In other words, it disables 1684** all mutexing and puts SQLite into a mode where it can only be used 1685** by a single thread. ^If SQLite is compiled with 1686** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1687** it is not possible to change the [threading mode] from its default 1688** value of Single-thread and so [sqlite3_config()] will return 1689** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1690** configuration option.</dd> 1691** 1692** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1693** <dd>There are no arguments to this option. ^This option sets the 1694** [threading mode] to Multi-thread. In other words, it disables 1695** mutexing on [database connection] and [prepared statement] objects. 1696** The application is responsible for serializing access to 1697** [database connections] and [prepared statements]. But other mutexes 1698** are enabled so that SQLite will be safe to use in a multi-threaded 1699** environment as long as no two threads attempt to use the same 1700** [database connection] at the same time. ^If SQLite is compiled with 1701** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1702** it is not possible to set the Multi-thread [threading mode] and 1703** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1704** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1705** 1706** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1707** <dd>There are no arguments to this option. ^This option sets the 1708** [threading mode] to Serialized. In other words, this option enables 1709** all mutexes including the recursive 1710** mutexes on [database connection] and [prepared statement] objects. 1711** In this mode (which is the default when SQLite is compiled with 1712** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1713** to [database connections] and [prepared statements] so that the 1714** application is free to use the same [database connection] or the 1715** same [prepared statement] in different threads at the same time. 1716** ^If SQLite is compiled with 1717** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1718** it is not possible to set the Serialized [threading mode] and 1719** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1720** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1721** 1722** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1723** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1724** a pointer to an instance of the [sqlite3_mem_methods] structure. 1725** The argument specifies 1726** alternative low-level memory allocation routines to be used in place of 1727** the memory allocation routines built into SQLite.)^ ^SQLite makes 1728** its own private copy of the content of the [sqlite3_mem_methods] structure 1729** before the [sqlite3_config()] call returns.</dd> 1730** 1731** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1732** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1733** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1734** The [sqlite3_mem_methods] 1735** structure is filled with the currently defined memory allocation routines.)^ 1736** This option can be used to overload the default memory allocation 1737** routines with a wrapper that simulations memory allocation failure or 1738** tracks memory usage, for example. </dd> 1739** 1740** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1741** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1742** type int, interpreted as a boolean, which if true provides a hint to 1743** SQLite that it should avoid large memory allocations if possible. 1744** SQLite will run faster if it is free to make large memory allocations, 1745** but some application might prefer to run slower in exchange for 1746** guarantees about memory fragmentation that are possible if large 1747** allocations are avoided. This hint is normally off. 1748** </dd> 1749** 1750** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1751** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1752** interpreted as a boolean, which enables or disables the collection of 1753** memory allocation statistics. ^(When memory allocation statistics are 1754** disabled, the following SQLite interfaces become non-operational: 1755** <ul> 1756** <li> [sqlite3_hard_heap_limit64()] 1757** <li> [sqlite3_memory_used()] 1758** <li> [sqlite3_memory_highwater()] 1759** <li> [sqlite3_soft_heap_limit64()] 1760** <li> [sqlite3_status64()] 1761** </ul>)^ 1762** ^Memory allocation statistics are enabled by default unless SQLite is 1763** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1764** allocation statistics are disabled by default. 1765** </dd> 1766** 1767** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1768** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1769** </dd> 1770** 1771** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1772** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1773** that SQLite can use for the database page cache with the default page 1774** cache implementation. 1775** This configuration option is a no-op if an application-defined page 1776** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1777** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1778** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1779** and the number of cache lines (N). 1780** The sz argument should be the size of the largest database page 1781** (a power of two between 512 and 65536) plus some extra bytes for each 1782** page header. ^The number of extra bytes needed by the page header 1783** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1784** ^It is harmless, apart from the wasted memory, 1785** for the sz parameter to be larger than necessary. The pMem 1786** argument must be either a NULL pointer or a pointer to an 8-byte 1787** aligned block of memory of at least sz*N bytes, otherwise 1788** subsequent behavior is undefined. 1789** ^When pMem is not NULL, SQLite will strive to use the memory provided 1790** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1791** a page cache line is larger than sz bytes or if all of the pMem buffer 1792** is exhausted. 1793** ^If pMem is NULL and N is non-zero, then each database connection 1794** does an initial bulk allocation for page cache memory 1795** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1796** of -1024*N bytes if N is negative, . ^If additional 1797** page cache memory is needed beyond what is provided by the initial 1798** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1799** additional cache line. </dd> 1800** 1801** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1802** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1803** that SQLite will use for all of its dynamic memory allocation needs 1804** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1805** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1806** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1807** [SQLITE_ERROR] if invoked otherwise. 1808** ^There are three arguments to SQLITE_CONFIG_HEAP: 1809** An 8-byte aligned pointer to the memory, 1810** the number of bytes in the memory buffer, and the minimum allocation size. 1811** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1812** to using its default memory allocator (the system malloc() implementation), 1813** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1814** memory pointer is not NULL then the alternative memory 1815** allocator is engaged to handle all of SQLites memory allocation needs. 1816** The first pointer (the memory pointer) must be aligned to an 8-byte 1817** boundary or subsequent behavior of SQLite will be undefined. 1818** The minimum allocation size is capped at 2**12. Reasonable values 1819** for the minimum allocation size are 2**5 through 2**8.</dd> 1820** 1821** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1822** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1823** pointer to an instance of the [sqlite3_mutex_methods] structure. 1824** The argument specifies alternative low-level mutex routines to be used 1825** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1826** the content of the [sqlite3_mutex_methods] structure before the call to 1827** [sqlite3_config()] returns. ^If SQLite is compiled with 1828** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1829** the entire mutexing subsystem is omitted from the build and hence calls to 1830** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1831** return [SQLITE_ERROR].</dd> 1832** 1833** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1834** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1835** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1836** [sqlite3_mutex_methods] 1837** structure is filled with the currently defined mutex routines.)^ 1838** This option can be used to overload the default mutex allocation 1839** routines with a wrapper used to track mutex usage for performance 1840** profiling or testing, for example. ^If SQLite is compiled with 1841** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1842** the entire mutexing subsystem is omitted from the build and hence calls to 1843** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1844** return [SQLITE_ERROR].</dd> 1845** 1846** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1847** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1848** the default size of lookaside memory on each [database connection]. 1849** The first argument is the 1850** size of each lookaside buffer slot and the second is the number of 1851** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1852** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1853** option to [sqlite3_db_config()] can be used to change the lookaside 1854** configuration on individual connections.)^ </dd> 1855** 1856** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1857** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1858** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1859** the interface to a custom page cache implementation.)^ 1860** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1861** 1862** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1863** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1864** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1865** the current page cache implementation into that object.)^ </dd> 1866** 1867** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1868** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1869** global [error log]. 1870** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1871** function with a call signature of void(*)(void*,int,const char*), 1872** and a pointer to void. ^If the function pointer is not NULL, it is 1873** invoked by [sqlite3_log()] to process each logging event. ^If the 1874** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1875** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1876** passed through as the first parameter to the application-defined logger 1877** function whenever that function is invoked. ^The second parameter to 1878** the logger function is a copy of the first parameter to the corresponding 1879** [sqlite3_log()] call and is intended to be a [result code] or an 1880** [extended result code]. ^The third parameter passed to the logger is 1881** log message after formatting via [sqlite3_snprintf()]. 1882** The SQLite logging interface is not reentrant; the logger function 1883** supplied by the application must not invoke any SQLite interface. 1884** In a multi-threaded application, the application-defined logger 1885** function must be threadsafe. </dd> 1886** 1887** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1888** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1889** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1890** then URI handling is globally disabled.)^ ^If URI handling is globally 1891** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1892** [sqlite3_open16()] or 1893** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1894** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1895** connection is opened. ^If it is globally disabled, filenames are 1896** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1897** database connection is opened. ^(By default, URI handling is globally 1898** disabled. The default value may be changed by compiling with the 1899** [SQLITE_USE_URI] symbol defined.)^ 1900** 1901** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1902** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1903** argument which is interpreted as a boolean in order to enable or disable 1904** the use of covering indices for full table scans in the query optimizer. 1905** ^The default setting is determined 1906** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1907** if that compile-time option is omitted. 1908** The ability to disable the use of covering indices for full table scans 1909** is because some incorrectly coded legacy applications might malfunction 1910** when the optimization is enabled. Providing the ability to 1911** disable the optimization allows the older, buggy application code to work 1912** without change even with newer versions of SQLite. 1913** 1914** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1915** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1916** <dd> These options are obsolete and should not be used by new code. 1917** They are retained for backwards compatibility but are now no-ops. 1918** </dd> 1919** 1920** [[SQLITE_CONFIG_SQLLOG]] 1921** <dt>SQLITE_CONFIG_SQLLOG 1922** <dd>This option is only available if sqlite is compiled with the 1923** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1924** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1925** The second should be of type (void*). The callback is invoked by the library 1926** in three separate circumstances, identified by the value passed as the 1927** fourth parameter. If the fourth parameter is 0, then the database connection 1928** passed as the second argument has just been opened. The third argument 1929** points to a buffer containing the name of the main database file. If the 1930** fourth parameter is 1, then the SQL statement that the third parameter 1931** points to has just been executed. Or, if the fourth parameter is 2, then 1932** the connection being passed as the second parameter is being closed. The 1933** third parameter is passed NULL In this case. An example of using this 1934** configuration option can be seen in the "test_sqllog.c" source file in 1935** the canonical SQLite source tree.</dd> 1936** 1937** [[SQLITE_CONFIG_MMAP_SIZE]] 1938** <dt>SQLITE_CONFIG_MMAP_SIZE 1939** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1940** that are the default mmap size limit (the default setting for 1941** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1942** ^The default setting can be overridden by each database connection using 1943** either the [PRAGMA mmap_size] command, or by using the 1944** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1945** will be silently truncated if necessary so that it does not exceed the 1946** compile-time maximum mmap size set by the 1947** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1948** ^If either argument to this option is negative, then that argument is 1949** changed to its compile-time default. 1950** 1951** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1952** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1953** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1954** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1955** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1956** that specifies the maximum size of the created heap. 1957** 1958** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1959** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1960** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1961** is a pointer to an integer and writes into that integer the number of extra 1962** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1963** The amount of extra space required can change depending on the compiler, 1964** target platform, and SQLite version. 1965** 1966** [[SQLITE_CONFIG_PMASZ]] 1967** <dt>SQLITE_CONFIG_PMASZ 1968** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1969** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1970** sorter to that integer. The default minimum PMA Size is set by the 1971** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1972** to help with sort operations when multithreaded sorting 1973** is enabled (using the [PRAGMA threads] command) and the amount of content 1974** to be sorted exceeds the page size times the minimum of the 1975** [PRAGMA cache_size] setting and this value. 1976** 1977** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1978** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1979** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1980** becomes the [statement journal] spill-to-disk threshold. 1981** [Statement journals] are held in memory until their size (in bytes) 1982** exceeds this threshold, at which point they are written to disk. 1983** Or if the threshold is -1, statement journals are always held 1984** exclusively in memory. 1985** Since many statement journals never become large, setting the spill 1986** threshold to a value such as 64KiB can greatly reduce the amount of 1987** I/O required to support statement rollback. 1988** The default value for this setting is controlled by the 1989** [SQLITE_STMTJRNL_SPILL] compile-time option. 1990** 1991** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1992** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1993** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1994** of type (int) - the new value of the sorter-reference size threshold. 1995** Usually, when SQLite uses an external sort to order records according 1996** to an ORDER BY clause, all fields required by the caller are present in the 1997** sorted records. However, if SQLite determines based on the declared type 1998** of a table column that its values are likely to be very large - larger 1999** than the configured sorter-reference size threshold - then a reference 2000** is stored in each sorted record and the required column values loaded 2001** from the database as records are returned in sorted order. The default 2002** value for this option is to never use this optimization. Specifying a 2003** negative value for this option restores the default behaviour. 2004** This option is only available if SQLite is compiled with the 2005** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2006** 2007** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2008** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2009** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2010** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2011** database created using [sqlite3_deserialize()]. This default maximum 2012** size can be adjusted up or down for individual databases using the 2013** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2014** configuration setting is never used, then the default maximum is determined 2015** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2016** compile-time option is not set, then the default maximum is 1073741824. 2017** </dl> 2018*/ 2019#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2020#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2021#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2022#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2023#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2024#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2025#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2026#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2027#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2028#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2029#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2030/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2031#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2032#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2033#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2034#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2035#define SQLITE_CONFIG_URI 17 /* int */ 2036#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2037#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2038#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2039#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2040#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2041#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2042#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2043#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2044#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2045#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2046#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2047#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2048 2049/* 2050** CAPI3REF: Database Connection Configuration Options 2051** 2052** These constants are the available integer configuration options that 2053** can be passed as the second argument to the [sqlite3_db_config()] interface. 2054** 2055** New configuration options may be added in future releases of SQLite. 2056** Existing configuration options might be discontinued. Applications 2057** should check the return code from [sqlite3_db_config()] to make sure that 2058** the call worked. ^The [sqlite3_db_config()] interface will return a 2059** non-zero [error code] if a discontinued or unsupported configuration option 2060** is invoked. 2061** 2062** <dl> 2063** [[SQLITE_DBCONFIG_LOOKASIDE]] 2064** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2065** <dd> ^This option takes three additional arguments that determine the 2066** [lookaside memory allocator] configuration for the [database connection]. 2067** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2068** pointer to a memory buffer to use for lookaside memory. 2069** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2070** may be NULL in which case SQLite will allocate the 2071** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2072** size of each lookaside buffer slot. ^The third argument is the number of 2073** slots. The size of the buffer in the first argument must be greater than 2074** or equal to the product of the second and third arguments. The buffer 2075** must be aligned to an 8-byte boundary. ^If the second argument to 2076** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2077** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2078** configuration for a database connection can only be changed when that 2079** connection is not currently using lookaside memory, or in other words 2080** when the "current value" returned by 2081** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2082** Any attempt to change the lookaside memory configuration when lookaside 2083** memory is in use leaves the configuration unchanged and returns 2084** [SQLITE_BUSY].)^</dd> 2085** 2086** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2087** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2088** <dd> ^This option is used to enable or disable the enforcement of 2089** [foreign key constraints]. There should be two additional arguments. 2090** The first argument is an integer which is 0 to disable FK enforcement, 2091** positive to enable FK enforcement or negative to leave FK enforcement 2092** unchanged. The second parameter is a pointer to an integer into which 2093** is written 0 or 1 to indicate whether FK enforcement is off or on 2094** following this call. The second parameter may be a NULL pointer, in 2095** which case the FK enforcement setting is not reported back. </dd> 2096** 2097** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2098** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2099** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2100** There should be two additional arguments. 2101** The first argument is an integer which is 0 to disable triggers, 2102** positive to enable triggers or negative to leave the setting unchanged. 2103** The second parameter is a pointer to an integer into which 2104** is written 0 or 1 to indicate whether triggers are disabled or enabled 2105** following this call. The second parameter may be a NULL pointer, in 2106** which case the trigger setting is not reported back. </dd> 2107** 2108** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2109** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2110** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2111** There should be two additional arguments. 2112** The first argument is an integer which is 0 to disable views, 2113** positive to enable views or negative to leave the setting unchanged. 2114** The second parameter is a pointer to an integer into which 2115** is written 0 or 1 to indicate whether views are disabled or enabled 2116** following this call. The second parameter may be a NULL pointer, in 2117** which case the view setting is not reported back. </dd> 2118** 2119** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2120** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2121** <dd> ^This option is used to enable or disable the 2122** [fts3_tokenizer()] function which is part of the 2123** [FTS3] full-text search engine extension. 2124** There should be two additional arguments. 2125** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2126** positive to enable fts3_tokenizer() or negative to leave the setting 2127** unchanged. 2128** The second parameter is a pointer to an integer into which 2129** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2130** following this call. The second parameter may be a NULL pointer, in 2131** which case the new setting is not reported back. </dd> 2132** 2133** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2134** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2135** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2136** interface independently of the [load_extension()] SQL function. 2137** The [sqlite3_enable_load_extension()] API enables or disables both the 2138** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2139** There should be two additional arguments. 2140** When the first argument to this interface is 1, then only the C-API is 2141** enabled and the SQL function remains disabled. If the first argument to 2142** this interface is 0, then both the C-API and the SQL function are disabled. 2143** If the first argument is -1, then no changes are made to state of either the 2144** C-API or the SQL function. 2145** The second parameter is a pointer to an integer into which 2146** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2147** is disabled or enabled following this call. The second parameter may 2148** be a NULL pointer, in which case the new setting is not reported back. 2149** </dd> 2150** 2151** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2152** <dd> ^This option is used to change the name of the "main" database 2153** schema. ^The sole argument is a pointer to a constant UTF8 string 2154** which will become the new schema name in place of "main". ^SQLite 2155** does not make a copy of the new main schema name string, so the application 2156** must ensure that the argument passed into this DBCONFIG option is unchanged 2157** until after the database connection closes. 2158** </dd> 2159** 2160** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2161** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2162** <dd> Usually, when a database in wal mode is closed or detached from a 2163** database handle, SQLite checks if this will mean that there are now no 2164** connections at all to the database. If so, it performs a checkpoint 2165** operation before closing the connection. This option may be used to 2166** override this behaviour. The first parameter passed to this operation 2167** is an integer - positive to disable checkpoints-on-close, or zero (the 2168** default) to enable them, and negative to leave the setting unchanged. 2169** The second parameter is a pointer to an integer 2170** into which is written 0 or 1 to indicate whether checkpoints-on-close 2171** have been disabled - 0 if they are not disabled, 1 if they are. 2172** </dd> 2173** 2174** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2175** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2176** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2177** a single SQL query statement will always use the same algorithm regardless 2178** of values of [bound parameters].)^ The QPSG disables some query optimizations 2179** that look at the values of bound parameters, which can make some queries 2180** slower. But the QPSG has the advantage of more predictable behavior. With 2181** the QPSG active, SQLite will always use the same query plan in the field as 2182** was used during testing in the lab. 2183** The first argument to this setting is an integer which is 0 to disable 2184** the QPSG, positive to enable QPSG, or negative to leave the setting 2185** unchanged. The second parameter is a pointer to an integer into which 2186** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2187** following this call. 2188** </dd> 2189** 2190** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2191** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2192** include output for any operations performed by trigger programs. This 2193** option is used to set or clear (the default) a flag that governs this 2194** behavior. The first parameter passed to this operation is an integer - 2195** positive to enable output for trigger programs, or zero to disable it, 2196** or negative to leave the setting unchanged. 2197** The second parameter is a pointer to an integer into which is written 2198** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2199** it is not disabled, 1 if it is. 2200** </dd> 2201** 2202** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2203** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2204** [VACUUM] in order to reset a database back to an empty database 2205** with no schema and no content. The following process works even for 2206** a badly corrupted database file: 2207** <ol> 2208** <li> If the database connection is newly opened, make sure it has read the 2209** database schema by preparing then discarding some query against the 2210** database, or calling sqlite3_table_column_metadata(), ignoring any 2211** errors. This step is only necessary if the application desires to keep 2212** the database in WAL mode after the reset if it was in WAL mode before 2213** the reset. 2214** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2215** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2216** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2217** </ol> 2218** Because resetting a database is destructive and irreversible, the 2219** process requires the use of this obscure API and multiple steps to help 2220** ensure that it does not happen by accident. 2221** 2222** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2223** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2224** "defensive" flag for a database connection. When the defensive 2225** flag is enabled, language features that allow ordinary SQL to 2226** deliberately corrupt the database file are disabled. The disabled 2227** features include but are not limited to the following: 2228** <ul> 2229** <li> The [PRAGMA writable_schema=ON] statement. 2230** <li> The [PRAGMA journal_mode=OFF] statement. 2231** <li> Writes to the [sqlite_dbpage] virtual table. 2232** <li> Direct writes to [shadow tables]. 2233** </ul> 2234** </dd> 2235** 2236** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2237** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2238** "writable_schema" flag. This has the same effect and is logically equivalent 2239** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2240** The first argument to this setting is an integer which is 0 to disable 2241** the writable_schema, positive to enable writable_schema, or negative to 2242** leave the setting unchanged. The second parameter is a pointer to an 2243** integer into which is written 0 or 1 to indicate whether the writable_schema 2244** is enabled or disabled following this call. 2245** </dd> 2246** 2247** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2248** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2249** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2250** the legacy behavior of the [ALTER TABLE RENAME] command such it 2251** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2252** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2253** additional information. This feature can also be turned on and off 2254** using the [PRAGMA legacy_alter_table] statement. 2255** </dd> 2256** 2257** [[SQLITE_DBCONFIG_DQS_DML]] 2258** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2259** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2260** the legacy [double-quoted string literal] misfeature for DML statements 2261** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2262** default value of this setting is determined by the [-DSQLITE_DQS] 2263** compile-time option. 2264** </dd> 2265** 2266** [[SQLITE_DBCONFIG_DQS_DDL]] 2267** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2268** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2269** the legacy [double-quoted string literal] misfeature for DDL statements, 2270** such as CREATE TABLE and CREATE INDEX. The 2271** default value of this setting is determined by the [-DSQLITE_DQS] 2272** compile-time option. 2273** </dd> 2274** 2275** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2276** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2277** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2278** assume that database schemas (the contents of the [sqlite_master] tables) 2279** are untainted by malicious content. 2280** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2281** takes additional defensive steps to protect the application from harm 2282** including: 2283** <ul> 2284** <li> Prohibit the use of SQL functions inside triggers, views, 2285** CHECK constraints, DEFAULT clauses, expression indexes, 2286** partial indexes, or generated columns 2287** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2288** <li> Prohibit the use of virtual tables inside of triggers or views 2289** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2290** </ul> 2291** This setting defaults to "on" for legacy compatibility, however 2292** all applications are advised to turn it off if possible. This setting 2293** can also be controlled using the [PRAGMA trusted_schema] statement. 2294** </dd> 2295** 2296** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2297** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2298** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2299** the legacy file format flag. When activated, this flag causes all newly 2300** created database file to have a schema format version number (the 4-byte 2301** integer found at offset 44 into the database header) of 1. This in turn 2302** means that the resulting database file will be readable and writable by 2303** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2304** newly created databases are generally not understandable by SQLite versions 2305** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2306** is now scarcely any need to generated database files that are compatible 2307** all the way back to version 3.0.0, and so this setting is of little 2308** practical use, but is provided so that SQLite can continue to claim the 2309** ability to generate new database files that are compatible with version 2310** 3.0.0. 2311** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2312** the [VACUUM] command will fail with an obscure error when attempting to 2313** process a table with generated columns and a descending index. This is 2314** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2315** either generated columns or decending indexes. 2316** </dd> 2317** </dl> 2318*/ 2319#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2320#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2321#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2322#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2323#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2324#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2325#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2326#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2327#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2328#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2329#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2330#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2331#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2332#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2333#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2334#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2335#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2336#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2337#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2338 2339/* 2340** CAPI3REF: Enable Or Disable Extended Result Codes 2341** METHOD: sqlite3 2342** 2343** ^The sqlite3_extended_result_codes() routine enables or disables the 2344** [extended result codes] feature of SQLite. ^The extended result 2345** codes are disabled by default for historical compatibility. 2346*/ 2347int sqlite3_extended_result_codes(sqlite3*, int onoff); 2348 2349/* 2350** CAPI3REF: Last Insert Rowid 2351** METHOD: sqlite3 2352** 2353** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2354** has a unique 64-bit signed 2355** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2356** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2357** names are not also used by explicitly declared columns. ^If 2358** the table has a column of type [INTEGER PRIMARY KEY] then that column 2359** is another alias for the rowid. 2360** 2361** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2362** the most recent successful [INSERT] into a rowid table or [virtual table] 2363** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2364** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2365** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2366** zero. 2367** 2368** As well as being set automatically as rows are inserted into database 2369** tables, the value returned by this function may be set explicitly by 2370** [sqlite3_set_last_insert_rowid()] 2371** 2372** Some virtual table implementations may INSERT rows into rowid tables as 2373** part of committing a transaction (e.g. to flush data accumulated in memory 2374** to disk). In this case subsequent calls to this function return the rowid 2375** associated with these internal INSERT operations, which leads to 2376** unintuitive results. Virtual table implementations that do write to rowid 2377** tables in this way can avoid this problem by restoring the original 2378** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2379** control to the user. 2380** 2381** ^(If an [INSERT] occurs within a trigger then this routine will 2382** return the [rowid] of the inserted row as long as the trigger is 2383** running. Once the trigger program ends, the value returned 2384** by this routine reverts to what it was before the trigger was fired.)^ 2385** 2386** ^An [INSERT] that fails due to a constraint violation is not a 2387** successful [INSERT] and does not change the value returned by this 2388** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2389** and INSERT OR ABORT make no changes to the return value of this 2390** routine when their insertion fails. ^(When INSERT OR REPLACE 2391** encounters a constraint violation, it does not fail. The 2392** INSERT continues to completion after deleting rows that caused 2393** the constraint problem so INSERT OR REPLACE will always change 2394** the return value of this interface.)^ 2395** 2396** ^For the purposes of this routine, an [INSERT] is considered to 2397** be successful even if it is subsequently rolled back. 2398** 2399** This function is accessible to SQL statements via the 2400** [last_insert_rowid() SQL function]. 2401** 2402** If a separate thread performs a new [INSERT] on the same 2403** database connection while the [sqlite3_last_insert_rowid()] 2404** function is running and thus changes the last insert [rowid], 2405** then the value returned by [sqlite3_last_insert_rowid()] is 2406** unpredictable and might not equal either the old or the new 2407** last insert [rowid]. 2408*/ 2409sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2410 2411/* 2412** CAPI3REF: Set the Last Insert Rowid value. 2413** METHOD: sqlite3 2414** 2415** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2416** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2417** without inserting a row into the database. 2418*/ 2419void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2420 2421/* 2422** CAPI3REF: Count The Number Of Rows Modified 2423** METHOD: sqlite3 2424** 2425** ^This function returns the number of rows modified, inserted or 2426** deleted by the most recently completed INSERT, UPDATE or DELETE 2427** statement on the database connection specified by the only parameter. 2428** ^Executing any other type of SQL statement does not modify the value 2429** returned by this function. 2430** 2431** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2432** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2433** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2434** 2435** Changes to a view that are intercepted by 2436** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2437** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2438** DELETE statement run on a view is always zero. Only changes made to real 2439** tables are counted. 2440** 2441** Things are more complicated if the sqlite3_changes() function is 2442** executed while a trigger program is running. This may happen if the 2443** program uses the [changes() SQL function], or if some other callback 2444** function invokes sqlite3_changes() directly. Essentially: 2445** 2446** <ul> 2447** <li> ^(Before entering a trigger program the value returned by 2448** sqlite3_changes() function is saved. After the trigger program 2449** has finished, the original value is restored.)^ 2450** 2451** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2452** statement sets the value returned by sqlite3_changes() 2453** upon completion as normal. Of course, this value will not include 2454** any changes performed by sub-triggers, as the sqlite3_changes() 2455** value will be saved and restored after each sub-trigger has run.)^ 2456** </ul> 2457** 2458** ^This means that if the changes() SQL function (or similar) is used 2459** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2460** returns the value as set when the calling statement began executing. 2461** ^If it is used by the second or subsequent such statement within a trigger 2462** program, the value returned reflects the number of rows modified by the 2463** previous INSERT, UPDATE or DELETE statement within the same trigger. 2464** 2465** If a separate thread makes changes on the same database connection 2466** while [sqlite3_changes()] is running then the value returned 2467** is unpredictable and not meaningful. 2468** 2469** See also: 2470** <ul> 2471** <li> the [sqlite3_total_changes()] interface 2472** <li> the [count_changes pragma] 2473** <li> the [changes() SQL function] 2474** <li> the [data_version pragma] 2475** </ul> 2476*/ 2477int sqlite3_changes(sqlite3*); 2478 2479/* 2480** CAPI3REF: Total Number Of Rows Modified 2481** METHOD: sqlite3 2482** 2483** ^This function returns the total number of rows inserted, modified or 2484** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2485** since the database connection was opened, including those executed as 2486** part of trigger programs. ^Executing any other type of SQL statement 2487** does not affect the value returned by sqlite3_total_changes(). 2488** 2489** ^Changes made as part of [foreign key actions] are included in the 2490** count, but those made as part of REPLACE constraint resolution are 2491** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2492** are not counted. 2493** 2494** The [sqlite3_total_changes(D)] interface only reports the number 2495** of rows that changed due to SQL statement run against database 2496** connection D. Any changes by other database connections are ignored. 2497** To detect changes against a database file from other database 2498** connections use the [PRAGMA data_version] command or the 2499** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2500** 2501** If a separate thread makes changes on the same database connection 2502** while [sqlite3_total_changes()] is running then the value 2503** returned is unpredictable and not meaningful. 2504** 2505** See also: 2506** <ul> 2507** <li> the [sqlite3_changes()] interface 2508** <li> the [count_changes pragma] 2509** <li> the [changes() SQL function] 2510** <li> the [data_version pragma] 2511** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2512** </ul> 2513*/ 2514int sqlite3_total_changes(sqlite3*); 2515 2516/* 2517** CAPI3REF: Interrupt A Long-Running Query 2518** METHOD: sqlite3 2519** 2520** ^This function causes any pending database operation to abort and 2521** return at its earliest opportunity. This routine is typically 2522** called in response to a user action such as pressing "Cancel" 2523** or Ctrl-C where the user wants a long query operation to halt 2524** immediately. 2525** 2526** ^It is safe to call this routine from a thread different from the 2527** thread that is currently running the database operation. But it 2528** is not safe to call this routine with a [database connection] that 2529** is closed or might close before sqlite3_interrupt() returns. 2530** 2531** ^If an SQL operation is very nearly finished at the time when 2532** sqlite3_interrupt() is called, then it might not have an opportunity 2533** to be interrupted and might continue to completion. 2534** 2535** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2536** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2537** that is inside an explicit transaction, then the entire transaction 2538** will be rolled back automatically. 2539** 2540** ^The sqlite3_interrupt(D) call is in effect until all currently running 2541** SQL statements on [database connection] D complete. ^Any new SQL statements 2542** that are started after the sqlite3_interrupt() call and before the 2543** running statement count reaches zero are interrupted as if they had been 2544** running prior to the sqlite3_interrupt() call. ^New SQL statements 2545** that are started after the running statement count reaches zero are 2546** not effected by the sqlite3_interrupt(). 2547** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2548** SQL statements is a no-op and has no effect on SQL statements 2549** that are started after the sqlite3_interrupt() call returns. 2550*/ 2551void sqlite3_interrupt(sqlite3*); 2552 2553/* 2554** CAPI3REF: Determine If An SQL Statement Is Complete 2555** 2556** These routines are useful during command-line input to determine if the 2557** currently entered text seems to form a complete SQL statement or 2558** if additional input is needed before sending the text into 2559** SQLite for parsing. ^These routines return 1 if the input string 2560** appears to be a complete SQL statement. ^A statement is judged to be 2561** complete if it ends with a semicolon token and is not a prefix of a 2562** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2563** string literals or quoted identifier names or comments are not 2564** independent tokens (they are part of the token in which they are 2565** embedded) and thus do not count as a statement terminator. ^Whitespace 2566** and comments that follow the final semicolon are ignored. 2567** 2568** ^These routines return 0 if the statement is incomplete. ^If a 2569** memory allocation fails, then SQLITE_NOMEM is returned. 2570** 2571** ^These routines do not parse the SQL statements thus 2572** will not detect syntactically incorrect SQL. 2573** 2574** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2575** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2576** automatically by sqlite3_complete16(). If that initialization fails, 2577** then the return value from sqlite3_complete16() will be non-zero 2578** regardless of whether or not the input SQL is complete.)^ 2579** 2580** The input to [sqlite3_complete()] must be a zero-terminated 2581** UTF-8 string. 2582** 2583** The input to [sqlite3_complete16()] must be a zero-terminated 2584** UTF-16 string in native byte order. 2585*/ 2586int sqlite3_complete(const char *sql); 2587int sqlite3_complete16(const void *sql); 2588 2589/* 2590** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2591** KEYWORDS: {busy-handler callback} {busy handler} 2592** METHOD: sqlite3 2593** 2594** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2595** that might be invoked with argument P whenever 2596** an attempt is made to access a database table associated with 2597** [database connection] D when another thread 2598** or process has the table locked. 2599** The sqlite3_busy_handler() interface is used to implement 2600** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2601** 2602** ^If the busy callback is NULL, then [SQLITE_BUSY] 2603** is returned immediately upon encountering the lock. ^If the busy callback 2604** is not NULL, then the callback might be invoked with two arguments. 2605** 2606** ^The first argument to the busy handler is a copy of the void* pointer which 2607** is the third argument to sqlite3_busy_handler(). ^The second argument to 2608** the busy handler callback is the number of times that the busy handler has 2609** been invoked previously for the same locking event. ^If the 2610** busy callback returns 0, then no additional attempts are made to 2611** access the database and [SQLITE_BUSY] is returned 2612** to the application. 2613** ^If the callback returns non-zero, then another attempt 2614** is made to access the database and the cycle repeats. 2615** 2616** The presence of a busy handler does not guarantee that it will be invoked 2617** when there is lock contention. ^If SQLite determines that invoking the busy 2618** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2619** to the application instead of invoking the 2620** busy handler. 2621** Consider a scenario where one process is holding a read lock that 2622** it is trying to promote to a reserved lock and 2623** a second process is holding a reserved lock that it is trying 2624** to promote to an exclusive lock. The first process cannot proceed 2625** because it is blocked by the second and the second process cannot 2626** proceed because it is blocked by the first. If both processes 2627** invoke the busy handlers, neither will make any progress. Therefore, 2628** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2629** will induce the first process to release its read lock and allow 2630** the second process to proceed. 2631** 2632** ^The default busy callback is NULL. 2633** 2634** ^(There can only be a single busy handler defined for each 2635** [database connection]. Setting a new busy handler clears any 2636** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2637** or evaluating [PRAGMA busy_timeout=N] will change the 2638** busy handler and thus clear any previously set busy handler. 2639** 2640** The busy callback should not take any actions which modify the 2641** database connection that invoked the busy handler. In other words, 2642** the busy handler is not reentrant. Any such actions 2643** result in undefined behavior. 2644** 2645** A busy handler must not close the database connection 2646** or [prepared statement] that invoked the busy handler. 2647*/ 2648int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2649 2650/* 2651** CAPI3REF: Set A Busy Timeout 2652** METHOD: sqlite3 2653** 2654** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2655** for a specified amount of time when a table is locked. ^The handler 2656** will sleep multiple times until at least "ms" milliseconds of sleeping 2657** have accumulated. ^After at least "ms" milliseconds of sleeping, 2658** the handler returns 0 which causes [sqlite3_step()] to return 2659** [SQLITE_BUSY]. 2660** 2661** ^Calling this routine with an argument less than or equal to zero 2662** turns off all busy handlers. 2663** 2664** ^(There can only be a single busy handler for a particular 2665** [database connection] at any given moment. If another busy handler 2666** was defined (using [sqlite3_busy_handler()]) prior to calling 2667** this routine, that other busy handler is cleared.)^ 2668** 2669** See also: [PRAGMA busy_timeout] 2670*/ 2671int sqlite3_busy_timeout(sqlite3*, int ms); 2672 2673/* 2674** CAPI3REF: Convenience Routines For Running Queries 2675** METHOD: sqlite3 2676** 2677** This is a legacy interface that is preserved for backwards compatibility. 2678** Use of this interface is not recommended. 2679** 2680** Definition: A <b>result table</b> is memory data structure created by the 2681** [sqlite3_get_table()] interface. A result table records the 2682** complete query results from one or more queries. 2683** 2684** The table conceptually has a number of rows and columns. But 2685** these numbers are not part of the result table itself. These 2686** numbers are obtained separately. Let N be the number of rows 2687** and M be the number of columns. 2688** 2689** A result table is an array of pointers to zero-terminated UTF-8 strings. 2690** There are (N+1)*M elements in the array. The first M pointers point 2691** to zero-terminated strings that contain the names of the columns. 2692** The remaining entries all point to query results. NULL values result 2693** in NULL pointers. All other values are in their UTF-8 zero-terminated 2694** string representation as returned by [sqlite3_column_text()]. 2695** 2696** A result table might consist of one or more memory allocations. 2697** It is not safe to pass a result table directly to [sqlite3_free()]. 2698** A result table should be deallocated using [sqlite3_free_table()]. 2699** 2700** ^(As an example of the result table format, suppose a query result 2701** is as follows: 2702** 2703** <blockquote><pre> 2704** Name | Age 2705** ----------------------- 2706** Alice | 43 2707** Bob | 28 2708** Cindy | 21 2709** </pre></blockquote> 2710** 2711** There are two columns (M==2) and three rows (N==3). Thus the 2712** result table has 8 entries. Suppose the result table is stored 2713** in an array named azResult. Then azResult holds this content: 2714** 2715** <blockquote><pre> 2716** azResult[0] = "Name"; 2717** azResult[1] = "Age"; 2718** azResult[2] = "Alice"; 2719** azResult[3] = "43"; 2720** azResult[4] = "Bob"; 2721** azResult[5] = "28"; 2722** azResult[6] = "Cindy"; 2723** azResult[7] = "21"; 2724** </pre></blockquote>)^ 2725** 2726** ^The sqlite3_get_table() function evaluates one or more 2727** semicolon-separated SQL statements in the zero-terminated UTF-8 2728** string of its 2nd parameter and returns a result table to the 2729** pointer given in its 3rd parameter. 2730** 2731** After the application has finished with the result from sqlite3_get_table(), 2732** it must pass the result table pointer to sqlite3_free_table() in order to 2733** release the memory that was malloced. Because of the way the 2734** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2735** function must not try to call [sqlite3_free()] directly. Only 2736** [sqlite3_free_table()] is able to release the memory properly and safely. 2737** 2738** The sqlite3_get_table() interface is implemented as a wrapper around 2739** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2740** to any internal data structures of SQLite. It uses only the public 2741** interface defined here. As a consequence, errors that occur in the 2742** wrapper layer outside of the internal [sqlite3_exec()] call are not 2743** reflected in subsequent calls to [sqlite3_errcode()] or 2744** [sqlite3_errmsg()]. 2745*/ 2746int sqlite3_get_table( 2747 sqlite3 *db, /* An open database */ 2748 const char *zSql, /* SQL to be evaluated */ 2749 char ***pazResult, /* Results of the query */ 2750 int *pnRow, /* Number of result rows written here */ 2751 int *pnColumn, /* Number of result columns written here */ 2752 char **pzErrmsg /* Error msg written here */ 2753); 2754void sqlite3_free_table(char **result); 2755 2756/* 2757** CAPI3REF: Formatted String Printing Functions 2758** 2759** These routines are work-alikes of the "printf()" family of functions 2760** from the standard C library. 2761** These routines understand most of the common formatting options from 2762** the standard library printf() 2763** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2764** See the [built-in printf()] documentation for details. 2765** 2766** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2767** results into memory obtained from [sqlite3_malloc64()]. 2768** The strings returned by these two routines should be 2769** released by [sqlite3_free()]. ^Both routines return a 2770** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2771** memory to hold the resulting string. 2772** 2773** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2774** the standard C library. The result is written into the 2775** buffer supplied as the second parameter whose size is given by 2776** the first parameter. Note that the order of the 2777** first two parameters is reversed from snprintf().)^ This is an 2778** historical accident that cannot be fixed without breaking 2779** backwards compatibility. ^(Note also that sqlite3_snprintf() 2780** returns a pointer to its buffer instead of the number of 2781** characters actually written into the buffer.)^ We admit that 2782** the number of characters written would be a more useful return 2783** value but we cannot change the implementation of sqlite3_snprintf() 2784** now without breaking compatibility. 2785** 2786** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2787** guarantees that the buffer is always zero-terminated. ^The first 2788** parameter "n" is the total size of the buffer, including space for 2789** the zero terminator. So the longest string that can be completely 2790** written will be n-1 characters. 2791** 2792** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2793** 2794** See also: [built-in printf()], [printf() SQL function] 2795*/ 2796char *sqlite3_mprintf(const char*,...); 2797char *sqlite3_vmprintf(const char*, va_list); 2798char *sqlite3_snprintf(int,char*,const char*, ...); 2799char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2800 2801/* 2802** CAPI3REF: Memory Allocation Subsystem 2803** 2804** The SQLite core uses these three routines for all of its own 2805** internal memory allocation needs. "Core" in the previous sentence 2806** does not include operating-system specific [VFS] implementation. The 2807** Windows VFS uses native malloc() and free() for some operations. 2808** 2809** ^The sqlite3_malloc() routine returns a pointer to a block 2810** of memory at least N bytes in length, where N is the parameter. 2811** ^If sqlite3_malloc() is unable to obtain sufficient free 2812** memory, it returns a NULL pointer. ^If the parameter N to 2813** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2814** a NULL pointer. 2815** 2816** ^The sqlite3_malloc64(N) routine works just like 2817** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2818** of a signed 32-bit integer. 2819** 2820** ^Calling sqlite3_free() with a pointer previously returned 2821** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2822** that it might be reused. ^The sqlite3_free() routine is 2823** a no-op if is called with a NULL pointer. Passing a NULL pointer 2824** to sqlite3_free() is harmless. After being freed, memory 2825** should neither be read nor written. Even reading previously freed 2826** memory might result in a segmentation fault or other severe error. 2827** Memory corruption, a segmentation fault, or other severe error 2828** might result if sqlite3_free() is called with a non-NULL pointer that 2829** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2830** 2831** ^The sqlite3_realloc(X,N) interface attempts to resize a 2832** prior memory allocation X to be at least N bytes. 2833** ^If the X parameter to sqlite3_realloc(X,N) 2834** is a NULL pointer then its behavior is identical to calling 2835** sqlite3_malloc(N). 2836** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2837** negative then the behavior is exactly the same as calling 2838** sqlite3_free(X). 2839** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2840** of at least N bytes in size or NULL if insufficient memory is available. 2841** ^If M is the size of the prior allocation, then min(N,M) bytes 2842** of the prior allocation are copied into the beginning of buffer returned 2843** by sqlite3_realloc(X,N) and the prior allocation is freed. 2844** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2845** prior allocation is not freed. 2846** 2847** ^The sqlite3_realloc64(X,N) interfaces works the same as 2848** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2849** of a 32-bit signed integer. 2850** 2851** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2852** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2853** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2854** ^The value returned by sqlite3_msize(X) might be larger than the number 2855** of bytes requested when X was allocated. ^If X is a NULL pointer then 2856** sqlite3_msize(X) returns zero. If X points to something that is not 2857** the beginning of memory allocation, or if it points to a formerly 2858** valid memory allocation that has now been freed, then the behavior 2859** of sqlite3_msize(X) is undefined and possibly harmful. 2860** 2861** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2862** sqlite3_malloc64(), and sqlite3_realloc64() 2863** is always aligned to at least an 8 byte boundary, or to a 2864** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2865** option is used. 2866** 2867** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2868** must be either NULL or else pointers obtained from a prior 2869** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2870** not yet been released. 2871** 2872** The application must not read or write any part of 2873** a block of memory after it has been released using 2874** [sqlite3_free()] or [sqlite3_realloc()]. 2875*/ 2876void *sqlite3_malloc(int); 2877void *sqlite3_malloc64(sqlite3_uint64); 2878void *sqlite3_realloc(void*, int); 2879void *sqlite3_realloc64(void*, sqlite3_uint64); 2880void sqlite3_free(void*); 2881sqlite3_uint64 sqlite3_msize(void*); 2882 2883/* 2884** CAPI3REF: Memory Allocator Statistics 2885** 2886** SQLite provides these two interfaces for reporting on the status 2887** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2888** routines, which form the built-in memory allocation subsystem. 2889** 2890** ^The [sqlite3_memory_used()] routine returns the number of bytes 2891** of memory currently outstanding (malloced but not freed). 2892** ^The [sqlite3_memory_highwater()] routine returns the maximum 2893** value of [sqlite3_memory_used()] since the high-water mark 2894** was last reset. ^The values returned by [sqlite3_memory_used()] and 2895** [sqlite3_memory_highwater()] include any overhead 2896** added by SQLite in its implementation of [sqlite3_malloc()], 2897** but not overhead added by the any underlying system library 2898** routines that [sqlite3_malloc()] may call. 2899** 2900** ^The memory high-water mark is reset to the current value of 2901** [sqlite3_memory_used()] if and only if the parameter to 2902** [sqlite3_memory_highwater()] is true. ^The value returned 2903** by [sqlite3_memory_highwater(1)] is the high-water mark 2904** prior to the reset. 2905*/ 2906sqlite3_int64 sqlite3_memory_used(void); 2907sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2908 2909/* 2910** CAPI3REF: Pseudo-Random Number Generator 2911** 2912** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2913** select random [ROWID | ROWIDs] when inserting new records into a table that 2914** already uses the largest possible [ROWID]. The PRNG is also used for 2915** the built-in random() and randomblob() SQL functions. This interface allows 2916** applications to access the same PRNG for other purposes. 2917** 2918** ^A call to this routine stores N bytes of randomness into buffer P. 2919** ^The P parameter can be a NULL pointer. 2920** 2921** ^If this routine has not been previously called or if the previous 2922** call had N less than one or a NULL pointer for P, then the PRNG is 2923** seeded using randomness obtained from the xRandomness method of 2924** the default [sqlite3_vfs] object. 2925** ^If the previous call to this routine had an N of 1 or more and a 2926** non-NULL P then the pseudo-randomness is generated 2927** internally and without recourse to the [sqlite3_vfs] xRandomness 2928** method. 2929*/ 2930void sqlite3_randomness(int N, void *P); 2931 2932/* 2933** CAPI3REF: Compile-Time Authorization Callbacks 2934** METHOD: sqlite3 2935** KEYWORDS: {authorizer callback} 2936** 2937** ^This routine registers an authorizer callback with a particular 2938** [database connection], supplied in the first argument. 2939** ^The authorizer callback is invoked as SQL statements are being compiled 2940** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2941** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2942** and [sqlite3_prepare16_v3()]. ^At various 2943** points during the compilation process, as logic is being created 2944** to perform various actions, the authorizer callback is invoked to 2945** see if those actions are allowed. ^The authorizer callback should 2946** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2947** specific action but allow the SQL statement to continue to be 2948** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2949** rejected with an error. ^If the authorizer callback returns 2950** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2951** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2952** the authorizer will fail with an error message. 2953** 2954** When the callback returns [SQLITE_OK], that means the operation 2955** requested is ok. ^When the callback returns [SQLITE_DENY], the 2956** [sqlite3_prepare_v2()] or equivalent call that triggered the 2957** authorizer will fail with an error message explaining that 2958** access is denied. 2959** 2960** ^The first parameter to the authorizer callback is a copy of the third 2961** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2962** to the callback is an integer [SQLITE_COPY | action code] that specifies 2963** the particular action to be authorized. ^The third through sixth parameters 2964** to the callback are either NULL pointers or zero-terminated strings 2965** that contain additional details about the action to be authorized. 2966** Applications must always be prepared to encounter a NULL pointer in any 2967** of the third through the sixth parameters of the authorization callback. 2968** 2969** ^If the action code is [SQLITE_READ] 2970** and the callback returns [SQLITE_IGNORE] then the 2971** [prepared statement] statement is constructed to substitute 2972** a NULL value in place of the table column that would have 2973** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2974** return can be used to deny an untrusted user access to individual 2975** columns of a table. 2976** ^When a table is referenced by a [SELECT] but no column values are 2977** extracted from that table (for example in a query like 2978** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2979** is invoked once for that table with a column name that is an empty string. 2980** ^If the action code is [SQLITE_DELETE] and the callback returns 2981** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2982** [truncate optimization] is disabled and all rows are deleted individually. 2983** 2984** An authorizer is used when [sqlite3_prepare | preparing] 2985** SQL statements from an untrusted source, to ensure that the SQL statements 2986** do not try to access data they are not allowed to see, or that they do not 2987** try to execute malicious statements that damage the database. For 2988** example, an application may allow a user to enter arbitrary 2989** SQL queries for evaluation by a database. But the application does 2990** not want the user to be able to make arbitrary changes to the 2991** database. An authorizer could then be put in place while the 2992** user-entered SQL is being [sqlite3_prepare | prepared] that 2993** disallows everything except [SELECT] statements. 2994** 2995** Applications that need to process SQL from untrusted sources 2996** might also consider lowering resource limits using [sqlite3_limit()] 2997** and limiting database size using the [max_page_count] [PRAGMA] 2998** in addition to using an authorizer. 2999** 3000** ^(Only a single authorizer can be in place on a database connection 3001** at a time. Each call to sqlite3_set_authorizer overrides the 3002** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3003** The authorizer is disabled by default. 3004** 3005** The authorizer callback must not do anything that will modify 3006** the database connection that invoked the authorizer callback. 3007** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3008** database connections for the meaning of "modify" in this paragraph. 3009** 3010** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3011** statement might be re-prepared during [sqlite3_step()] due to a 3012** schema change. Hence, the application should ensure that the 3013** correct authorizer callback remains in place during the [sqlite3_step()]. 3014** 3015** ^Note that the authorizer callback is invoked only during 3016** [sqlite3_prepare()] or its variants. Authorization is not 3017** performed during statement evaluation in [sqlite3_step()], unless 3018** as stated in the previous paragraph, sqlite3_step() invokes 3019** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3020*/ 3021int sqlite3_set_authorizer( 3022 sqlite3*, 3023 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3024 void *pUserData 3025); 3026 3027/* 3028** CAPI3REF: Authorizer Return Codes 3029** 3030** The [sqlite3_set_authorizer | authorizer callback function] must 3031** return either [SQLITE_OK] or one of these two constants in order 3032** to signal SQLite whether or not the action is permitted. See the 3033** [sqlite3_set_authorizer | authorizer documentation] for additional 3034** information. 3035** 3036** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3037** returned from the [sqlite3_vtab_on_conflict()] interface. 3038*/ 3039#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3040#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3041 3042/* 3043** CAPI3REF: Authorizer Action Codes 3044** 3045** The [sqlite3_set_authorizer()] interface registers a callback function 3046** that is invoked to authorize certain SQL statement actions. The 3047** second parameter to the callback is an integer code that specifies 3048** what action is being authorized. These are the integer action codes that 3049** the authorizer callback may be passed. 3050** 3051** These action code values signify what kind of operation is to be 3052** authorized. The 3rd and 4th parameters to the authorization 3053** callback function will be parameters or NULL depending on which of these 3054** codes is used as the second parameter. ^(The 5th parameter to the 3055** authorizer callback is the name of the database ("main", "temp", 3056** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3057** is the name of the inner-most trigger or view that is responsible for 3058** the access attempt or NULL if this access attempt is directly from 3059** top-level SQL code. 3060*/ 3061/******************************************* 3rd ************ 4th ***********/ 3062#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3063#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3064#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3065#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3066#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3067#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3068#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3069#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3070#define SQLITE_DELETE 9 /* Table Name NULL */ 3071#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3072#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3073#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3074#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3075#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3076#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3077#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3078#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3079#define SQLITE_INSERT 18 /* Table Name NULL */ 3080#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3081#define SQLITE_READ 20 /* Table Name Column Name */ 3082#define SQLITE_SELECT 21 /* NULL NULL */ 3083#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3084#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3085#define SQLITE_ATTACH 24 /* Filename NULL */ 3086#define SQLITE_DETACH 25 /* Database Name NULL */ 3087#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3088#define SQLITE_REINDEX 27 /* Index Name NULL */ 3089#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3090#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3091#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3092#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3093#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3094#define SQLITE_COPY 0 /* No longer used */ 3095#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3096 3097/* 3098** CAPI3REF: Tracing And Profiling Functions 3099** METHOD: sqlite3 3100** 3101** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3102** instead of the routines described here. 3103** 3104** These routines register callback functions that can be used for 3105** tracing and profiling the execution of SQL statements. 3106** 3107** ^The callback function registered by sqlite3_trace() is invoked at 3108** various times when an SQL statement is being run by [sqlite3_step()]. 3109** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3110** SQL statement text as the statement first begins executing. 3111** ^(Additional sqlite3_trace() callbacks might occur 3112** as each triggered subprogram is entered. The callbacks for triggers 3113** contain a UTF-8 SQL comment that identifies the trigger.)^ 3114** 3115** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3116** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3117** 3118** ^The callback function registered by sqlite3_profile() is invoked 3119** as each SQL statement finishes. ^The profile callback contains 3120** the original statement text and an estimate of wall-clock time 3121** of how long that statement took to run. ^The profile callback 3122** time is in units of nanoseconds, however the current implementation 3123** is only capable of millisecond resolution so the six least significant 3124** digits in the time are meaningless. Future versions of SQLite 3125** might provide greater resolution on the profiler callback. Invoking 3126** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3127** profile callback. 3128*/ 3129SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3130 void(*xTrace)(void*,const char*), void*); 3131SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3132 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3133 3134/* 3135** CAPI3REF: SQL Trace Event Codes 3136** KEYWORDS: SQLITE_TRACE 3137** 3138** These constants identify classes of events that can be monitored 3139** using the [sqlite3_trace_v2()] tracing logic. The M argument 3140** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3141** the following constants. ^The first argument to the trace callback 3142** is one of the following constants. 3143** 3144** New tracing constants may be added in future releases. 3145** 3146** ^A trace callback has four arguments: xCallback(T,C,P,X). 3147** ^The T argument is one of the integer type codes above. 3148** ^The C argument is a copy of the context pointer passed in as the 3149** fourth argument to [sqlite3_trace_v2()]. 3150** The P and X arguments are pointers whose meanings depend on T. 3151** 3152** <dl> 3153** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3154** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3155** first begins running and possibly at other times during the 3156** execution of the prepared statement, such as at the start of each 3157** trigger subprogram. ^The P argument is a pointer to the 3158** [prepared statement]. ^The X argument is a pointer to a string which 3159** is the unexpanded SQL text of the prepared statement or an SQL comment 3160** that indicates the invocation of a trigger. ^The callback can compute 3161** the same text that would have been returned by the legacy [sqlite3_trace()] 3162** interface by using the X argument when X begins with "--" and invoking 3163** [sqlite3_expanded_sql(P)] otherwise. 3164** 3165** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3166** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3167** information as is provided by the [sqlite3_profile()] callback. 3168** ^The P argument is a pointer to the [prepared statement] and the 3169** X argument points to a 64-bit integer which is the estimated of 3170** the number of nanosecond that the prepared statement took to run. 3171** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3172** 3173** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3174** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3175** statement generates a single row of result. 3176** ^The P argument is a pointer to the [prepared statement] and the 3177** X argument is unused. 3178** 3179** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3180** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3181** connection closes. 3182** ^The P argument is a pointer to the [database connection] object 3183** and the X argument is unused. 3184** </dl> 3185*/ 3186#define SQLITE_TRACE_STMT 0x01 3187#define SQLITE_TRACE_PROFILE 0x02 3188#define SQLITE_TRACE_ROW 0x04 3189#define SQLITE_TRACE_CLOSE 0x08 3190 3191/* 3192** CAPI3REF: SQL Trace Hook 3193** METHOD: sqlite3 3194** 3195** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3196** function X against [database connection] D, using property mask M 3197** and context pointer P. ^If the X callback is 3198** NULL or if the M mask is zero, then tracing is disabled. The 3199** M argument should be the bitwise OR-ed combination of 3200** zero or more [SQLITE_TRACE] constants. 3201** 3202** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3203** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3204** 3205** ^The X callback is invoked whenever any of the events identified by 3206** mask M occur. ^The integer return value from the callback is currently 3207** ignored, though this may change in future releases. Callback 3208** implementations should return zero to ensure future compatibility. 3209** 3210** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3211** ^The T argument is one of the [SQLITE_TRACE] 3212** constants to indicate why the callback was invoked. 3213** ^The C argument is a copy of the context pointer. 3214** The P and X arguments are pointers whose meanings depend on T. 3215** 3216** The sqlite3_trace_v2() interface is intended to replace the legacy 3217** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3218** are deprecated. 3219*/ 3220int sqlite3_trace_v2( 3221 sqlite3*, 3222 unsigned uMask, 3223 int(*xCallback)(unsigned,void*,void*,void*), 3224 void *pCtx 3225); 3226 3227/* 3228** CAPI3REF: Query Progress Callbacks 3229** METHOD: sqlite3 3230** 3231** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3232** function X to be invoked periodically during long running calls to 3233** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3234** database connection D. An example use for this 3235** interface is to keep a GUI updated during a large query. 3236** 3237** ^The parameter P is passed through as the only parameter to the 3238** callback function X. ^The parameter N is the approximate number of 3239** [virtual machine instructions] that are evaluated between successive 3240** invocations of the callback X. ^If N is less than one then the progress 3241** handler is disabled. 3242** 3243** ^Only a single progress handler may be defined at one time per 3244** [database connection]; setting a new progress handler cancels the 3245** old one. ^Setting parameter X to NULL disables the progress handler. 3246** ^The progress handler is also disabled by setting N to a value less 3247** than 1. 3248** 3249** ^If the progress callback returns non-zero, the operation is 3250** interrupted. This feature can be used to implement a 3251** "Cancel" button on a GUI progress dialog box. 3252** 3253** The progress handler callback must not do anything that will modify 3254** the database connection that invoked the progress handler. 3255** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3256** database connections for the meaning of "modify" in this paragraph. 3257** 3258*/ 3259void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3260 3261/* 3262** CAPI3REF: Opening A New Database Connection 3263** CONSTRUCTOR: sqlite3 3264** 3265** ^These routines open an SQLite database file as specified by the 3266** filename argument. ^The filename argument is interpreted as UTF-8 for 3267** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3268** order for sqlite3_open16(). ^(A [database connection] handle is usually 3269** returned in *ppDb, even if an error occurs. The only exception is that 3270** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3271** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3272** object.)^ ^(If the database is opened (and/or created) successfully, then 3273** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3274** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3275** an English language description of the error following a failure of any 3276** of the sqlite3_open() routines. 3277** 3278** ^The default encoding will be UTF-8 for databases created using 3279** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3280** created using sqlite3_open16() will be UTF-16 in the native byte order. 3281** 3282** Whether or not an error occurs when it is opened, resources 3283** associated with the [database connection] handle should be released by 3284** passing it to [sqlite3_close()] when it is no longer required. 3285** 3286** The sqlite3_open_v2() interface works like sqlite3_open() 3287** except that it accepts two additional parameters for additional control 3288** over the new database connection. ^(The flags parameter to 3289** sqlite3_open_v2() must include, at a minimum, one of the following 3290** three flag combinations:)^ 3291** 3292** <dl> 3293** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3294** <dd>The database is opened in read-only mode. If the database does not 3295** already exist, an error is returned.</dd>)^ 3296** 3297** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3298** <dd>The database is opened for reading and writing if possible, or reading 3299** only if the file is write protected by the operating system. In either 3300** case the database must already exist, otherwise an error is returned.</dd>)^ 3301** 3302** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3303** <dd>The database is opened for reading and writing, and is created if 3304** it does not already exist. This is the behavior that is always used for 3305** sqlite3_open() and sqlite3_open16().</dd>)^ 3306** </dl> 3307** 3308** In addition to the required flags, the following optional flags are 3309** also supported: 3310** 3311** <dl> 3312** ^(<dt>[SQLITE_OPEN_URI]</dt> 3313** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3314** 3315** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3316** <dd>The database will be opened as an in-memory database. The database 3317** is named by the "filename" argument for the purposes of cache-sharing, 3318** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3319** </dd>)^ 3320** 3321** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3322** <dd>The new database connection will use the "multi-thread" 3323** [threading mode].)^ This means that separate threads are allowed 3324** to use SQLite at the same time, as long as each thread is using 3325** a different [database connection]. 3326** 3327** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3328** <dd>The new database connection will use the "serialized" 3329** [threading mode].)^ This means the multiple threads can safely 3330** attempt to use the same database connection at the same time. 3331** (Mutexes will block any actual concurrency, but in this mode 3332** there is no harm in trying.) 3333** 3334** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3335** <dd>The database is opened [shared cache] enabled, overriding 3336** the default shared cache setting provided by 3337** [sqlite3_enable_shared_cache()].)^ 3338** 3339** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3340** <dd>The database is opened [shared cache] disabled, overriding 3341** the default shared cache setting provided by 3342** [sqlite3_enable_shared_cache()].)^ 3343** 3344** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3345** <dd>The database filename is not allowed to be a symbolic link</dd> 3346** </dl>)^ 3347** 3348** If the 3rd parameter to sqlite3_open_v2() is not one of the 3349** required combinations shown above optionally combined with other 3350** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3351** then the behavior is undefined. 3352** 3353** ^The fourth parameter to sqlite3_open_v2() is the name of the 3354** [sqlite3_vfs] object that defines the operating system interface that 3355** the new database connection should use. ^If the fourth parameter is 3356** a NULL pointer then the default [sqlite3_vfs] object is used. 3357** 3358** ^If the filename is ":memory:", then a private, temporary in-memory database 3359** is created for the connection. ^This in-memory database will vanish when 3360** the database connection is closed. Future versions of SQLite might 3361** make use of additional special filenames that begin with the ":" character. 3362** It is recommended that when a database filename actually does begin with 3363** a ":" character you should prefix the filename with a pathname such as 3364** "./" to avoid ambiguity. 3365** 3366** ^If the filename is an empty string, then a private, temporary 3367** on-disk database will be created. ^This private database will be 3368** automatically deleted as soon as the database connection is closed. 3369** 3370** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3371** 3372** ^If [URI filename] interpretation is enabled, and the filename argument 3373** begins with "file:", then the filename is interpreted as a URI. ^URI 3374** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3375** set in the third argument to sqlite3_open_v2(), or if it has 3376** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3377** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3378** URI filename interpretation is turned off 3379** by default, but future releases of SQLite might enable URI filename 3380** interpretation by default. See "[URI filenames]" for additional 3381** information. 3382** 3383** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3384** authority, then it must be either an empty string or the string 3385** "localhost". ^If the authority is not an empty string or "localhost", an 3386** error is returned to the caller. ^The fragment component of a URI, if 3387** present, is ignored. 3388** 3389** ^SQLite uses the path component of the URI as the name of the disk file 3390** which contains the database. ^If the path begins with a '/' character, 3391** then it is interpreted as an absolute path. ^If the path does not begin 3392** with a '/' (meaning that the authority section is omitted from the URI) 3393** then the path is interpreted as a relative path. 3394** ^(On windows, the first component of an absolute path 3395** is a drive specification (e.g. "C:").)^ 3396** 3397** [[core URI query parameters]] 3398** The query component of a URI may contain parameters that are interpreted 3399** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3400** SQLite and its built-in [VFSes] interpret the 3401** following query parameters: 3402** 3403** <ul> 3404** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3405** a VFS object that provides the operating system interface that should 3406** be used to access the database file on disk. ^If this option is set to 3407** an empty string the default VFS object is used. ^Specifying an unknown 3408** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3409** present, then the VFS specified by the option takes precedence over 3410** the value passed as the fourth parameter to sqlite3_open_v2(). 3411** 3412** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3413** "rwc", or "memory". Attempting to set it to any other value is 3414** an error)^. 3415** ^If "ro" is specified, then the database is opened for read-only 3416** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3417** third argument to sqlite3_open_v2(). ^If the mode option is set to 3418** "rw", then the database is opened for read-write (but not create) 3419** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3420** been set. ^Value "rwc" is equivalent to setting both 3421** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3422** set to "memory" then a pure [in-memory database] that never reads 3423** or writes from disk is used. ^It is an error to specify a value for 3424** the mode parameter that is less restrictive than that specified by 3425** the flags passed in the third parameter to sqlite3_open_v2(). 3426** 3427** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3428** "private". ^Setting it to "shared" is equivalent to setting the 3429** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3430** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3431** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3432** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3433** a URI filename, its value overrides any behavior requested by setting 3434** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3435** 3436** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3437** [powersafe overwrite] property does or does not apply to the 3438** storage media on which the database file resides. 3439** 3440** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3441** which if set disables file locking in rollback journal modes. This 3442** is useful for accessing a database on a filesystem that does not 3443** support locking. Caution: Database corruption might result if two 3444** or more processes write to the same database and any one of those 3445** processes uses nolock=1. 3446** 3447** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3448** parameter that indicates that the database file is stored on 3449** read-only media. ^When immutable is set, SQLite assumes that the 3450** database file cannot be changed, even by a process with higher 3451** privilege, and so the database is opened read-only and all locking 3452** and change detection is disabled. Caution: Setting the immutable 3453** property on a database file that does in fact change can result 3454** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3455** See also: [SQLITE_IOCAP_IMMUTABLE]. 3456** 3457** </ul> 3458** 3459** ^Specifying an unknown parameter in the query component of a URI is not an 3460** error. Future versions of SQLite might understand additional query 3461** parameters. See "[query parameters with special meaning to SQLite]" for 3462** additional information. 3463** 3464** [[URI filename examples]] <h3>URI filename examples</h3> 3465** 3466** <table border="1" align=center cellpadding=5> 3467** <tr><th> URI filenames <th> Results 3468** <tr><td> file:data.db <td> 3469** Open the file "data.db" in the current directory. 3470** <tr><td> file:/home/fred/data.db<br> 3471** file:///home/fred/data.db <br> 3472** file://localhost/home/fred/data.db <br> <td> 3473** Open the database file "/home/fred/data.db". 3474** <tr><td> file://darkstar/home/fred/data.db <td> 3475** An error. "darkstar" is not a recognized authority. 3476** <tr><td style="white-space:nowrap"> 3477** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3478** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3479** C:. Note that the %20 escaping in this example is not strictly 3480** necessary - space characters can be used literally 3481** in URI filenames. 3482** <tr><td> file:data.db?mode=ro&cache=private <td> 3483** Open file "data.db" in the current directory for read-only access. 3484** Regardless of whether or not shared-cache mode is enabled by 3485** default, use a private cache. 3486** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3487** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3488** that uses dot-files in place of posix advisory locking. 3489** <tr><td> file:data.db?mode=readonly <td> 3490** An error. "readonly" is not a valid option for the "mode" parameter. 3491** </table> 3492** 3493** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3494** query components of a URI. A hexadecimal escape sequence consists of a 3495** percent sign - "%" - followed by exactly two hexadecimal digits 3496** specifying an octet value. ^Before the path or query components of a 3497** URI filename are interpreted, they are encoded using UTF-8 and all 3498** hexadecimal escape sequences replaced by a single byte containing the 3499** corresponding octet. If this process generates an invalid UTF-8 encoding, 3500** the results are undefined. 3501** 3502** <b>Note to Windows users:</b> The encoding used for the filename argument 3503** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3504** codepage is currently defined. Filenames containing international 3505** characters must be converted to UTF-8 prior to passing them into 3506** sqlite3_open() or sqlite3_open_v2(). 3507** 3508** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3509** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3510** features that require the use of temporary files may fail. 3511** 3512** See also: [sqlite3_temp_directory] 3513*/ 3514int sqlite3_open( 3515 const char *filename, /* Database filename (UTF-8) */ 3516 sqlite3 **ppDb /* OUT: SQLite db handle */ 3517); 3518int sqlite3_open16( 3519 const void *filename, /* Database filename (UTF-16) */ 3520 sqlite3 **ppDb /* OUT: SQLite db handle */ 3521); 3522int sqlite3_open_v2( 3523 const char *filename, /* Database filename (UTF-8) */ 3524 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3525 int flags, /* Flags */ 3526 const char *zVfs /* Name of VFS module to use */ 3527); 3528 3529/* 3530** CAPI3REF: Obtain Values For URI Parameters 3531** 3532** These are utility routines, useful to [VFS|custom VFS implementations], 3533** that check if a database file was a URI that contained a specific query 3534** parameter, and if so obtains the value of that query parameter. 3535** 3536** If F is the database filename pointer passed into the xOpen() method of 3537** a VFS implementation or it is the return value of [sqlite3_db_filename()] 3538** and if P is the name of the query parameter, then 3539** sqlite3_uri_parameter(F,P) returns the value of the P 3540** parameter if it exists or a NULL pointer if P does not appear as a 3541** query parameter on F. If P is a query parameter of F and it 3542** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3543** a pointer to an empty string. 3544** 3545** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3546** parameter and returns true (1) or false (0) according to the value 3547** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3548** value of query parameter P is one of "yes", "true", or "on" in any 3549** case or if the value begins with a non-zero number. The 3550** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3551** query parameter P is one of "no", "false", or "off" in any case or 3552** if the value begins with a numeric zero. If P is not a query 3553** parameter on F or if the value of P does not match any of the 3554** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3555** 3556** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3557** 64-bit signed integer and returns that integer, or D if P does not 3558** exist. If the value of P is something other than an integer, then 3559** zero is returned. 3560** 3561** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3562** the value) of the N-th query parameter for filename F, or a NULL 3563** pointer if N is less than zero or greater than the number of query 3564** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3565** the name of the first query parameter, 1 for the second parameter, and 3566** so forth. 3567** 3568** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3569** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3570** is not a database file pathname pointer that the SQLite core passed 3571** into the xOpen VFS method, then the behavior of this routine is undefined 3572** and probably undesirable. 3573** 3574** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3575** parameter can also be the name of a rollback journal file or WAL file 3576** in addition to the main database file. Prior to version 3.31.0, these 3577** routines would only work if F was the name of the main database file. 3578** When the F parameter is the name of the rollback journal or WAL file, 3579** it has access to all the same query parameters as were found on the 3580** main database file. 3581** 3582** See the [URI filename] documentation for additional information. 3583*/ 3584const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3585int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3586sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3587const char *sqlite3_uri_key(const char *zFilename, int N); 3588 3589/* 3590** CAPI3REF: Translate filenames 3591** 3592** These routines are available to [VFS|custom VFS implementations] for 3593** translating filenames between the main database file, the journal file, 3594** and the WAL file. 3595** 3596** If F is the name of an sqlite database file, journal file, or WAL file 3597** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3598** returns the name of the corresponding database file. 3599** 3600** If F is the name of an sqlite database file, journal file, or WAL file 3601** passed by the SQLite core into the VFS, or if F is a database filename 3602** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3603** returns the name of the corresponding rollback journal file. 3604** 3605** If F is the name of an sqlite database file, journal file, or WAL file 3606** that was passed by the SQLite core into the VFS, or if F is a database 3607** filename obtained from [sqlite3_db_filename()], then 3608** sqlite3_filename_wal(F) returns the name of the corresponding 3609** WAL file. 3610** 3611** In all of the above, if F is not the name of a database, journal or WAL 3612** filename passed into the VFS from the SQLite core and F is not the 3613** return value from [sqlite3_db_filename()], then the result is 3614** undefined and is likely a memory access violation. 3615*/ 3616const char *sqlite3_filename_database(const char*); 3617const char *sqlite3_filename_journal(const char*); 3618const char *sqlite3_filename_wal(const char*); 3619 3620 3621/* 3622** CAPI3REF: Error Codes And Messages 3623** METHOD: sqlite3 3624** 3625** ^If the most recent sqlite3_* API call associated with 3626** [database connection] D failed, then the sqlite3_errcode(D) interface 3627** returns the numeric [result code] or [extended result code] for that 3628** API call. 3629** ^The sqlite3_extended_errcode() 3630** interface is the same except that it always returns the 3631** [extended result code] even when extended result codes are 3632** disabled. 3633** 3634** The values returned by sqlite3_errcode() and/or 3635** sqlite3_extended_errcode() might change with each API call. 3636** Except, there are some interfaces that are guaranteed to never 3637** change the value of the error code. The error-code preserving 3638** interfaces are: 3639** 3640** <ul> 3641** <li> sqlite3_errcode() 3642** <li> sqlite3_extended_errcode() 3643** <li> sqlite3_errmsg() 3644** <li> sqlite3_errmsg16() 3645** </ul> 3646** 3647** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3648** text that describes the error, as either UTF-8 or UTF-16 respectively. 3649** ^(Memory to hold the error message string is managed internally. 3650** The application does not need to worry about freeing the result. 3651** However, the error string might be overwritten or deallocated by 3652** subsequent calls to other SQLite interface functions.)^ 3653** 3654** ^The sqlite3_errstr() interface returns the English-language text 3655** that describes the [result code], as UTF-8. 3656** ^(Memory to hold the error message string is managed internally 3657** and must not be freed by the application)^. 3658** 3659** When the serialized [threading mode] is in use, it might be the 3660** case that a second error occurs on a separate thread in between 3661** the time of the first error and the call to these interfaces. 3662** When that happens, the second error will be reported since these 3663** interfaces always report the most recent result. To avoid 3664** this, each thread can obtain exclusive use of the [database connection] D 3665** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3666** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3667** all calls to the interfaces listed here are completed. 3668** 3669** If an interface fails with SQLITE_MISUSE, that means the interface 3670** was invoked incorrectly by the application. In that case, the 3671** error code and message may or may not be set. 3672*/ 3673int sqlite3_errcode(sqlite3 *db); 3674int sqlite3_extended_errcode(sqlite3 *db); 3675const char *sqlite3_errmsg(sqlite3*); 3676const void *sqlite3_errmsg16(sqlite3*); 3677const char *sqlite3_errstr(int); 3678 3679/* 3680** CAPI3REF: Prepared Statement Object 3681** KEYWORDS: {prepared statement} {prepared statements} 3682** 3683** An instance of this object represents a single SQL statement that 3684** has been compiled into binary form and is ready to be evaluated. 3685** 3686** Think of each SQL statement as a separate computer program. The 3687** original SQL text is source code. A prepared statement object 3688** is the compiled object code. All SQL must be converted into a 3689** prepared statement before it can be run. 3690** 3691** The life-cycle of a prepared statement object usually goes like this: 3692** 3693** <ol> 3694** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3695** <li> Bind values to [parameters] using the sqlite3_bind_*() 3696** interfaces. 3697** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3698** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3699** to step 2. Do this zero or more times. 3700** <li> Destroy the object using [sqlite3_finalize()]. 3701** </ol> 3702*/ 3703typedef struct sqlite3_stmt sqlite3_stmt; 3704 3705/* 3706** CAPI3REF: Run-time Limits 3707** METHOD: sqlite3 3708** 3709** ^(This interface allows the size of various constructs to be limited 3710** on a connection by connection basis. The first parameter is the 3711** [database connection] whose limit is to be set or queried. The 3712** second parameter is one of the [limit categories] that define a 3713** class of constructs to be size limited. The third parameter is the 3714** new limit for that construct.)^ 3715** 3716** ^If the new limit is a negative number, the limit is unchanged. 3717** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3718** [limits | hard upper bound] 3719** set at compile-time by a C preprocessor macro called 3720** [limits | SQLITE_MAX_<i>NAME</i>]. 3721** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3722** ^Attempts to increase a limit above its hard upper bound are 3723** silently truncated to the hard upper bound. 3724** 3725** ^Regardless of whether or not the limit was changed, the 3726** [sqlite3_limit()] interface returns the prior value of the limit. 3727** ^Hence, to find the current value of a limit without changing it, 3728** simply invoke this interface with the third parameter set to -1. 3729** 3730** Run-time limits are intended for use in applications that manage 3731** both their own internal database and also databases that are controlled 3732** by untrusted external sources. An example application might be a 3733** web browser that has its own databases for storing history and 3734** separate databases controlled by JavaScript applications downloaded 3735** off the Internet. The internal databases can be given the 3736** large, default limits. Databases managed by external sources can 3737** be given much smaller limits designed to prevent a denial of service 3738** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3739** interface to further control untrusted SQL. The size of the database 3740** created by an untrusted script can be contained using the 3741** [max_page_count] [PRAGMA]. 3742** 3743** New run-time limit categories may be added in future releases. 3744*/ 3745int sqlite3_limit(sqlite3*, int id, int newVal); 3746 3747/* 3748** CAPI3REF: Run-Time Limit Categories 3749** KEYWORDS: {limit category} {*limit categories} 3750** 3751** These constants define various performance limits 3752** that can be lowered at run-time using [sqlite3_limit()]. 3753** The synopsis of the meanings of the various limits is shown below. 3754** Additional information is available at [limits | Limits in SQLite]. 3755** 3756** <dl> 3757** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3758** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3759** 3760** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3761** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3762** 3763** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3764** <dd>The maximum number of columns in a table definition or in the 3765** result set of a [SELECT] or the maximum number of columns in an index 3766** or in an ORDER BY or GROUP BY clause.</dd>)^ 3767** 3768** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3769** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3770** 3771** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3772** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3773** 3774** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3775** <dd>The maximum number of instructions in a virtual machine program 3776** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3777** the equivalent tries to allocate space for more than this many opcodes 3778** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3779** 3780** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3781** <dd>The maximum number of arguments on a function.</dd>)^ 3782** 3783** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3784** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3785** 3786** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3787** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3788** <dd>The maximum length of the pattern argument to the [LIKE] or 3789** [GLOB] operators.</dd>)^ 3790** 3791** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3792** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3793** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3794** 3795** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3796** <dd>The maximum depth of recursion for triggers.</dd>)^ 3797** 3798** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3799** <dd>The maximum number of auxiliary worker threads that a single 3800** [prepared statement] may start.</dd>)^ 3801** </dl> 3802*/ 3803#define SQLITE_LIMIT_LENGTH 0 3804#define SQLITE_LIMIT_SQL_LENGTH 1 3805#define SQLITE_LIMIT_COLUMN 2 3806#define SQLITE_LIMIT_EXPR_DEPTH 3 3807#define SQLITE_LIMIT_COMPOUND_SELECT 4 3808#define SQLITE_LIMIT_VDBE_OP 5 3809#define SQLITE_LIMIT_FUNCTION_ARG 6 3810#define SQLITE_LIMIT_ATTACHED 7 3811#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3812#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3813#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3814#define SQLITE_LIMIT_WORKER_THREADS 11 3815 3816/* 3817** CAPI3REF: Prepare Flags 3818** 3819** These constants define various flags that can be passed into 3820** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3821** [sqlite3_prepare16_v3()] interfaces. 3822** 3823** New flags may be added in future releases of SQLite. 3824** 3825** <dl> 3826** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3827** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3828** that the prepared statement will be retained for a long time and 3829** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3830** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3831** be used just once or at most a few times and then destroyed using 3832** [sqlite3_finalize()] relatively soon. The current implementation acts 3833** on this hint by avoiding the use of [lookaside memory] so as not to 3834** deplete the limited store of lookaside memory. Future versions of 3835** SQLite may act on this hint differently. 3836** 3837** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3838** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3839** to be required for any prepared statement that wanted to use the 3840** [sqlite3_normalized_sql()] interface. However, the 3841** [sqlite3_normalized_sql()] interface is now available to all 3842** prepared statements, regardless of whether or not they use this 3843** flag. 3844** 3845** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3846** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3847** to return an error (error code SQLITE_ERROR) if the statement uses 3848** any virtual tables. 3849** </dl> 3850*/ 3851#define SQLITE_PREPARE_PERSISTENT 0x01 3852#define SQLITE_PREPARE_NORMALIZE 0x02 3853#define SQLITE_PREPARE_NO_VTAB 0x04 3854 3855/* 3856** CAPI3REF: Compiling An SQL Statement 3857** KEYWORDS: {SQL statement compiler} 3858** METHOD: sqlite3 3859** CONSTRUCTOR: sqlite3_stmt 3860** 3861** To execute an SQL statement, it must first be compiled into a byte-code 3862** program using one of these routines. Or, in other words, these routines 3863** are constructors for the [prepared statement] object. 3864** 3865** The preferred routine to use is [sqlite3_prepare_v2()]. The 3866** [sqlite3_prepare()] interface is legacy and should be avoided. 3867** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3868** for special purposes. 3869** 3870** The use of the UTF-8 interfaces is preferred, as SQLite currently 3871** does all parsing using UTF-8. The UTF-16 interfaces are provided 3872** as a convenience. The UTF-16 interfaces work by converting the 3873** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3874** 3875** The first argument, "db", is a [database connection] obtained from a 3876** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3877** [sqlite3_open16()]. The database connection must not have been closed. 3878** 3879** The second argument, "zSql", is the statement to be compiled, encoded 3880** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3881** and sqlite3_prepare_v3() 3882** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3883** and sqlite3_prepare16_v3() use UTF-16. 3884** 3885** ^If the nByte argument is negative, then zSql is read up to the 3886** first zero terminator. ^If nByte is positive, then it is the 3887** number of bytes read from zSql. ^If nByte is zero, then no prepared 3888** statement is generated. 3889** If the caller knows that the supplied string is nul-terminated, then 3890** there is a small performance advantage to passing an nByte parameter that 3891** is the number of bytes in the input string <i>including</i> 3892** the nul-terminator. 3893** 3894** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3895** past the end of the first SQL statement in zSql. These routines only 3896** compile the first statement in zSql, so *pzTail is left pointing to 3897** what remains uncompiled. 3898** 3899** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3900** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3901** to NULL. ^If the input text contains no SQL (if the input is an empty 3902** string or a comment) then *ppStmt is set to NULL. 3903** The calling procedure is responsible for deleting the compiled 3904** SQL statement using [sqlite3_finalize()] after it has finished with it. 3905** ppStmt may not be NULL. 3906** 3907** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3908** otherwise an [error code] is returned. 3909** 3910** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3911** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3912** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3913** are retained for backwards compatibility, but their use is discouraged. 3914** ^In the "vX" interfaces, the prepared statement 3915** that is returned (the [sqlite3_stmt] object) contains a copy of the 3916** original SQL text. This causes the [sqlite3_step()] interface to 3917** behave differently in three ways: 3918** 3919** <ol> 3920** <li> 3921** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3922** always used to do, [sqlite3_step()] will automatically recompile the SQL 3923** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3924** retries will occur before sqlite3_step() gives up and returns an error. 3925** </li> 3926** 3927** <li> 3928** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3929** [error codes] or [extended error codes]. ^The legacy behavior was that 3930** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3931** and the application would have to make a second call to [sqlite3_reset()] 3932** in order to find the underlying cause of the problem. With the "v2" prepare 3933** interfaces, the underlying reason for the error is returned immediately. 3934** </li> 3935** 3936** <li> 3937** ^If the specific value bound to a [parameter | host parameter] in the 3938** WHERE clause might influence the choice of query plan for a statement, 3939** then the statement will be automatically recompiled, as if there had been 3940** a schema change, on the first [sqlite3_step()] call following any change 3941** to the [sqlite3_bind_text | bindings] of that [parameter]. 3942** ^The specific value of a WHERE-clause [parameter] might influence the 3943** choice of query plan if the parameter is the left-hand side of a [LIKE] 3944** or [GLOB] operator or if the parameter is compared to an indexed column 3945** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3946** </li> 3947** </ol> 3948** 3949** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3950** the extra prepFlags parameter, which is a bit array consisting of zero or 3951** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3952** sqlite3_prepare_v2() interface works exactly the same as 3953** sqlite3_prepare_v3() with a zero prepFlags parameter. 3954*/ 3955int sqlite3_prepare( 3956 sqlite3 *db, /* Database handle */ 3957 const char *zSql, /* SQL statement, UTF-8 encoded */ 3958 int nByte, /* Maximum length of zSql in bytes. */ 3959 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3960 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3961); 3962int sqlite3_prepare_v2( 3963 sqlite3 *db, /* Database handle */ 3964 const char *zSql, /* SQL statement, UTF-8 encoded */ 3965 int nByte, /* Maximum length of zSql in bytes. */ 3966 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3967 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3968); 3969int sqlite3_prepare_v3( 3970 sqlite3 *db, /* Database handle */ 3971 const char *zSql, /* SQL statement, UTF-8 encoded */ 3972 int nByte, /* Maximum length of zSql in bytes. */ 3973 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3974 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3975 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3976); 3977int sqlite3_prepare16( 3978 sqlite3 *db, /* Database handle */ 3979 const void *zSql, /* SQL statement, UTF-16 encoded */ 3980 int nByte, /* Maximum length of zSql in bytes. */ 3981 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3982 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3983); 3984int sqlite3_prepare16_v2( 3985 sqlite3 *db, /* Database handle */ 3986 const void *zSql, /* SQL statement, UTF-16 encoded */ 3987 int nByte, /* Maximum length of zSql in bytes. */ 3988 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3989 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3990); 3991int sqlite3_prepare16_v3( 3992 sqlite3 *db, /* Database handle */ 3993 const void *zSql, /* SQL statement, UTF-16 encoded */ 3994 int nByte, /* Maximum length of zSql in bytes. */ 3995 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3996 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3997 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3998); 3999 4000/* 4001** CAPI3REF: Retrieving Statement SQL 4002** METHOD: sqlite3_stmt 4003** 4004** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4005** SQL text used to create [prepared statement] P if P was 4006** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4007** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4008** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4009** string containing the SQL text of prepared statement P with 4010** [bound parameters] expanded. 4011** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4012** string containing the normalized SQL text of prepared statement P. The 4013** semantics used to normalize a SQL statement are unspecified and subject 4014** to change. At a minimum, literal values will be replaced with suitable 4015** placeholders. 4016** 4017** ^(For example, if a prepared statement is created using the SQL 4018** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4019** and parameter :xyz is unbound, then sqlite3_sql() will return 4020** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4021** will return "SELECT 2345,NULL".)^ 4022** 4023** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4024** is available to hold the result, or if the result would exceed the 4025** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4026** 4027** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4028** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4029** option causes sqlite3_expanded_sql() to always return NULL. 4030** 4031** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4032** are managed by SQLite and are automatically freed when the prepared 4033** statement is finalized. 4034** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4035** is obtained from [sqlite3_malloc()] and must be free by the application 4036** by passing it to [sqlite3_free()]. 4037*/ 4038const char *sqlite3_sql(sqlite3_stmt *pStmt); 4039char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4040const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4041 4042/* 4043** CAPI3REF: Determine If An SQL Statement Writes The Database 4044** METHOD: sqlite3_stmt 4045** 4046** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4047** and only if the [prepared statement] X makes no direct changes to 4048** the content of the database file. 4049** 4050** Note that [application-defined SQL functions] or 4051** [virtual tables] might change the database indirectly as a side effect. 4052** ^(For example, if an application defines a function "eval()" that 4053** calls [sqlite3_exec()], then the following SQL statement would 4054** change the database file through side-effects: 4055** 4056** <blockquote><pre> 4057** SELECT eval('DELETE FROM t1') FROM t2; 4058** </pre></blockquote> 4059** 4060** But because the [SELECT] statement does not change the database file 4061** directly, sqlite3_stmt_readonly() would still return true.)^ 4062** 4063** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4064** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4065** since the statements themselves do not actually modify the database but 4066** rather they control the timing of when other statements modify the 4067** database. ^The [ATTACH] and [DETACH] statements also cause 4068** sqlite3_stmt_readonly() to return true since, while those statements 4069** change the configuration of a database connection, they do not make 4070** changes to the content of the database files on disk. 4071** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4072** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4073** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4074** sqlite3_stmt_readonly() returns false for those commands. 4075*/ 4076int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4077 4078/* 4079** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4080** METHOD: sqlite3_stmt 4081** 4082** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4083** prepared statement S is an EXPLAIN statement, or 2 if the 4084** statement S is an EXPLAIN QUERY PLAN. 4085** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4086** an ordinary statement or a NULL pointer. 4087*/ 4088int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4089 4090/* 4091** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4092** METHOD: sqlite3_stmt 4093** 4094** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4095** [prepared statement] S has been stepped at least once using 4096** [sqlite3_step(S)] but has neither run to completion (returned 4097** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4098** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4099** interface returns false if S is a NULL pointer. If S is not a 4100** NULL pointer and is not a pointer to a valid [prepared statement] 4101** object, then the behavior is undefined and probably undesirable. 4102** 4103** This interface can be used in combination [sqlite3_next_stmt()] 4104** to locate all prepared statements associated with a database 4105** connection that are in need of being reset. This can be used, 4106** for example, in diagnostic routines to search for prepared 4107** statements that are holding a transaction open. 4108*/ 4109int sqlite3_stmt_busy(sqlite3_stmt*); 4110 4111/* 4112** CAPI3REF: Dynamically Typed Value Object 4113** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4114** 4115** SQLite uses the sqlite3_value object to represent all values 4116** that can be stored in a database table. SQLite uses dynamic typing 4117** for the values it stores. ^Values stored in sqlite3_value objects 4118** can be integers, floating point values, strings, BLOBs, or NULL. 4119** 4120** An sqlite3_value object may be either "protected" or "unprotected". 4121** Some interfaces require a protected sqlite3_value. Other interfaces 4122** will accept either a protected or an unprotected sqlite3_value. 4123** Every interface that accepts sqlite3_value arguments specifies 4124** whether or not it requires a protected sqlite3_value. The 4125** [sqlite3_value_dup()] interface can be used to construct a new 4126** protected sqlite3_value from an unprotected sqlite3_value. 4127** 4128** The terms "protected" and "unprotected" refer to whether or not 4129** a mutex is held. An internal mutex is held for a protected 4130** sqlite3_value object but no mutex is held for an unprotected 4131** sqlite3_value object. If SQLite is compiled to be single-threaded 4132** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4133** or if SQLite is run in one of reduced mutex modes 4134** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4135** then there is no distinction between protected and unprotected 4136** sqlite3_value objects and they can be used interchangeably. However, 4137** for maximum code portability it is recommended that applications 4138** still make the distinction between protected and unprotected 4139** sqlite3_value objects even when not strictly required. 4140** 4141** ^The sqlite3_value objects that are passed as parameters into the 4142** implementation of [application-defined SQL functions] are protected. 4143** ^The sqlite3_value object returned by 4144** [sqlite3_column_value()] is unprotected. 4145** Unprotected sqlite3_value objects may only be used as arguments 4146** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4147** [sqlite3_value_dup()]. 4148** The [sqlite3_value_blob | sqlite3_value_type()] family of 4149** interfaces require protected sqlite3_value objects. 4150*/ 4151typedef struct sqlite3_value sqlite3_value; 4152 4153/* 4154** CAPI3REF: SQL Function Context Object 4155** 4156** The context in which an SQL function executes is stored in an 4157** sqlite3_context object. ^A pointer to an sqlite3_context object 4158** is always first parameter to [application-defined SQL functions]. 4159** The application-defined SQL function implementation will pass this 4160** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4161** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4162** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4163** and/or [sqlite3_set_auxdata()]. 4164*/ 4165typedef struct sqlite3_context sqlite3_context; 4166 4167/* 4168** CAPI3REF: Binding Values To Prepared Statements 4169** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4170** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4171** METHOD: sqlite3_stmt 4172** 4173** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4174** literals may be replaced by a [parameter] that matches one of following 4175** templates: 4176** 4177** <ul> 4178** <li> ? 4179** <li> ?NNN 4180** <li> :VVV 4181** <li> @VVV 4182** <li> $VVV 4183** </ul> 4184** 4185** In the templates above, NNN represents an integer literal, 4186** and VVV represents an alphanumeric identifier.)^ ^The values of these 4187** parameters (also called "host parameter names" or "SQL parameters") 4188** can be set using the sqlite3_bind_*() routines defined here. 4189** 4190** ^The first argument to the sqlite3_bind_*() routines is always 4191** a pointer to the [sqlite3_stmt] object returned from 4192** [sqlite3_prepare_v2()] or its variants. 4193** 4194** ^The second argument is the index of the SQL parameter to be set. 4195** ^The leftmost SQL parameter has an index of 1. ^When the same named 4196** SQL parameter is used more than once, second and subsequent 4197** occurrences have the same index as the first occurrence. 4198** ^The index for named parameters can be looked up using the 4199** [sqlite3_bind_parameter_index()] API if desired. ^The index 4200** for "?NNN" parameters is the value of NNN. 4201** ^The NNN value must be between 1 and the [sqlite3_limit()] 4202** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4203** 4204** ^The third argument is the value to bind to the parameter. 4205** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4206** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4207** is ignored and the end result is the same as sqlite3_bind_null(). 4208** 4209** ^(In those routines that have a fourth argument, its value is the 4210** number of bytes in the parameter. To be clear: the value is the 4211** number of <u>bytes</u> in the value, not the number of characters.)^ 4212** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4213** is negative, then the length of the string is 4214** the number of bytes up to the first zero terminator. 4215** If the fourth parameter to sqlite3_bind_blob() is negative, then 4216** the behavior is undefined. 4217** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4218** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4219** that parameter must be the byte offset 4220** where the NUL terminator would occur assuming the string were NUL 4221** terminated. If any NUL characters occur at byte offsets less than 4222** the value of the fourth parameter then the resulting string value will 4223** contain embedded NULs. The result of expressions involving strings 4224** with embedded NULs is undefined. 4225** 4226** ^The fifth argument to the BLOB and string binding interfaces 4227** is a destructor used to dispose of the BLOB or 4228** string after SQLite has finished with it. ^The destructor is called 4229** to dispose of the BLOB or string even if the call to the bind API fails, 4230** except the destructor is not called if the third parameter is a NULL 4231** pointer or the fourth parameter is negative. 4232** ^If the fifth argument is 4233** the special value [SQLITE_STATIC], then SQLite assumes that the 4234** information is in static, unmanaged space and does not need to be freed. 4235** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4236** SQLite makes its own private copy of the data immediately, before 4237** the sqlite3_bind_*() routine returns. 4238** 4239** ^The sixth argument to sqlite3_bind_text64() must be one of 4240** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4241** to specify the encoding of the text in the third parameter. If 4242** the sixth argument to sqlite3_bind_text64() is not one of the 4243** allowed values shown above, or if the text encoding is different 4244** from the encoding specified by the sixth parameter, then the behavior 4245** is undefined. 4246** 4247** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4248** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4249** (just an integer to hold its size) while it is being processed. 4250** Zeroblobs are intended to serve as placeholders for BLOBs whose 4251** content is later written using 4252** [sqlite3_blob_open | incremental BLOB I/O] routines. 4253** ^A negative value for the zeroblob results in a zero-length BLOB. 4254** 4255** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4256** [prepared statement] S to have an SQL value of NULL, but to also be 4257** associated with the pointer P of type T. ^D is either a NULL pointer or 4258** a pointer to a destructor function for P. ^SQLite will invoke the 4259** destructor D with a single argument of P when it is finished using 4260** P. The T parameter should be a static string, preferably a string 4261** literal. The sqlite3_bind_pointer() routine is part of the 4262** [pointer passing interface] added for SQLite 3.20.0. 4263** 4264** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4265** for the [prepared statement] or with a prepared statement for which 4266** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4267** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4268** routine is passed a [prepared statement] that has been finalized, the 4269** result is undefined and probably harmful. 4270** 4271** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4272** ^Unbound parameters are interpreted as NULL. 4273** 4274** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4275** [error code] if anything goes wrong. 4276** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4277** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4278** [SQLITE_MAX_LENGTH]. 4279** ^[SQLITE_RANGE] is returned if the parameter 4280** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4281** 4282** See also: [sqlite3_bind_parameter_count()], 4283** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4284*/ 4285int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4286int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4287 void(*)(void*)); 4288int sqlite3_bind_double(sqlite3_stmt*, int, double); 4289int sqlite3_bind_int(sqlite3_stmt*, int, int); 4290int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4291int sqlite3_bind_null(sqlite3_stmt*, int); 4292int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4293int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4294int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4295 void(*)(void*), unsigned char encoding); 4296int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4297int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4298int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4299int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4300 4301/* 4302** CAPI3REF: Number Of SQL Parameters 4303** METHOD: sqlite3_stmt 4304** 4305** ^This routine can be used to find the number of [SQL parameters] 4306** in a [prepared statement]. SQL parameters are tokens of the 4307** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4308** placeholders for values that are [sqlite3_bind_blob | bound] 4309** to the parameters at a later time. 4310** 4311** ^(This routine actually returns the index of the largest (rightmost) 4312** parameter. For all forms except ?NNN, this will correspond to the 4313** number of unique parameters. If parameters of the ?NNN form are used, 4314** there may be gaps in the list.)^ 4315** 4316** See also: [sqlite3_bind_blob|sqlite3_bind()], 4317** [sqlite3_bind_parameter_name()], and 4318** [sqlite3_bind_parameter_index()]. 4319*/ 4320int sqlite3_bind_parameter_count(sqlite3_stmt*); 4321 4322/* 4323** CAPI3REF: Name Of A Host Parameter 4324** METHOD: sqlite3_stmt 4325** 4326** ^The sqlite3_bind_parameter_name(P,N) interface returns 4327** the name of the N-th [SQL parameter] in the [prepared statement] P. 4328** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4329** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4330** respectively. 4331** In other words, the initial ":" or "$" or "@" or "?" 4332** is included as part of the name.)^ 4333** ^Parameters of the form "?" without a following integer have no name 4334** and are referred to as "nameless" or "anonymous parameters". 4335** 4336** ^The first host parameter has an index of 1, not 0. 4337** 4338** ^If the value N is out of range or if the N-th parameter is 4339** nameless, then NULL is returned. ^The returned string is 4340** always in UTF-8 encoding even if the named parameter was 4341** originally specified as UTF-16 in [sqlite3_prepare16()], 4342** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4343** 4344** See also: [sqlite3_bind_blob|sqlite3_bind()], 4345** [sqlite3_bind_parameter_count()], and 4346** [sqlite3_bind_parameter_index()]. 4347*/ 4348const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4349 4350/* 4351** CAPI3REF: Index Of A Parameter With A Given Name 4352** METHOD: sqlite3_stmt 4353** 4354** ^Return the index of an SQL parameter given its name. ^The 4355** index value returned is suitable for use as the second 4356** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4357** is returned if no matching parameter is found. ^The parameter 4358** name must be given in UTF-8 even if the original statement 4359** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4360** [sqlite3_prepare16_v3()]. 4361** 4362** See also: [sqlite3_bind_blob|sqlite3_bind()], 4363** [sqlite3_bind_parameter_count()], and 4364** [sqlite3_bind_parameter_name()]. 4365*/ 4366int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4367 4368/* 4369** CAPI3REF: Reset All Bindings On A Prepared Statement 4370** METHOD: sqlite3_stmt 4371** 4372** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4373** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4374** ^Use this routine to reset all host parameters to NULL. 4375*/ 4376int sqlite3_clear_bindings(sqlite3_stmt*); 4377 4378/* 4379** CAPI3REF: Number Of Columns In A Result Set 4380** METHOD: sqlite3_stmt 4381** 4382** ^Return the number of columns in the result set returned by the 4383** [prepared statement]. ^If this routine returns 0, that means the 4384** [prepared statement] returns no data (for example an [UPDATE]). 4385** ^However, just because this routine returns a positive number does not 4386** mean that one or more rows of data will be returned. ^A SELECT statement 4387** will always have a positive sqlite3_column_count() but depending on the 4388** WHERE clause constraints and the table content, it might return no rows. 4389** 4390** See also: [sqlite3_data_count()] 4391*/ 4392int sqlite3_column_count(sqlite3_stmt *pStmt); 4393 4394/* 4395** CAPI3REF: Column Names In A Result Set 4396** METHOD: sqlite3_stmt 4397** 4398** ^These routines return the name assigned to a particular column 4399** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4400** interface returns a pointer to a zero-terminated UTF-8 string 4401** and sqlite3_column_name16() returns a pointer to a zero-terminated 4402** UTF-16 string. ^The first parameter is the [prepared statement] 4403** that implements the [SELECT] statement. ^The second parameter is the 4404** column number. ^The leftmost column is number 0. 4405** 4406** ^The returned string pointer is valid until either the [prepared statement] 4407** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4408** reprepared by the first call to [sqlite3_step()] for a particular run 4409** or until the next call to 4410** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4411** 4412** ^If sqlite3_malloc() fails during the processing of either routine 4413** (for example during a conversion from UTF-8 to UTF-16) then a 4414** NULL pointer is returned. 4415** 4416** ^The name of a result column is the value of the "AS" clause for 4417** that column, if there is an AS clause. If there is no AS clause 4418** then the name of the column is unspecified and may change from 4419** one release of SQLite to the next. 4420*/ 4421const char *sqlite3_column_name(sqlite3_stmt*, int N); 4422const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4423 4424/* 4425** CAPI3REF: Source Of Data In A Query Result 4426** METHOD: sqlite3_stmt 4427** 4428** ^These routines provide a means to determine the database, table, and 4429** table column that is the origin of a particular result column in 4430** [SELECT] statement. 4431** ^The name of the database or table or column can be returned as 4432** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4433** the database name, the _table_ routines return the table name, and 4434** the origin_ routines return the column name. 4435** ^The returned string is valid until the [prepared statement] is destroyed 4436** using [sqlite3_finalize()] or until the statement is automatically 4437** reprepared by the first call to [sqlite3_step()] for a particular run 4438** or until the same information is requested 4439** again in a different encoding. 4440** 4441** ^The names returned are the original un-aliased names of the 4442** database, table, and column. 4443** 4444** ^The first argument to these interfaces is a [prepared statement]. 4445** ^These functions return information about the Nth result column returned by 4446** the statement, where N is the second function argument. 4447** ^The left-most column is column 0 for these routines. 4448** 4449** ^If the Nth column returned by the statement is an expression or 4450** subquery and is not a column value, then all of these functions return 4451** NULL. ^These routines might also return NULL if a memory allocation error 4452** occurs. ^Otherwise, they return the name of the attached database, table, 4453** or column that query result column was extracted from. 4454** 4455** ^As with all other SQLite APIs, those whose names end with "16" return 4456** UTF-16 encoded strings and the other functions return UTF-8. 4457** 4458** ^These APIs are only available if the library was compiled with the 4459** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4460** 4461** If two or more threads call one or more 4462** [sqlite3_column_database_name | column metadata interfaces] 4463** for the same [prepared statement] and result column 4464** at the same time then the results are undefined. 4465*/ 4466const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4467const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4468const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4469const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4470const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4471const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4472 4473/* 4474** CAPI3REF: Declared Datatype Of A Query Result 4475** METHOD: sqlite3_stmt 4476** 4477** ^(The first parameter is a [prepared statement]. 4478** If this statement is a [SELECT] statement and the Nth column of the 4479** returned result set of that [SELECT] is a table column (not an 4480** expression or subquery) then the declared type of the table 4481** column is returned.)^ ^If the Nth column of the result set is an 4482** expression or subquery, then a NULL pointer is returned. 4483** ^The returned string is always UTF-8 encoded. 4484** 4485** ^(For example, given the database schema: 4486** 4487** CREATE TABLE t1(c1 VARIANT); 4488** 4489** and the following statement to be compiled: 4490** 4491** SELECT c1 + 1, c1 FROM t1; 4492** 4493** this routine would return the string "VARIANT" for the second result 4494** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4495** 4496** ^SQLite uses dynamic run-time typing. ^So just because a column 4497** is declared to contain a particular type does not mean that the 4498** data stored in that column is of the declared type. SQLite is 4499** strongly typed, but the typing is dynamic not static. ^Type 4500** is associated with individual values, not with the containers 4501** used to hold those values. 4502*/ 4503const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4504const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4505 4506/* 4507** CAPI3REF: Evaluate An SQL Statement 4508** METHOD: sqlite3_stmt 4509** 4510** After a [prepared statement] has been prepared using any of 4511** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4512** or [sqlite3_prepare16_v3()] or one of the legacy 4513** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4514** must be called one or more times to evaluate the statement. 4515** 4516** The details of the behavior of the sqlite3_step() interface depend 4517** on whether the statement was prepared using the newer "vX" interfaces 4518** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4519** [sqlite3_prepare16_v2()] or the older legacy 4520** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4521** new "vX" interface is recommended for new applications but the legacy 4522** interface will continue to be supported. 4523** 4524** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4525** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4526** ^With the "v2" interface, any of the other [result codes] or 4527** [extended result codes] might be returned as well. 4528** 4529** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4530** database locks it needs to do its job. ^If the statement is a [COMMIT] 4531** or occurs outside of an explicit transaction, then you can retry the 4532** statement. If the statement is not a [COMMIT] and occurs within an 4533** explicit transaction then you should rollback the transaction before 4534** continuing. 4535** 4536** ^[SQLITE_DONE] means that the statement has finished executing 4537** successfully. sqlite3_step() should not be called again on this virtual 4538** machine without first calling [sqlite3_reset()] to reset the virtual 4539** machine back to its initial state. 4540** 4541** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4542** is returned each time a new row of data is ready for processing by the 4543** caller. The values may be accessed using the [column access functions]. 4544** sqlite3_step() is called again to retrieve the next row of data. 4545** 4546** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4547** violation) has occurred. sqlite3_step() should not be called again on 4548** the VM. More information may be found by calling [sqlite3_errmsg()]. 4549** ^With the legacy interface, a more specific error code (for example, 4550** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4551** can be obtained by calling [sqlite3_reset()] on the 4552** [prepared statement]. ^In the "v2" interface, 4553** the more specific error code is returned directly by sqlite3_step(). 4554** 4555** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4556** Perhaps it was called on a [prepared statement] that has 4557** already been [sqlite3_finalize | finalized] or on one that had 4558** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4559** be the case that the same database connection is being used by two or 4560** more threads at the same moment in time. 4561** 4562** For all versions of SQLite up to and including 3.6.23.1, a call to 4563** [sqlite3_reset()] was required after sqlite3_step() returned anything 4564** other than [SQLITE_ROW] before any subsequent invocation of 4565** sqlite3_step(). Failure to reset the prepared statement using 4566** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4567** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4568** sqlite3_step() began 4569** calling [sqlite3_reset()] automatically in this circumstance rather 4570** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4571** break because any application that ever receives an SQLITE_MISUSE error 4572** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4573** can be used to restore the legacy behavior. 4574** 4575** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4576** API always returns a generic error code, [SQLITE_ERROR], following any 4577** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4578** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4579** specific [error codes] that better describes the error. 4580** We admit that this is a goofy design. The problem has been fixed 4581** with the "v2" interface. If you prepare all of your SQL statements 4582** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4583** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4584** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4585** then the more specific [error codes] are returned directly 4586** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4587*/ 4588int sqlite3_step(sqlite3_stmt*); 4589 4590/* 4591** CAPI3REF: Number of columns in a result set 4592** METHOD: sqlite3_stmt 4593** 4594** ^The sqlite3_data_count(P) interface returns the number of columns in the 4595** current row of the result set of [prepared statement] P. 4596** ^If prepared statement P does not have results ready to return 4597** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4598** interfaces) then sqlite3_data_count(P) returns 0. 4599** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4600** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4601** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4602** will return non-zero if previous call to [sqlite3_step](P) returned 4603** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4604** where it always returns zero since each step of that multi-step 4605** pragma returns 0 columns of data. 4606** 4607** See also: [sqlite3_column_count()] 4608*/ 4609int sqlite3_data_count(sqlite3_stmt *pStmt); 4610 4611/* 4612** CAPI3REF: Fundamental Datatypes 4613** KEYWORDS: SQLITE_TEXT 4614** 4615** ^(Every value in SQLite has one of five fundamental datatypes: 4616** 4617** <ul> 4618** <li> 64-bit signed integer 4619** <li> 64-bit IEEE floating point number 4620** <li> string 4621** <li> BLOB 4622** <li> NULL 4623** </ul>)^ 4624** 4625** These constants are codes for each of those types. 4626** 4627** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4628** for a completely different meaning. Software that links against both 4629** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4630** SQLITE_TEXT. 4631*/ 4632#define SQLITE_INTEGER 1 4633#define SQLITE_FLOAT 2 4634#define SQLITE_BLOB 4 4635#define SQLITE_NULL 5 4636#ifdef SQLITE_TEXT 4637# undef SQLITE_TEXT 4638#else 4639# define SQLITE_TEXT 3 4640#endif 4641#define SQLITE3_TEXT 3 4642 4643/* 4644** CAPI3REF: Result Values From A Query 4645** KEYWORDS: {column access functions} 4646** METHOD: sqlite3_stmt 4647** 4648** <b>Summary:</b> 4649** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4650** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4651** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4652** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4653** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4654** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4655** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4656** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4657** [sqlite3_value|unprotected sqlite3_value] object. 4658** <tr><td> <td> <td> 4659** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4660** or a UTF-8 TEXT result in bytes 4661** <tr><td><b>sqlite3_column_bytes16 </b> 4662** <td>→ <td>Size of UTF-16 4663** TEXT in bytes 4664** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4665** datatype of the result 4666** </table></blockquote> 4667** 4668** <b>Details:</b> 4669** 4670** ^These routines return information about a single column of the current 4671** result row of a query. ^In every case the first argument is a pointer 4672** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4673** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4674** and the second argument is the index of the column for which information 4675** should be returned. ^The leftmost column of the result set has the index 0. 4676** ^The number of columns in the result can be determined using 4677** [sqlite3_column_count()]. 4678** 4679** If the SQL statement does not currently point to a valid row, or if the 4680** column index is out of range, the result is undefined. 4681** These routines may only be called when the most recent call to 4682** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4683** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4684** If any of these routines are called after [sqlite3_reset()] or 4685** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4686** something other than [SQLITE_ROW], the results are undefined. 4687** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4688** are called from a different thread while any of these routines 4689** are pending, then the results are undefined. 4690** 4691** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4692** each return the value of a result column in a specific data format. If 4693** the result column is not initially in the requested format (for example, 4694** if the query returns an integer but the sqlite3_column_text() interface 4695** is used to extract the value) then an automatic type conversion is performed. 4696** 4697** ^The sqlite3_column_type() routine returns the 4698** [SQLITE_INTEGER | datatype code] for the initial data type 4699** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4700** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4701** The return value of sqlite3_column_type() can be used to decide which 4702** of the first six interface should be used to extract the column value. 4703** The value returned by sqlite3_column_type() is only meaningful if no 4704** automatic type conversions have occurred for the value in question. 4705** After a type conversion, the result of calling sqlite3_column_type() 4706** is undefined, though harmless. Future 4707** versions of SQLite may change the behavior of sqlite3_column_type() 4708** following a type conversion. 4709** 4710** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4711** or sqlite3_column_bytes16() interfaces can be used to determine the size 4712** of that BLOB or string. 4713** 4714** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4715** routine returns the number of bytes in that BLOB or string. 4716** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4717** the string to UTF-8 and then returns the number of bytes. 4718** ^If the result is a numeric value then sqlite3_column_bytes() uses 4719** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4720** the number of bytes in that string. 4721** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4722** 4723** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4724** routine returns the number of bytes in that BLOB or string. 4725** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4726** the string to UTF-16 and then returns the number of bytes. 4727** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4728** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4729** the number of bytes in that string. 4730** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4731** 4732** ^The values returned by [sqlite3_column_bytes()] and 4733** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4734** of the string. ^For clarity: the values returned by 4735** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4736** bytes in the string, not the number of characters. 4737** 4738** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4739** even empty strings, are always zero-terminated. ^The return 4740** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4741** 4742** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4743** [unprotected sqlite3_value] object. In a multithreaded environment, 4744** an unprotected sqlite3_value object may only be used safely with 4745** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4746** If the [unprotected sqlite3_value] object returned by 4747** [sqlite3_column_value()] is used in any other way, including calls 4748** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4749** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4750** Hence, the sqlite3_column_value() interface 4751** is normally only useful within the implementation of 4752** [application-defined SQL functions] or [virtual tables], not within 4753** top-level application code. 4754** 4755** The these routines may attempt to convert the datatype of the result. 4756** ^For example, if the internal representation is FLOAT and a text result 4757** is requested, [sqlite3_snprintf()] is used internally to perform the 4758** conversion automatically. ^(The following table details the conversions 4759** that are applied: 4760** 4761** <blockquote> 4762** <table border="1"> 4763** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4764** 4765** <tr><td> NULL <td> INTEGER <td> Result is 0 4766** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4767** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4768** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4769** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4770** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4771** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4772** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4773** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4774** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4775** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4776** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4777** <tr><td> TEXT <td> BLOB <td> No change 4778** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4779** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4780** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4781** </table> 4782** </blockquote>)^ 4783** 4784** Note that when type conversions occur, pointers returned by prior 4785** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4786** sqlite3_column_text16() may be invalidated. 4787** Type conversions and pointer invalidations might occur 4788** in the following cases: 4789** 4790** <ul> 4791** <li> The initial content is a BLOB and sqlite3_column_text() or 4792** sqlite3_column_text16() is called. A zero-terminator might 4793** need to be added to the string.</li> 4794** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4795** sqlite3_column_text16() is called. The content must be converted 4796** to UTF-16.</li> 4797** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4798** sqlite3_column_text() is called. The content must be converted 4799** to UTF-8.</li> 4800** </ul> 4801** 4802** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4803** not invalidate a prior pointer, though of course the content of the buffer 4804** that the prior pointer references will have been modified. Other kinds 4805** of conversion are done in place when it is possible, but sometimes they 4806** are not possible and in those cases prior pointers are invalidated. 4807** 4808** The safest policy is to invoke these routines 4809** in one of the following ways: 4810** 4811** <ul> 4812** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4813** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4814** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4815** </ul> 4816** 4817** In other words, you should call sqlite3_column_text(), 4818** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4819** into the desired format, then invoke sqlite3_column_bytes() or 4820** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4821** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4822** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4823** with calls to sqlite3_column_bytes(). 4824** 4825** ^The pointers returned are valid until a type conversion occurs as 4826** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4827** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4828** and BLOBs is freed automatically. Do not pass the pointers returned 4829** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4830** [sqlite3_free()]. 4831** 4832** As long as the input parameters are correct, these routines will only 4833** fail if an out-of-memory error occurs during a format conversion. 4834** Only the following subset of interfaces are subject to out-of-memory 4835** errors: 4836** 4837** <ul> 4838** <li> sqlite3_column_blob() 4839** <li> sqlite3_column_text() 4840** <li> sqlite3_column_text16() 4841** <li> sqlite3_column_bytes() 4842** <li> sqlite3_column_bytes16() 4843** </ul> 4844** 4845** If an out-of-memory error occurs, then the return value from these 4846** routines is the same as if the column had contained an SQL NULL value. 4847** Valid SQL NULL returns can be distinguished from out-of-memory errors 4848** by invoking the [sqlite3_errcode()] immediately after the suspect 4849** return value is obtained and before any 4850** other SQLite interface is called on the same [database connection]. 4851*/ 4852const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4853double sqlite3_column_double(sqlite3_stmt*, int iCol); 4854int sqlite3_column_int(sqlite3_stmt*, int iCol); 4855sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4856const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4857const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4858sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4859int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4860int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4861int sqlite3_column_type(sqlite3_stmt*, int iCol); 4862 4863/* 4864** CAPI3REF: Destroy A Prepared Statement Object 4865** DESTRUCTOR: sqlite3_stmt 4866** 4867** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4868** ^If the most recent evaluation of the statement encountered no errors 4869** or if the statement is never been evaluated, then sqlite3_finalize() returns 4870** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4871** sqlite3_finalize(S) returns the appropriate [error code] or 4872** [extended error code]. 4873** 4874** ^The sqlite3_finalize(S) routine can be called at any point during 4875** the life cycle of [prepared statement] S: 4876** before statement S is ever evaluated, after 4877** one or more calls to [sqlite3_reset()], or after any call 4878** to [sqlite3_step()] regardless of whether or not the statement has 4879** completed execution. 4880** 4881** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4882** 4883** The application must finalize every [prepared statement] in order to avoid 4884** resource leaks. It is a grievous error for the application to try to use 4885** a prepared statement after it has been finalized. Any use of a prepared 4886** statement after it has been finalized can result in undefined and 4887** undesirable behavior such as segfaults and heap corruption. 4888*/ 4889int sqlite3_finalize(sqlite3_stmt *pStmt); 4890 4891/* 4892** CAPI3REF: Reset A Prepared Statement Object 4893** METHOD: sqlite3_stmt 4894** 4895** The sqlite3_reset() function is called to reset a [prepared statement] 4896** object back to its initial state, ready to be re-executed. 4897** ^Any SQL statement variables that had values bound to them using 4898** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4899** Use [sqlite3_clear_bindings()] to reset the bindings. 4900** 4901** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4902** back to the beginning of its program. 4903** 4904** ^If the most recent call to [sqlite3_step(S)] for the 4905** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4906** or if [sqlite3_step(S)] has never before been called on S, 4907** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4908** 4909** ^If the most recent call to [sqlite3_step(S)] for the 4910** [prepared statement] S indicated an error, then 4911** [sqlite3_reset(S)] returns an appropriate [error code]. 4912** 4913** ^The [sqlite3_reset(S)] interface does not change the values 4914** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4915*/ 4916int sqlite3_reset(sqlite3_stmt *pStmt); 4917 4918/* 4919** CAPI3REF: Create Or Redefine SQL Functions 4920** KEYWORDS: {function creation routines} 4921** METHOD: sqlite3 4922** 4923** ^These functions (collectively known as "function creation routines") 4924** are used to add SQL functions or aggregates or to redefine the behavior 4925** of existing SQL functions or aggregates. The only differences between 4926** the three "sqlite3_create_function*" routines are the text encoding 4927** expected for the second parameter (the name of the function being 4928** created) and the presence or absence of a destructor callback for 4929** the application data pointer. Function sqlite3_create_window_function() 4930** is similar, but allows the user to supply the extra callback functions 4931** needed by [aggregate window functions]. 4932** 4933** ^The first parameter is the [database connection] to which the SQL 4934** function is to be added. ^If an application uses more than one database 4935** connection then application-defined SQL functions must be added 4936** to each database connection separately. 4937** 4938** ^The second parameter is the name of the SQL function to be created or 4939** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4940** representation, exclusive of the zero-terminator. ^Note that the name 4941** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4942** ^Any attempt to create a function with a longer name 4943** will result in [SQLITE_MISUSE] being returned. 4944** 4945** ^The third parameter (nArg) 4946** is the number of arguments that the SQL function or 4947** aggregate takes. ^If this parameter is -1, then the SQL function or 4948** aggregate may take any number of arguments between 0 and the limit 4949** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4950** parameter is less than -1 or greater than 127 then the behavior is 4951** undefined. 4952** 4953** ^The fourth parameter, eTextRep, specifies what 4954** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4955** its parameters. The application should set this parameter to 4956** [SQLITE_UTF16LE] if the function implementation invokes 4957** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4958** implementation invokes [sqlite3_value_text16be()] on an input, or 4959** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4960** otherwise. ^The same SQL function may be registered multiple times using 4961** different preferred text encodings, with different implementations for 4962** each encoding. 4963** ^When multiple implementations of the same function are available, SQLite 4964** will pick the one that involves the least amount of data conversion. 4965** 4966** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4967** to signal that the function will always return the same result given 4968** the same inputs within a single SQL statement. Most SQL functions are 4969** deterministic. The built-in [random()] SQL function is an example of a 4970** function that is not deterministic. The SQLite query planner is able to 4971** perform additional optimizations on deterministic functions, so use 4972** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4973** 4974** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4975** flag, which if present prevents the function from being invoked from 4976** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 4977** index expressions, or the WHERE clause of partial indexes. 4978** 4979** <span style="background-color:#ffff90;"> 4980** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 4981** all application-defined SQL functions that do not need to be 4982** used inside of triggers, view, CHECK constraints, or other elements of 4983** the database schema. This flags is especially recommended for SQL 4984** functions that have side effects or reveal internal application state. 4985** Without this flag, an attacker might be able to modify the schema of 4986** a database file to include invocations of the function with parameters 4987** chosen by the attacker, which the application will then execute when 4988** the database file is opened and read. 4989** </span> 4990** 4991** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4992** function can gain access to this pointer using [sqlite3_user_data()].)^ 4993** 4994** ^The sixth, seventh and eighth parameters passed to the three 4995** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4996** pointers to C-language functions that implement the SQL function or 4997** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4998** callback only; NULL pointers must be passed as the xStep and xFinal 4999** parameters. ^An aggregate SQL function requires an implementation of xStep 5000** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5001** SQL function or aggregate, pass NULL pointers for all three function 5002** callbacks. 5003** 5004** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5005** and xInverse) passed to sqlite3_create_window_function are pointers to 5006** C-language callbacks that implement the new function. xStep and xFinal 5007** must both be non-NULL. xValue and xInverse may either both be NULL, in 5008** which case a regular aggregate function is created, or must both be 5009** non-NULL, in which case the new function may be used as either an aggregate 5010** or aggregate window function. More details regarding the implementation 5011** of aggregate window functions are 5012** [user-defined window functions|available here]. 5013** 5014** ^(If the final parameter to sqlite3_create_function_v2() or 5015** sqlite3_create_window_function() is not NULL, then it is destructor for 5016** the application data pointer. The destructor is invoked when the function 5017** is deleted, either by being overloaded or when the database connection 5018** closes.)^ ^The destructor is also invoked if the call to 5019** sqlite3_create_function_v2() fails. ^When the destructor callback is 5020** invoked, it is passed a single argument which is a copy of the application 5021** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5022** 5023** ^It is permitted to register multiple implementations of the same 5024** functions with the same name but with either differing numbers of 5025** arguments or differing preferred text encodings. ^SQLite will use 5026** the implementation that most closely matches the way in which the 5027** SQL function is used. ^A function implementation with a non-negative 5028** nArg parameter is a better match than a function implementation with 5029** a negative nArg. ^A function where the preferred text encoding 5030** matches the database encoding is a better 5031** match than a function where the encoding is different. 5032** ^A function where the encoding difference is between UTF16le and UTF16be 5033** is a closer match than a function where the encoding difference is 5034** between UTF8 and UTF16. 5035** 5036** ^Built-in functions may be overloaded by new application-defined functions. 5037** 5038** ^An application-defined function is permitted to call other 5039** SQLite interfaces. However, such calls must not 5040** close the database connection nor finalize or reset the prepared 5041** statement in which the function is running. 5042*/ 5043int sqlite3_create_function( 5044 sqlite3 *db, 5045 const char *zFunctionName, 5046 int nArg, 5047 int eTextRep, 5048 void *pApp, 5049 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5050 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5051 void (*xFinal)(sqlite3_context*) 5052); 5053int sqlite3_create_function16( 5054 sqlite3 *db, 5055 const void *zFunctionName, 5056 int nArg, 5057 int eTextRep, 5058 void *pApp, 5059 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5060 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5061 void (*xFinal)(sqlite3_context*) 5062); 5063int sqlite3_create_function_v2( 5064 sqlite3 *db, 5065 const char *zFunctionName, 5066 int nArg, 5067 int eTextRep, 5068 void *pApp, 5069 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5070 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5071 void (*xFinal)(sqlite3_context*), 5072 void(*xDestroy)(void*) 5073); 5074int sqlite3_create_window_function( 5075 sqlite3 *db, 5076 const char *zFunctionName, 5077 int nArg, 5078 int eTextRep, 5079 void *pApp, 5080 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5081 void (*xFinal)(sqlite3_context*), 5082 void (*xValue)(sqlite3_context*), 5083 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5084 void(*xDestroy)(void*) 5085); 5086 5087/* 5088** CAPI3REF: Text Encodings 5089** 5090** These constant define integer codes that represent the various 5091** text encodings supported by SQLite. 5092*/ 5093#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5094#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5095#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5096#define SQLITE_UTF16 4 /* Use native byte order */ 5097#define SQLITE_ANY 5 /* Deprecated */ 5098#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5099 5100/* 5101** CAPI3REF: Function Flags 5102** 5103** These constants may be ORed together with the 5104** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5105** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5106** [sqlite3_create_function_v2()]. 5107** 5108** <dl> 5109** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5110** The SQLITE_DETERMINISTIC flag means that the new function always gives 5111** the same output when the input parameters are the same. 5112** The [abs|abs() function] is deterministic, for example, but 5113** [randomblob|randomblob()] is not. Functions must 5114** be deterministic in order to be used in certain contexts such as 5115** with the WHERE clause of [partial indexes] or in [generated columns]. 5116** SQLite might also optimize deterministic functions by factoring them 5117** out of inner loops. 5118** </dd> 5119** 5120** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5121** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5122** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5123** schema structures such as [CHECK constraints], [DEFAULT clauses], 5124** [expression indexes], [partial indexes], or [generated columns]. 5125** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5126** for all [application-defined SQL functions], and especially for functions 5127** that have side-effects or that could potentially leak sensitive 5128** information. 5129** </dd> 5130** 5131** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5132** The SQLITE_INNOCUOUS flag means that the function is unlikely 5133** to cause problems even if misused. An innocuous function should have 5134** no side effects and should not depend on any values other than its 5135** input parameters. The [abs|abs() function] is an example of an 5136** innocuous function. 5137** The [load_extension() SQL function] is not innocuous because of its 5138** side effects. 5139** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5140** exactly the same. The [random|random() function] is an example of a 5141** function that is innocuous but not deterministic. 5142** <p>Some heightened security settings 5143** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5144** disable the use of SQL functions inside views and triggers and in 5145** schema structures such as [CHECK constraints], [DEFAULT clauses], 5146** [expression indexes], [partial indexes], and [generated columns] unless 5147** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5148** are innocuous. Developers are advised to avoid using the 5149** SQLITE_INNOCUOUS flag for application-defined functions unless the 5150** function has been carefully audited and found to be free of potentially 5151** security-adverse side-effects and information-leaks. 5152** </dd> 5153** 5154** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5155** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5156** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5157** Specifying this flag makes no difference for scalar or aggregate user 5158** functions. However, if it is not specified for a user-defined window 5159** function, then any sub-types belonging to arguments passed to the window 5160** function may be discarded before the window function is called (i.e. 5161** sqlite3_value_subtype() will always return 0). 5162** </dd> 5163** </dl> 5164*/ 5165#define SQLITE_DETERMINISTIC 0x000000800 5166#define SQLITE_DIRECTONLY 0x000080000 5167#define SQLITE_SUBTYPE 0x000100000 5168#define SQLITE_INNOCUOUS 0x000200000 5169 5170/* 5171** CAPI3REF: Deprecated Functions 5172** DEPRECATED 5173** 5174** These functions are [deprecated]. In order to maintain 5175** backwards compatibility with older code, these functions continue 5176** to be supported. However, new applications should avoid 5177** the use of these functions. To encourage programmers to avoid 5178** these functions, we will not explain what they do. 5179*/ 5180#ifndef SQLITE_OMIT_DEPRECATED 5181SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5182SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5183SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5184SQLITE_DEPRECATED int sqlite3_global_recover(void); 5185SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5186SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5187 void*,sqlite3_int64); 5188#endif 5189 5190/* 5191** CAPI3REF: Obtaining SQL Values 5192** METHOD: sqlite3_value 5193** 5194** <b>Summary:</b> 5195** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5196** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5197** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5198** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5199** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5200** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5201** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5202** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5203** the native byteorder 5204** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5205** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5206** <tr><td> <td> <td> 5207** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5208** or a UTF-8 TEXT in bytes 5209** <tr><td><b>sqlite3_value_bytes16 </b> 5210** <td>→ <td>Size of UTF-16 5211** TEXT in bytes 5212** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5213** datatype of the value 5214** <tr><td><b>sqlite3_value_numeric_type </b> 5215** <td>→ <td>Best numeric datatype of the value 5216** <tr><td><b>sqlite3_value_nochange </b> 5217** <td>→ <td>True if the column is unchanged in an UPDATE 5218** against a virtual table. 5219** <tr><td><b>sqlite3_value_frombind </b> 5220** <td>→ <td>True if value originated from a [bound parameter] 5221** </table></blockquote> 5222** 5223** <b>Details:</b> 5224** 5225** These routines extract type, size, and content information from 5226** [protected sqlite3_value] objects. Protected sqlite3_value objects 5227** are used to pass parameter information into the functions that 5228** implement [application-defined SQL functions] and [virtual tables]. 5229** 5230** These routines work only with [protected sqlite3_value] objects. 5231** Any attempt to use these routines on an [unprotected sqlite3_value] 5232** is not threadsafe. 5233** 5234** ^These routines work just like the corresponding [column access functions] 5235** except that these routines take a single [protected sqlite3_value] object 5236** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5237** 5238** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5239** in the native byte-order of the host machine. ^The 5240** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5241** extract UTF-16 strings as big-endian and little-endian respectively. 5242** 5243** ^If [sqlite3_value] object V was initialized 5244** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5245** and if X and Y are strings that compare equal according to strcmp(X,Y), 5246** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5247** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5248** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5249** 5250** ^(The sqlite3_value_type(V) interface returns the 5251** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5252** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5253** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5254** Other interfaces might change the datatype for an sqlite3_value object. 5255** For example, if the datatype is initially SQLITE_INTEGER and 5256** sqlite3_value_text(V) is called to extract a text value for that 5257** integer, then subsequent calls to sqlite3_value_type(V) might return 5258** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5259** occurs is undefined and may change from one release of SQLite to the next. 5260** 5261** ^(The sqlite3_value_numeric_type() interface attempts to apply 5262** numeric affinity to the value. This means that an attempt is 5263** made to convert the value to an integer or floating point. If 5264** such a conversion is possible without loss of information (in other 5265** words, if the value is a string that looks like a number) 5266** then the conversion is performed. Otherwise no conversion occurs. 5267** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5268** 5269** ^Within the [xUpdate] method of a [virtual table], the 5270** sqlite3_value_nochange(X) interface returns true if and only if 5271** the column corresponding to X is unchanged by the UPDATE operation 5272** that the xUpdate method call was invoked to implement and if 5273** and the prior [xColumn] method call that was invoked to extracted 5274** the value for that column returned without setting a result (probably 5275** because it queried [sqlite3_vtab_nochange()] and found that the column 5276** was unchanging). ^Within an [xUpdate] method, any value for which 5277** sqlite3_value_nochange(X) is true will in all other respects appear 5278** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5279** than within an [xUpdate] method call for an UPDATE statement, then 5280** the return value is arbitrary and meaningless. 5281** 5282** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5283** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5284** interfaces. ^If X comes from an SQL literal value, or a table column, 5285** or an expression, then sqlite3_value_frombind(X) returns zero. 5286** 5287** Please pay particular attention to the fact that the pointer returned 5288** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5289** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5290** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5291** or [sqlite3_value_text16()]. 5292** 5293** These routines must be called from the same thread as 5294** the SQL function that supplied the [sqlite3_value*] parameters. 5295** 5296** As long as the input parameter is correct, these routines can only 5297** fail if an out-of-memory error occurs during a format conversion. 5298** Only the following subset of interfaces are subject to out-of-memory 5299** errors: 5300** 5301** <ul> 5302** <li> sqlite3_value_blob() 5303** <li> sqlite3_value_text() 5304** <li> sqlite3_value_text16() 5305** <li> sqlite3_value_text16le() 5306** <li> sqlite3_value_text16be() 5307** <li> sqlite3_value_bytes() 5308** <li> sqlite3_value_bytes16() 5309** </ul> 5310** 5311** If an out-of-memory error occurs, then the return value from these 5312** routines is the same as if the column had contained an SQL NULL value. 5313** Valid SQL NULL returns can be distinguished from out-of-memory errors 5314** by invoking the [sqlite3_errcode()] immediately after the suspect 5315** return value is obtained and before any 5316** other SQLite interface is called on the same [database connection]. 5317*/ 5318const void *sqlite3_value_blob(sqlite3_value*); 5319double sqlite3_value_double(sqlite3_value*); 5320int sqlite3_value_int(sqlite3_value*); 5321sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5322void *sqlite3_value_pointer(sqlite3_value*, const char*); 5323const unsigned char *sqlite3_value_text(sqlite3_value*); 5324const void *sqlite3_value_text16(sqlite3_value*); 5325const void *sqlite3_value_text16le(sqlite3_value*); 5326const void *sqlite3_value_text16be(sqlite3_value*); 5327int sqlite3_value_bytes(sqlite3_value*); 5328int sqlite3_value_bytes16(sqlite3_value*); 5329int sqlite3_value_type(sqlite3_value*); 5330int sqlite3_value_numeric_type(sqlite3_value*); 5331int sqlite3_value_nochange(sqlite3_value*); 5332int sqlite3_value_frombind(sqlite3_value*); 5333 5334/* 5335** CAPI3REF: Finding The Subtype Of SQL Values 5336** METHOD: sqlite3_value 5337** 5338** The sqlite3_value_subtype(V) function returns the subtype for 5339** an [application-defined SQL function] argument V. The subtype 5340** information can be used to pass a limited amount of context from 5341** one SQL function to another. Use the [sqlite3_result_subtype()] 5342** routine to set the subtype for the return value of an SQL function. 5343*/ 5344unsigned int sqlite3_value_subtype(sqlite3_value*); 5345 5346/* 5347** CAPI3REF: Copy And Free SQL Values 5348** METHOD: sqlite3_value 5349** 5350** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5351** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5352** is a [protected sqlite3_value] object even if the input is not. 5353** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5354** memory allocation fails. 5355** 5356** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5357** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5358** then sqlite3_value_free(V) is a harmless no-op. 5359*/ 5360sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5361void sqlite3_value_free(sqlite3_value*); 5362 5363/* 5364** CAPI3REF: Obtain Aggregate Function Context 5365** METHOD: sqlite3_context 5366** 5367** Implementations of aggregate SQL functions use this 5368** routine to allocate memory for storing their state. 5369** 5370** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5371** for a particular aggregate function, SQLite allocates 5372** N bytes of memory, zeroes out that memory, and returns a pointer 5373** to the new memory. ^On second and subsequent calls to 5374** sqlite3_aggregate_context() for the same aggregate function instance, 5375** the same buffer is returned. Sqlite3_aggregate_context() is normally 5376** called once for each invocation of the xStep callback and then one 5377** last time when the xFinal callback is invoked. ^(When no rows match 5378** an aggregate query, the xStep() callback of the aggregate function 5379** implementation is never called and xFinal() is called exactly once. 5380** In those cases, sqlite3_aggregate_context() might be called for the 5381** first time from within xFinal().)^ 5382** 5383** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5384** when first called if N is less than or equal to zero or if a memory 5385** allocate error occurs. 5386** 5387** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5388** determined by the N parameter on first successful call. Changing the 5389** value of N in any subsequents call to sqlite3_aggregate_context() within 5390** the same aggregate function instance will not resize the memory 5391** allocation.)^ Within the xFinal callback, it is customary to set 5392** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5393** pointless memory allocations occur. 5394** 5395** ^SQLite automatically frees the memory allocated by 5396** sqlite3_aggregate_context() when the aggregate query concludes. 5397** 5398** The first parameter must be a copy of the 5399** [sqlite3_context | SQL function context] that is the first parameter 5400** to the xStep or xFinal callback routine that implements the aggregate 5401** function. 5402** 5403** This routine must be called from the same thread in which 5404** the aggregate SQL function is running. 5405*/ 5406void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5407 5408/* 5409** CAPI3REF: User Data For Functions 5410** METHOD: sqlite3_context 5411** 5412** ^The sqlite3_user_data() interface returns a copy of 5413** the pointer that was the pUserData parameter (the 5th parameter) 5414** of the [sqlite3_create_function()] 5415** and [sqlite3_create_function16()] routines that originally 5416** registered the application defined function. 5417** 5418** This routine must be called from the same thread in which 5419** the application-defined function is running. 5420*/ 5421void *sqlite3_user_data(sqlite3_context*); 5422 5423/* 5424** CAPI3REF: Database Connection For Functions 5425** METHOD: sqlite3_context 5426** 5427** ^The sqlite3_context_db_handle() interface returns a copy of 5428** the pointer to the [database connection] (the 1st parameter) 5429** of the [sqlite3_create_function()] 5430** and [sqlite3_create_function16()] routines that originally 5431** registered the application defined function. 5432*/ 5433sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5434 5435/* 5436** CAPI3REF: Function Auxiliary Data 5437** METHOD: sqlite3_context 5438** 5439** These functions may be used by (non-aggregate) SQL functions to 5440** associate metadata with argument values. If the same value is passed to 5441** multiple invocations of the same SQL function during query execution, under 5442** some circumstances the associated metadata may be preserved. An example 5443** of where this might be useful is in a regular-expression matching 5444** function. The compiled version of the regular expression can be stored as 5445** metadata associated with the pattern string. 5446** Then as long as the pattern string remains the same, 5447** the compiled regular expression can be reused on multiple 5448** invocations of the same function. 5449** 5450** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5451** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5452** value to the application-defined function. ^N is zero for the left-most 5453** function argument. ^If there is no metadata 5454** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5455** returns a NULL pointer. 5456** 5457** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5458** argument of the application-defined function. ^Subsequent 5459** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5460** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5461** NULL if the metadata has been discarded. 5462** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5463** SQLite will invoke the destructor function X with parameter P exactly 5464** once, when the metadata is discarded. 5465** SQLite is free to discard the metadata at any time, including: <ul> 5466** <li> ^(when the corresponding function parameter changes)^, or 5467** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5468** SQL statement)^, or 5469** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5470** parameter)^, or 5471** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5472** allocation error occurs.)^ </ul> 5473** 5474** Note the last bullet in particular. The destructor X in 5475** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5476** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5477** should be called near the end of the function implementation and the 5478** function implementation should not make any use of P after 5479** sqlite3_set_auxdata() has been called. 5480** 5481** ^(In practice, metadata is preserved between function calls for 5482** function parameters that are compile-time constants, including literal 5483** values and [parameters] and expressions composed from the same.)^ 5484** 5485** The value of the N parameter to these interfaces should be non-negative. 5486** Future enhancements may make use of negative N values to define new 5487** kinds of function caching behavior. 5488** 5489** These routines must be called from the same thread in which 5490** the SQL function is running. 5491*/ 5492void *sqlite3_get_auxdata(sqlite3_context*, int N); 5493void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5494 5495 5496/* 5497** CAPI3REF: Constants Defining Special Destructor Behavior 5498** 5499** These are special values for the destructor that is passed in as the 5500** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5501** argument is SQLITE_STATIC, it means that the content pointer is constant 5502** and will never change. It does not need to be destroyed. ^The 5503** SQLITE_TRANSIENT value means that the content will likely change in 5504** the near future and that SQLite should make its own private copy of 5505** the content before returning. 5506** 5507** The typedef is necessary to work around problems in certain 5508** C++ compilers. 5509*/ 5510typedef void (*sqlite3_destructor_type)(void*); 5511#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5512#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5513 5514/* 5515** CAPI3REF: Setting The Result Of An SQL Function 5516** METHOD: sqlite3_context 5517** 5518** These routines are used by the xFunc or xFinal callbacks that 5519** implement SQL functions and aggregates. See 5520** [sqlite3_create_function()] and [sqlite3_create_function16()] 5521** for additional information. 5522** 5523** These functions work very much like the [parameter binding] family of 5524** functions used to bind values to host parameters in prepared statements. 5525** Refer to the [SQL parameter] documentation for additional information. 5526** 5527** ^The sqlite3_result_blob() interface sets the result from 5528** an application-defined function to be the BLOB whose content is pointed 5529** to by the second parameter and which is N bytes long where N is the 5530** third parameter. 5531** 5532** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5533** interfaces set the result of the application-defined function to be 5534** a BLOB containing all zero bytes and N bytes in size. 5535** 5536** ^The sqlite3_result_double() interface sets the result from 5537** an application-defined function to be a floating point value specified 5538** by its 2nd argument. 5539** 5540** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5541** cause the implemented SQL function to throw an exception. 5542** ^SQLite uses the string pointed to by the 5543** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5544** as the text of an error message. ^SQLite interprets the error 5545** message string from sqlite3_result_error() as UTF-8. ^SQLite 5546** interprets the string from sqlite3_result_error16() as UTF-16 in native 5547** byte order. ^If the third parameter to sqlite3_result_error() 5548** or sqlite3_result_error16() is negative then SQLite takes as the error 5549** message all text up through the first zero character. 5550** ^If the third parameter to sqlite3_result_error() or 5551** sqlite3_result_error16() is non-negative then SQLite takes that many 5552** bytes (not characters) from the 2nd parameter as the error message. 5553** ^The sqlite3_result_error() and sqlite3_result_error16() 5554** routines make a private copy of the error message text before 5555** they return. Hence, the calling function can deallocate or 5556** modify the text after they return without harm. 5557** ^The sqlite3_result_error_code() function changes the error code 5558** returned by SQLite as a result of an error in a function. ^By default, 5559** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5560** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5561** 5562** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5563** error indicating that a string or BLOB is too long to represent. 5564** 5565** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5566** error indicating that a memory allocation failed. 5567** 5568** ^The sqlite3_result_int() interface sets the return value 5569** of the application-defined function to be the 32-bit signed integer 5570** value given in the 2nd argument. 5571** ^The sqlite3_result_int64() interface sets the return value 5572** of the application-defined function to be the 64-bit signed integer 5573** value given in the 2nd argument. 5574** 5575** ^The sqlite3_result_null() interface sets the return value 5576** of the application-defined function to be NULL. 5577** 5578** ^The sqlite3_result_text(), sqlite3_result_text16(), 5579** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5580** set the return value of the application-defined function to be 5581** a text string which is represented as UTF-8, UTF-16 native byte order, 5582** UTF-16 little endian, or UTF-16 big endian, respectively. 5583** ^The sqlite3_result_text64() interface sets the return value of an 5584** application-defined function to be a text string in an encoding 5585** specified by the fifth (and last) parameter, which must be one 5586** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5587** ^SQLite takes the text result from the application from 5588** the 2nd parameter of the sqlite3_result_text* interfaces. 5589** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5590** is negative, then SQLite takes result text from the 2nd parameter 5591** through the first zero character. 5592** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5593** is non-negative, then as many bytes (not characters) of the text 5594** pointed to by the 2nd parameter are taken as the application-defined 5595** function result. If the 3rd parameter is non-negative, then it 5596** must be the byte offset into the string where the NUL terminator would 5597** appear if the string where NUL terminated. If any NUL characters occur 5598** in the string at a byte offset that is less than the value of the 3rd 5599** parameter, then the resulting string will contain embedded NULs and the 5600** result of expressions operating on strings with embedded NULs is undefined. 5601** ^If the 4th parameter to the sqlite3_result_text* interfaces 5602** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5603** function as the destructor on the text or BLOB result when it has 5604** finished using that result. 5605** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5606** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5607** assumes that the text or BLOB result is in constant space and does not 5608** copy the content of the parameter nor call a destructor on the content 5609** when it has finished using that result. 5610** ^If the 4th parameter to the sqlite3_result_text* interfaces 5611** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5612** then SQLite makes a copy of the result into space obtained 5613** from [sqlite3_malloc()] before it returns. 5614** 5615** ^The sqlite3_result_value() interface sets the result of 5616** the application-defined function to be a copy of the 5617** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5618** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5619** so that the [sqlite3_value] specified in the parameter may change or 5620** be deallocated after sqlite3_result_value() returns without harm. 5621** ^A [protected sqlite3_value] object may always be used where an 5622** [unprotected sqlite3_value] object is required, so either 5623** kind of [sqlite3_value] object can be used with this interface. 5624** 5625** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5626** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5627** also associates the host-language pointer P or type T with that 5628** NULL value such that the pointer can be retrieved within an 5629** [application-defined SQL function] using [sqlite3_value_pointer()]. 5630** ^If the D parameter is not NULL, then it is a pointer to a destructor 5631** for the P parameter. ^SQLite invokes D with P as its only argument 5632** when SQLite is finished with P. The T parameter should be a static 5633** string and preferably a string literal. The sqlite3_result_pointer() 5634** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5635** 5636** If these routines are called from within the different thread 5637** than the one containing the application-defined function that received 5638** the [sqlite3_context] pointer, the results are undefined. 5639*/ 5640void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5641void sqlite3_result_blob64(sqlite3_context*,const void*, 5642 sqlite3_uint64,void(*)(void*)); 5643void sqlite3_result_double(sqlite3_context*, double); 5644void sqlite3_result_error(sqlite3_context*, const char*, int); 5645void sqlite3_result_error16(sqlite3_context*, const void*, int); 5646void sqlite3_result_error_toobig(sqlite3_context*); 5647void sqlite3_result_error_nomem(sqlite3_context*); 5648void sqlite3_result_error_code(sqlite3_context*, int); 5649void sqlite3_result_int(sqlite3_context*, int); 5650void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5651void sqlite3_result_null(sqlite3_context*); 5652void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5653void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5654 void(*)(void*), unsigned char encoding); 5655void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5656void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5657void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5658void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5659void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5660void sqlite3_result_zeroblob(sqlite3_context*, int n); 5661int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5662 5663 5664/* 5665** CAPI3REF: Setting The Subtype Of An SQL Function 5666** METHOD: sqlite3_context 5667** 5668** The sqlite3_result_subtype(C,T) function causes the subtype of 5669** the result from the [application-defined SQL function] with 5670** [sqlite3_context] C to be the value T. Only the lower 8 bits 5671** of the subtype T are preserved in current versions of SQLite; 5672** higher order bits are discarded. 5673** The number of subtype bytes preserved by SQLite might increase 5674** in future releases of SQLite. 5675*/ 5676void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5677 5678/* 5679** CAPI3REF: Define New Collating Sequences 5680** METHOD: sqlite3 5681** 5682** ^These functions add, remove, or modify a [collation] associated 5683** with the [database connection] specified as the first argument. 5684** 5685** ^The name of the collation is a UTF-8 string 5686** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5687** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5688** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5689** considered to be the same name. 5690** 5691** ^(The third argument (eTextRep) must be one of the constants: 5692** <ul> 5693** <li> [SQLITE_UTF8], 5694** <li> [SQLITE_UTF16LE], 5695** <li> [SQLITE_UTF16BE], 5696** <li> [SQLITE_UTF16], or 5697** <li> [SQLITE_UTF16_ALIGNED]. 5698** </ul>)^ 5699** ^The eTextRep argument determines the encoding of strings passed 5700** to the collating function callback, xCompare. 5701** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5702** force strings to be UTF16 with native byte order. 5703** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5704** on an even byte address. 5705** 5706** ^The fourth argument, pArg, is an application data pointer that is passed 5707** through as the first argument to the collating function callback. 5708** 5709** ^The fifth argument, xCompare, is a pointer to the collating function. 5710** ^Multiple collating functions can be registered using the same name but 5711** with different eTextRep parameters and SQLite will use whichever 5712** function requires the least amount of data transformation. 5713** ^If the xCompare argument is NULL then the collating function is 5714** deleted. ^When all collating functions having the same name are deleted, 5715** that collation is no longer usable. 5716** 5717** ^The collating function callback is invoked with a copy of the pArg 5718** application data pointer and with two strings in the encoding specified 5719** by the eTextRep argument. The two integer parameters to the collating 5720** function callback are the length of the two strings, in bytes. The collating 5721** function must return an integer that is negative, zero, or positive 5722** if the first string is less than, equal to, or greater than the second, 5723** respectively. A collating function must always return the same answer 5724** given the same inputs. If two or more collating functions are registered 5725** to the same collation name (using different eTextRep values) then all 5726** must give an equivalent answer when invoked with equivalent strings. 5727** The collating function must obey the following properties for all 5728** strings A, B, and C: 5729** 5730** <ol> 5731** <li> If A==B then B==A. 5732** <li> If A==B and B==C then A==C. 5733** <li> If A<B THEN B>A. 5734** <li> If A<B and B<C then A<C. 5735** </ol> 5736** 5737** If a collating function fails any of the above constraints and that 5738** collating function is registered and used, then the behavior of SQLite 5739** is undefined. 5740** 5741** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5742** with the addition that the xDestroy callback is invoked on pArg when 5743** the collating function is deleted. 5744** ^Collating functions are deleted when they are overridden by later 5745** calls to the collation creation functions or when the 5746** [database connection] is closed using [sqlite3_close()]. 5747** 5748** ^The xDestroy callback is <u>not</u> called if the 5749** sqlite3_create_collation_v2() function fails. Applications that invoke 5750** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5751** check the return code and dispose of the application data pointer 5752** themselves rather than expecting SQLite to deal with it for them. 5753** This is different from every other SQLite interface. The inconsistency 5754** is unfortunate but cannot be changed without breaking backwards 5755** compatibility. 5756** 5757** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5758*/ 5759int sqlite3_create_collation( 5760 sqlite3*, 5761 const char *zName, 5762 int eTextRep, 5763 void *pArg, 5764 int(*xCompare)(void*,int,const void*,int,const void*) 5765); 5766int sqlite3_create_collation_v2( 5767 sqlite3*, 5768 const char *zName, 5769 int eTextRep, 5770 void *pArg, 5771 int(*xCompare)(void*,int,const void*,int,const void*), 5772 void(*xDestroy)(void*) 5773); 5774int sqlite3_create_collation16( 5775 sqlite3*, 5776 const void *zName, 5777 int eTextRep, 5778 void *pArg, 5779 int(*xCompare)(void*,int,const void*,int,const void*) 5780); 5781 5782/* 5783** CAPI3REF: Collation Needed Callbacks 5784** METHOD: sqlite3 5785** 5786** ^To avoid having to register all collation sequences before a database 5787** can be used, a single callback function may be registered with the 5788** [database connection] to be invoked whenever an undefined collation 5789** sequence is required. 5790** 5791** ^If the function is registered using the sqlite3_collation_needed() API, 5792** then it is passed the names of undefined collation sequences as strings 5793** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5794** the names are passed as UTF-16 in machine native byte order. 5795** ^A call to either function replaces the existing collation-needed callback. 5796** 5797** ^(When the callback is invoked, the first argument passed is a copy 5798** of the second argument to sqlite3_collation_needed() or 5799** sqlite3_collation_needed16(). The second argument is the database 5800** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5801** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5802** sequence function required. The fourth parameter is the name of the 5803** required collation sequence.)^ 5804** 5805** The callback function should register the desired collation using 5806** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5807** [sqlite3_create_collation_v2()]. 5808*/ 5809int sqlite3_collation_needed( 5810 sqlite3*, 5811 void*, 5812 void(*)(void*,sqlite3*,int eTextRep,const char*) 5813); 5814int sqlite3_collation_needed16( 5815 sqlite3*, 5816 void*, 5817 void(*)(void*,sqlite3*,int eTextRep,const void*) 5818); 5819 5820#ifdef SQLITE_HAS_CODEC 5821/* 5822** Specify the key for an encrypted database. This routine should be 5823** called right after sqlite3_open(). 5824** 5825** The code to implement this API is not available in the public release 5826** of SQLite. 5827*/ 5828int sqlite3_key( 5829 sqlite3 *db, /* Database to be rekeyed */ 5830 const void *pKey, int nKey /* The key */ 5831); 5832int sqlite3_key_v2( 5833 sqlite3 *db, /* Database to be rekeyed */ 5834 const char *zDbName, /* Name of the database */ 5835 const void *pKey, int nKey /* The key */ 5836); 5837 5838/* 5839** Change the key on an open database. If the current database is not 5840** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5841** database is decrypted. 5842** 5843** The code to implement this API is not available in the public release 5844** of SQLite. 5845*/ 5846int sqlite3_rekey( 5847 sqlite3 *db, /* Database to be rekeyed */ 5848 const void *pKey, int nKey /* The new key */ 5849); 5850int sqlite3_rekey_v2( 5851 sqlite3 *db, /* Database to be rekeyed */ 5852 const char *zDbName, /* Name of the database */ 5853 const void *pKey, int nKey /* The new key */ 5854); 5855 5856/* 5857** Specify the activation key for a SEE database. Unless 5858** activated, none of the SEE routines will work. 5859*/ 5860void sqlite3_activate_see( 5861 const char *zPassPhrase /* Activation phrase */ 5862); 5863#endif 5864 5865#ifdef SQLITE_ENABLE_CEROD 5866/* 5867** Specify the activation key for a CEROD database. Unless 5868** activated, none of the CEROD routines will work. 5869*/ 5870void sqlite3_activate_cerod( 5871 const char *zPassPhrase /* Activation phrase */ 5872); 5873#endif 5874 5875/* 5876** CAPI3REF: Suspend Execution For A Short Time 5877** 5878** The sqlite3_sleep() function causes the current thread to suspend execution 5879** for at least a number of milliseconds specified in its parameter. 5880** 5881** If the operating system does not support sleep requests with 5882** millisecond time resolution, then the time will be rounded up to 5883** the nearest second. The number of milliseconds of sleep actually 5884** requested from the operating system is returned. 5885** 5886** ^SQLite implements this interface by calling the xSleep() 5887** method of the default [sqlite3_vfs] object. If the xSleep() method 5888** of the default VFS is not implemented correctly, or not implemented at 5889** all, then the behavior of sqlite3_sleep() may deviate from the description 5890** in the previous paragraphs. 5891*/ 5892int sqlite3_sleep(int); 5893 5894/* 5895** CAPI3REF: Name Of The Folder Holding Temporary Files 5896** 5897** ^(If this global variable is made to point to a string which is 5898** the name of a folder (a.k.a. directory), then all temporary files 5899** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5900** will be placed in that directory.)^ ^If this variable 5901** is a NULL pointer, then SQLite performs a search for an appropriate 5902** temporary file directory. 5903** 5904** Applications are strongly discouraged from using this global variable. 5905** It is required to set a temporary folder on Windows Runtime (WinRT). 5906** But for all other platforms, it is highly recommended that applications 5907** neither read nor write this variable. This global variable is a relic 5908** that exists for backwards compatibility of legacy applications and should 5909** be avoided in new projects. 5910** 5911** It is not safe to read or modify this variable in more than one 5912** thread at a time. It is not safe to read or modify this variable 5913** if a [database connection] is being used at the same time in a separate 5914** thread. 5915** It is intended that this variable be set once 5916** as part of process initialization and before any SQLite interface 5917** routines have been called and that this variable remain unchanged 5918** thereafter. 5919** 5920** ^The [temp_store_directory pragma] may modify this variable and cause 5921** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5922** the [temp_store_directory pragma] always assumes that any string 5923** that this variable points to is held in memory obtained from 5924** [sqlite3_malloc] and the pragma may attempt to free that memory 5925** using [sqlite3_free]. 5926** Hence, if this variable is modified directly, either it should be 5927** made NULL or made to point to memory obtained from [sqlite3_malloc] 5928** or else the use of the [temp_store_directory pragma] should be avoided. 5929** Except when requested by the [temp_store_directory pragma], SQLite 5930** does not free the memory that sqlite3_temp_directory points to. If 5931** the application wants that memory to be freed, it must do 5932** so itself, taking care to only do so after all [database connection] 5933** objects have been destroyed. 5934** 5935** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5936** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5937** features that require the use of temporary files may fail. Here is an 5938** example of how to do this using C++ with the Windows Runtime: 5939** 5940** <blockquote><pre> 5941** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5942** TemporaryFolder->Path->Data(); 5943** char zPathBuf[MAX_PATH + 1]; 5944** memset(zPathBuf, 0, sizeof(zPathBuf)); 5945** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5946** NULL, NULL); 5947** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5948** </pre></blockquote> 5949*/ 5950SQLITE_EXTERN char *sqlite3_temp_directory; 5951 5952/* 5953** CAPI3REF: Name Of The Folder Holding Database Files 5954** 5955** ^(If this global variable is made to point to a string which is 5956** the name of a folder (a.k.a. directory), then all database files 5957** specified with a relative pathname and created or accessed by 5958** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5959** to be relative to that directory.)^ ^If this variable is a NULL 5960** pointer, then SQLite assumes that all database files specified 5961** with a relative pathname are relative to the current directory 5962** for the process. Only the windows VFS makes use of this global 5963** variable; it is ignored by the unix VFS. 5964** 5965** Changing the value of this variable while a database connection is 5966** open can result in a corrupt database. 5967** 5968** It is not safe to read or modify this variable in more than one 5969** thread at a time. It is not safe to read or modify this variable 5970** if a [database connection] is being used at the same time in a separate 5971** thread. 5972** It is intended that this variable be set once 5973** as part of process initialization and before any SQLite interface 5974** routines have been called and that this variable remain unchanged 5975** thereafter. 5976** 5977** ^The [data_store_directory pragma] may modify this variable and cause 5978** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5979** the [data_store_directory pragma] always assumes that any string 5980** that this variable points to is held in memory obtained from 5981** [sqlite3_malloc] and the pragma may attempt to free that memory 5982** using [sqlite3_free]. 5983** Hence, if this variable is modified directly, either it should be 5984** made NULL or made to point to memory obtained from [sqlite3_malloc] 5985** or else the use of the [data_store_directory pragma] should be avoided. 5986*/ 5987SQLITE_EXTERN char *sqlite3_data_directory; 5988 5989/* 5990** CAPI3REF: Win32 Specific Interface 5991** 5992** These interfaces are available only on Windows. The 5993** [sqlite3_win32_set_directory] interface is used to set the value associated 5994** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5995** zValue, depending on the value of the type parameter. The zValue parameter 5996** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5997** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5998** prior to being used. The [sqlite3_win32_set_directory] interface returns 5999** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6000** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6001** [sqlite3_data_directory] variable is intended to act as a replacement for 6002** the current directory on the sub-platforms of Win32 where that concept is 6003** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6004** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6005** sqlite3_win32_set_directory interface except the string parameter must be 6006** UTF-8 or UTF-16, respectively. 6007*/ 6008int sqlite3_win32_set_directory( 6009 unsigned long type, /* Identifier for directory being set or reset */ 6010 void *zValue /* New value for directory being set or reset */ 6011); 6012int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6013int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6014 6015/* 6016** CAPI3REF: Win32 Directory Types 6017** 6018** These macros are only available on Windows. They define the allowed values 6019** for the type argument to the [sqlite3_win32_set_directory] interface. 6020*/ 6021#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6022#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6023 6024/* 6025** CAPI3REF: Test For Auto-Commit Mode 6026** KEYWORDS: {autocommit mode} 6027** METHOD: sqlite3 6028** 6029** ^The sqlite3_get_autocommit() interface returns non-zero or 6030** zero if the given database connection is or is not in autocommit mode, 6031** respectively. ^Autocommit mode is on by default. 6032** ^Autocommit mode is disabled by a [BEGIN] statement. 6033** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6034** 6035** If certain kinds of errors occur on a statement within a multi-statement 6036** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6037** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6038** transaction might be rolled back automatically. The only way to 6039** find out whether SQLite automatically rolled back the transaction after 6040** an error is to use this function. 6041** 6042** If another thread changes the autocommit status of the database 6043** connection while this routine is running, then the return value 6044** is undefined. 6045*/ 6046int sqlite3_get_autocommit(sqlite3*); 6047 6048/* 6049** CAPI3REF: Find The Database Handle Of A Prepared Statement 6050** METHOD: sqlite3_stmt 6051** 6052** ^The sqlite3_db_handle interface returns the [database connection] handle 6053** to which a [prepared statement] belongs. ^The [database connection] 6054** returned by sqlite3_db_handle is the same [database connection] 6055** that was the first argument 6056** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6057** create the statement in the first place. 6058*/ 6059sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6060 6061/* 6062** CAPI3REF: Return The Filename For A Database Connection 6063** METHOD: sqlite3 6064** 6065** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6066** associated with database N of connection D. 6067** ^If there is no attached database N on the database 6068** connection D, or if database N is a temporary or in-memory database, then 6069** this function will return either a NULL pointer or an empty string. 6070** 6071** ^The string value returned by this routine is owned and managed by 6072** the database connection. ^The value will be valid until the database N 6073** is [DETACH]-ed or until the database connection closes. 6074** 6075** ^The filename returned by this function is the output of the 6076** xFullPathname method of the [VFS]. ^In other words, the filename 6077** will be an absolute pathname, even if the filename used 6078** to open the database originally was a URI or relative pathname. 6079** 6080** If the filename pointer returned by this routine is not NULL, then it 6081** can be used as the filename input parameter to these routines: 6082** <ul> 6083** <li> [sqlite3_uri_parameter()] 6084** <li> [sqlite3_uri_boolean()] 6085** <li> [sqlite3_uri_int64()] 6086** <li> [sqlite3_filename_database()] 6087** <li> [sqlite3_filename_journal()] 6088** <li> [sqlite3_filename_wal()] 6089** </ul> 6090*/ 6091const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6092 6093/* 6094** CAPI3REF: Determine if a database is read-only 6095** METHOD: sqlite3 6096** 6097** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6098** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6099** the name of a database on connection D. 6100*/ 6101int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6102 6103/* 6104** CAPI3REF: Find the next prepared statement 6105** METHOD: sqlite3 6106** 6107** ^This interface returns a pointer to the next [prepared statement] after 6108** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6109** then this interface returns a pointer to the first prepared statement 6110** associated with the database connection pDb. ^If no prepared statement 6111** satisfies the conditions of this routine, it returns NULL. 6112** 6113** The [database connection] pointer D in a call to 6114** [sqlite3_next_stmt(D,S)] must refer to an open database 6115** connection and in particular must not be a NULL pointer. 6116*/ 6117sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6118 6119/* 6120** CAPI3REF: Commit And Rollback Notification Callbacks 6121** METHOD: sqlite3 6122** 6123** ^The sqlite3_commit_hook() interface registers a callback 6124** function to be invoked whenever a transaction is [COMMIT | committed]. 6125** ^Any callback set by a previous call to sqlite3_commit_hook() 6126** for the same database connection is overridden. 6127** ^The sqlite3_rollback_hook() interface registers a callback 6128** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6129** ^Any callback set by a previous call to sqlite3_rollback_hook() 6130** for the same database connection is overridden. 6131** ^The pArg argument is passed through to the callback. 6132** ^If the callback on a commit hook function returns non-zero, 6133** then the commit is converted into a rollback. 6134** 6135** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6136** return the P argument from the previous call of the same function 6137** on the same [database connection] D, or NULL for 6138** the first call for each function on D. 6139** 6140** The commit and rollback hook callbacks are not reentrant. 6141** The callback implementation must not do anything that will modify 6142** the database connection that invoked the callback. Any actions 6143** to modify the database connection must be deferred until after the 6144** completion of the [sqlite3_step()] call that triggered the commit 6145** or rollback hook in the first place. 6146** Note that running any other SQL statements, including SELECT statements, 6147** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6148** the database connections for the meaning of "modify" in this paragraph. 6149** 6150** ^Registering a NULL function disables the callback. 6151** 6152** ^When the commit hook callback routine returns zero, the [COMMIT] 6153** operation is allowed to continue normally. ^If the commit hook 6154** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6155** ^The rollback hook is invoked on a rollback that results from a commit 6156** hook returning non-zero, just as it would be with any other rollback. 6157** 6158** ^For the purposes of this API, a transaction is said to have been 6159** rolled back if an explicit "ROLLBACK" statement is executed, or 6160** an error or constraint causes an implicit rollback to occur. 6161** ^The rollback callback is not invoked if a transaction is 6162** automatically rolled back because the database connection is closed. 6163** 6164** See also the [sqlite3_update_hook()] interface. 6165*/ 6166void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6167void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6168 6169/* 6170** CAPI3REF: Data Change Notification Callbacks 6171** METHOD: sqlite3 6172** 6173** ^The sqlite3_update_hook() interface registers a callback function 6174** with the [database connection] identified by the first argument 6175** to be invoked whenever a row is updated, inserted or deleted in 6176** a [rowid table]. 6177** ^Any callback set by a previous call to this function 6178** for the same database connection is overridden. 6179** 6180** ^The second argument is a pointer to the function to invoke when a 6181** row is updated, inserted or deleted in a rowid table. 6182** ^The first argument to the callback is a copy of the third argument 6183** to sqlite3_update_hook(). 6184** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6185** or [SQLITE_UPDATE], depending on the operation that caused the callback 6186** to be invoked. 6187** ^The third and fourth arguments to the callback contain pointers to the 6188** database and table name containing the affected row. 6189** ^The final callback parameter is the [rowid] of the row. 6190** ^In the case of an update, this is the [rowid] after the update takes place. 6191** 6192** ^(The update hook is not invoked when internal system tables are 6193** modified (i.e. sqlite_master and sqlite_sequence).)^ 6194** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6195** 6196** ^In the current implementation, the update hook 6197** is not invoked when conflicting rows are deleted because of an 6198** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6199** invoked when rows are deleted using the [truncate optimization]. 6200** The exceptions defined in this paragraph might change in a future 6201** release of SQLite. 6202** 6203** The update hook implementation must not do anything that will modify 6204** the database connection that invoked the update hook. Any actions 6205** to modify the database connection must be deferred until after the 6206** completion of the [sqlite3_step()] call that triggered the update hook. 6207** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6208** database connections for the meaning of "modify" in this paragraph. 6209** 6210** ^The sqlite3_update_hook(D,C,P) function 6211** returns the P argument from the previous call 6212** on the same [database connection] D, or NULL for 6213** the first call on D. 6214** 6215** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6216** and [sqlite3_preupdate_hook()] interfaces. 6217*/ 6218void *sqlite3_update_hook( 6219 sqlite3*, 6220 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6221 void* 6222); 6223 6224/* 6225** CAPI3REF: Enable Or Disable Shared Pager Cache 6226** 6227** ^(This routine enables or disables the sharing of the database cache 6228** and schema data structures between [database connection | connections] 6229** to the same database. Sharing is enabled if the argument is true 6230** and disabled if the argument is false.)^ 6231** 6232** ^Cache sharing is enabled and disabled for an entire process. 6233** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6234** In prior versions of SQLite, 6235** sharing was enabled or disabled for each thread separately. 6236** 6237** ^(The cache sharing mode set by this interface effects all subsequent 6238** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6239** Existing database connections continue to use the sharing mode 6240** that was in effect at the time they were opened.)^ 6241** 6242** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6243** successfully. An [error code] is returned otherwise.)^ 6244** 6245** ^Shared cache is disabled by default. It is recommended that it stay 6246** that way. In other words, do not use this routine. This interface 6247** continues to be provided for historical compatibility, but its use is 6248** discouraged. Any use of shared cache is discouraged. If shared cache 6249** must be used, it is recommended that shared cache only be enabled for 6250** individual database connections using the [sqlite3_open_v2()] interface 6251** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6252** 6253** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6254** and will always return SQLITE_MISUSE. On those systems, 6255** shared cache mode should be enabled per-database connection via 6256** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6257** 6258** This interface is threadsafe on processors where writing a 6259** 32-bit integer is atomic. 6260** 6261** See Also: [SQLite Shared-Cache Mode] 6262*/ 6263int sqlite3_enable_shared_cache(int); 6264 6265/* 6266** CAPI3REF: Attempt To Free Heap Memory 6267** 6268** ^The sqlite3_release_memory() interface attempts to free N bytes 6269** of heap memory by deallocating non-essential memory allocations 6270** held by the database library. Memory used to cache database 6271** pages to improve performance is an example of non-essential memory. 6272** ^sqlite3_release_memory() returns the number of bytes actually freed, 6273** which might be more or less than the amount requested. 6274** ^The sqlite3_release_memory() routine is a no-op returning zero 6275** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6276** 6277** See also: [sqlite3_db_release_memory()] 6278*/ 6279int sqlite3_release_memory(int); 6280 6281/* 6282** CAPI3REF: Free Memory Used By A Database Connection 6283** METHOD: sqlite3 6284** 6285** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6286** memory as possible from database connection D. Unlike the 6287** [sqlite3_release_memory()] interface, this interface is in effect even 6288** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6289** omitted. 6290** 6291** See also: [sqlite3_release_memory()] 6292*/ 6293int sqlite3_db_release_memory(sqlite3*); 6294 6295/* 6296** CAPI3REF: Impose A Limit On Heap Size 6297** 6298** These interfaces impose limits on the amount of heap memory that will be 6299** by all database connections within a single process. 6300** 6301** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6302** soft limit on the amount of heap memory that may be allocated by SQLite. 6303** ^SQLite strives to keep heap memory utilization below the soft heap 6304** limit by reducing the number of pages held in the page cache 6305** as heap memory usages approaches the limit. 6306** ^The soft heap limit is "soft" because even though SQLite strives to stay 6307** below the limit, it will exceed the limit rather than generate 6308** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6309** is advisory only. 6310** 6311** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6312** N bytes on the amount of memory that will be allocated. ^The 6313** sqlite3_hard_heap_limit64(N) interface is similar to 6314** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6315** when the hard heap limit is reached. 6316** 6317** ^The return value from both sqlite3_soft_heap_limit64() and 6318** sqlite3_hard_heap_limit64() is the size of 6319** the heap limit prior to the call, or negative in the case of an 6320** error. ^If the argument N is negative 6321** then no change is made to the heap limit. Hence, the current 6322** size of heap limits can be determined by invoking 6323** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6324** 6325** ^Setting the heap limits to zero disables the heap limiter mechanism. 6326** 6327** ^The soft heap limit may not be greater than the hard heap limit. 6328** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6329** is invoked with a value of N that is greater than the hard heap limit, 6330** the the soft heap limit is set to the value of the hard heap limit. 6331** ^The soft heap limit is automatically enabled whenever the hard heap 6332** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6333** the soft heap limit is outside the range of 1..N, then the soft heap 6334** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6335** hard heap limit is enabled makes the soft heap limit equal to the 6336** hard heap limit. 6337** 6338** The memory allocation limits can also be adjusted using 6339** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6340** 6341** ^(The heap limits are not enforced in the current implementation 6342** if one or more of following conditions are true: 6343** 6344** <ul> 6345** <li> The limit value is set to zero. 6346** <li> Memory accounting is disabled using a combination of the 6347** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6348** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6349** <li> An alternative page cache implementation is specified using 6350** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6351** <li> The page cache allocates from its own memory pool supplied 6352** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6353** from the heap. 6354** </ul>)^ 6355** 6356** The circumstances under which SQLite will enforce the heap limits may 6357** changes in future releases of SQLite. 6358*/ 6359sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6360sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6361 6362/* 6363** CAPI3REF: Deprecated Soft Heap Limit Interface 6364** DEPRECATED 6365** 6366** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6367** interface. This routine is provided for historical compatibility 6368** only. All new applications should use the 6369** [sqlite3_soft_heap_limit64()] interface rather than this one. 6370*/ 6371SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6372 6373 6374/* 6375** CAPI3REF: Extract Metadata About A Column Of A Table 6376** METHOD: sqlite3 6377** 6378** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6379** information about column C of table T in database D 6380** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6381** interface returns SQLITE_OK and fills in the non-NULL pointers in 6382** the final five arguments with appropriate values if the specified 6383** column exists. ^The sqlite3_table_column_metadata() interface returns 6384** SQLITE_ERROR if the specified column does not exist. 6385** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6386** NULL pointer, then this routine simply checks for the existence of the 6387** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6388** does not. If the table name parameter T in a call to 6389** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6390** undefined behavior. 6391** 6392** ^The column is identified by the second, third and fourth parameters to 6393** this function. ^(The second parameter is either the name of the database 6394** (i.e. "main", "temp", or an attached database) containing the specified 6395** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6396** for the table using the same algorithm used by the database engine to 6397** resolve unqualified table references. 6398** 6399** ^The third and fourth parameters to this function are the table and column 6400** name of the desired column, respectively. 6401** 6402** ^Metadata is returned by writing to the memory locations passed as the 5th 6403** and subsequent parameters to this function. ^Any of these arguments may be 6404** NULL, in which case the corresponding element of metadata is omitted. 6405** 6406** ^(<blockquote> 6407** <table border="1"> 6408** <tr><th> Parameter <th> Output<br>Type <th> Description 6409** 6410** <tr><td> 5th <td> const char* <td> Data type 6411** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6412** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6413** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6414** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6415** </table> 6416** </blockquote>)^ 6417** 6418** ^The memory pointed to by the character pointers returned for the 6419** declaration type and collation sequence is valid until the next 6420** call to any SQLite API function. 6421** 6422** ^If the specified table is actually a view, an [error code] is returned. 6423** 6424** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6425** is not a [WITHOUT ROWID] table and an 6426** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6427** parameters are set for the explicitly declared column. ^(If there is no 6428** [INTEGER PRIMARY KEY] column, then the outputs 6429** for the [rowid] are set as follows: 6430** 6431** <pre> 6432** data type: "INTEGER" 6433** collation sequence: "BINARY" 6434** not null: 0 6435** primary key: 1 6436** auto increment: 0 6437** </pre>)^ 6438** 6439** ^This function causes all database schemas to be read from disk and 6440** parsed, if that has not already been done, and returns an error if 6441** any errors are encountered while loading the schema. 6442*/ 6443int sqlite3_table_column_metadata( 6444 sqlite3 *db, /* Connection handle */ 6445 const char *zDbName, /* Database name or NULL */ 6446 const char *zTableName, /* Table name */ 6447 const char *zColumnName, /* Column name */ 6448 char const **pzDataType, /* OUTPUT: Declared data type */ 6449 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6450 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6451 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6452 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6453); 6454 6455/* 6456** CAPI3REF: Load An Extension 6457** METHOD: sqlite3 6458** 6459** ^This interface loads an SQLite extension library from the named file. 6460** 6461** ^The sqlite3_load_extension() interface attempts to load an 6462** [SQLite extension] library contained in the file zFile. If 6463** the file cannot be loaded directly, attempts are made to load 6464** with various operating-system specific extensions added. 6465** So for example, if "samplelib" cannot be loaded, then names like 6466** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6467** be tried also. 6468** 6469** ^The entry point is zProc. 6470** ^(zProc may be 0, in which case SQLite will try to come up with an 6471** entry point name on its own. It first tries "sqlite3_extension_init". 6472** If that does not work, it constructs a name "sqlite3_X_init" where the 6473** X is consists of the lower-case equivalent of all ASCII alphabetic 6474** characters in the filename from the last "/" to the first following 6475** "." and omitting any initial "lib".)^ 6476** ^The sqlite3_load_extension() interface returns 6477** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6478** ^If an error occurs and pzErrMsg is not 0, then the 6479** [sqlite3_load_extension()] interface shall attempt to 6480** fill *pzErrMsg with error message text stored in memory 6481** obtained from [sqlite3_malloc()]. The calling function 6482** should free this memory by calling [sqlite3_free()]. 6483** 6484** ^Extension loading must be enabled using 6485** [sqlite3_enable_load_extension()] or 6486** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6487** prior to calling this API, 6488** otherwise an error will be returned. 6489** 6490** <b>Security warning:</b> It is recommended that the 6491** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6492** interface. The use of the [sqlite3_enable_load_extension()] interface 6493** should be avoided. This will keep the SQL function [load_extension()] 6494** disabled and prevent SQL injections from giving attackers 6495** access to extension loading capabilities. 6496** 6497** See also the [load_extension() SQL function]. 6498*/ 6499int sqlite3_load_extension( 6500 sqlite3 *db, /* Load the extension into this database connection */ 6501 const char *zFile, /* Name of the shared library containing extension */ 6502 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6503 char **pzErrMsg /* Put error message here if not 0 */ 6504); 6505 6506/* 6507** CAPI3REF: Enable Or Disable Extension Loading 6508** METHOD: sqlite3 6509** 6510** ^So as not to open security holes in older applications that are 6511** unprepared to deal with [extension loading], and as a means of disabling 6512** [extension loading] while evaluating user-entered SQL, the following API 6513** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6514** 6515** ^Extension loading is off by default. 6516** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6517** to turn extension loading on and call it with onoff==0 to turn 6518** it back off again. 6519** 6520** ^This interface enables or disables both the C-API 6521** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6522** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6523** to enable or disable only the C-API.)^ 6524** 6525** <b>Security warning:</b> It is recommended that extension loading 6526** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6527** rather than this interface, so the [load_extension()] SQL function 6528** remains disabled. This will prevent SQL injections from giving attackers 6529** access to extension loading capabilities. 6530*/ 6531int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6532 6533/* 6534** CAPI3REF: Automatically Load Statically Linked Extensions 6535** 6536** ^This interface causes the xEntryPoint() function to be invoked for 6537** each new [database connection] that is created. The idea here is that 6538** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6539** that is to be automatically loaded into all new database connections. 6540** 6541** ^(Even though the function prototype shows that xEntryPoint() takes 6542** no arguments and returns void, SQLite invokes xEntryPoint() with three 6543** arguments and expects an integer result as if the signature of the 6544** entry point where as follows: 6545** 6546** <blockquote><pre> 6547** int xEntryPoint( 6548** sqlite3 *db, 6549** const char **pzErrMsg, 6550** const struct sqlite3_api_routines *pThunk 6551** ); 6552** </pre></blockquote>)^ 6553** 6554** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6555** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6556** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6557** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6558** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6559** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6560** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6561** 6562** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6563** on the list of automatic extensions is a harmless no-op. ^No entry point 6564** will be called more than once for each database connection that is opened. 6565** 6566** See also: [sqlite3_reset_auto_extension()] 6567** and [sqlite3_cancel_auto_extension()] 6568*/ 6569int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6570 6571/* 6572** CAPI3REF: Cancel Automatic Extension Loading 6573** 6574** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6575** initialization routine X that was registered using a prior call to 6576** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6577** routine returns 1 if initialization routine X was successfully 6578** unregistered and it returns 0 if X was not on the list of initialization 6579** routines. 6580*/ 6581int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6582 6583/* 6584** CAPI3REF: Reset Automatic Extension Loading 6585** 6586** ^This interface disables all automatic extensions previously 6587** registered using [sqlite3_auto_extension()]. 6588*/ 6589void sqlite3_reset_auto_extension(void); 6590 6591/* 6592** The interface to the virtual-table mechanism is currently considered 6593** to be experimental. The interface might change in incompatible ways. 6594** If this is a problem for you, do not use the interface at this time. 6595** 6596** When the virtual-table mechanism stabilizes, we will declare the 6597** interface fixed, support it indefinitely, and remove this comment. 6598*/ 6599 6600/* 6601** Structures used by the virtual table interface 6602*/ 6603typedef struct sqlite3_vtab sqlite3_vtab; 6604typedef struct sqlite3_index_info sqlite3_index_info; 6605typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6606typedef struct sqlite3_module sqlite3_module; 6607 6608/* 6609** CAPI3REF: Virtual Table Object 6610** KEYWORDS: sqlite3_module {virtual table module} 6611** 6612** This structure, sometimes called a "virtual table module", 6613** defines the implementation of a [virtual table]. 6614** This structure consists mostly of methods for the module. 6615** 6616** ^A virtual table module is created by filling in a persistent 6617** instance of this structure and passing a pointer to that instance 6618** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6619** ^The registration remains valid until it is replaced by a different 6620** module or until the [database connection] closes. The content 6621** of this structure must not change while it is registered with 6622** any database connection. 6623*/ 6624struct sqlite3_module { 6625 int iVersion; 6626 int (*xCreate)(sqlite3*, void *pAux, 6627 int argc, const char *const*argv, 6628 sqlite3_vtab **ppVTab, char**); 6629 int (*xConnect)(sqlite3*, void *pAux, 6630 int argc, const char *const*argv, 6631 sqlite3_vtab **ppVTab, char**); 6632 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6633 int (*xDisconnect)(sqlite3_vtab *pVTab); 6634 int (*xDestroy)(sqlite3_vtab *pVTab); 6635 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6636 int (*xClose)(sqlite3_vtab_cursor*); 6637 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6638 int argc, sqlite3_value **argv); 6639 int (*xNext)(sqlite3_vtab_cursor*); 6640 int (*xEof)(sqlite3_vtab_cursor*); 6641 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6642 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6643 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6644 int (*xBegin)(sqlite3_vtab *pVTab); 6645 int (*xSync)(sqlite3_vtab *pVTab); 6646 int (*xCommit)(sqlite3_vtab *pVTab); 6647 int (*xRollback)(sqlite3_vtab *pVTab); 6648 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6649 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6650 void **ppArg); 6651 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6652 /* The methods above are in version 1 of the sqlite_module object. Those 6653 ** below are for version 2 and greater. */ 6654 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6655 int (*xRelease)(sqlite3_vtab *pVTab, int); 6656 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6657 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6658 ** Those below are for version 3 and greater. */ 6659 int (*xShadowName)(const char*); 6660}; 6661 6662/* 6663** CAPI3REF: Virtual Table Indexing Information 6664** KEYWORDS: sqlite3_index_info 6665** 6666** The sqlite3_index_info structure and its substructures is used as part 6667** of the [virtual table] interface to 6668** pass information into and receive the reply from the [xBestIndex] 6669** method of a [virtual table module]. The fields under **Inputs** are the 6670** inputs to xBestIndex and are read-only. xBestIndex inserts its 6671** results into the **Outputs** fields. 6672** 6673** ^(The aConstraint[] array records WHERE clause constraints of the form: 6674** 6675** <blockquote>column OP expr</blockquote> 6676** 6677** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6678** stored in aConstraint[].op using one of the 6679** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6680** ^(The index of the column is stored in 6681** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6682** expr on the right-hand side can be evaluated (and thus the constraint 6683** is usable) and false if it cannot.)^ 6684** 6685** ^The optimizer automatically inverts terms of the form "expr OP column" 6686** and makes other simplifications to the WHERE clause in an attempt to 6687** get as many WHERE clause terms into the form shown above as possible. 6688** ^The aConstraint[] array only reports WHERE clause terms that are 6689** relevant to the particular virtual table being queried. 6690** 6691** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6692** ^Each term of aOrderBy records a column of the ORDER BY clause. 6693** 6694** The colUsed field indicates which columns of the virtual table may be 6695** required by the current scan. Virtual table columns are numbered from 6696** zero in the order in which they appear within the CREATE TABLE statement 6697** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6698** the corresponding bit is set within the colUsed mask if the column may be 6699** required by SQLite. If the table has at least 64 columns and any column 6700** to the right of the first 63 is required, then bit 63 of colUsed is also 6701** set. In other words, column iCol may be required if the expression 6702** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6703** non-zero. 6704** 6705** The [xBestIndex] method must fill aConstraintUsage[] with information 6706** about what parameters to pass to xFilter. ^If argvIndex>0 then 6707** the right-hand side of the corresponding aConstraint[] is evaluated 6708** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6709** is true, then the constraint is assumed to be fully handled by the 6710** virtual table and might not be checked again by the byte code.)^ ^(The 6711** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6712** is left in its default setting of false, the constraint will always be 6713** checked separately in byte code. If the omit flag is change to true, then 6714** the constraint may or may not be checked in byte code. In other words, 6715** when the omit flag is true there is no guarantee that the constraint will 6716** not be checked again using byte code.)^ 6717** 6718** ^The idxNum and idxPtr values are recorded and passed into the 6719** [xFilter] method. 6720** ^[sqlite3_free()] is used to free idxPtr if and only if 6721** needToFreeIdxPtr is true. 6722** 6723** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6724** the correct order to satisfy the ORDER BY clause so that no separate 6725** sorting step is required. 6726** 6727** ^The estimatedCost value is an estimate of the cost of a particular 6728** strategy. A cost of N indicates that the cost of the strategy is similar 6729** to a linear scan of an SQLite table with N rows. A cost of log(N) 6730** indicates that the expense of the operation is similar to that of a 6731** binary search on a unique indexed field of an SQLite table with N rows. 6732** 6733** ^The estimatedRows value is an estimate of the number of rows that 6734** will be returned by the strategy. 6735** 6736** The xBestIndex method may optionally populate the idxFlags field with a 6737** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6738** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6739** assumes that the strategy may visit at most one row. 6740** 6741** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6742** SQLite also assumes that if a call to the xUpdate() method is made as 6743** part of the same statement to delete or update a virtual table row and the 6744** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6745** any database changes. In other words, if the xUpdate() returns 6746** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6747** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6748** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6749** the xUpdate method are automatically rolled back by SQLite. 6750** 6751** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6752** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6753** If a virtual table extension is 6754** used with an SQLite version earlier than 3.8.2, the results of attempting 6755** to read or write the estimatedRows field are undefined (but are likely 6756** to include crashing the application). The estimatedRows field should 6757** therefore only be used if [sqlite3_libversion_number()] returns a 6758** value greater than or equal to 3008002. Similarly, the idxFlags field 6759** was added for [version 3.9.0] ([dateof:3.9.0]). 6760** It may therefore only be used if 6761** sqlite3_libversion_number() returns a value greater than or equal to 6762** 3009000. 6763*/ 6764struct sqlite3_index_info { 6765 /* Inputs */ 6766 int nConstraint; /* Number of entries in aConstraint */ 6767 struct sqlite3_index_constraint { 6768 int iColumn; /* Column constrained. -1 for ROWID */ 6769 unsigned char op; /* Constraint operator */ 6770 unsigned char usable; /* True if this constraint is usable */ 6771 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6772 } *aConstraint; /* Table of WHERE clause constraints */ 6773 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6774 struct sqlite3_index_orderby { 6775 int iColumn; /* Column number */ 6776 unsigned char desc; /* True for DESC. False for ASC. */ 6777 } *aOrderBy; /* The ORDER BY clause */ 6778 /* Outputs */ 6779 struct sqlite3_index_constraint_usage { 6780 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6781 unsigned char omit; /* Do not code a test for this constraint */ 6782 } *aConstraintUsage; 6783 int idxNum; /* Number used to identify the index */ 6784 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6785 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6786 int orderByConsumed; /* True if output is already ordered */ 6787 double estimatedCost; /* Estimated cost of using this index */ 6788 /* Fields below are only available in SQLite 3.8.2 and later */ 6789 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6790 /* Fields below are only available in SQLite 3.9.0 and later */ 6791 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6792 /* Fields below are only available in SQLite 3.10.0 and later */ 6793 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6794}; 6795 6796/* 6797** CAPI3REF: Virtual Table Scan Flags 6798** 6799** Virtual table implementations are allowed to set the 6800** [sqlite3_index_info].idxFlags field to some combination of 6801** these bits. 6802*/ 6803#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6804 6805/* 6806** CAPI3REF: Virtual Table Constraint Operator Codes 6807** 6808** These macros define the allowed values for the 6809** [sqlite3_index_info].aConstraint[].op field. Each value represents 6810** an operator that is part of a constraint term in the wHERE clause of 6811** a query that uses a [virtual table]. 6812*/ 6813#define SQLITE_INDEX_CONSTRAINT_EQ 2 6814#define SQLITE_INDEX_CONSTRAINT_GT 4 6815#define SQLITE_INDEX_CONSTRAINT_LE 8 6816#define SQLITE_INDEX_CONSTRAINT_LT 16 6817#define SQLITE_INDEX_CONSTRAINT_GE 32 6818#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6819#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6820#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6821#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6822#define SQLITE_INDEX_CONSTRAINT_NE 68 6823#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6824#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6825#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6826#define SQLITE_INDEX_CONSTRAINT_IS 72 6827#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6828 6829/* 6830** CAPI3REF: Register A Virtual Table Implementation 6831** METHOD: sqlite3 6832** 6833** ^These routines are used to register a new [virtual table module] name. 6834** ^Module names must be registered before 6835** creating a new [virtual table] using the module and before using a 6836** preexisting [virtual table] for the module. 6837** 6838** ^The module name is registered on the [database connection] specified 6839** by the first parameter. ^The name of the module is given by the 6840** second parameter. ^The third parameter is a pointer to 6841** the implementation of the [virtual table module]. ^The fourth 6842** parameter is an arbitrary client data pointer that is passed through 6843** into the [xCreate] and [xConnect] methods of the virtual table module 6844** when a new virtual table is be being created or reinitialized. 6845** 6846** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6847** is a pointer to a destructor for the pClientData. ^SQLite will 6848** invoke the destructor function (if it is not NULL) when SQLite 6849** no longer needs the pClientData pointer. ^The destructor will also 6850** be invoked if the call to sqlite3_create_module_v2() fails. 6851** ^The sqlite3_create_module() 6852** interface is equivalent to sqlite3_create_module_v2() with a NULL 6853** destructor. 6854** 6855** ^If the third parameter (the pointer to the sqlite3_module object) is 6856** NULL then no new module is create and any existing modules with the 6857** same name are dropped. 6858** 6859** See also: [sqlite3_drop_modules()] 6860*/ 6861int sqlite3_create_module( 6862 sqlite3 *db, /* SQLite connection to register module with */ 6863 const char *zName, /* Name of the module */ 6864 const sqlite3_module *p, /* Methods for the module */ 6865 void *pClientData /* Client data for xCreate/xConnect */ 6866); 6867int sqlite3_create_module_v2( 6868 sqlite3 *db, /* SQLite connection to register module with */ 6869 const char *zName, /* Name of the module */ 6870 const sqlite3_module *p, /* Methods for the module */ 6871 void *pClientData, /* Client data for xCreate/xConnect */ 6872 void(*xDestroy)(void*) /* Module destructor function */ 6873); 6874 6875/* 6876** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6877** METHOD: sqlite3 6878** 6879** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6880** table modules from database connection D except those named on list L. 6881** The L parameter must be either NULL or a pointer to an array of pointers 6882** to strings where the array is terminated by a single NULL pointer. 6883** ^If the L parameter is NULL, then all virtual table modules are removed. 6884** 6885** See also: [sqlite3_create_module()] 6886*/ 6887int sqlite3_drop_modules( 6888 sqlite3 *db, /* Remove modules from this connection */ 6889 const char **azKeep /* Except, do not remove the ones named here */ 6890); 6891 6892/* 6893** CAPI3REF: Virtual Table Instance Object 6894** KEYWORDS: sqlite3_vtab 6895** 6896** Every [virtual table module] implementation uses a subclass 6897** of this object to describe a particular instance 6898** of the [virtual table]. Each subclass will 6899** be tailored to the specific needs of the module implementation. 6900** The purpose of this superclass is to define certain fields that are 6901** common to all module implementations. 6902** 6903** ^Virtual tables methods can set an error message by assigning a 6904** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6905** take care that any prior string is freed by a call to [sqlite3_free()] 6906** prior to assigning a new string to zErrMsg. ^After the error message 6907** is delivered up to the client application, the string will be automatically 6908** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6909*/ 6910struct sqlite3_vtab { 6911 const sqlite3_module *pModule; /* The module for this virtual table */ 6912 int nRef; /* Number of open cursors */ 6913 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6914 /* Virtual table implementations will typically add additional fields */ 6915}; 6916 6917/* 6918** CAPI3REF: Virtual Table Cursor Object 6919** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6920** 6921** Every [virtual table module] implementation uses a subclass of the 6922** following structure to describe cursors that point into the 6923** [virtual table] and are used 6924** to loop through the virtual table. Cursors are created using the 6925** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6926** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6927** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6928** of the module. Each module implementation will define 6929** the content of a cursor structure to suit its own needs. 6930** 6931** This superclass exists in order to define fields of the cursor that 6932** are common to all implementations. 6933*/ 6934struct sqlite3_vtab_cursor { 6935 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6936 /* Virtual table implementations will typically add additional fields */ 6937}; 6938 6939/* 6940** CAPI3REF: Declare The Schema Of A Virtual Table 6941** 6942** ^The [xCreate] and [xConnect] methods of a 6943** [virtual table module] call this interface 6944** to declare the format (the names and datatypes of the columns) of 6945** the virtual tables they implement. 6946*/ 6947int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6948 6949/* 6950** CAPI3REF: Overload A Function For A Virtual Table 6951** METHOD: sqlite3 6952** 6953** ^(Virtual tables can provide alternative implementations of functions 6954** using the [xFindFunction] method of the [virtual table module]. 6955** But global versions of those functions 6956** must exist in order to be overloaded.)^ 6957** 6958** ^(This API makes sure a global version of a function with a particular 6959** name and number of parameters exists. If no such function exists 6960** before this API is called, a new function is created.)^ ^The implementation 6961** of the new function always causes an exception to be thrown. So 6962** the new function is not good for anything by itself. Its only 6963** purpose is to be a placeholder function that can be overloaded 6964** by a [virtual table]. 6965*/ 6966int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6967 6968/* 6969** The interface to the virtual-table mechanism defined above (back up 6970** to a comment remarkably similar to this one) is currently considered 6971** to be experimental. The interface might change in incompatible ways. 6972** If this is a problem for you, do not use the interface at this time. 6973** 6974** When the virtual-table mechanism stabilizes, we will declare the 6975** interface fixed, support it indefinitely, and remove this comment. 6976*/ 6977 6978/* 6979** CAPI3REF: A Handle To An Open BLOB 6980** KEYWORDS: {BLOB handle} {BLOB handles} 6981** 6982** An instance of this object represents an open BLOB on which 6983** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6984** ^Objects of this type are created by [sqlite3_blob_open()] 6985** and destroyed by [sqlite3_blob_close()]. 6986** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6987** can be used to read or write small subsections of the BLOB. 6988** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6989*/ 6990typedef struct sqlite3_blob sqlite3_blob; 6991 6992/* 6993** CAPI3REF: Open A BLOB For Incremental I/O 6994** METHOD: sqlite3 6995** CONSTRUCTOR: sqlite3_blob 6996** 6997** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6998** in row iRow, column zColumn, table zTable in database zDb; 6999** in other words, the same BLOB that would be selected by: 7000** 7001** <pre> 7002** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7003** </pre>)^ 7004** 7005** ^(Parameter zDb is not the filename that contains the database, but 7006** rather the symbolic name of the database. For attached databases, this is 7007** the name that appears after the AS keyword in the [ATTACH] statement. 7008** For the main database file, the database name is "main". For TEMP 7009** tables, the database name is "temp".)^ 7010** 7011** ^If the flags parameter is non-zero, then the BLOB is opened for read 7012** and write access. ^If the flags parameter is zero, the BLOB is opened for 7013** read-only access. 7014** 7015** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7016** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7017** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7018** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7019** on *ppBlob after this function it returns. 7020** 7021** This function fails with SQLITE_ERROR if any of the following are true: 7022** <ul> 7023** <li> ^(Database zDb does not exist)^, 7024** <li> ^(Table zTable does not exist within database zDb)^, 7025** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7026** <li> ^(Column zColumn does not exist)^, 7027** <li> ^(Row iRow is not present in the table)^, 7028** <li> ^(The specified column of row iRow contains a value that is not 7029** a TEXT or BLOB value)^, 7030** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7031** constraint and the blob is being opened for read/write access)^, 7032** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7033** column zColumn is part of a [child key] definition and the blob is 7034** being opened for read/write access)^. 7035** </ul> 7036** 7037** ^Unless it returns SQLITE_MISUSE, this function sets the 7038** [database connection] error code and message accessible via 7039** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7040** 7041** A BLOB referenced by sqlite3_blob_open() may be read using the 7042** [sqlite3_blob_read()] interface and modified by using 7043** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7044** different row of the same table using the [sqlite3_blob_reopen()] 7045** interface. However, the column, table, or database of a [BLOB handle] 7046** cannot be changed after the [BLOB handle] is opened. 7047** 7048** ^(If the row that a BLOB handle points to is modified by an 7049** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7050** then the BLOB handle is marked as "expired". 7051** This is true if any column of the row is changed, even a column 7052** other than the one the BLOB handle is open on.)^ 7053** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7054** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7055** ^(Changes written into a BLOB prior to the BLOB expiring are not 7056** rolled back by the expiration of the BLOB. Such changes will eventually 7057** commit if the transaction continues to completion.)^ 7058** 7059** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7060** the opened blob. ^The size of a blob may not be changed by this 7061** interface. Use the [UPDATE] SQL command to change the size of a 7062** blob. 7063** 7064** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7065** and the built-in [zeroblob] SQL function may be used to create a 7066** zero-filled blob to read or write using the incremental-blob interface. 7067** 7068** To avoid a resource leak, every open [BLOB handle] should eventually 7069** be released by a call to [sqlite3_blob_close()]. 7070** 7071** See also: [sqlite3_blob_close()], 7072** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7073** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7074*/ 7075int sqlite3_blob_open( 7076 sqlite3*, 7077 const char *zDb, 7078 const char *zTable, 7079 const char *zColumn, 7080 sqlite3_int64 iRow, 7081 int flags, 7082 sqlite3_blob **ppBlob 7083); 7084 7085/* 7086** CAPI3REF: Move a BLOB Handle to a New Row 7087** METHOD: sqlite3_blob 7088** 7089** ^This function is used to move an existing [BLOB handle] so that it points 7090** to a different row of the same database table. ^The new row is identified 7091** by the rowid value passed as the second argument. Only the row can be 7092** changed. ^The database, table and column on which the blob handle is open 7093** remain the same. Moving an existing [BLOB handle] to a new row is 7094** faster than closing the existing handle and opening a new one. 7095** 7096** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7097** it must exist and there must be either a blob or text value stored in 7098** the nominated column.)^ ^If the new row is not present in the table, or if 7099** it does not contain a blob or text value, or if another error occurs, an 7100** SQLite error code is returned and the blob handle is considered aborted. 7101** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7102** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7103** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7104** always returns zero. 7105** 7106** ^This function sets the database handle error code and message. 7107*/ 7108int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7109 7110/* 7111** CAPI3REF: Close A BLOB Handle 7112** DESTRUCTOR: sqlite3_blob 7113** 7114** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7115** unconditionally. Even if this routine returns an error code, the 7116** handle is still closed.)^ 7117** 7118** ^If the blob handle being closed was opened for read-write access, and if 7119** the database is in auto-commit mode and there are no other open read-write 7120** blob handles or active write statements, the current transaction is 7121** committed. ^If an error occurs while committing the transaction, an error 7122** code is returned and the transaction rolled back. 7123** 7124** Calling this function with an argument that is not a NULL pointer or an 7125** open blob handle results in undefined behaviour. ^Calling this routine 7126** with a null pointer (such as would be returned by a failed call to 7127** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7128** is passed a valid open blob handle, the values returned by the 7129** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7130*/ 7131int sqlite3_blob_close(sqlite3_blob *); 7132 7133/* 7134** CAPI3REF: Return The Size Of An Open BLOB 7135** METHOD: sqlite3_blob 7136** 7137** ^Returns the size in bytes of the BLOB accessible via the 7138** successfully opened [BLOB handle] in its only argument. ^The 7139** incremental blob I/O routines can only read or overwriting existing 7140** blob content; they cannot change the size of a blob. 7141** 7142** This routine only works on a [BLOB handle] which has been created 7143** by a prior successful call to [sqlite3_blob_open()] and which has not 7144** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7145** to this routine results in undefined and probably undesirable behavior. 7146*/ 7147int sqlite3_blob_bytes(sqlite3_blob *); 7148 7149/* 7150** CAPI3REF: Read Data From A BLOB Incrementally 7151** METHOD: sqlite3_blob 7152** 7153** ^(This function is used to read data from an open [BLOB handle] into a 7154** caller-supplied buffer. N bytes of data are copied into buffer Z 7155** from the open BLOB, starting at offset iOffset.)^ 7156** 7157** ^If offset iOffset is less than N bytes from the end of the BLOB, 7158** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7159** less than zero, [SQLITE_ERROR] is returned and no data is read. 7160** ^The size of the blob (and hence the maximum value of N+iOffset) 7161** can be determined using the [sqlite3_blob_bytes()] interface. 7162** 7163** ^An attempt to read from an expired [BLOB handle] fails with an 7164** error code of [SQLITE_ABORT]. 7165** 7166** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7167** Otherwise, an [error code] or an [extended error code] is returned.)^ 7168** 7169** This routine only works on a [BLOB handle] which has been created 7170** by a prior successful call to [sqlite3_blob_open()] and which has not 7171** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7172** to this routine results in undefined and probably undesirable behavior. 7173** 7174** See also: [sqlite3_blob_write()]. 7175*/ 7176int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7177 7178/* 7179** CAPI3REF: Write Data Into A BLOB Incrementally 7180** METHOD: sqlite3_blob 7181** 7182** ^(This function is used to write data into an open [BLOB handle] from a 7183** caller-supplied buffer. N bytes of data are copied from the buffer Z 7184** into the open BLOB, starting at offset iOffset.)^ 7185** 7186** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7187** Otherwise, an [error code] or an [extended error code] is returned.)^ 7188** ^Unless SQLITE_MISUSE is returned, this function sets the 7189** [database connection] error code and message accessible via 7190** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7191** 7192** ^If the [BLOB handle] passed as the first argument was not opened for 7193** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7194** this function returns [SQLITE_READONLY]. 7195** 7196** This function may only modify the contents of the BLOB; it is 7197** not possible to increase the size of a BLOB using this API. 7198** ^If offset iOffset is less than N bytes from the end of the BLOB, 7199** [SQLITE_ERROR] is returned and no data is written. The size of the 7200** BLOB (and hence the maximum value of N+iOffset) can be determined 7201** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7202** than zero [SQLITE_ERROR] is returned and no data is written. 7203** 7204** ^An attempt to write to an expired [BLOB handle] fails with an 7205** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7206** before the [BLOB handle] expired are not rolled back by the 7207** expiration of the handle, though of course those changes might 7208** have been overwritten by the statement that expired the BLOB handle 7209** or by other independent statements. 7210** 7211** This routine only works on a [BLOB handle] which has been created 7212** by a prior successful call to [sqlite3_blob_open()] and which has not 7213** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7214** to this routine results in undefined and probably undesirable behavior. 7215** 7216** See also: [sqlite3_blob_read()]. 7217*/ 7218int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7219 7220/* 7221** CAPI3REF: Virtual File System Objects 7222** 7223** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7224** that SQLite uses to interact 7225** with the underlying operating system. Most SQLite builds come with a 7226** single default VFS that is appropriate for the host computer. 7227** New VFSes can be registered and existing VFSes can be unregistered. 7228** The following interfaces are provided. 7229** 7230** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7231** ^Names are case sensitive. 7232** ^Names are zero-terminated UTF-8 strings. 7233** ^If there is no match, a NULL pointer is returned. 7234** ^If zVfsName is NULL then the default VFS is returned. 7235** 7236** ^New VFSes are registered with sqlite3_vfs_register(). 7237** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7238** ^The same VFS can be registered multiple times without injury. 7239** ^To make an existing VFS into the default VFS, register it again 7240** with the makeDflt flag set. If two different VFSes with the 7241** same name are registered, the behavior is undefined. If a 7242** VFS is registered with a name that is NULL or an empty string, 7243** then the behavior is undefined. 7244** 7245** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7246** ^(If the default VFS is unregistered, another VFS is chosen as 7247** the default. The choice for the new VFS is arbitrary.)^ 7248*/ 7249sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7250int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7251int sqlite3_vfs_unregister(sqlite3_vfs*); 7252 7253/* 7254** CAPI3REF: Mutexes 7255** 7256** The SQLite core uses these routines for thread 7257** synchronization. Though they are intended for internal 7258** use by SQLite, code that links against SQLite is 7259** permitted to use any of these routines. 7260** 7261** The SQLite source code contains multiple implementations 7262** of these mutex routines. An appropriate implementation 7263** is selected automatically at compile-time. The following 7264** implementations are available in the SQLite core: 7265** 7266** <ul> 7267** <li> SQLITE_MUTEX_PTHREADS 7268** <li> SQLITE_MUTEX_W32 7269** <li> SQLITE_MUTEX_NOOP 7270** </ul> 7271** 7272** The SQLITE_MUTEX_NOOP implementation is a set of routines 7273** that does no real locking and is appropriate for use in 7274** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7275** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7276** and Windows. 7277** 7278** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7279** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7280** implementation is included with the library. In this case the 7281** application must supply a custom mutex implementation using the 7282** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7283** before calling sqlite3_initialize() or any other public sqlite3_ 7284** function that calls sqlite3_initialize(). 7285** 7286** ^The sqlite3_mutex_alloc() routine allocates a new 7287** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7288** routine returns NULL if it is unable to allocate the requested 7289** mutex. The argument to sqlite3_mutex_alloc() must one of these 7290** integer constants: 7291** 7292** <ul> 7293** <li> SQLITE_MUTEX_FAST 7294** <li> SQLITE_MUTEX_RECURSIVE 7295** <li> SQLITE_MUTEX_STATIC_MASTER 7296** <li> SQLITE_MUTEX_STATIC_MEM 7297** <li> SQLITE_MUTEX_STATIC_OPEN 7298** <li> SQLITE_MUTEX_STATIC_PRNG 7299** <li> SQLITE_MUTEX_STATIC_LRU 7300** <li> SQLITE_MUTEX_STATIC_PMEM 7301** <li> SQLITE_MUTEX_STATIC_APP1 7302** <li> SQLITE_MUTEX_STATIC_APP2 7303** <li> SQLITE_MUTEX_STATIC_APP3 7304** <li> SQLITE_MUTEX_STATIC_VFS1 7305** <li> SQLITE_MUTEX_STATIC_VFS2 7306** <li> SQLITE_MUTEX_STATIC_VFS3 7307** </ul> 7308** 7309** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7310** cause sqlite3_mutex_alloc() to create 7311** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7312** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7313** The mutex implementation does not need to make a distinction 7314** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7315** not want to. SQLite will only request a recursive mutex in 7316** cases where it really needs one. If a faster non-recursive mutex 7317** implementation is available on the host platform, the mutex subsystem 7318** might return such a mutex in response to SQLITE_MUTEX_FAST. 7319** 7320** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7321** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7322** a pointer to a static preexisting mutex. ^Nine static mutexes are 7323** used by the current version of SQLite. Future versions of SQLite 7324** may add additional static mutexes. Static mutexes are for internal 7325** use by SQLite only. Applications that use SQLite mutexes should 7326** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7327** SQLITE_MUTEX_RECURSIVE. 7328** 7329** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7330** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7331** returns a different mutex on every call. ^For the static 7332** mutex types, the same mutex is returned on every call that has 7333** the same type number. 7334** 7335** ^The sqlite3_mutex_free() routine deallocates a previously 7336** allocated dynamic mutex. Attempting to deallocate a static 7337** mutex results in undefined behavior. 7338** 7339** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7340** to enter a mutex. ^If another thread is already within the mutex, 7341** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7342** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7343** upon successful entry. ^(Mutexes created using 7344** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7345** In such cases, the 7346** mutex must be exited an equal number of times before another thread 7347** can enter.)^ If the same thread tries to enter any mutex other 7348** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7349** 7350** ^(Some systems (for example, Windows 95) do not support the operation 7351** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7352** will always return SQLITE_BUSY. The SQLite core only ever uses 7353** sqlite3_mutex_try() as an optimization so this is acceptable 7354** behavior.)^ 7355** 7356** ^The sqlite3_mutex_leave() routine exits a mutex that was 7357** previously entered by the same thread. The behavior 7358** is undefined if the mutex is not currently entered by the 7359** calling thread or is not currently allocated. 7360** 7361** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7362** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7363** behave as no-ops. 7364** 7365** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7366*/ 7367sqlite3_mutex *sqlite3_mutex_alloc(int); 7368void sqlite3_mutex_free(sqlite3_mutex*); 7369void sqlite3_mutex_enter(sqlite3_mutex*); 7370int sqlite3_mutex_try(sqlite3_mutex*); 7371void sqlite3_mutex_leave(sqlite3_mutex*); 7372 7373/* 7374** CAPI3REF: Mutex Methods Object 7375** 7376** An instance of this structure defines the low-level routines 7377** used to allocate and use mutexes. 7378** 7379** Usually, the default mutex implementations provided by SQLite are 7380** sufficient, however the application has the option of substituting a custom 7381** implementation for specialized deployments or systems for which SQLite 7382** does not provide a suitable implementation. In this case, the application 7383** creates and populates an instance of this structure to pass 7384** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7385** Additionally, an instance of this structure can be used as an 7386** output variable when querying the system for the current mutex 7387** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7388** 7389** ^The xMutexInit method defined by this structure is invoked as 7390** part of system initialization by the sqlite3_initialize() function. 7391** ^The xMutexInit routine is called by SQLite exactly once for each 7392** effective call to [sqlite3_initialize()]. 7393** 7394** ^The xMutexEnd method defined by this structure is invoked as 7395** part of system shutdown by the sqlite3_shutdown() function. The 7396** implementation of this method is expected to release all outstanding 7397** resources obtained by the mutex methods implementation, especially 7398** those obtained by the xMutexInit method. ^The xMutexEnd() 7399** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7400** 7401** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7402** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7403** xMutexNotheld) implement the following interfaces (respectively): 7404** 7405** <ul> 7406** <li> [sqlite3_mutex_alloc()] </li> 7407** <li> [sqlite3_mutex_free()] </li> 7408** <li> [sqlite3_mutex_enter()] </li> 7409** <li> [sqlite3_mutex_try()] </li> 7410** <li> [sqlite3_mutex_leave()] </li> 7411** <li> [sqlite3_mutex_held()] </li> 7412** <li> [sqlite3_mutex_notheld()] </li> 7413** </ul>)^ 7414** 7415** The only difference is that the public sqlite3_XXX functions enumerated 7416** above silently ignore any invocations that pass a NULL pointer instead 7417** of a valid mutex handle. The implementations of the methods defined 7418** by this structure are not required to handle this case. The results 7419** of passing a NULL pointer instead of a valid mutex handle are undefined 7420** (i.e. it is acceptable to provide an implementation that segfaults if 7421** it is passed a NULL pointer). 7422** 7423** The xMutexInit() method must be threadsafe. It must be harmless to 7424** invoke xMutexInit() multiple times within the same process and without 7425** intervening calls to xMutexEnd(). Second and subsequent calls to 7426** xMutexInit() must be no-ops. 7427** 7428** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7429** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7430** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7431** memory allocation for a fast or recursive mutex. 7432** 7433** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7434** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7435** If xMutexInit fails in any way, it is expected to clean up after itself 7436** prior to returning. 7437*/ 7438typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7439struct sqlite3_mutex_methods { 7440 int (*xMutexInit)(void); 7441 int (*xMutexEnd)(void); 7442 sqlite3_mutex *(*xMutexAlloc)(int); 7443 void (*xMutexFree)(sqlite3_mutex *); 7444 void (*xMutexEnter)(sqlite3_mutex *); 7445 int (*xMutexTry)(sqlite3_mutex *); 7446 void (*xMutexLeave)(sqlite3_mutex *); 7447 int (*xMutexHeld)(sqlite3_mutex *); 7448 int (*xMutexNotheld)(sqlite3_mutex *); 7449}; 7450 7451/* 7452** CAPI3REF: Mutex Verification Routines 7453** 7454** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7455** are intended for use inside assert() statements. The SQLite core 7456** never uses these routines except inside an assert() and applications 7457** are advised to follow the lead of the core. The SQLite core only 7458** provides implementations for these routines when it is compiled 7459** with the SQLITE_DEBUG flag. External mutex implementations 7460** are only required to provide these routines if SQLITE_DEBUG is 7461** defined and if NDEBUG is not defined. 7462** 7463** These routines should return true if the mutex in their argument 7464** is held or not held, respectively, by the calling thread. 7465** 7466** The implementation is not required to provide versions of these 7467** routines that actually work. If the implementation does not provide working 7468** versions of these routines, it should at least provide stubs that always 7469** return true so that one does not get spurious assertion failures. 7470** 7471** If the argument to sqlite3_mutex_held() is a NULL pointer then 7472** the routine should return 1. This seems counter-intuitive since 7473** clearly the mutex cannot be held if it does not exist. But 7474** the reason the mutex does not exist is because the build is not 7475** using mutexes. And we do not want the assert() containing the 7476** call to sqlite3_mutex_held() to fail, so a non-zero return is 7477** the appropriate thing to do. The sqlite3_mutex_notheld() 7478** interface should also return 1 when given a NULL pointer. 7479*/ 7480#ifndef NDEBUG 7481int sqlite3_mutex_held(sqlite3_mutex*); 7482int sqlite3_mutex_notheld(sqlite3_mutex*); 7483#endif 7484 7485/* 7486** CAPI3REF: Mutex Types 7487** 7488** The [sqlite3_mutex_alloc()] interface takes a single argument 7489** which is one of these integer constants. 7490** 7491** The set of static mutexes may change from one SQLite release to the 7492** next. Applications that override the built-in mutex logic must be 7493** prepared to accommodate additional static mutexes. 7494*/ 7495#define SQLITE_MUTEX_FAST 0 7496#define SQLITE_MUTEX_RECURSIVE 1 7497#define SQLITE_MUTEX_STATIC_MASTER 2 7498#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7499#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7500#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7501#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7502#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7503#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7504#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7505#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7506#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7507#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7508#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7509#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7510#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7511 7512/* 7513** CAPI3REF: Retrieve the mutex for a database connection 7514** METHOD: sqlite3 7515** 7516** ^This interface returns a pointer the [sqlite3_mutex] object that 7517** serializes access to the [database connection] given in the argument 7518** when the [threading mode] is Serialized. 7519** ^If the [threading mode] is Single-thread or Multi-thread then this 7520** routine returns a NULL pointer. 7521*/ 7522sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7523 7524/* 7525** CAPI3REF: Low-Level Control Of Database Files 7526** METHOD: sqlite3 7527** KEYWORDS: {file control} 7528** 7529** ^The [sqlite3_file_control()] interface makes a direct call to the 7530** xFileControl method for the [sqlite3_io_methods] object associated 7531** with a particular database identified by the second argument. ^The 7532** name of the database is "main" for the main database or "temp" for the 7533** TEMP database, or the name that appears after the AS keyword for 7534** databases that are added using the [ATTACH] SQL command. 7535** ^A NULL pointer can be used in place of "main" to refer to the 7536** main database file. 7537** ^The third and fourth parameters to this routine 7538** are passed directly through to the second and third parameters of 7539** the xFileControl method. ^The return value of the xFileControl 7540** method becomes the return value of this routine. 7541** 7542** A few opcodes for [sqlite3_file_control()] are handled directly 7543** by the SQLite core and never invoke the 7544** sqlite3_io_methods.xFileControl method. 7545** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7546** a pointer to the underlying [sqlite3_file] object to be written into 7547** the space pointed to by the 4th parameter. The 7548** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7549** the [sqlite3_file] object associated with the journal file instead of 7550** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7551** a pointer to the underlying [sqlite3_vfs] object for the file. 7552** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7553** from the pager. 7554** 7555** ^If the second parameter (zDbName) does not match the name of any 7556** open database file, then SQLITE_ERROR is returned. ^This error 7557** code is not remembered and will not be recalled by [sqlite3_errcode()] 7558** or [sqlite3_errmsg()]. The underlying xFileControl method might 7559** also return SQLITE_ERROR. There is no way to distinguish between 7560** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7561** xFileControl method. 7562** 7563** See also: [file control opcodes] 7564*/ 7565int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7566 7567/* 7568** CAPI3REF: Testing Interface 7569** 7570** ^The sqlite3_test_control() interface is used to read out internal 7571** state of SQLite and to inject faults into SQLite for testing 7572** purposes. ^The first parameter is an operation code that determines 7573** the number, meaning, and operation of all subsequent parameters. 7574** 7575** This interface is not for use by applications. It exists solely 7576** for verifying the correct operation of the SQLite library. Depending 7577** on how the SQLite library is compiled, this interface might not exist. 7578** 7579** The details of the operation codes, their meanings, the parameters 7580** they take, and what they do are all subject to change without notice. 7581** Unlike most of the SQLite API, this function is not guaranteed to 7582** operate consistently from one release to the next. 7583*/ 7584int sqlite3_test_control(int op, ...); 7585 7586/* 7587** CAPI3REF: Testing Interface Operation Codes 7588** 7589** These constants are the valid operation code parameters used 7590** as the first argument to [sqlite3_test_control()]. 7591** 7592** These parameters and their meanings are subject to change 7593** without notice. These values are for testing purposes only. 7594** Applications should not use any of these parameters or the 7595** [sqlite3_test_control()] interface. 7596*/ 7597#define SQLITE_TESTCTRL_FIRST 5 7598#define SQLITE_TESTCTRL_PRNG_SAVE 5 7599#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7600#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7601#define SQLITE_TESTCTRL_BITVEC_TEST 8 7602#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7603#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7604#define SQLITE_TESTCTRL_PENDING_BYTE 11 7605#define SQLITE_TESTCTRL_ASSERT 12 7606#define SQLITE_TESTCTRL_ALWAYS 13 7607#define SQLITE_TESTCTRL_RESERVE 14 7608#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7609#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7610#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7611#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7612#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7613#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7614#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7615#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7616#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7617#define SQLITE_TESTCTRL_BYTEORDER 22 7618#define SQLITE_TESTCTRL_ISINIT 23 7619#define SQLITE_TESTCTRL_SORTER_MMAP 24 7620#define SQLITE_TESTCTRL_IMPOSTER 25 7621#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7622#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7623#define SQLITE_TESTCTRL_PRNG_SEED 28 7624#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7625#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7626 7627/* 7628** CAPI3REF: SQL Keyword Checking 7629** 7630** These routines provide access to the set of SQL language keywords 7631** recognized by SQLite. Applications can uses these routines to determine 7632** whether or not a specific identifier needs to be escaped (for example, 7633** by enclosing in double-quotes) so as not to confuse the parser. 7634** 7635** The sqlite3_keyword_count() interface returns the number of distinct 7636** keywords understood by SQLite. 7637** 7638** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7639** makes *Z point to that keyword expressed as UTF8 and writes the number 7640** of bytes in the keyword into *L. The string that *Z points to is not 7641** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7642** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7643** or L are NULL or invalid pointers then calls to 7644** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7645** 7646** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7647** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7648** if it is and zero if not. 7649** 7650** The parser used by SQLite is forgiving. It is often possible to use 7651** a keyword as an identifier as long as such use does not result in a 7652** parsing ambiguity. For example, the statement 7653** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7654** creates a new table named "BEGIN" with three columns named 7655** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7656** using keywords as identifiers. Common techniques used to avoid keyword 7657** name collisions include: 7658** <ul> 7659** <li> Put all identifier names inside double-quotes. This is the official 7660** SQL way to escape identifier names. 7661** <li> Put identifier names inside [...]. This is not standard SQL, 7662** but it is what SQL Server does and so lots of programmers use this 7663** technique. 7664** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7665** with "Z". 7666** <li> Include a digit somewhere in every identifier name. 7667** </ul> 7668** 7669** Note that the number of keywords understood by SQLite can depend on 7670** compile-time options. For example, "VACUUM" is not a keyword if 7671** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7672** new keywords may be added to future releases of SQLite. 7673*/ 7674int sqlite3_keyword_count(void); 7675int sqlite3_keyword_name(int,const char**,int*); 7676int sqlite3_keyword_check(const char*,int); 7677 7678/* 7679** CAPI3REF: Dynamic String Object 7680** KEYWORDS: {dynamic string} 7681** 7682** An instance of the sqlite3_str object contains a dynamically-sized 7683** string under construction. 7684** 7685** The lifecycle of an sqlite3_str object is as follows: 7686** <ol> 7687** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7688** <li> ^Text is appended to the sqlite3_str object using various 7689** methods, such as [sqlite3_str_appendf()]. 7690** <li> ^The sqlite3_str object is destroyed and the string it created 7691** is returned using the [sqlite3_str_finish()] interface. 7692** </ol> 7693*/ 7694typedef struct sqlite3_str sqlite3_str; 7695 7696/* 7697** CAPI3REF: Create A New Dynamic String Object 7698** CONSTRUCTOR: sqlite3_str 7699** 7700** ^The [sqlite3_str_new(D)] interface allocates and initializes 7701** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7702** [sqlite3_str_new()] must be freed by a subsequent call to 7703** [sqlite3_str_finish(X)]. 7704** 7705** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7706** valid [sqlite3_str] object, though in the event of an out-of-memory 7707** error the returned object might be a special singleton that will 7708** silently reject new text, always return SQLITE_NOMEM from 7709** [sqlite3_str_errcode()], always return 0 for 7710** [sqlite3_str_length()], and always return NULL from 7711** [sqlite3_str_finish(X)]. It is always safe to use the value 7712** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7713** to any of the other [sqlite3_str] methods. 7714** 7715** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7716** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7717** length of the string contained in the [sqlite3_str] object will be 7718** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7719** of [SQLITE_MAX_LENGTH]. 7720*/ 7721sqlite3_str *sqlite3_str_new(sqlite3*); 7722 7723/* 7724** CAPI3REF: Finalize A Dynamic String 7725** DESTRUCTOR: sqlite3_str 7726** 7727** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7728** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7729** that contains the constructed string. The calling application should 7730** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7731** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7732** errors were encountered during construction of the string. ^The 7733** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7734** string in [sqlite3_str] object X is zero bytes long. 7735*/ 7736char *sqlite3_str_finish(sqlite3_str*); 7737 7738/* 7739** CAPI3REF: Add Content To A Dynamic String 7740** METHOD: sqlite3_str 7741** 7742** These interfaces add content to an sqlite3_str object previously obtained 7743** from [sqlite3_str_new()]. 7744** 7745** ^The [sqlite3_str_appendf(X,F,...)] and 7746** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7747** functionality of SQLite to append formatted text onto the end of 7748** [sqlite3_str] object X. 7749** 7750** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7751** onto the end of the [sqlite3_str] object X. N must be non-negative. 7752** S must contain at least N non-zero bytes of content. To append a 7753** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7754** method instead. 7755** 7756** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7757** zero-terminated string S onto the end of [sqlite3_str] object X. 7758** 7759** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7760** single-byte character C onto the end of [sqlite3_str] object X. 7761** ^This method can be used, for example, to add whitespace indentation. 7762** 7763** ^The [sqlite3_str_reset(X)] method resets the string under construction 7764** inside [sqlite3_str] object X back to zero bytes in length. 7765** 7766** These methods do not return a result code. ^If an error occurs, that fact 7767** is recorded in the [sqlite3_str] object and can be recovered by a 7768** subsequent call to [sqlite3_str_errcode(X)]. 7769*/ 7770void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7771void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7772void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7773void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7774void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7775void sqlite3_str_reset(sqlite3_str*); 7776 7777/* 7778** CAPI3REF: Status Of A Dynamic String 7779** METHOD: sqlite3_str 7780** 7781** These interfaces return the current status of an [sqlite3_str] object. 7782** 7783** ^If any prior errors have occurred while constructing the dynamic string 7784** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7785** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7786** [SQLITE_NOMEM] following any out-of-memory error, or 7787** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7788** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7789** 7790** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7791** of the dynamic string under construction in [sqlite3_str] object X. 7792** ^The length returned by [sqlite3_str_length(X)] does not include the 7793** zero-termination byte. 7794** 7795** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7796** content of the dynamic string under construction in X. The value 7797** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7798** and might be freed or altered by any subsequent method on the same 7799** [sqlite3_str] object. Applications must not used the pointer returned 7800** [sqlite3_str_value(X)] after any subsequent method call on the same 7801** object. ^Applications may change the content of the string returned 7802** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7803** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7804** write any byte after any subsequent sqlite3_str method call. 7805*/ 7806int sqlite3_str_errcode(sqlite3_str*); 7807int sqlite3_str_length(sqlite3_str*); 7808char *sqlite3_str_value(sqlite3_str*); 7809 7810/* 7811** CAPI3REF: SQLite Runtime Status 7812** 7813** ^These interfaces are used to retrieve runtime status information 7814** about the performance of SQLite, and optionally to reset various 7815** highwater marks. ^The first argument is an integer code for 7816** the specific parameter to measure. ^(Recognized integer codes 7817** are of the form [status parameters | SQLITE_STATUS_...].)^ 7818** ^The current value of the parameter is returned into *pCurrent. 7819** ^The highest recorded value is returned in *pHighwater. ^If the 7820** resetFlag is true, then the highest record value is reset after 7821** *pHighwater is written. ^(Some parameters do not record the highest 7822** value. For those parameters 7823** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7824** ^(Other parameters record only the highwater mark and not the current 7825** value. For these latter parameters nothing is written into *pCurrent.)^ 7826** 7827** ^The sqlite3_status() and sqlite3_status64() routines return 7828** SQLITE_OK on success and a non-zero [error code] on failure. 7829** 7830** If either the current value or the highwater mark is too large to 7831** be represented by a 32-bit integer, then the values returned by 7832** sqlite3_status() are undefined. 7833** 7834** See also: [sqlite3_db_status()] 7835*/ 7836int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7837int sqlite3_status64( 7838 int op, 7839 sqlite3_int64 *pCurrent, 7840 sqlite3_int64 *pHighwater, 7841 int resetFlag 7842); 7843 7844 7845/* 7846** CAPI3REF: Status Parameters 7847** KEYWORDS: {status parameters} 7848** 7849** These integer constants designate various run-time status parameters 7850** that can be returned by [sqlite3_status()]. 7851** 7852** <dl> 7853** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7854** <dd>This parameter is the current amount of memory checked out 7855** using [sqlite3_malloc()], either directly or indirectly. The 7856** figure includes calls made to [sqlite3_malloc()] by the application 7857** and internal memory usage by the SQLite library. Auxiliary page-cache 7858** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7859** this parameter. The amount returned is the sum of the allocation 7860** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7861** 7862** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7863** <dd>This parameter records the largest memory allocation request 7864** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7865** internal equivalents). Only the value returned in the 7866** *pHighwater parameter to [sqlite3_status()] is of interest. 7867** The value written into the *pCurrent parameter is undefined.</dd>)^ 7868** 7869** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7870** <dd>This parameter records the number of separate memory allocations 7871** currently checked out.</dd>)^ 7872** 7873** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7874** <dd>This parameter returns the number of pages used out of the 7875** [pagecache memory allocator] that was configured using 7876** [SQLITE_CONFIG_PAGECACHE]. The 7877** value returned is in pages, not in bytes.</dd>)^ 7878** 7879** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7880** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7881** <dd>This parameter returns the number of bytes of page cache 7882** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7883** buffer and where forced to overflow to [sqlite3_malloc()]. The 7884** returned value includes allocations that overflowed because they 7885** where too large (they were larger than the "sz" parameter to 7886** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7887** no space was left in the page cache.</dd>)^ 7888** 7889** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7890** <dd>This parameter records the largest memory allocation request 7891** handed to the [pagecache memory allocator]. Only the value returned in the 7892** *pHighwater parameter to [sqlite3_status()] is of interest. 7893** The value written into the *pCurrent parameter is undefined.</dd>)^ 7894** 7895** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7896** <dd>No longer used.</dd> 7897** 7898** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7899** <dd>No longer used.</dd> 7900** 7901** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7902** <dd>No longer used.</dd> 7903** 7904** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7905** <dd>The *pHighwater parameter records the deepest parser stack. 7906** The *pCurrent value is undefined. The *pHighwater value is only 7907** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7908** </dl> 7909** 7910** New status parameters may be added from time to time. 7911*/ 7912#define SQLITE_STATUS_MEMORY_USED 0 7913#define SQLITE_STATUS_PAGECACHE_USED 1 7914#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7915#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7916#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7917#define SQLITE_STATUS_MALLOC_SIZE 5 7918#define SQLITE_STATUS_PARSER_STACK 6 7919#define SQLITE_STATUS_PAGECACHE_SIZE 7 7920#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7921#define SQLITE_STATUS_MALLOC_COUNT 9 7922 7923/* 7924** CAPI3REF: Database Connection Status 7925** METHOD: sqlite3 7926** 7927** ^This interface is used to retrieve runtime status information 7928** about a single [database connection]. ^The first argument is the 7929** database connection object to be interrogated. ^The second argument 7930** is an integer constant, taken from the set of 7931** [SQLITE_DBSTATUS options], that 7932** determines the parameter to interrogate. The set of 7933** [SQLITE_DBSTATUS options] is likely 7934** to grow in future releases of SQLite. 7935** 7936** ^The current value of the requested parameter is written into *pCur 7937** and the highest instantaneous value is written into *pHiwtr. ^If 7938** the resetFlg is true, then the highest instantaneous value is 7939** reset back down to the current value. 7940** 7941** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7942** non-zero [error code] on failure. 7943** 7944** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7945*/ 7946int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7947 7948/* 7949** CAPI3REF: Status Parameters for database connections 7950** KEYWORDS: {SQLITE_DBSTATUS options} 7951** 7952** These constants are the available integer "verbs" that can be passed as 7953** the second argument to the [sqlite3_db_status()] interface. 7954** 7955** New verbs may be added in future releases of SQLite. Existing verbs 7956** might be discontinued. Applications should check the return code from 7957** [sqlite3_db_status()] to make sure that the call worked. 7958** The [sqlite3_db_status()] interface will return a non-zero error code 7959** if a discontinued or unsupported verb is invoked. 7960** 7961** <dl> 7962** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7963** <dd>This parameter returns the number of lookaside memory slots currently 7964** checked out.</dd>)^ 7965** 7966** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7967** <dd>This parameter returns the number of malloc attempts that were 7968** satisfied using lookaside memory. Only the high-water value is meaningful; 7969** the current value is always zero.)^ 7970** 7971** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7972** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7973** <dd>This parameter returns the number malloc attempts that might have 7974** been satisfied using lookaside memory but failed due to the amount of 7975** memory requested being larger than the lookaside slot size. 7976** Only the high-water value is meaningful; 7977** the current value is always zero.)^ 7978** 7979** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7980** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7981** <dd>This parameter returns the number malloc attempts that might have 7982** been satisfied using lookaside memory but failed due to all lookaside 7983** memory already being in use. 7984** Only the high-water value is meaningful; 7985** the current value is always zero.)^ 7986** 7987** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7988** <dd>This parameter returns the approximate number of bytes of heap 7989** memory used by all pager caches associated with the database connection.)^ 7990** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7991** 7992** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7993** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7994** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7995** pager cache is shared between two or more connections the bytes of heap 7996** memory used by that pager cache is divided evenly between the attached 7997** connections.)^ In other words, if none of the pager caches associated 7998** with the database connection are shared, this request returns the same 7999** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8000** shared, the value returned by this call will be smaller than that returned 8001** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8002** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8003** 8004** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8005** <dd>This parameter returns the approximate number of bytes of heap 8006** memory used to store the schema for all databases associated 8007** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8008** ^The full amount of memory used by the schemas is reported, even if the 8009** schema memory is shared with other database connections due to 8010** [shared cache mode] being enabled. 8011** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8012** 8013** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8014** <dd>This parameter returns the approximate number of bytes of heap 8015** and lookaside memory used by all prepared statements associated with 8016** the database connection.)^ 8017** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8018** </dd> 8019** 8020** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8021** <dd>This parameter returns the number of pager cache hits that have 8022** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8023** is always 0. 8024** </dd> 8025** 8026** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8027** <dd>This parameter returns the number of pager cache misses that have 8028** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8029** is always 0. 8030** </dd> 8031** 8032** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8033** <dd>This parameter returns the number of dirty cache entries that have 8034** been written to disk. Specifically, the number of pages written to the 8035** wal file in wal mode databases, or the number of pages written to the 8036** database file in rollback mode databases. Any pages written as part of 8037** transaction rollback or database recovery operations are not included. 8038** If an IO or other error occurs while writing a page to disk, the effect 8039** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8040** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8041** </dd> 8042** 8043** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8044** <dd>This parameter returns the number of dirty cache entries that have 8045** been written to disk in the middle of a transaction due to the page 8046** cache overflowing. Transactions are more efficient if they are written 8047** to disk all at once. When pages spill mid-transaction, that introduces 8048** additional overhead. This parameter can be used help identify 8049** inefficiencies that can be resolved by increasing the cache size. 8050** </dd> 8051** 8052** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8053** <dd>This parameter returns zero for the current value if and only if 8054** all foreign key constraints (deferred or immediate) have been 8055** resolved.)^ ^The highwater mark is always 0. 8056** </dd> 8057** </dl> 8058*/ 8059#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8060#define SQLITE_DBSTATUS_CACHE_USED 1 8061#define SQLITE_DBSTATUS_SCHEMA_USED 2 8062#define SQLITE_DBSTATUS_STMT_USED 3 8063#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8064#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8065#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8066#define SQLITE_DBSTATUS_CACHE_HIT 7 8067#define SQLITE_DBSTATUS_CACHE_MISS 8 8068#define SQLITE_DBSTATUS_CACHE_WRITE 9 8069#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8070#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8071#define SQLITE_DBSTATUS_CACHE_SPILL 12 8072#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8073 8074 8075/* 8076** CAPI3REF: Prepared Statement Status 8077** METHOD: sqlite3_stmt 8078** 8079** ^(Each prepared statement maintains various 8080** [SQLITE_STMTSTATUS counters] that measure the number 8081** of times it has performed specific operations.)^ These counters can 8082** be used to monitor the performance characteristics of the prepared 8083** statements. For example, if the number of table steps greatly exceeds 8084** the number of table searches or result rows, that would tend to indicate 8085** that the prepared statement is using a full table scan rather than 8086** an index. 8087** 8088** ^(This interface is used to retrieve and reset counter values from 8089** a [prepared statement]. The first argument is the prepared statement 8090** object to be interrogated. The second argument 8091** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8092** to be interrogated.)^ 8093** ^The current value of the requested counter is returned. 8094** ^If the resetFlg is true, then the counter is reset to zero after this 8095** interface call returns. 8096** 8097** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8098*/ 8099int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8100 8101/* 8102** CAPI3REF: Status Parameters for prepared statements 8103** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8104** 8105** These preprocessor macros define integer codes that name counter 8106** values associated with the [sqlite3_stmt_status()] interface. 8107** The meanings of the various counters are as follows: 8108** 8109** <dl> 8110** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8111** <dd>^This is the number of times that SQLite has stepped forward in 8112** a table as part of a full table scan. Large numbers for this counter 8113** may indicate opportunities for performance improvement through 8114** careful use of indices.</dd> 8115** 8116** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8117** <dd>^This is the number of sort operations that have occurred. 8118** A non-zero value in this counter may indicate an opportunity to 8119** improvement performance through careful use of indices.</dd> 8120** 8121** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8122** <dd>^This is the number of rows inserted into transient indices that 8123** were created automatically in order to help joins run faster. 8124** A non-zero value in this counter may indicate an opportunity to 8125** improvement performance by adding permanent indices that do not 8126** need to be reinitialized each time the statement is run.</dd> 8127** 8128** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8129** <dd>^This is the number of virtual machine operations executed 8130** by the prepared statement if that number is less than or equal 8131** to 2147483647. The number of virtual machine operations can be 8132** used as a proxy for the total work done by the prepared statement. 8133** If the number of virtual machine operations exceeds 2147483647 8134** then the value returned by this statement status code is undefined. 8135** 8136** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8137** <dd>^This is the number of times that the prepare statement has been 8138** automatically regenerated due to schema changes or changes to 8139** [bound parameters] that might affect the query plan. 8140** 8141** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8142** <dd>^This is the number of times that the prepared statement has 8143** been run. A single "run" for the purposes of this counter is one 8144** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8145** The counter is incremented on the first [sqlite3_step()] call of each 8146** cycle. 8147** 8148** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8149** <dd>^This is the approximate number of bytes of heap memory 8150** used to store the prepared statement. ^This value is not actually 8151** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8152** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8153** </dd> 8154** </dl> 8155*/ 8156#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8157#define SQLITE_STMTSTATUS_SORT 2 8158#define SQLITE_STMTSTATUS_AUTOINDEX 3 8159#define SQLITE_STMTSTATUS_VM_STEP 4 8160#define SQLITE_STMTSTATUS_REPREPARE 5 8161#define SQLITE_STMTSTATUS_RUN 6 8162#define SQLITE_STMTSTATUS_MEMUSED 99 8163 8164/* 8165** CAPI3REF: Custom Page Cache Object 8166** 8167** The sqlite3_pcache type is opaque. It is implemented by 8168** the pluggable module. The SQLite core has no knowledge of 8169** its size or internal structure and never deals with the 8170** sqlite3_pcache object except by holding and passing pointers 8171** to the object. 8172** 8173** See [sqlite3_pcache_methods2] for additional information. 8174*/ 8175typedef struct sqlite3_pcache sqlite3_pcache; 8176 8177/* 8178** CAPI3REF: Custom Page Cache Object 8179** 8180** The sqlite3_pcache_page object represents a single page in the 8181** page cache. The page cache will allocate instances of this 8182** object. Various methods of the page cache use pointers to instances 8183** of this object as parameters or as their return value. 8184** 8185** See [sqlite3_pcache_methods2] for additional information. 8186*/ 8187typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8188struct sqlite3_pcache_page { 8189 void *pBuf; /* The content of the page */ 8190 void *pExtra; /* Extra information associated with the page */ 8191}; 8192 8193/* 8194** CAPI3REF: Application Defined Page Cache. 8195** KEYWORDS: {page cache} 8196** 8197** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8198** register an alternative page cache implementation by passing in an 8199** instance of the sqlite3_pcache_methods2 structure.)^ 8200** In many applications, most of the heap memory allocated by 8201** SQLite is used for the page cache. 8202** By implementing a 8203** custom page cache using this API, an application can better control 8204** the amount of memory consumed by SQLite, the way in which 8205** that memory is allocated and released, and the policies used to 8206** determine exactly which parts of a database file are cached and for 8207** how long. 8208** 8209** The alternative page cache mechanism is an 8210** extreme measure that is only needed by the most demanding applications. 8211** The built-in page cache is recommended for most uses. 8212** 8213** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8214** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8215** the application may discard the parameter after the call to 8216** [sqlite3_config()] returns.)^ 8217** 8218** [[the xInit() page cache method]] 8219** ^(The xInit() method is called once for each effective 8220** call to [sqlite3_initialize()])^ 8221** (usually only once during the lifetime of the process). ^(The xInit() 8222** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8223** The intent of the xInit() method is to set up global data structures 8224** required by the custom page cache implementation. 8225** ^(If the xInit() method is NULL, then the 8226** built-in default page cache is used instead of the application defined 8227** page cache.)^ 8228** 8229** [[the xShutdown() page cache method]] 8230** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8231** It can be used to clean up 8232** any outstanding resources before process shutdown, if required. 8233** ^The xShutdown() method may be NULL. 8234** 8235** ^SQLite automatically serializes calls to the xInit method, 8236** so the xInit method need not be threadsafe. ^The 8237** xShutdown method is only called from [sqlite3_shutdown()] so it does 8238** not need to be threadsafe either. All other methods must be threadsafe 8239** in multithreaded applications. 8240** 8241** ^SQLite will never invoke xInit() more than once without an intervening 8242** call to xShutdown(). 8243** 8244** [[the xCreate() page cache methods]] 8245** ^SQLite invokes the xCreate() method to construct a new cache instance. 8246** SQLite will typically create one cache instance for each open database file, 8247** though this is not guaranteed. ^The 8248** first parameter, szPage, is the size in bytes of the pages that must 8249** be allocated by the cache. ^szPage will always a power of two. ^The 8250** second parameter szExtra is a number of bytes of extra storage 8251** associated with each page cache entry. ^The szExtra parameter will 8252** a number less than 250. SQLite will use the 8253** extra szExtra bytes on each page to store metadata about the underlying 8254** database page on disk. The value passed into szExtra depends 8255** on the SQLite version, the target platform, and how SQLite was compiled. 8256** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8257** created will be used to cache database pages of a file stored on disk, or 8258** false if it is used for an in-memory database. The cache implementation 8259** does not have to do anything special based with the value of bPurgeable; 8260** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8261** never invoke xUnpin() except to deliberately delete a page. 8262** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8263** false will always have the "discard" flag set to true. 8264** ^Hence, a cache created with bPurgeable false will 8265** never contain any unpinned pages. 8266** 8267** [[the xCachesize() page cache method]] 8268** ^(The xCachesize() method may be called at any time by SQLite to set the 8269** suggested maximum cache-size (number of pages stored by) the cache 8270** instance passed as the first argument. This is the value configured using 8271** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8272** parameter, the implementation is not required to do anything with this 8273** value; it is advisory only. 8274** 8275** [[the xPagecount() page cache methods]] 8276** The xPagecount() method must return the number of pages currently 8277** stored in the cache, both pinned and unpinned. 8278** 8279** [[the xFetch() page cache methods]] 8280** The xFetch() method locates a page in the cache and returns a pointer to 8281** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8282** The pBuf element of the returned sqlite3_pcache_page object will be a 8283** pointer to a buffer of szPage bytes used to store the content of a 8284** single database page. The pExtra element of sqlite3_pcache_page will be 8285** a pointer to the szExtra bytes of extra storage that SQLite has requested 8286** for each entry in the page cache. 8287** 8288** The page to be fetched is determined by the key. ^The minimum key value 8289** is 1. After it has been retrieved using xFetch, the page is considered 8290** to be "pinned". 8291** 8292** If the requested page is already in the page cache, then the page cache 8293** implementation must return a pointer to the page buffer with its content 8294** intact. If the requested page is not already in the cache, then the 8295** cache implementation should use the value of the createFlag 8296** parameter to help it determined what action to take: 8297** 8298** <table border=1 width=85% align=center> 8299** <tr><th> createFlag <th> Behavior when page is not already in cache 8300** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8301** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8302** Otherwise return NULL. 8303** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8304** NULL if allocating a new page is effectively impossible. 8305** </table> 8306** 8307** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8308** will only use a createFlag of 2 after a prior call with a createFlag of 1 8309** failed.)^ In between the xFetch() calls, SQLite may 8310** attempt to unpin one or more cache pages by spilling the content of 8311** pinned pages to disk and synching the operating system disk cache. 8312** 8313** [[the xUnpin() page cache method]] 8314** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8315** as its second argument. If the third parameter, discard, is non-zero, 8316** then the page must be evicted from the cache. 8317** ^If the discard parameter is 8318** zero, then the page may be discarded or retained at the discretion of 8319** page cache implementation. ^The page cache implementation 8320** may choose to evict unpinned pages at any time. 8321** 8322** The cache must not perform any reference counting. A single 8323** call to xUnpin() unpins the page regardless of the number of prior calls 8324** to xFetch(). 8325** 8326** [[the xRekey() page cache methods]] 8327** The xRekey() method is used to change the key value associated with the 8328** page passed as the second argument. If the cache 8329** previously contains an entry associated with newKey, it must be 8330** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8331** to be pinned. 8332** 8333** When SQLite calls the xTruncate() method, the cache must discard all 8334** existing cache entries with page numbers (keys) greater than or equal 8335** to the value of the iLimit parameter passed to xTruncate(). If any 8336** of these pages are pinned, they are implicitly unpinned, meaning that 8337** they can be safely discarded. 8338** 8339** [[the xDestroy() page cache method]] 8340** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8341** All resources associated with the specified cache should be freed. ^After 8342** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8343** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8344** functions. 8345** 8346** [[the xShrink() page cache method]] 8347** ^SQLite invokes the xShrink() method when it wants the page cache to 8348** free up as much of heap memory as possible. The page cache implementation 8349** is not obligated to free any memory, but well-behaved implementations should 8350** do their best. 8351*/ 8352typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8353struct sqlite3_pcache_methods2 { 8354 int iVersion; 8355 void *pArg; 8356 int (*xInit)(void*); 8357 void (*xShutdown)(void*); 8358 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8359 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8360 int (*xPagecount)(sqlite3_pcache*); 8361 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8362 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8363 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8364 unsigned oldKey, unsigned newKey); 8365 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8366 void (*xDestroy)(sqlite3_pcache*); 8367 void (*xShrink)(sqlite3_pcache*); 8368}; 8369 8370/* 8371** This is the obsolete pcache_methods object that has now been replaced 8372** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8373** retained in the header file for backwards compatibility only. 8374*/ 8375typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8376struct sqlite3_pcache_methods { 8377 void *pArg; 8378 int (*xInit)(void*); 8379 void (*xShutdown)(void*); 8380 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8381 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8382 int (*xPagecount)(sqlite3_pcache*); 8383 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8384 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8385 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8386 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8387 void (*xDestroy)(sqlite3_pcache*); 8388}; 8389 8390 8391/* 8392** CAPI3REF: Online Backup Object 8393** 8394** The sqlite3_backup object records state information about an ongoing 8395** online backup operation. ^The sqlite3_backup object is created by 8396** a call to [sqlite3_backup_init()] and is destroyed by a call to 8397** [sqlite3_backup_finish()]. 8398** 8399** See Also: [Using the SQLite Online Backup API] 8400*/ 8401typedef struct sqlite3_backup sqlite3_backup; 8402 8403/* 8404** CAPI3REF: Online Backup API. 8405** 8406** The backup API copies the content of one database into another. 8407** It is useful either for creating backups of databases or 8408** for copying in-memory databases to or from persistent files. 8409** 8410** See Also: [Using the SQLite Online Backup API] 8411** 8412** ^SQLite holds a write transaction open on the destination database file 8413** for the duration of the backup operation. 8414** ^The source database is read-locked only while it is being read; 8415** it is not locked continuously for the entire backup operation. 8416** ^Thus, the backup may be performed on a live source database without 8417** preventing other database connections from 8418** reading or writing to the source database while the backup is underway. 8419** 8420** ^(To perform a backup operation: 8421** <ol> 8422** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8423** backup, 8424** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8425** the data between the two databases, and finally 8426** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8427** associated with the backup operation. 8428** </ol>)^ 8429** There should be exactly one call to sqlite3_backup_finish() for each 8430** successful call to sqlite3_backup_init(). 8431** 8432** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8433** 8434** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8435** [database connection] associated with the destination database 8436** and the database name, respectively. 8437** ^The database name is "main" for the main database, "temp" for the 8438** temporary database, or the name specified after the AS keyword in 8439** an [ATTACH] statement for an attached database. 8440** ^The S and M arguments passed to 8441** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8442** and database name of the source database, respectively. 8443** ^The source and destination [database connections] (parameters S and D) 8444** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8445** an error. 8446** 8447** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8448** there is already a read or read-write transaction open on the 8449** destination database. 8450** 8451** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8452** returned and an error code and error message are stored in the 8453** destination [database connection] D. 8454** ^The error code and message for the failed call to sqlite3_backup_init() 8455** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8456** [sqlite3_errmsg16()] functions. 8457** ^A successful call to sqlite3_backup_init() returns a pointer to an 8458** [sqlite3_backup] object. 8459** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8460** sqlite3_backup_finish() functions to perform the specified backup 8461** operation. 8462** 8463** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8464** 8465** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8466** the source and destination databases specified by [sqlite3_backup] object B. 8467** ^If N is negative, all remaining source pages are copied. 8468** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8469** are still more pages to be copied, then the function returns [SQLITE_OK]. 8470** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8471** from source to destination, then it returns [SQLITE_DONE]. 8472** ^If an error occurs while running sqlite3_backup_step(B,N), 8473** then an [error code] is returned. ^As well as [SQLITE_OK] and 8474** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8475** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8476** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8477** 8478** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8479** <ol> 8480** <li> the destination database was opened read-only, or 8481** <li> the destination database is using write-ahead-log journaling 8482** and the destination and source page sizes differ, or 8483** <li> the destination database is an in-memory database and the 8484** destination and source page sizes differ. 8485** </ol>)^ 8486** 8487** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8488** the [sqlite3_busy_handler | busy-handler function] 8489** is invoked (if one is specified). ^If the 8490** busy-handler returns non-zero before the lock is available, then 8491** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8492** sqlite3_backup_step() can be retried later. ^If the source 8493** [database connection] 8494** is being used to write to the source database when sqlite3_backup_step() 8495** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8496** case the call to sqlite3_backup_step() can be retried later on. ^(If 8497** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8498** [SQLITE_READONLY] is returned, then 8499** there is no point in retrying the call to sqlite3_backup_step(). These 8500** errors are considered fatal.)^ The application must accept 8501** that the backup operation has failed and pass the backup operation handle 8502** to the sqlite3_backup_finish() to release associated resources. 8503** 8504** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8505** on the destination file. ^The exclusive lock is not released until either 8506** sqlite3_backup_finish() is called or the backup operation is complete 8507** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8508** sqlite3_backup_step() obtains a [shared lock] on the source database that 8509** lasts for the duration of the sqlite3_backup_step() call. 8510** ^Because the source database is not locked between calls to 8511** sqlite3_backup_step(), the source database may be modified mid-way 8512** through the backup process. ^If the source database is modified by an 8513** external process or via a database connection other than the one being 8514** used by the backup operation, then the backup will be automatically 8515** restarted by the next call to sqlite3_backup_step(). ^If the source 8516** database is modified by the using the same database connection as is used 8517** by the backup operation, then the backup database is automatically 8518** updated at the same time. 8519** 8520** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8521** 8522** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8523** application wishes to abandon the backup operation, the application 8524** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8525** ^The sqlite3_backup_finish() interfaces releases all 8526** resources associated with the [sqlite3_backup] object. 8527** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8528** active write-transaction on the destination database is rolled back. 8529** The [sqlite3_backup] object is invalid 8530** and may not be used following a call to sqlite3_backup_finish(). 8531** 8532** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8533** sqlite3_backup_step() errors occurred, regardless or whether or not 8534** sqlite3_backup_step() completed. 8535** ^If an out-of-memory condition or IO error occurred during any prior 8536** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8537** sqlite3_backup_finish() returns the corresponding [error code]. 8538** 8539** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8540** is not a permanent error and does not affect the return value of 8541** sqlite3_backup_finish(). 8542** 8543** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8544** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8545** 8546** ^The sqlite3_backup_remaining() routine returns the number of pages still 8547** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8548** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8549** in the source database at the conclusion of the most recent 8550** sqlite3_backup_step(). 8551** ^(The values returned by these functions are only updated by 8552** sqlite3_backup_step(). If the source database is modified in a way that 8553** changes the size of the source database or the number of pages remaining, 8554** those changes are not reflected in the output of sqlite3_backup_pagecount() 8555** and sqlite3_backup_remaining() until after the next 8556** sqlite3_backup_step().)^ 8557** 8558** <b>Concurrent Usage of Database Handles</b> 8559** 8560** ^The source [database connection] may be used by the application for other 8561** purposes while a backup operation is underway or being initialized. 8562** ^If SQLite is compiled and configured to support threadsafe database 8563** connections, then the source database connection may be used concurrently 8564** from within other threads. 8565** 8566** However, the application must guarantee that the destination 8567** [database connection] is not passed to any other API (by any thread) after 8568** sqlite3_backup_init() is called and before the corresponding call to 8569** sqlite3_backup_finish(). SQLite does not currently check to see 8570** if the application incorrectly accesses the destination [database connection] 8571** and so no error code is reported, but the operations may malfunction 8572** nevertheless. Use of the destination database connection while a 8573** backup is in progress might also also cause a mutex deadlock. 8574** 8575** If running in [shared cache mode], the application must 8576** guarantee that the shared cache used by the destination database 8577** is not accessed while the backup is running. In practice this means 8578** that the application must guarantee that the disk file being 8579** backed up to is not accessed by any connection within the process, 8580** not just the specific connection that was passed to sqlite3_backup_init(). 8581** 8582** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8583** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8584** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8585** APIs are not strictly speaking threadsafe. If they are invoked at the 8586** same time as another thread is invoking sqlite3_backup_step() it is 8587** possible that they return invalid values. 8588*/ 8589sqlite3_backup *sqlite3_backup_init( 8590 sqlite3 *pDest, /* Destination database handle */ 8591 const char *zDestName, /* Destination database name */ 8592 sqlite3 *pSource, /* Source database handle */ 8593 const char *zSourceName /* Source database name */ 8594); 8595int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8596int sqlite3_backup_finish(sqlite3_backup *p); 8597int sqlite3_backup_remaining(sqlite3_backup *p); 8598int sqlite3_backup_pagecount(sqlite3_backup *p); 8599 8600/* 8601** CAPI3REF: Unlock Notification 8602** METHOD: sqlite3 8603** 8604** ^When running in shared-cache mode, a database operation may fail with 8605** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8606** individual tables within the shared-cache cannot be obtained. See 8607** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8608** ^This API may be used to register a callback that SQLite will invoke 8609** when the connection currently holding the required lock relinquishes it. 8610** ^This API is only available if the library was compiled with the 8611** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8612** 8613** See Also: [Using the SQLite Unlock Notification Feature]. 8614** 8615** ^Shared-cache locks are released when a database connection concludes 8616** its current transaction, either by committing it or rolling it back. 8617** 8618** ^When a connection (known as the blocked connection) fails to obtain a 8619** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8620** identity of the database connection (the blocking connection) that 8621** has locked the required resource is stored internally. ^After an 8622** application receives an SQLITE_LOCKED error, it may call the 8623** sqlite3_unlock_notify() method with the blocked connection handle as 8624** the first argument to register for a callback that will be invoked 8625** when the blocking connections current transaction is concluded. ^The 8626** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8627** call that concludes the blocking connection's transaction. 8628** 8629** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8630** there is a chance that the blocking connection will have already 8631** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8632** If this happens, then the specified callback is invoked immediately, 8633** from within the call to sqlite3_unlock_notify().)^ 8634** 8635** ^If the blocked connection is attempting to obtain a write-lock on a 8636** shared-cache table, and more than one other connection currently holds 8637** a read-lock on the same table, then SQLite arbitrarily selects one of 8638** the other connections to use as the blocking connection. 8639** 8640** ^(There may be at most one unlock-notify callback registered by a 8641** blocked connection. If sqlite3_unlock_notify() is called when the 8642** blocked connection already has a registered unlock-notify callback, 8643** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8644** called with a NULL pointer as its second argument, then any existing 8645** unlock-notify callback is canceled. ^The blocked connections 8646** unlock-notify callback may also be canceled by closing the blocked 8647** connection using [sqlite3_close()]. 8648** 8649** The unlock-notify callback is not reentrant. If an application invokes 8650** any sqlite3_xxx API functions from within an unlock-notify callback, a 8651** crash or deadlock may be the result. 8652** 8653** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8654** returns SQLITE_OK. 8655** 8656** <b>Callback Invocation Details</b> 8657** 8658** When an unlock-notify callback is registered, the application provides a 8659** single void* pointer that is passed to the callback when it is invoked. 8660** However, the signature of the callback function allows SQLite to pass 8661** it an array of void* context pointers. The first argument passed to 8662** an unlock-notify callback is a pointer to an array of void* pointers, 8663** and the second is the number of entries in the array. 8664** 8665** When a blocking connection's transaction is concluded, there may be 8666** more than one blocked connection that has registered for an unlock-notify 8667** callback. ^If two or more such blocked connections have specified the 8668** same callback function, then instead of invoking the callback function 8669** multiple times, it is invoked once with the set of void* context pointers 8670** specified by the blocked connections bundled together into an array. 8671** This gives the application an opportunity to prioritize any actions 8672** related to the set of unblocked database connections. 8673** 8674** <b>Deadlock Detection</b> 8675** 8676** Assuming that after registering for an unlock-notify callback a 8677** database waits for the callback to be issued before taking any further 8678** action (a reasonable assumption), then using this API may cause the 8679** application to deadlock. For example, if connection X is waiting for 8680** connection Y's transaction to be concluded, and similarly connection 8681** Y is waiting on connection X's transaction, then neither connection 8682** will proceed and the system may remain deadlocked indefinitely. 8683** 8684** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8685** detection. ^If a given call to sqlite3_unlock_notify() would put the 8686** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8687** unlock-notify callback is registered. The system is said to be in 8688** a deadlocked state if connection A has registered for an unlock-notify 8689** callback on the conclusion of connection B's transaction, and connection 8690** B has itself registered for an unlock-notify callback when connection 8691** A's transaction is concluded. ^Indirect deadlock is also detected, so 8692** the system is also considered to be deadlocked if connection B has 8693** registered for an unlock-notify callback on the conclusion of connection 8694** C's transaction, where connection C is waiting on connection A. ^Any 8695** number of levels of indirection are allowed. 8696** 8697** <b>The "DROP TABLE" Exception</b> 8698** 8699** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8700** always appropriate to call sqlite3_unlock_notify(). There is however, 8701** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8702** SQLite checks if there are any currently executing SELECT statements 8703** that belong to the same connection. If there are, SQLITE_LOCKED is 8704** returned. In this case there is no "blocking connection", so invoking 8705** sqlite3_unlock_notify() results in the unlock-notify callback being 8706** invoked immediately. If the application then re-attempts the "DROP TABLE" 8707** or "DROP INDEX" query, an infinite loop might be the result. 8708** 8709** One way around this problem is to check the extended error code returned 8710** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8711** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8712** the special "DROP TABLE/INDEX" case, the extended error code is just 8713** SQLITE_LOCKED.)^ 8714*/ 8715int sqlite3_unlock_notify( 8716 sqlite3 *pBlocked, /* Waiting connection */ 8717 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8718 void *pNotifyArg /* Argument to pass to xNotify */ 8719); 8720 8721 8722/* 8723** CAPI3REF: String Comparison 8724** 8725** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8726** and extensions to compare the contents of two buffers containing UTF-8 8727** strings in a case-independent fashion, using the same definition of "case 8728** independence" that SQLite uses internally when comparing identifiers. 8729*/ 8730int sqlite3_stricmp(const char *, const char *); 8731int sqlite3_strnicmp(const char *, const char *, int); 8732 8733/* 8734** CAPI3REF: String Globbing 8735* 8736** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8737** string X matches the [GLOB] pattern P. 8738** ^The definition of [GLOB] pattern matching used in 8739** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8740** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8741** is case sensitive. 8742** 8743** Note that this routine returns zero on a match and non-zero if the strings 8744** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8745** 8746** See also: [sqlite3_strlike()]. 8747*/ 8748int sqlite3_strglob(const char *zGlob, const char *zStr); 8749 8750/* 8751** CAPI3REF: String LIKE Matching 8752* 8753** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8754** string X matches the [LIKE] pattern P with escape character E. 8755** ^The definition of [LIKE] pattern matching used in 8756** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8757** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8758** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8759** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8760** insensitive - equivalent upper and lower case ASCII characters match 8761** one another. 8762** 8763** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8764** only ASCII characters are case folded. 8765** 8766** Note that this routine returns zero on a match and non-zero if the strings 8767** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8768** 8769** See also: [sqlite3_strglob()]. 8770*/ 8771int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8772 8773/* 8774** CAPI3REF: Error Logging Interface 8775** 8776** ^The [sqlite3_log()] interface writes a message into the [error log] 8777** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8778** ^If logging is enabled, the zFormat string and subsequent arguments are 8779** used with [sqlite3_snprintf()] to generate the final output string. 8780** 8781** The sqlite3_log() interface is intended for use by extensions such as 8782** virtual tables, collating functions, and SQL functions. While there is 8783** nothing to prevent an application from calling sqlite3_log(), doing so 8784** is considered bad form. 8785** 8786** The zFormat string must not be NULL. 8787** 8788** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8789** will not use dynamically allocated memory. The log message is stored in 8790** a fixed-length buffer on the stack. If the log message is longer than 8791** a few hundred characters, it will be truncated to the length of the 8792** buffer. 8793*/ 8794void sqlite3_log(int iErrCode, const char *zFormat, ...); 8795 8796/* 8797** CAPI3REF: Write-Ahead Log Commit Hook 8798** METHOD: sqlite3 8799** 8800** ^The [sqlite3_wal_hook()] function is used to register a callback that 8801** is invoked each time data is committed to a database in wal mode. 8802** 8803** ^(The callback is invoked by SQLite after the commit has taken place and 8804** the associated write-lock on the database released)^, so the implementation 8805** may read, write or [checkpoint] the database as required. 8806** 8807** ^The first parameter passed to the callback function when it is invoked 8808** is a copy of the third parameter passed to sqlite3_wal_hook() when 8809** registering the callback. ^The second is a copy of the database handle. 8810** ^The third parameter is the name of the database that was written to - 8811** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8812** is the number of pages currently in the write-ahead log file, 8813** including those that were just committed. 8814** 8815** The callback function should normally return [SQLITE_OK]. ^If an error 8816** code is returned, that error will propagate back up through the 8817** SQLite code base to cause the statement that provoked the callback 8818** to report an error, though the commit will have still occurred. If the 8819** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8820** that does not correspond to any valid SQLite error code, the results 8821** are undefined. 8822** 8823** A single database handle may have at most a single write-ahead log callback 8824** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8825** previously registered write-ahead log callback. ^Note that the 8826** [sqlite3_wal_autocheckpoint()] interface and the 8827** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8828** overwrite any prior [sqlite3_wal_hook()] settings. 8829*/ 8830void *sqlite3_wal_hook( 8831 sqlite3*, 8832 int(*)(void *,sqlite3*,const char*,int), 8833 void* 8834); 8835 8836/* 8837** CAPI3REF: Configure an auto-checkpoint 8838** METHOD: sqlite3 8839** 8840** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8841** [sqlite3_wal_hook()] that causes any database on [database connection] D 8842** to automatically [checkpoint] 8843** after committing a transaction if there are N or 8844** more frames in the [write-ahead log] file. ^Passing zero or 8845** a negative value as the nFrame parameter disables automatic 8846** checkpoints entirely. 8847** 8848** ^The callback registered by this function replaces any existing callback 8849** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8850** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8851** configured by this function. 8852** 8853** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8854** from SQL. 8855** 8856** ^Checkpoints initiated by this mechanism are 8857** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8858** 8859** ^Every new [database connection] defaults to having the auto-checkpoint 8860** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8861** pages. The use of this interface 8862** is only necessary if the default setting is found to be suboptimal 8863** for a particular application. 8864*/ 8865int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8866 8867/* 8868** CAPI3REF: Checkpoint a database 8869** METHOD: sqlite3 8870** 8871** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8872** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8873** 8874** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8875** [write-ahead log] for database X on [database connection] D to be 8876** transferred into the database file and for the write-ahead log to 8877** be reset. See the [checkpointing] documentation for addition 8878** information. 8879** 8880** This interface used to be the only way to cause a checkpoint to 8881** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8882** interface was added. This interface is retained for backwards 8883** compatibility and as a convenience for applications that need to manually 8884** start a callback but which do not need the full power (and corresponding 8885** complication) of [sqlite3_wal_checkpoint_v2()]. 8886*/ 8887int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8888 8889/* 8890** CAPI3REF: Checkpoint a database 8891** METHOD: sqlite3 8892** 8893** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8894** operation on database X of [database connection] D in mode M. Status 8895** information is written back into integers pointed to by L and C.)^ 8896** ^(The M parameter must be a valid [checkpoint mode]:)^ 8897** 8898** <dl> 8899** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8900** ^Checkpoint as many frames as possible without waiting for any database 8901** readers or writers to finish, then sync the database file if all frames 8902** in the log were checkpointed. ^The [busy-handler callback] 8903** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8904** ^On the other hand, passive mode might leave the checkpoint unfinished 8905** if there are concurrent readers or writers. 8906** 8907** <dt>SQLITE_CHECKPOINT_FULL<dd> 8908** ^This mode blocks (it invokes the 8909** [sqlite3_busy_handler|busy-handler callback]) until there is no 8910** database writer and all readers are reading from the most recent database 8911** snapshot. ^It then checkpoints all frames in the log file and syncs the 8912** database file. ^This mode blocks new database writers while it is pending, 8913** but new database readers are allowed to continue unimpeded. 8914** 8915** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8916** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8917** that after checkpointing the log file it blocks (calls the 8918** [busy-handler callback]) 8919** until all readers are reading from the database file only. ^This ensures 8920** that the next writer will restart the log file from the beginning. 8921** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8922** database writer attempts while it is pending, but does not impede readers. 8923** 8924** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8925** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8926** addition that it also truncates the log file to zero bytes just prior 8927** to a successful return. 8928** </dl> 8929** 8930** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8931** the log file or to -1 if the checkpoint could not run because 8932** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8933** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8934** log file (including any that were already checkpointed before the function 8935** was called) or to -1 if the checkpoint could not run due to an error or 8936** because the database is not in WAL mode. ^Note that upon successful 8937** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8938** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8939** 8940** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8941** any other process is running a checkpoint operation at the same time, the 8942** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8943** busy-handler configured, it will not be invoked in this case. 8944** 8945** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8946** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8947** obtained immediately, and a busy-handler is configured, it is invoked and 8948** the writer lock retried until either the busy-handler returns 0 or the lock 8949** is successfully obtained. ^The busy-handler is also invoked while waiting for 8950** database readers as described above. ^If the busy-handler returns 0 before 8951** the writer lock is obtained or while waiting for database readers, the 8952** checkpoint operation proceeds from that point in the same way as 8953** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8954** without blocking any further. ^SQLITE_BUSY is returned in this case. 8955** 8956** ^If parameter zDb is NULL or points to a zero length string, then the 8957** specified operation is attempted on all WAL databases [attached] to 8958** [database connection] db. In this case the 8959** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8960** an SQLITE_BUSY error is encountered when processing one or more of the 8961** attached WAL databases, the operation is still attempted on any remaining 8962** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8963** error occurs while processing an attached database, processing is abandoned 8964** and the error code is returned to the caller immediately. ^If no error 8965** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8966** databases, SQLITE_OK is returned. 8967** 8968** ^If database zDb is the name of an attached database that is not in WAL 8969** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8970** zDb is not NULL (or a zero length string) and is not the name of any 8971** attached database, SQLITE_ERROR is returned to the caller. 8972** 8973** ^Unless it returns SQLITE_MISUSE, 8974** the sqlite3_wal_checkpoint_v2() interface 8975** sets the error information that is queried by 8976** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8977** 8978** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8979** from SQL. 8980*/ 8981int sqlite3_wal_checkpoint_v2( 8982 sqlite3 *db, /* Database handle */ 8983 const char *zDb, /* Name of attached database (or NULL) */ 8984 int eMode, /* SQLITE_CHECKPOINT_* value */ 8985 int *pnLog, /* OUT: Size of WAL log in frames */ 8986 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8987); 8988 8989/* 8990** CAPI3REF: Checkpoint Mode Values 8991** KEYWORDS: {checkpoint mode} 8992** 8993** These constants define all valid values for the "checkpoint mode" passed 8994** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8995** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8996** meaning of each of these checkpoint modes. 8997*/ 8998#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8999#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9000#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 9001#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9002 9003/* 9004** CAPI3REF: Virtual Table Interface Configuration 9005** 9006** This function may be called by either the [xConnect] or [xCreate] method 9007** of a [virtual table] implementation to configure 9008** various facets of the virtual table interface. 9009** 9010** If this interface is invoked outside the context of an xConnect or 9011** xCreate virtual table method then the behavior is undefined. 9012** 9013** At present, there is only one option that may be configured using 9014** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 9015** may be added in the future. 9016*/ 9017int sqlite3_vtab_config(sqlite3*, int op, ...); 9018 9019/* 9020** CAPI3REF: Virtual Table Configuration Options 9021** 9022** These macros define the various options to the 9023** [sqlite3_vtab_config()] interface that [virtual table] implementations 9024** can use to customize and optimize their behavior. 9025** 9026** <dl> 9027** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9028** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9029** <dd>Calls of the form 9030** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9031** where X is an integer. If X is zero, then the [virtual table] whose 9032** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9033** support constraints. In this configuration (which is the default) if 9034** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9035** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9036** specified as part of the users SQL statement, regardless of the actual 9037** ON CONFLICT mode specified. 9038** 9039** If X is non-zero, then the virtual table implementation guarantees 9040** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9041** any modifications to internal or persistent data structures have been made. 9042** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9043** is able to roll back a statement or database transaction, and abandon 9044** or continue processing the current SQL statement as appropriate. 9045** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9046** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9047** had been ABORT. 9048** 9049** Virtual table implementations that are required to handle OR REPLACE 9050** must do so within the [xUpdate] method. If a call to the 9051** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9052** CONFLICT policy is REPLACE, the virtual table implementation should 9053** silently replace the appropriate rows within the xUpdate callback and 9054** return SQLITE_OK. Or, if this is not possible, it may return 9055** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9056** constraint handling. 9057** </dd> 9058** 9059** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9060** <dd>Calls of the form 9061** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9062** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9063** prohibits that virtual table from being used from within triggers and 9064** views. 9065** </dd> 9066** 9067** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9068** <dd>Calls of the form 9069** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9070** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9071** identify that virtual table as being safe to use from within triggers 9072** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9073** virtual table can do no serious harm even if it is controlled by a 9074** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9075** flag unless absolutely necessary. 9076** </dd> 9077** </dl> 9078*/ 9079#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9080#define SQLITE_VTAB_INNOCUOUS 2 9081#define SQLITE_VTAB_DIRECTONLY 3 9082 9083/* 9084** CAPI3REF: Determine The Virtual Table Conflict Policy 9085** 9086** This function may only be called from within a call to the [xUpdate] method 9087** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9088** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9089** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9090** of the SQL statement that triggered the call to the [xUpdate] method of the 9091** [virtual table]. 9092*/ 9093int sqlite3_vtab_on_conflict(sqlite3 *); 9094 9095/* 9096** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9097** 9098** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9099** method of a [virtual table], then it returns true if and only if the 9100** column is being fetched as part of an UPDATE operation during which the 9101** column value will not change. Applications might use this to substitute 9102** a return value that is less expensive to compute and that the corresponding 9103** [xUpdate] method understands as a "no-change" value. 9104** 9105** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9106** the column is not changed by the UPDATE statement, then the xColumn 9107** method can optionally return without setting a result, without calling 9108** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9109** In that case, [sqlite3_value_nochange(X)] will return true for the 9110** same column in the [xUpdate] method. 9111*/ 9112int sqlite3_vtab_nochange(sqlite3_context*); 9113 9114/* 9115** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9116** 9117** This function may only be called from within a call to the [xBestIndex] 9118** method of a [virtual table]. 9119** 9120** The first argument must be the sqlite3_index_info object that is the 9121** first parameter to the xBestIndex() method. The second argument must be 9122** an index into the aConstraint[] array belonging to the sqlite3_index_info 9123** structure passed to xBestIndex. This function returns a pointer to a buffer 9124** containing the name of the collation sequence for the corresponding 9125** constraint. 9126*/ 9127SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9128 9129/* 9130** CAPI3REF: Conflict resolution modes 9131** KEYWORDS: {conflict resolution mode} 9132** 9133** These constants are returned by [sqlite3_vtab_on_conflict()] to 9134** inform a [virtual table] implementation what the [ON CONFLICT] mode 9135** is for the SQL statement being evaluated. 9136** 9137** Note that the [SQLITE_IGNORE] constant is also used as a potential 9138** return value from the [sqlite3_set_authorizer()] callback and that 9139** [SQLITE_ABORT] is also a [result code]. 9140*/ 9141#define SQLITE_ROLLBACK 1 9142/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9143#define SQLITE_FAIL 3 9144/* #define SQLITE_ABORT 4 // Also an error code */ 9145#define SQLITE_REPLACE 5 9146 9147/* 9148** CAPI3REF: Prepared Statement Scan Status Opcodes 9149** KEYWORDS: {scanstatus options} 9150** 9151** The following constants can be used for the T parameter to the 9152** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9153** different metric for sqlite3_stmt_scanstatus() to return. 9154** 9155** When the value returned to V is a string, space to hold that string is 9156** managed by the prepared statement S and will be automatically freed when 9157** S is finalized. 9158** 9159** <dl> 9160** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9161** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9162** set to the total number of times that the X-th loop has run.</dd> 9163** 9164** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9165** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9166** to the total number of rows examined by all iterations of the X-th loop.</dd> 9167** 9168** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9169** <dd>^The "double" variable pointed to by the V parameter will be set to the 9170** query planner's estimate for the average number of rows output from each 9171** iteration of the X-th loop. If the query planner's estimates was accurate, 9172** then this value will approximate the quotient NVISIT/NLOOP and the 9173** product of this value for all prior loops with the same SELECTID will 9174** be the NLOOP value for the current loop. 9175** 9176** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9177** <dd>^The "const char *" variable pointed to by the V parameter will be set 9178** to a zero-terminated UTF-8 string containing the name of the index or table 9179** used for the X-th loop. 9180** 9181** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9182** <dd>^The "const char *" variable pointed to by the V parameter will be set 9183** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9184** description for the X-th loop. 9185** 9186** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9187** <dd>^The "int" variable pointed to by the V parameter will be set to the 9188** "select-id" for the X-th loop. The select-id identifies which query or 9189** subquery the loop is part of. The main query has a select-id of zero. 9190** The select-id is the same value as is output in the first column 9191** of an [EXPLAIN QUERY PLAN] query. 9192** </dl> 9193*/ 9194#define SQLITE_SCANSTAT_NLOOP 0 9195#define SQLITE_SCANSTAT_NVISIT 1 9196#define SQLITE_SCANSTAT_EST 2 9197#define SQLITE_SCANSTAT_NAME 3 9198#define SQLITE_SCANSTAT_EXPLAIN 4 9199#define SQLITE_SCANSTAT_SELECTID 5 9200 9201/* 9202** CAPI3REF: Prepared Statement Scan Status 9203** METHOD: sqlite3_stmt 9204** 9205** This interface returns information about the predicted and measured 9206** performance for pStmt. Advanced applications can use this 9207** interface to compare the predicted and the measured performance and 9208** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9209** 9210** Since this interface is expected to be rarely used, it is only 9211** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9212** compile-time option. 9213** 9214** The "iScanStatusOp" parameter determines which status information to return. 9215** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9216** of this interface is undefined. 9217** ^The requested measurement is written into a variable pointed to by 9218** the "pOut" parameter. 9219** Parameter "idx" identifies the specific loop to retrieve statistics for. 9220** Loops are numbered starting from zero. ^If idx is out of range - less than 9221** zero or greater than or equal to the total number of loops used to implement 9222** the statement - a non-zero value is returned and the variable that pOut 9223** points to is unchanged. 9224** 9225** ^Statistics might not be available for all loops in all statements. ^In cases 9226** where there exist loops with no available statistics, this function behaves 9227** as if the loop did not exist - it returns non-zero and leave the variable 9228** that pOut points to unchanged. 9229** 9230** See also: [sqlite3_stmt_scanstatus_reset()] 9231*/ 9232int sqlite3_stmt_scanstatus( 9233 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9234 int idx, /* Index of loop to report on */ 9235 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9236 void *pOut /* Result written here */ 9237); 9238 9239/* 9240** CAPI3REF: Zero Scan-Status Counters 9241** METHOD: sqlite3_stmt 9242** 9243** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9244** 9245** This API is only available if the library is built with pre-processor 9246** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9247*/ 9248void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9249 9250/* 9251** CAPI3REF: Flush caches to disk mid-transaction 9252** 9253** ^If a write-transaction is open on [database connection] D when the 9254** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9255** pages in the pager-cache that are not currently in use are written out 9256** to disk. A dirty page may be in use if a database cursor created by an 9257** active SQL statement is reading from it, or if it is page 1 of a database 9258** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9259** interface flushes caches for all schemas - "main", "temp", and 9260** any [attached] databases. 9261** 9262** ^If this function needs to obtain extra database locks before dirty pages 9263** can be flushed to disk, it does so. ^If those locks cannot be obtained 9264** immediately and there is a busy-handler callback configured, it is invoked 9265** in the usual manner. ^If the required lock still cannot be obtained, then 9266** the database is skipped and an attempt made to flush any dirty pages 9267** belonging to the next (if any) database. ^If any databases are skipped 9268** because locks cannot be obtained, but no other error occurs, this 9269** function returns SQLITE_BUSY. 9270** 9271** ^If any other error occurs while flushing dirty pages to disk (for 9272** example an IO error or out-of-memory condition), then processing is 9273** abandoned and an SQLite [error code] is returned to the caller immediately. 9274** 9275** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9276** 9277** ^This function does not set the database handle error code or message 9278** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9279*/ 9280int sqlite3_db_cacheflush(sqlite3*); 9281 9282/* 9283** CAPI3REF: The pre-update hook. 9284** 9285** ^These interfaces are only available if SQLite is compiled using the 9286** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9287** 9288** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9289** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9290** on a database table. 9291** ^At most one preupdate hook may be registered at a time on a single 9292** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9293** the previous setting. 9294** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9295** with a NULL pointer as the second parameter. 9296** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9297** the first parameter to callbacks. 9298** 9299** ^The preupdate hook only fires for changes to real database tables; the 9300** preupdate hook is not invoked for changes to [virtual tables] or to 9301** system tables like sqlite_master or sqlite_stat1. 9302** 9303** ^The second parameter to the preupdate callback is a pointer to 9304** the [database connection] that registered the preupdate hook. 9305** ^The third parameter to the preupdate callback is one of the constants 9306** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9307** kind of update operation that is about to occur. 9308** ^(The fourth parameter to the preupdate callback is the name of the 9309** database within the database connection that is being modified. This 9310** will be "main" for the main database or "temp" for TEMP tables or 9311** the name given after the AS keyword in the [ATTACH] statement for attached 9312** databases.)^ 9313** ^The fifth parameter to the preupdate callback is the name of the 9314** table that is being modified. 9315** 9316** For an UPDATE or DELETE operation on a [rowid table], the sixth 9317** parameter passed to the preupdate callback is the initial [rowid] of the 9318** row being modified or deleted. For an INSERT operation on a rowid table, 9319** or any operation on a WITHOUT ROWID table, the value of the sixth 9320** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9321** seventh parameter is the final rowid value of the row being inserted 9322** or updated. The value of the seventh parameter passed to the callback 9323** function is not defined for operations on WITHOUT ROWID tables, or for 9324** INSERT operations on rowid tables. 9325** 9326** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9327** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9328** provide additional information about a preupdate event. These routines 9329** may only be called from within a preupdate callback. Invoking any of 9330** these routines from outside of a preupdate callback or with a 9331** [database connection] pointer that is different from the one supplied 9332** to the preupdate callback results in undefined and probably undesirable 9333** behavior. 9334** 9335** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9336** in the row that is being inserted, updated, or deleted. 9337** 9338** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9339** a [protected sqlite3_value] that contains the value of the Nth column of 9340** the table row before it is updated. The N parameter must be between 0 9341** and one less than the number of columns or the behavior will be 9342** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9343** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9344** behavior is undefined. The [sqlite3_value] that P points to 9345** will be destroyed when the preupdate callback returns. 9346** 9347** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9348** a [protected sqlite3_value] that contains the value of the Nth column of 9349** the table row after it is updated. The N parameter must be between 0 9350** and one less than the number of columns or the behavior will be 9351** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9352** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9353** behavior is undefined. The [sqlite3_value] that P points to 9354** will be destroyed when the preupdate callback returns. 9355** 9356** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9357** callback was invoked as a result of a direct insert, update, or delete 9358** operation; or 1 for inserts, updates, or deletes invoked by top-level 9359** triggers; or 2 for changes resulting from triggers called by top-level 9360** triggers; and so forth. 9361** 9362** See also: [sqlite3_update_hook()] 9363*/ 9364#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9365void *sqlite3_preupdate_hook( 9366 sqlite3 *db, 9367 void(*xPreUpdate)( 9368 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9369 sqlite3 *db, /* Database handle */ 9370 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9371 char const *zDb, /* Database name */ 9372 char const *zName, /* Table name */ 9373 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9374 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9375 ), 9376 void* 9377); 9378int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9379int sqlite3_preupdate_count(sqlite3 *); 9380int sqlite3_preupdate_depth(sqlite3 *); 9381int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9382#endif 9383 9384/* 9385** CAPI3REF: Low-level system error code 9386** 9387** ^Attempt to return the underlying operating system error code or error 9388** number that caused the most recent I/O error or failure to open a file. 9389** The return value is OS-dependent. For example, on unix systems, after 9390** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9391** called to get back the underlying "errno" that caused the problem, such 9392** as ENOSPC, EAUTH, EISDIR, and so forth. 9393*/ 9394int sqlite3_system_errno(sqlite3*); 9395 9396/* 9397** CAPI3REF: Database Snapshot 9398** KEYWORDS: {snapshot} {sqlite3_snapshot} 9399** 9400** An instance of the snapshot object records the state of a [WAL mode] 9401** database for some specific point in history. 9402** 9403** In [WAL mode], multiple [database connections] that are open on the 9404** same database file can each be reading a different historical version 9405** of the database file. When a [database connection] begins a read 9406** transaction, that connection sees an unchanging copy of the database 9407** as it existed for the point in time when the transaction first started. 9408** Subsequent changes to the database from other connections are not seen 9409** by the reader until a new read transaction is started. 9410** 9411** The sqlite3_snapshot object records state information about an historical 9412** version of the database file so that it is possible to later open a new read 9413** transaction that sees that historical version of the database rather than 9414** the most recent version. 9415*/ 9416typedef struct sqlite3_snapshot { 9417 unsigned char hidden[48]; 9418} sqlite3_snapshot; 9419 9420/* 9421** CAPI3REF: Record A Database Snapshot 9422** CONSTRUCTOR: sqlite3_snapshot 9423** 9424** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9425** new [sqlite3_snapshot] object that records the current state of 9426** schema S in database connection D. ^On success, the 9427** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9428** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9429** If there is not already a read-transaction open on schema S when 9430** this function is called, one is opened automatically. 9431** 9432** The following must be true for this function to succeed. If any of 9433** the following statements are false when sqlite3_snapshot_get() is 9434** called, SQLITE_ERROR is returned. The final value of *P is undefined 9435** in this case. 9436** 9437** <ul> 9438** <li> The database handle must not be in [autocommit mode]. 9439** 9440** <li> Schema S of [database connection] D must be a [WAL mode] database. 9441** 9442** <li> There must not be a write transaction open on schema S of database 9443** connection D. 9444** 9445** <li> One or more transactions must have been written to the current wal 9446** file since it was created on disk (by any connection). This means 9447** that a snapshot cannot be taken on a wal mode database with no wal 9448** file immediately after it is first opened. At least one transaction 9449** must be written to it first. 9450** </ul> 9451** 9452** This function may also return SQLITE_NOMEM. If it is called with the 9453** database handle in autocommit mode but fails for some other reason, 9454** whether or not a read transaction is opened on schema S is undefined. 9455** 9456** The [sqlite3_snapshot] object returned from a successful call to 9457** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9458** to avoid a memory leak. 9459** 9460** The [sqlite3_snapshot_get()] interface is only available when the 9461** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9462*/ 9463SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9464 sqlite3 *db, 9465 const char *zSchema, 9466 sqlite3_snapshot **ppSnapshot 9467); 9468 9469/* 9470** CAPI3REF: Start a read transaction on an historical snapshot 9471** METHOD: sqlite3_snapshot 9472** 9473** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9474** transaction or upgrades an existing one for schema S of 9475** [database connection] D such that the read transaction refers to 9476** historical [snapshot] P, rather than the most recent change to the 9477** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9478** on success or an appropriate [error code] if it fails. 9479** 9480** ^In order to succeed, the database connection must not be in 9481** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9482** is already a read transaction open on schema S, then the database handle 9483** must have no active statements (SELECT statements that have been passed 9484** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9485** SQLITE_ERROR is returned if either of these conditions is violated, or 9486** if schema S does not exist, or if the snapshot object is invalid. 9487** 9488** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9489** snapshot has been overwritten by a [checkpoint]. In this case 9490** SQLITE_ERROR_SNAPSHOT is returned. 9491** 9492** If there is already a read transaction open when this function is 9493** invoked, then the same read transaction remains open (on the same 9494** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9495** is returned. If another error code - for example SQLITE_PROTOCOL or an 9496** SQLITE_IOERR error code - is returned, then the final state of the 9497** read transaction is undefined. If SQLITE_OK is returned, then the 9498** read transaction is now open on database snapshot P. 9499** 9500** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9501** database connection D does not know that the database file for 9502** schema S is in [WAL mode]. A database connection might not know 9503** that the database file is in [WAL mode] if there has been no prior 9504** I/O on that database connection, or if the database entered [WAL mode] 9505** after the most recent I/O on the database connection.)^ 9506** (Hint: Run "[PRAGMA application_id]" against a newly opened 9507** database connection in order to make it ready to use snapshots.) 9508** 9509** The [sqlite3_snapshot_open()] interface is only available when the 9510** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9511*/ 9512SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9513 sqlite3 *db, 9514 const char *zSchema, 9515 sqlite3_snapshot *pSnapshot 9516); 9517 9518/* 9519** CAPI3REF: Destroy a snapshot 9520** DESTRUCTOR: sqlite3_snapshot 9521** 9522** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9523** The application must eventually free every [sqlite3_snapshot] object 9524** using this routine to avoid a memory leak. 9525** 9526** The [sqlite3_snapshot_free()] interface is only available when the 9527** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9528*/ 9529SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9530 9531/* 9532** CAPI3REF: Compare the ages of two snapshot handles. 9533** METHOD: sqlite3_snapshot 9534** 9535** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9536** of two valid snapshot handles. 9537** 9538** If the two snapshot handles are not associated with the same database 9539** file, the result of the comparison is undefined. 9540** 9541** Additionally, the result of the comparison is only valid if both of the 9542** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9543** last time the wal file was deleted. The wal file is deleted when the 9544** database is changed back to rollback mode or when the number of database 9545** clients drops to zero. If either snapshot handle was obtained before the 9546** wal file was last deleted, the value returned by this function 9547** is undefined. 9548** 9549** Otherwise, this API returns a negative value if P1 refers to an older 9550** snapshot than P2, zero if the two handles refer to the same database 9551** snapshot, and a positive value if P1 is a newer snapshot than P2. 9552** 9553** This interface is only available if SQLite is compiled with the 9554** [SQLITE_ENABLE_SNAPSHOT] option. 9555*/ 9556SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9557 sqlite3_snapshot *p1, 9558 sqlite3_snapshot *p2 9559); 9560 9561/* 9562** CAPI3REF: Recover snapshots from a wal file 9563** METHOD: sqlite3_snapshot 9564** 9565** If a [WAL file] remains on disk after all database connections close 9566** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9567** or because the last process to have the database opened exited without 9568** calling [sqlite3_close()]) and a new connection is subsequently opened 9569** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9570** will only be able to open the last transaction added to the WAL file 9571** even though the WAL file contains other valid transactions. 9572** 9573** This function attempts to scan the WAL file associated with database zDb 9574** of database handle db and make all valid snapshots available to 9575** sqlite3_snapshot_open(). It is an error if there is already a read 9576** transaction open on the database, or if the database is not a WAL mode 9577** database. 9578** 9579** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9580** 9581** This interface is only available if SQLite is compiled with the 9582** [SQLITE_ENABLE_SNAPSHOT] option. 9583*/ 9584SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9585 9586/* 9587** CAPI3REF: Serialize a database 9588** 9589** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9590** that is a serialization of the S database on [database connection] D. 9591** If P is not a NULL pointer, then the size of the database in bytes 9592** is written into *P. 9593** 9594** For an ordinary on-disk database file, the serialization is just a 9595** copy of the disk file. For an in-memory database or a "TEMP" database, 9596** the serialization is the same sequence of bytes which would be written 9597** to disk if that database where backed up to disk. 9598** 9599** The usual case is that sqlite3_serialize() copies the serialization of 9600** the database into memory obtained from [sqlite3_malloc64()] and returns 9601** a pointer to that memory. The caller is responsible for freeing the 9602** returned value to avoid a memory leak. However, if the F argument 9603** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9604** are made, and the sqlite3_serialize() function will return a pointer 9605** to the contiguous memory representation of the database that SQLite 9606** is currently using for that database, or NULL if the no such contiguous 9607** memory representation of the database exists. A contiguous memory 9608** representation of the database will usually only exist if there has 9609** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9610** values of D and S. 9611** The size of the database is written into *P even if the 9612** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9613** of the database exists. 9614** 9615** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9616** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9617** allocation error occurs. 9618** 9619** This interface is only available if SQLite is compiled with the 9620** [SQLITE_ENABLE_DESERIALIZE] option. 9621*/ 9622unsigned char *sqlite3_serialize( 9623 sqlite3 *db, /* The database connection */ 9624 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9625 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9626 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9627); 9628 9629/* 9630** CAPI3REF: Flags for sqlite3_serialize 9631** 9632** Zero or more of the following constants can be OR-ed together for 9633** the F argument to [sqlite3_serialize(D,S,P,F)]. 9634** 9635** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9636** a pointer to contiguous in-memory database that it is currently using, 9637** without making a copy of the database. If SQLite is not currently using 9638** a contiguous in-memory database, then this option causes 9639** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9640** using a contiguous in-memory database if it has been initialized by a 9641** prior call to [sqlite3_deserialize()]. 9642*/ 9643#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9644 9645/* 9646** CAPI3REF: Deserialize a database 9647** 9648** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9649** [database connection] D to disconnect from database S and then 9650** reopen S as an in-memory database based on the serialization contained 9651** in P. The serialized database P is N bytes in size. M is the size of 9652** the buffer P, which might be larger than N. If M is larger than N, and 9653** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9654** permitted to add content to the in-memory database as long as the total 9655** size does not exceed M bytes. 9656** 9657** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9658** invoke sqlite3_free() on the serialization buffer when the database 9659** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9660** SQLite will try to increase the buffer size using sqlite3_realloc64() 9661** if writes on the database cause it to grow larger than M bytes. 9662** 9663** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9664** database is currently in a read transaction or is involved in a backup 9665** operation. 9666** 9667** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9668** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9669** [sqlite3_free()] is invoked on argument P prior to returning. 9670** 9671** This interface is only available if SQLite is compiled with the 9672** [SQLITE_ENABLE_DESERIALIZE] option. 9673*/ 9674int sqlite3_deserialize( 9675 sqlite3 *db, /* The database connection */ 9676 const char *zSchema, /* Which DB to reopen with the deserialization */ 9677 unsigned char *pData, /* The serialized database content */ 9678 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9679 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9680 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9681); 9682 9683/* 9684** CAPI3REF: Flags for sqlite3_deserialize() 9685** 9686** The following are allowed values for 6th argument (the F argument) to 9687** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9688** 9689** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9690** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9691** and that SQLite should take ownership of this memory and automatically 9692** free it when it has finished using it. Without this flag, the caller 9693** is responsible for freeing any dynamically allocated memory. 9694** 9695** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9696** grow the size of the database using calls to [sqlite3_realloc64()]. This 9697** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9698** Without this flag, the deserialized database cannot increase in size beyond 9699** the number of bytes specified by the M parameter. 9700** 9701** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9702** should be treated as read-only. 9703*/ 9704#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9705#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9706#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9707 9708/* 9709** Undo the hack that converts floating point types to integer for 9710** builds on processors without floating point support. 9711*/ 9712#ifdef SQLITE_OMIT_FLOATING_POINT 9713# undef double 9714#endif 9715 9716#ifdef __cplusplus 9717} /* End of the 'extern "C"' block */ 9718#endif 9719#endif /* SQLITE3_H */ 9720