diff options
Diffstat (limited to 'src/sqlite.h.in')
| -rw-r--r-- | src/sqlite.h.in | 484 |
1 files changed, 307 insertions, 177 deletions
diff --git a/src/sqlite.h.in b/src/sqlite.h.in index f1d4e406e..4427f39d0 100644 --- a/src/sqlite.h.in +++ b/src/sqlite.h.in @@ -52,7 +52,7 @@ extern "C" { /* ** These no-op macros are used in front of interfaces to mark those ** interfaces as either deprecated or experimental. New applications -** should not use deprecated interfaces - they are support for backwards +** should not use deprecated interfaces - they are supported for backwards ** compatibility only. Application writers should be aware that ** experimental interfaces are subject to change in point releases. ** @@ -1499,25 +1499,27 @@ struct sqlite3_mem_methods { ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> ** ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> -** <dd> ^(This option takes a single argument which is a pointer to an -** instance of the [sqlite3_mem_methods] structure. The argument specifies +** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is +** a pointer to an instance of the [sqlite3_mem_methods] structure. +** The argument specifies ** alternative low-level memory allocation routines to be used in place of ** the memory allocation routines built into SQLite.)^ ^SQLite makes ** its own private copy of the content of the [sqlite3_mem_methods] structure ** before the [sqlite3_config()] call returns.</dd> ** ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> -** <dd> ^(This option takes a single argument which is a pointer to an -** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] +** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which +** is a pointer to an instance of the [sqlite3_mem_methods] structure. +** The [sqlite3_mem_methods] ** structure is filled with the currently defined memory allocation routines.)^ ** This option can be used to overload the default memory allocation ** routines with a wrapper that simulations memory allocation failure or ** tracks memory usage, for example. </dd> ** ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> -** <dd> ^This option takes single argument of type int, interpreted as a -** boolean, which enables or disables the collection of memory allocation -** statistics. ^(When memory allocation statistics are disabled, the +** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, +** interpreted as a boolean, which enables or disables the collection of +** memory allocation statistics. ^(When memory allocation statistics are disabled, the ** following SQLite interfaces become non-operational: ** <ul> ** <li> [sqlite3_memory_used()] @@ -1531,53 +1533,65 @@ struct sqlite3_mem_methods { ** </dd> ** ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> -** <dd> ^This option specifies a static memory buffer that SQLite can use for -** scratch memory. There are three arguments: A pointer an 8-byte +** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer +** that SQLite can use for scratch memory. ^(There are three arguments +** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte ** aligned memory buffer from which the scratch allocations will be ** drawn, the size of each scratch allocation (sz), -** and the maximum number of scratch allocations (N). The sz -** argument must be a multiple of 16. +** and the maximum number of scratch allocations (N).)^ ** The first argument must be a pointer to an 8-byte aligned buffer ** of at least sz*N bytes of memory. -** ^SQLite will use no more than two scratch buffers per thread. So -** N should be set to twice the expected maximum number of threads. -** ^SQLite will never require a scratch buffer that is more than 6 -** times the database page size. ^If SQLite needs needs additional +** ^SQLite will not use more than one scratch buffers per thread. +** ^SQLite will never request a scratch buffer that is more than 6 +** times the database page size. +** ^If SQLite needs needs additional ** scratch memory beyond what is provided by this configuration option, then -** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> +** [sqlite3_malloc()] will be used to obtain the memory needed.<p> +** ^When the application provides any amount of scratch memory using +** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large +** [sqlite3_malloc|heap allocations]. +** This can help [Robson proof|prevent memory allocation failures] due to heap +** fragmentation in low-memory embedded systems. +** </dd> ** ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> -** <dd> ^This option specifies a static memory buffer that SQLite can use for -** the database page cache with the default page cache implementation. +** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a static memory buffer +** that SQLite can use for the database page cache with the default page +** cache implementation. ** This configuration should not be used if an application-define page -** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. -** There are three arguments to this option: A pointer to 8-byte aligned +** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2] +** configuration option. +** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned ** memory, the size of each page buffer (sz), and the number of pages (N). ** The sz argument should be the size of the largest database page -** (a power of two between 512 and 32768) plus a little extra for each -** page header. ^The page header size is 20 to 40 bytes depending on -** the host architecture. ^It is harmless, apart from the wasted memory, -** to make sz a little too large. The first -** argument should point to an allocation of at least sz*N bytes of memory. +** (a power of two between 512 and 32768) plus some extra bytes for each +** page header. ^The number of extra bytes needed by the page header +** can be determined using the [SQLITE_CONFIG_PCACHE_HDRSZ] option +** to [sqlite3_config()]. +** ^It is harmless, apart from the wasted memory, +** for the sz parameter to be larger than necessary. The first +** argument should pointer to an 8-byte aligned block of memory that +** is at least sz*N bytes of memory, otherwise subsequent behavior is +** undefined. ** ^SQLite will use the memory provided by the first argument to satisfy its ** memory needs for the first N pages that it adds to cache. ^If additional ** page cache memory is needed beyond what is provided by this option, then -** SQLite goes to [sqlite3_malloc()] for the additional storage space. -** The pointer in the first argument must -** be aligned to an 8-byte boundary or subsequent behavior of SQLite -** will be undefined.</dd> +** SQLite goes to [sqlite3_malloc()] for the additional storage space.</dd> ** ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> -** <dd> ^This option specifies a static memory buffer that SQLite will use -** for all of its dynamic memory allocation needs beyond those provided -** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. -** There are three arguments: An 8-byte aligned pointer to the memory, +** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer +** that SQLite will use for all of its dynamic memory allocation needs +** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. +** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled +** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns +** [SQLITE_ERROR] if invoked otherwise. +** ^There are three arguments to SQLITE_CONFIG_HEAP: +** An 8-byte aligned pointer to the memory, ** the number of bytes in the memory buffer, and the minimum allocation size. ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts ** to using its default memory allocator (the system malloc() implementation), ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the -** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or -** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory +** memory pointer is not NULL then the alternative memory ** allocator is engaged to handle all of SQLites memory allocation needs. ** The first pointer (the memory pointer) must be aligned to an 8-byte ** boundary or subsequent behavior of SQLite will be undefined. @@ -1585,9 +1599,9 @@ struct sqlite3_mem_methods { ** for the minimum allocation size are 2**5 through 2**8.</dd> ** ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> -** <dd> ^(This option takes a single argument which is a pointer to an -** instance of the [sqlite3_mutex_methods] structure. The argument specifies -** alternative low-level mutex routines to be used in place +** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a +** pointer to an instance of the [sqlite3_mutex_methods] structure. +** The argument specifies alternative low-level mutex routines to be used in place ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the ** content of the [sqlite3_mutex_methods] structure before the call to ** [sqlite3_config()] returns. ^If SQLite is compiled with @@ -1597,8 +1611,8 @@ struct sqlite3_mem_methods { ** return [SQLITE_ERROR].</dd> ** ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> -** <dd> ^(This option takes a single argument which is a pointer to an -** instance of the [sqlite3_mutex_methods] structure. The +** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which +** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The ** [sqlite3_mutex_methods] ** structure is filled with the currently defined mutex routines.)^ ** This option can be used to overload the default mutex allocation @@ -1610,24 +1624,24 @@ struct sqlite3_mem_methods { ** return [SQLITE_ERROR].</dd> ** ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> -** <dd> ^(This option takes two arguments that determine the default -** memory allocation for the lookaside memory allocator on each -** [database connection]. The first argument is the +** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine +** the default size of lookaside memory on each [database connection]. +** The first argument is the ** size of each lookaside buffer slot and the second is the number of -** slots allocated to each database connection.)^ ^(This option sets the -** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] -** verb to [sqlite3_db_config()] can be used to change the lookaside +** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE +** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] +** option to [sqlite3_db_config()] can be used to change the lookaside ** configuration on individual connections.)^ </dd> ** ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> -** <dd> ^(This option takes a single argument which is a pointer to -** an [sqlite3_pcache_methods2] object. This object specifies the interface -** to a custom page cache implementation.)^ ^SQLite makes a copy of the -** object and uses it for page cache memory allocations.</dd> +** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is +** a pointer to an [sqlite3_pcache_methods2] object. This object specifies +** the interface to a custom page cache implementation.)^ +** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> ** ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> -** <dd> ^(This option takes a single argument which is a pointer to an -** [sqlite3_pcache_methods2] object. SQLite copies of the current +** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which +** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of the current ** page cache implementation into that object.)^ </dd> ** ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> @@ -1651,10 +1665,10 @@ struct sqlite3_mem_methods { ** function must be threadsafe. </dd> ** ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI -** <dd>^(This option takes a single argument of type int. If non-zero, then -** URI handling is globally enabled. If the parameter is zero, then URI handling -** is globally disabled.)^ ^If URI handling is globally enabled, all filenames -** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or +** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. +** If non-zero, then URI handling is globally enabled. If the parameter is zero, +** then URI handling is globally disabled.)^ ^If URI handling is globally enabled, +** all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or ** specified as part of [ATTACH] commands are interpreted as URIs, regardless ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database ** connection is opened. ^If it is globally disabled, filenames are @@ -1664,9 +1678,10 @@ struct sqlite3_mem_methods { ** [SQLITE_USE_URI] symbol defined.)^ ** ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN -** <dd>^This option takes a single integer argument which is interpreted as -** a boolean in order to enable or disable the use of covering indices for -** full table scans in the query optimizer. ^The default setting is determined +** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer +** argument which is interpreted as a boolean in order to enable or disable +** the use of covering indices for full table scans in the query optimizer. +** ^The default setting is determined ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" ** if that compile-time option is omitted. ** The ability to disable the use of covering indices for full table scans @@ -1706,19 +1721,28 @@ struct sqlite3_mem_methods { ** ^The default setting can be overridden by each database connection using ** either the [PRAGMA mmap_size] command, or by using the ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size -** cannot be changed at run-time. Nor may the maximum allowed mmap size -** exceed the compile-time maximum mmap size set by the +** will be silently truncated if necessary so that it does not exceed the +** compile-time maximum mmap size set by the ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ ** ^If either argument to this option is negative, then that argument is ** changed to its compile-time default. ** ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE -** <dd>^This option is only available if SQLite is compiled for Windows -** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. -** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value +** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is +** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. +** ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value ** that specifies the maximum size of the created heap. ** </dl> +** +** [[SQLITE_CONFIG_PCACHE_HDRSZ]] +** <dt>SQLITE_CONFIG_PCACHE_HDRSZ +** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which +** is a pointer to an integer and writes into that integer the number of extra +** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. The amount of +** extra space required can change depending on the compiler, +** target platform, and SQLite version. +** </dl> */ #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ @@ -1743,6 +1767,7 @@ struct sqlite3_mem_methods { #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ +#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ /* ** CAPI3REF: Database Connection Configuration Options @@ -1870,47 +1895,45 @@ sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); /* ** CAPI3REF: Count The Number Of Rows Modified ** -** ^This function returns the number of database rows that were changed -** or inserted or deleted by the most recently completed SQL statement -** on the [database connection] specified by the first parameter. -** ^(Only changes that are directly specified by the [INSERT], [UPDATE], -** or [DELETE] statement are counted. Auxiliary changes caused by -** triggers or [foreign key actions] are not counted.)^ Use the -** [sqlite3_total_changes()] function to find the total number of changes -** including changes caused by triggers and foreign key actions. -** -** ^Changes to a view that are simulated by an [INSTEAD OF trigger] -** are not counted. Only real table changes are counted. -** -** ^(A "row change" is a change to a single row of a single table -** caused by an INSERT, DELETE, or UPDATE statement. Rows that -** are changed as side effects of [REPLACE] constraint resolution, -** rollback, ABORT processing, [DROP TABLE], or by any other -** mechanisms do not count as direct row changes.)^ -** -** A "trigger context" is a scope of execution that begins and -** ends with the script of a [CREATE TRIGGER | trigger]. -** Most SQL statements are -** evaluated outside of any trigger. This is the "top level" -** trigger context. If a trigger fires from the top level, a -** new trigger context is entered for the duration of that one -** trigger. Subtriggers create subcontexts for their duration. -** -** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does -** not create a new trigger context. -** -** ^This function returns the number of direct row changes in the -** most recent INSERT, UPDATE, or DELETE statement within the same -** trigger context. -** -** ^Thus, when called from the top level, this function returns the -** number of changes in the most recent INSERT, UPDATE, or DELETE -** that also occurred at the top level. ^(Within the body of a trigger, -** the sqlite3_changes() interface can be called to find the number of -** changes in the most recently completed INSERT, UPDATE, or DELETE -** statement within the body of the same trigger. -** However, the number returned does not include changes -** caused by subtriggers since those have their own context.)^ +** ^This function returns the number of rows modified, inserted or +** deleted by the most recently completed INSERT, UPDATE or DELETE +** statement on the database connection specified by the only parameter. +** ^Executing any other type of SQL statement does not modify the value +** returned by this function. +** +** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are +** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], +** [foreign key actions] or [REPLACE] constraint resolution are not counted. +** +** Changes to a view that are intercepted by +** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value +** returned by sqlite3_changes() immediately after an INSERT, UPDATE or +** DELETE statement run on a view is always zero. Only changes made to real +** tables are counted. +** +** Things are more complicated if the sqlite3_changes() function is +** executed while a trigger program is running. This may happen if the +** program uses the [changes() SQL function], or if some other callback +** function invokes sqlite3_changes() directly. Essentially: +** +** <ul> +** <li> ^(Before entering a trigger program the value returned by +** sqlite3_changes() function is saved. After the trigger program +** has finished, the original value is restored.)^ +** +** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE +** statement sets the value returned by sqlite3_changes() +** upon completion as normal. Of course, this value will not include +** any changes performed by sub-triggers, as the sqlite3_changes() +** value will be saved and restored after each sub-trigger has run.)^ +** </ul> +** +** ^This means that if the changes() SQL function (or similar) is used +** by the first INSERT, UPDATE or DELETE statement within a trigger, it +** returns the value as set when the calling statement began executing. +** ^If it is used by the second or subsequent such statement within a trigger +** program, the value returned reflects the number of rows modified by the +** previous INSERT, UPDATE or DELETE statement within the same trigger. ** ** See also the [sqlite3_total_changes()] interface, the ** [count_changes pragma], and the [changes() SQL function]. @@ -1924,20 +1947,17 @@ int sqlite3_changes(sqlite3*); /* ** CAPI3REF: Total Number Of Rows Modified ** -** ^This function returns the number of row changes caused by [INSERT], -** [UPDATE] or [DELETE] statements since the [database connection] was opened. -** ^(The count returned by sqlite3_total_changes() includes all changes -** from all [CREATE TRIGGER | trigger] contexts and changes made by -** [foreign key actions]. However, -** the count does not include changes used to implement [REPLACE] constraints, -** do rollbacks or ABORT processing, or [DROP TABLE] processing. The -** count does not include rows of views that fire an [INSTEAD OF trigger], -** though if the INSTEAD OF trigger makes changes of its own, those changes -** are counted.)^ -** ^The sqlite3_total_changes() function counts the changes as soon as -** the statement that makes them is completed (when the statement handle -** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). -** +** ^This function returns the total number of rows inserted, modified or +** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed +** since the database connection was opened, including those executed as +** part of trigger programs. ^Executing any other type of SQL statement +** does not affect the value returned by sqlite3_total_changes(). +** +** ^Changes made as part of [foreign key actions] are included in the +** count, but those made as part of REPLACE constraint resolution are +** not. ^Changes to a view that are intercepted by INSTEAD OF triggers +** are not counted. +** ** See also the [sqlite3_changes()] interface, the ** [count_changes pragma], and the [total_changes() SQL function]. ** @@ -2415,13 +2435,14 @@ sqlite3_int64 sqlite3_memory_highwater(int resetFlag); ** applications to access the same PRNG for other purposes. ** ** ^A call to this routine stores N bytes of randomness into buffer P. -** ^If N is less than one, then P can be a NULL pointer. +** ^The P parameter can be a NULL pointer. ** ** ^If this routine has not been previously called or if the previous -** call had N less than one, then the PRNG is seeded using randomness -** obtained from the xRandomness method of the default [sqlite3_vfs] object. -** ^If the previous call to this routine had an N of 1 or more then -** the pseudo-randomness is generated +** call had N less than one or a NULL pointer for P, then the PRNG is +** seeded using randomness obtained from the xRandomness method of +** the default [sqlite3_vfs] object. +** ^If the previous call to this routine had an N of 1 or more and a +** non-NULL P then the pseudo-randomness is generated ** internally and without recourse to the [sqlite3_vfs] xRandomness ** method. */ @@ -5636,26 +5657,42 @@ typedef struct sqlite3_blob sqlite3_blob; ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; ** </pre>)^ ** +** ^(Parameter zDb is not the filename that contains the database, but +** rather the symbolic name of the database. For attached databases, this is +** the name that appears after the AS keyword in the [ATTACH] statement. +** For the main database file, the database name is "main". For TEMP +** tables, the database name is "temp".)^ +** ** ^If the flags parameter is non-zero, then the BLOB is opened for read -** and write access. ^If it is zero, the BLOB is opened for read access. -** ^It is not possible to open a column that is part of an index or primary -** key for writing. ^If [foreign key constraints] are enabled, it is -** not possible to open a column that is part of a [child key] for writing. -** -** ^Note that the database name is not the filename that contains -** the database but rather the symbolic name of the database that -** appears after the AS keyword when the database is connected using [ATTACH]. -** ^For the main database file, the database name is "main". -** ^For TEMP tables, the database name is "temp". -** -** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written -** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set -** to be a null pointer.)^ -** ^This function sets the [database connection] error code and message -** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related -** functions. ^Note that the *ppBlob variable is always initialized in a -** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob -** regardless of the success or failure of this routine. +** and write access. ^If the flags parameter is zero, the BLOB is opened for +** read-only access. +** +** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored +** in *ppBlob. Otherwise an [error code] is returned and, unless the error +** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided +** the API is not misused, it is always safe to call [sqlite3_blob_close()] +** on *ppBlob after this function it returns. +** +** This function fails with SQLITE_ERROR if any of the following are true: +** <ul> +** <li> ^(Database zDb does not exist)^, +** <li> ^(Table zTable does not exist within database zDb)^, +** <li> ^(Table zTable is a WITHOUT ROWID table)^, +** <li> ^(Column zColumn does not exist)^, +** <li> ^(Row iRow is not present in the table)^, +** <li> ^(The specified column of row iRow contains a value that is not +** a TEXT or BLOB value)^, +** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE +** constraint and the blob is being opened for read/write access)^, +** <li> ^([foreign key constraints | Foreign key constraints] are enabled, +** column zColumn is part of a [child key] definition and the blob is +** being opened for read/write access)^. +** </ul> +** +** ^Unless it returns SQLITE_MISUSE, this function sets the +** [database connection] error code and message accessible via +** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. +** ** ** ^(If the row that a BLOB handle points to is modified by an ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects @@ -5673,13 +5710,9 @@ typedef struct sqlite3_blob sqlite3_blob; ** interface. Use the [UPDATE] SQL command to change the size of a ** blob. ** -** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] -** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. -** ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces -** and the built-in [zeroblob] SQL function can be used, if desired, -** to create an empty, zero-filled blob in which to read or write using -** this interface. +** and the built-in [zeroblob] SQL function may be used to create a +** zero-filled blob to read or write using the incremental-blob interface. ** ** To avoid a resource leak, every open [BLOB handle] should eventually ** be released by a call to [sqlite3_blob_close()]. @@ -5721,24 +5754,22 @@ SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); /* ** CAPI3REF: Close A BLOB Handle ** -** ^Closes an open [BLOB handle]. -** -** ^Closing a BLOB shall cause the current transaction to commit -** if there are no other BLOBs, no pending prepared statements, and the -** database connection is in [autocommit mode]. -** ^If any writes were made to the BLOB, they might be held in cache -** until the close operation if they will fit. +** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed +** unconditionally. Even if this routine returns an error code, the +** handle is still closed.)^ ** -** ^(Closing the BLOB often forces the changes -** out to disk and so if any I/O errors occur, they will likely occur -** at the time when the BLOB is closed. Any errors that occur during -** closing are reported as a non-zero return value.)^ +** ^If the blob handle being closed was opened for read-write access, and if +** the database is in auto-commit mode and there are no other open read-write +** blob handles or active write statements, the current transaction is +** committed. ^If an error occurs while committing the transaction, an error +** code is returned and the transaction rolled back. ** -** ^(The BLOB is closed unconditionally. Even if this routine returns -** an error code, the BLOB is still closed.)^ -** -** ^Calling this routine with a null pointer (such as would be returned -** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. +** Calling this function with an argument that is not a NULL pointer or an +** open blob handle results in undefined behaviour. ^Calling this routine +** with a null pointer (such as would be returned by a failed call to +** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function +** is passed a valid open blob handle, the values returned by the +** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. */ int sqlite3_blob_close(sqlite3_blob *); @@ -5788,21 +5819,27 @@ int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); /* ** CAPI3REF: Write Data Into A BLOB Incrementally ** -** ^This function is used to write data into an open [BLOB handle] from a -** caller-supplied buffer. ^N bytes of data are copied from the buffer Z -** into the open BLOB, starting at offset iOffset. +** ^(This function is used to write data into an open [BLOB handle] from a +** caller-supplied buffer. N bytes of data are copied from the buffer Z +** into the open BLOB, starting at offset iOffset.)^ +** +** ^(On success, sqlite3_blob_write() returns SQLITE_OK. +** Otherwise, an [error code] or an [extended error code] is returned.)^ +** ^Unless SQLITE_MISUSE is returned, this function sets the +** [database connection] error code and message accessible via +** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. ** ** ^If the [BLOB handle] passed as the first argument was not opened for ** writing (the flags parameter to [sqlite3_blob_open()] was zero), ** this function returns [SQLITE_READONLY]. ** -** ^This function may only modify the contents of the BLOB; it is +** This function may only modify the contents of the BLOB; it is ** not possible to increase the size of a BLOB using this API. ** ^If offset iOffset is less than N bytes from the end of the BLOB, -** [SQLITE_ERROR] is returned and no data is written. ^If N is -** less than zero [SQLITE_ERROR] is returned and no data is written. -** The size of the BLOB (and hence the maximum value of N+iOffset) -** can be determined using the [sqlite3_blob_bytes()] interface. +** [SQLITE_ERROR] is returned and no data is written. The size of the +** BLOB (and hence the maximum value of N+iOffset) can be determined +** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less +** than zero [SQLITE_ERROR] is returned and no data is written. ** ** ^An attempt to write to an expired [BLOB handle] fails with an ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred @@ -5811,9 +5848,6 @@ int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); ** have been overwritten by the statement that expired the BLOB handle ** or by other independent statements. ** -** ^(On success, sqlite3_blob_write() returns SQLITE_OK. -** Otherwise, an [error code] or an [extended error code] is returned.)^ -** ** This routine only works on a [BLOB handle] which has been created ** by a prior successful call to [sqlite3_blob_open()] and which has not ** been closed by [sqlite3_blob_close()]. Passing any other pointer in @@ -6814,6 +6848,10 @@ typedef struct sqlite3_backup sqlite3_backup; ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with ** an error. ** +** ^A call to sqlite3_backup_init() will fail, returning SQLITE_ERROR, if +** there is already a read or read-write transaction open on the +** destination database. +** ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is ** returned and an error code and error message are stored in the ** destination [database connection] D. @@ -7406,6 +7444,98 @@ int sqlite3_vtab_on_conflict(sqlite3 *); /* #define SQLITE_ABORT 4 // Also an error code */ #define SQLITE_REPLACE 5 +/* +** CAPI3REF: Prepared Statement Scan Status Opcodes +** KEYWORDS: {scanstatus options} +** +** The following constants can be used for the T parameter to the +** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a +** different metric for sqlite3_stmt_scanstatus() to return. +** +** <dl> +** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> +** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the +** total number of times that the X-th loop has run.</dd> +** +** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> +** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the +** total number of rows examined by all iterations of the X-th loop.</dd> +** +** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> +** <dd>^The "double" variable pointed to by the T parameter will be set to the +** query planner's estimate for the average number of rows output from each +** iteration of the X-th loop. If the query planner's estimates was accurate, +** then this value will approximate the quotient NVISIT/NLOOP and the +** product of this value for all prior loops with the same SELECTID will +** be the NLOOP value for the current loop. +** +** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> +** <dd>^The "const char *" variable pointed to by the T parameter will be set to +** a zero-terminated UTF-8 string containing the name of the index or table used +** for the X-th loop. +** +** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> +** <dd>^The "const char *" variable pointed to by the T parameter will be set to +** a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] description +** for the X-th loop. +** +** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> +** <dd>^The "int" variable pointed to by the T parameter will be set to the +** "select-id" for the X-th loop. The select-id identifies which query or +** subquery the loop is part of. The main query has a select-id of zero. +** The select-id is the same value as is output in the first column +** of an [EXPLAIN QUERY PLAN] query. +** </dl> +*/ +#define SQLITE_SCANSTAT_NLOOP 0 +#define SQLITE_SCANSTAT_NVISIT 1 +#define SQLITE_SCANSTAT_EST 2 +#define SQLITE_SCANSTAT_NAME 3 +#define SQLITE_SCANSTAT_EXPLAIN 4 +#define SQLITE_SCANSTAT_SELECTID 5 + +/* +** CAPI3REF: Prepared Statement Scan Status +** +** Return status data for a single loop within query pStmt. +** +** The "iScanStatusOp" parameter determines which status information to return. +** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior of +** this interface is undefined. +** ^The requested measurement is written into a variable pointed to by +** the "pOut" parameter. +** Parameter "idx" identifies the specific loop to retrieve statistics for. +** Loops are numbered starting from zero. ^If idx is out of range - less than +** zero or greater than or equal to the total number of loops used to implement +** the statement - a non-zero value is returned and the variable that pOut +** points to is unchanged. +** +** ^Statistics might not be available for all loops in all statements. ^In cases +** where there exist loops with no available statistics, this function behaves +** as if the loop did not exist - it returns non-zero and leave the variable +** that pOut points to unchanged. +** +** This API is only available if the library is built with pre-processor +** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. +** +** See also: [sqlite3_stmt_scanstatus_reset()] +*/ +SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus( + sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ + int idx, /* Index of loop to report on */ + int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ + void *pOut /* Result written here */ +); + +/* +** CAPI3REF: Zero Scan-Status Counters +** +** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. +** +** This API is only available if the library is built with pre-processor +** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. +*/ +SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); /* |