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sqlite3.h：源码内容

** or until [sqlite3_finalize(S)] is called.
**
** {F13727} When a result column of a [SELECT] statement contains
** an AS clause, the name of that column is the indentifier
** to the right of the AS keyword.
*/
const char *sqlite3_column_name(sqlite3_stmt*, int N);
const void *sqlite3_column_name16(sqlite3_stmt*, int N);
/*
** CAPI3REF: Source Of Data In A Query Result {F13740}
**
** These routines provide a means to determine what column of what
** table in which database a result of a SELECT statement comes from.
** The name of the database or table or column can be returned as
** either a UTF8 or UTF16 string. The _database_ routines return
** the database name, the _table_ routines return the table name, and
** the origin_ routines return the column name.
** The returned string is valid until
** the [prepared statement] is destroyed using
** [sqlite3_finalize()] or until the same information is requested
** again in a different encoding.
**
** The names returned are the original un-aliased names of the
** database, table, and column.
**
** The first argument to the following calls is a [prepared statement].
** These functions return information about the Nth column returned by
** the statement, where N is the second function argument.
**
** If the Nth column returned by the statement is an expression
** or subquery and is not a column value, then all of these functions
** return NULL. These routine might also return NULL if a memory
** allocation error occurs. Otherwise, they return the
** name of the attached database, table and column that query result
** column was extracted from.
**
** As with all other SQLite APIs, those postfixed with "16" return
** UTF-16 encoded strings, the other functions return UTF-8. {END}
**
** These APIs are only available if the library was compiled with the
** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
**
** {U13751}
** If two or more threads call one or more of these routines against the same
** prepared statement and column at the same time then the results are
** undefined.
**
** INVARIANTS:
**
** {F13741} The [sqlite3_column_database_name(S,N)] interface returns either
** the UTF-8 zero-terminated name of the database from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13742} The [sqlite3_column_database_name16(S,N)] interface returns either
** the UTF-16 native byte order
** zero-terminated name of the database from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13743} The [sqlite3_column_table_name(S,N)] interface returns either
** the UTF-8 zero-terminated name of the table from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13744} The [sqlite3_column_table_name16(S,N)] interface returns either
** the UTF-16 native byte order
** zero-terminated name of the table from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13745} The [sqlite3_column_origin_name(S,N)] interface returns either
** the UTF-8 zero-terminated name of the table column from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13746} The [sqlite3_column_origin_name16(S,N)] interface returns either
** the UTF-16 native byte order
** zero-terminated name of the table column from which the
** Nth result column of [prepared statement] S
** is extracted, or NULL if the the Nth column of S is a
** general expression or if unable to allocate memory
** to store the name.
**
** {F13748} The return values from
** [sqlite3_column_database_name|column metadata interfaces]
** are valid
** for the lifetime of the [prepared statement]
** or until the encoding is changed by another metadata
** interface call for the same prepared statement and column.
**
** LIMITATIONS:
**
** {U13751} If two or more threads call one or more
** [sqlite3_column_database_name|column metadata interfaces]
** the same [prepared statement] and result column
** at the same time then the results are undefined.
*/
const char *sqlite3_column_database_name(sqlite3_stmt*,int);
const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
const char *sqlite3_column_table_name(sqlite3_stmt*,int);
const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
/*
** CAPI3REF: Declared Datatype Of A Query Result {F13760}
**
** The first parameter is a [prepared statement].
** If this statement is a SELECT statement and the Nth column of the
** returned result set of that SELECT is a table column (not an
** expression or subquery) then the declared type of the table
** column is returned. If the Nth column of the result set is an
** expression or subquery, then a NULL pointer is returned.
** The returned string is always UTF-8 encoded. {END}
** For example, in the database schema:
**
** CREATE TABLE t1(c1 VARIANT);
**
** And the following statement compiled:
**
** SELECT c1 + 1, c1 FROM t1;
**
** Then this routine would return the string "VARIANT" for the second
** result column (i==1), and a NULL pointer for the first result column
** (i==0).
**
** SQLite uses dynamic run-time typing. So just because a column
** is declared to contain a particular type does not mean that the
** data stored in that column is of the declared type. SQLite is
** strongly typed, but the typing is dynamic not static. Type
** is associated with individual values, not with the containers
** used to hold those values.
**
** INVARIANTS:
**
** {F13761} A successful call to [sqlite3_column_decltype(S,N)]
** returns a zero-terminated UTF-8 string containing the
** the declared datatype of the table column that appears
** as the Nth column (numbered from 0) of the result set to the
** [prepared statement] S.
**
** {F13762} A successful call to [sqlite3_column_decltype16(S,N)]
** returns a zero-terminated UTF-16 native byte order string
** containing the declared datatype of the table column that appears
** as the Nth column (numbered from 0) of the result set to the
** [prepared statement] S.
**
** {F13763} If N is less than 0 or N is greater than or equal to
** the number of columns in [prepared statement] S
** or if the Nth column of S is an expression or subquery rather
** than a table column or if a memory allocation failure
** occurs during encoding conversions, then
** calls to [sqlite3_column_decltype(S,N)] or
** [sqlite3_column_decltype16(S,N)] return NULL.
*/
const char *sqlite3_column_decltype(sqlite3_stmt*,int);
const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
/*
** CAPI3REF: Evaluate An SQL Statement {F13200}
**
** After an [prepared statement] has been prepared with a call
** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
** then this function must be called one or more times to evaluate the
** statement.
**
** The details of the behavior of this sqlite3_step() interface depend
** on whether the statement was prepared using the newer "v2" interface
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
** new "v2" interface is recommended for new applications but the legacy
** interface will continue to be supported.
**
** In the lagacy interface, the return value will be either [SQLITE_BUSY],
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
** With the "v2" interface, any of the other [SQLITE_OK | result code]
** or [SQLITE_IOERR_READ | extended result code] might be returned as
** well.
**
** [SQLITE_BUSY] means that the database engine was unable to acquire the
** database locks it needs to do its job. If the statement is a COMMIT
** or occurs outside of an explicit transaction, then you can retry the
** statement. If the statement is not a COMMIT and occurs within a
** explicit transaction then you should rollback the transaction before
** continuing.
**
** [SQLITE_DONE] means that the statement has finished executing
** successfully. sqlite3_step() should not be called again on this virtual
** machine without first calling [sqlite3_reset()] to reset the virtual
** machine back to its initial state.
**
** If the SQL statement being executed returns any data, then
** [SQLITE_ROW] is returned each time a new row of data is ready
** for processing by the caller. The values may be accessed using
** the [sqlite3_column_int | column access functions].
** sqlite3_step() is called again to retrieve the next row of data.
**
** [SQLITE_ERROR] means that a run-time error (such as a constraint
** violation) has occurred. sqlite3_step() should not be called again on
** the VM. More information may be found by calling [sqlite3_errmsg()].
** With the legacy interface, a more specific error code (example:
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
** can be obtained by calling [sqlite3_reset()] on the
** [prepared statement]. In the "v2" interface,
** the more specific error code is returned directly by sqlite3_step().
**
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
** Perhaps it was called on a [prepared statement] that has
** already been [sqlite3_finalize | finalized] or on one that had
** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
** be the case that the same database connection is being used by two or
** more threads at the same moment in time.
**
** Goofy Interface Alert:
** In the legacy interface,
** the sqlite3_step() API always returns a generic error code,
** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
** and [SQLITE_MISUSE]. You must call [sqlite3_reset()] or
** [sqlite3_finalize()] in order to find one of the specific
** [error codes] that better describes the error.
** We admit that this is a goofy design. The problem has been fixed
** with the "v2" interface. If you prepare all of your SQL statements
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the
** more specific [error codes] are returned directly
** by sqlite3_step(). The use of the "v2" interface is recommended.
**
** INVARIANTS:
**
** {F13202} If [prepared statement] S is ready to be
** run, then [sqlite3_step(S)] advances that prepared statement
** until to completion or until it is ready to return another
** row of the result set or an interrupt or run-time error occurs.
**
** {F15304} When a call to [sqlite3_step(S)] causes the
** [prepared statement] S to run to completion,
** the function returns [SQLITE_DONE].
**
** {F15306} When a call to [sqlite3_step(S)] stops because it is ready
** to return another row of the result set, it returns
** [SQLITE_ROW].
**
** {F15308} If a call to [sqlite3_step(S)] encounters an
** [sqlite3_interrupt|interrupt] or a run-time error,
** it returns an appropraite error code that is not one of
** [SQLITE_OK], [SQLITE_ROW], or [SQLITE_DONE].
**
** {F15310} If an [sqlite3_interrupt|interrupt] or run-time error
** occurs during a call to [sqlite3_step(S)]
** for a [prepared statement] S created using
** legacy interfaces [sqlite3_prepare()] or
** [sqlite3_prepare16()] then the function returns either
** [SQLITE_ERROR], [SQLITE_BUSY], or [SQLITE_MISUSE].
*/
int sqlite3_step(sqlite3_stmt*);
/*
** CAPI3REF: Number of columns in a result set {F13770}
**
** Return the number of values in the current row of the result set.
**
** INVARIANTS:
**
** {F13771} After a call to [sqlite3_step(S)] that returns
** [SQLITE_ROW], the [sqlite3_data_count(S)] routine
** will return the same value as the
** [sqlite3_column_count(S)] function.
**
** {F13772} After [sqlite3_step(S)] has returned any value other than
** [SQLITE_ROW] or before [sqlite3_step(S)] has been
** called on the [prepared statement] for
** the first time since it was [sqlite3_prepare|prepared]
** or [sqlite3_reset|reset], the [sqlite3_data_count(S)]
** routine returns zero.
*/
int sqlite3_data_count(sqlite3_stmt *pStmt);
/*
** CAPI3REF: Fundamental Datatypes {F10265}
** KEYWORDS: SQLITE_TEXT
**
** {F10266}Every value in SQLite has one of five fundamental datatypes:
**
** <ul>
** <li> 64-bit signed integer
** <li> 64-bit IEEE floating point number
** <li> string
** <li> BLOB
** <li> NULL
** </ul> {END}
**
** These constants are codes for each of those types.
**
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
** for a completely different meaning. Software that links against both
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
** SQLITE_TEXT.
*/
#define SQLITE_INTEGER 1
#define SQLITE_FLOAT 2
#define SQLITE_BLOB 4
#define SQLITE_NULL 5
#ifdef SQLITE_TEXT
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT 3
#endif
#define SQLITE3_TEXT 3
/*
** CAPI3REF: Results Values From A Query {F13800}
**
** These routines form the "result set query" interface.
**
** These routines return information about
** a single column of the current result row of a query. In every
** case the first argument is a pointer to the
** [prepared statement] that is being
** evaluated (the [sqlite3_stmt*] that was returned from
** [sqlite3_prepare_v2()] or one of its variants) and
** the second argument is the index of the column for which information
** should be returned. The left-most column of the result set
** has an index of 0.
**
** If the SQL statement is not currently point to a valid row, or if the
** the column index is out of range, the result is undefined.
** These routines may only be called when the most recent call to
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently.
** If any of these routines are called after [sqlite3_reset()] or
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
** something other than [SQLITE_ROW], the results are undefined.
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
** are called from a different thread while any of these routines
** are pending, then the results are undefined.
**
** The sqlite3_column_type() routine returns
** [SQLITE_INTEGER | datatype code] for the initial data type
** of the result column. The returned value is one of [SQLITE_INTEGER],
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
** returned by sqlite3_column_type() is only meaningful if no type
** conversions have occurred as described below. After a type conversion,
** the value returned by sqlite3_column_type() is undefined. Future
** versions of SQLite may change the behavior of sqlite3_column_type()
** following a type conversion.
**
** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
** routine returns the number of bytes in that BLOB or string.
** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
** the string to UTF-8 and then returns the number of bytes.
** If the result is a numeric value then sqlite3_column_bytes() uses
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
** the number of bytes in that string.
** The value returned does not include the zero terminator at the end
** of the string. For clarity: the value returned is the number of
** bytes in the string, not the number of characters.
**
** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
** even empty strings, are always zero terminated. The return
** value from sqlite3_column_blob() for a zero-length blob is an arbitrary
** pointer, possibly even a NULL pointer.
**
** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
** but leaves the result in UTF-16 in native byte order instead of UTF-8.
** The zero terminator is not included in this count.
**
** The object returned by [sqlite3_column_value()] is an
** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
** If the [unprotected sqlite3_value] object returned by
** [sqlite3_column_value()] is used in any other way, including calls
** to routines like
** [sqlite3_value_int()], [sqlite3_value_text()], or [sqlite3_value_bytes()],
** then the behavior is undefined.
**
** These routines attempt to convert the value where appropriate. For
** example, if the internal representation is FLOAT and a text result
** is requested, [sqlite3_snprintf()] is used internally to do the conversion
** automatically. The following table details the conversions that
** are applied:
**
** <blockquote>
** <table border="1">
** <tr><th> Internal Type <th> Requested Type <th> Conversion
**
** <tr><td> NULL <td> INTEGER <td> Result is 0
** <tr><td> NULL <td> FLOAT <td> Result is 0.0
** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
** <tr><td> INTEGER <td> BLOB <td> Same as for INTEGER->TEXT
** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
** <tr><td> TEXT <td> INTEGER <td> Use atoi()
** <tr><td> TEXT <td> FLOAT <td> Use atof()
** <tr><td> TEXT <td> BLOB <td> No change
** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
** </table>
** </blockquote>
**
** The table above makes reference to standard C library functions atoi()
** and atof(). SQLite does not really use these functions. It has its
** on equavalent internal routines. The atoi() and atof() names are
** used in the table for brevity and because they are familiar to most
** C programmers.
**
** Note that when type conversions occur, pointers returned by prior
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
** sqlite3_column_text16() may be invalidated.
** Type conversions and pointer invalidations might occur
** in the following cases:
**
** <ul>
** <li> The initial content is a BLOB and sqlite3_column_text()
** or sqlite3_column_text16() is called. A zero-terminator might
** need to be added to the string.</li>
**
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
** sqlite3_column_text16() is called. The content must be converted
** to UTF-16.</li>
**
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
** sqlite3_column_text() is called. The content must be converted
** to UTF-8.</li>
** </ul>
**
** Conversions between UTF-16be and UTF-16le are always done in place and do
** not invalidate a prior pointer, though of course the content of the buffer
** that the prior pointer points to will have been modified. Other kinds
** of conversion are done in place when it is possible, but sometime it is
** not possible and in those cases prior pointers are invalidated.
**
** The safest and easiest to remember policy is to invoke these routines
** in one of the following ways:
**
** <ul>
** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
** </ul>
**
** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
** or sqlite3_column_text16() first to force the result into the desired
** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
** find the size of the result. Do not mix call to sqlite3_column_text() or
** sqlite3_column_blob() with calls to sqlite3_column_bytes16(). And do not
** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
**
** The pointers returned are valid until a type conversion occurs as
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
** [sqlite3_finalize()] is called. The memory space used to hold strings
** and blobs is freed automatically. Do not pass the pointers returned
** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
** [sqlite3_free()].
**
** If a memory allocation error occurs during the evaluation of any
** of these routines, a default value is returned. The default value
** is either the integer 0, the floating point number 0.0, or a NULL
** pointer. Subsequent calls to [sqlite3_errcode()] will return
** [SQLITE_NOMEM].
**
** INVARIANTS:
**
** {F13803} The [sqlite3_column_blob(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a blob and then returns a
** pointer to the converted value.
**
** {F13806} The [sqlite3_column_bytes(S,N)] interface returns the
** number of bytes in the blob or string (exclusive of the
** zero terminator on the string) that was returned by the
** most recent call to [sqlite3_column_blob(S,N)] or
** [sqlite3_column_text(S,N)].
**
** {F13809} The [sqlite3_column_bytes16(S,N)] interface returns the
** number of bytes in the string (exclusive of the
** zero terminator on the string) that was returned by the
** most recent call to [sqlite3_column_text16(S,N)].
**
** {F13812} The [sqlite3_column_double(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a floating point value and
** returns a copy of that value.
**
** {F13815} The [sqlite3_column_int(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a 64-bit signed integer and
** returns the lower 32 bits of that integer.
**
** {F13818} The [sqlite3_column_int64(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a 64-bit signed integer and
** returns a copy of that integer.
**
** {F13821} The [sqlite3_column_text(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a zero-terminated UTF-8
** string and returns a pointer to that string.
**
** {F13824} The [sqlite3_column_text16(S,N)] interface converts the
** Nth column in the current row of the result set for
** [prepared statement] S into a zero-terminated 2-byte
** aligned UTF-16 native byte order
** string and returns a pointer to that string.
**
** {F13827} The [sqlite3_column_type(S,N)] interface returns
** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
** the Nth column in the current row of the result set for
** [prepared statement] S.
**
** {F13830} The [sqlite3_column_value(S,N)] interface returns a
** pointer to an [unprotected sqlite3_value] object for the
** Nth column in the current row of the result set for
** [prepared statement] S.
*/
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);
int sqlite3_column_int(sqlite3_stmt*, int iCol);
sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
int sqlite3_column_type(sqlite3_stmt*, int iCol);
sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
/*
** CAPI3REF: Destroy A Prepared Statement Object {F13300}
**
** The sqlite3_finalize() function is called to delete a
** [prepared statement]. If the statement was
** executed successfully, or not executed at all, then SQLITE_OK is returned.
** If execution of the statement failed then an
** [error code] or [extended error code]
** is returned.
**
** This routine can be called at any point during the execution of the
** [prepared statement]. If the virtual machine has not
** completed execution when this routine is called, that is like
** encountering an error or an interrupt. (See [sqlite3_interrupt()].)
** Incomplete updates may be rolled back and transactions cancelled,
** depending on the circumstances, and the
** [error code] returned will be [SQLITE_ABORT].
**
** INVARIANTS:
**
** {F11302} The [sqlite3_finalize(S)] interface destroys the
** [prepared statement] S and releases all
** memory and file resources held by that object.
**
** {F11304} If the most recent call to [sqlite3_step(S)] for the
** [prepared statement] S returned an error,
** then [sqlite3_finalize(S)] returns that same error.
*/
int sqlite3_finalize(sqlite3_stmt *pStmt);
/*
** CAPI3REF: Reset A Prepared Statement Object {F13330}
**
** The sqlite3_reset() function is called to reset a
** [prepared statement] object.
** back to its initial state, ready to be re-executed.
** Any SQL statement variables that had values bound to them using
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
** Use [sqlite3_clear_bindings()] to reset the bindings.
**
** {F11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S
** back to the beginning of its program.
**
** {F11334} If the most recent call to [sqlite3_step(S)] for
** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
** or if [sqlite3_step(S)] has never before been called on S,
** then [sqlite3_reset(S)] returns [SQLITE_OK].
**
** {F11336} If the most recent call to [sqlite3_step(S)] for
** [prepared statement] S indicated an error, then
** [sqlite3_reset(S)] returns an appropriate [error code].
**
** {F11338} The [sqlite3_reset(S)] interface does not change the values
** of any [sqlite3_bind_blob|bindings] on [prepared statement] S.
*/
int sqlite3_reset(sqlite3_stmt *pStmt);
/*
** CAPI3REF: Create Or Redefine SQL Functions {F16100}
** KEYWORDS: {function creation routines}
**
** These two functions (collectively known as
** "function creation routines") are used to add SQL functions or aggregates
** or to redefine the behavior of existing SQL functions or aggregates. The
** difference only between the two is that the second parameter, the
** name of the (scalar) function or aggregate, is encoded in UTF-8 for
** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
**
** The first parameter is the [database connection] to which the SQL
** function is to be added. If a single
** program uses more than one [database connection] internally, then SQL
** functions must be added individually to each [database connection].
**
** The second parameter is the name of the SQL function to be created
** or redefined.
** The length of the name is limited to 255 bytes, exclusive of the
** zero-terminator. Note that the name length limit is in bytes, not
** characters. Any attempt to create a function with a longer name
** will result in an SQLITE_ERROR error.
**
** The third parameter is the number of arguments that the SQL function or
** aggregate takes. If this parameter is negative, then the SQL function or
** aggregate may take any number of arguments.
**
** The fourth parameter, eTextRep, specifies what
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
** its parameters. Any SQL function implementation should be able to work
** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
** more efficient with one encoding than another. It is allowed to
** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
** times with the same function but with different values of eTextRep.
** When multiple implementations of the same function are available, SQLite
** will pick the one that involves the least amount of data conversion.
** If there is only a single implementation which does not care what
** text encoding is used, then the fourth argument should be
** [SQLITE_ANY].
**
** The fifth parameter is an arbitrary pointer. The implementation
** of the function can gain access to this pointer using
** [sqlite3_user_data()].
**
** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL
** function or aggregate. A scalar SQL function requires an implementation of
** the xFunc callback only, NULL pointers should be passed as the xStep
** and xFinal parameters. An aggregate SQL function requires an implementation
** of xStep and xFinal and NULL should be passed for xFunc. To delete an
** existing SQL function or aggregate, pass NULL for all three function
** callback.
**
** It is permitted to register multiple implementations of the same
** functions with the same name but with either differing numbers of
** arguments or differing perferred text encodings. SQLite will use
** the implementation most closely matches the way in which the
** SQL function is used.
**
** INVARIANTS:
**
** {F16103} The [sqlite3_create_function16()] interface behaves exactly
** like [sqlite3_create_function()] in every way except that it
** interprets the zFunctionName argument as
** zero-terminated UTF-16 native byte order instead of as a
** zero-terminated UTF-8.
**
** {F16106} A successful invocation of
** the [sqlite3_create_function(D,X,N,E,...)] interface registers
** or replaces callback functions in [database connection] D
** used to implement the SQL function named X with N parameters
** and having a perferred text encoding of E.
**
** {F16109} A successful call to [sqlite3_create_function(D,X,N,E,P,F,S,L)]
** replaces the P, F, S, and L values from any prior calls with
** the same D, X, N, and E values.
**
** {F16112} The [sqlite3_create_function(D,X,...)] interface fails with
** a return code of [SQLITE_ERROR] if the SQL function name X is
** longer than 255 bytes exclusive of the zero terminator.
**
** {F16118} Either F must be NULL and S and L are non-NULL or else F
** is non-NULL and S and L are NULL, otherwise
** [sqlite3_create_function(D,X,N,E,P,F,S,L)] returns [SQLITE_ERROR].
**
** {F16121} The [sqlite3_create_function(D,...)] interface fails with an
** error code of [SQLITE_BUSY] if there exist [prepared statements]
** associated with the [database connection] D.
**
** {F16124} The [sqlite3_create_function(D,X,N,...)] interface fails with an
** error code of [SQLITE_ERROR] if parameter N (specifying the number
** of arguments to the SQL function being registered) is less
** than -1 or greater than 127.
**
** {F16127} When N is non-negative, the [sqlite3_create_function(D,X,N,...)]
** interface causes callbacks to be invoked for the SQL function
** named X when the number of arguments to the SQL function is
** exactly N.
**
** {F16130} When N is -1, the [sqlite3_create_function(D,X,N,...)]
** interface causes callbacks to be invoked for the SQL function
** named X with any number of arguments.
**
** {F16133} When calls to [sqlite3_create_function(D,X,N,...)]
** specify multiple implementations of the same function X
** and when one implementation has N>=0 and the other has N=(-1)
** the implementation with a non-zero N is preferred.
**
** {F16136} When calls to [sqlite3_create_function(D,X,N,E,...)]
** specify multiple implementations of the same function X with
** the same number of arguments N but with different
** encodings E, then the implementation where E matches the
** database encoding is preferred.
**
** {F16139} For an aggregate SQL function created using
** [sqlite3_create_function(D,X,N,E,P,0,S,L)] the finializer
** function L will always be invoked exactly once if the
** step function S is called one or more times.
**
** {F16142} When SQLite invokes either the xFunc or xStep function of
** an application-defined SQL function or aggregate created
** by [sqlite3_create_function()] or [sqlite3_create_function16()],
** then the array of [sqlite3_value] objects passed as the
** third parameter are always [protected sqlite3_value] objects.
*/
int sqlite3_create_function(
sqlite3 *db,
const char *zFunctionName,
int nArg,
int eTextRep,
void *pApp,
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
void (*xFinal)(sqlite3_context*)
);
int sqlite3_create_function16(
sqlite3 *db,
const void *zFunctionName,
int nArg,
int eTextRep,
void *pApp,
void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
void (*xStep)(sqlite3_context*,int,sqlite3_value**),
void (*xFinal)(sqlite3_context*)
);
/*
** CAPI3REF: Text Encodings {F10267}
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8 1
#define SQLITE_UTF16LE 2
#define SQLITE_UTF16BE 3
#define SQLITE_UTF16 4 /* Use native byte order */
#define SQLITE_ANY 5 /* sqlite3_create_function only */
#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
/*
** CAPI3REF: Obsolete Functions
**
** These functions are all now obsolete. In order to maintain
** backwards compatibility with older code, we continue to support
** these functions. However, new development projects should avoid
** the use of these functions. To help encourage people to avoid
** using these functions, we are not going to tell you want they do.
*/
int sqlite3_aggregate_count(sqlite3_context*);
int sqlite3_expired(sqlite3_stmt*);
int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
int sqlite3_global_recover(void);
void sqlite3_thread_cleanup(void);
int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
/*
** CAPI3REF: Obtaining SQL Function Parameter Values {F15100}
**
** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
** define callbacks that implement the SQL functions and aggregates.
** The 4th parameter to these callbacks is an array of pointers to
** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
** each parameter to the SQL function. These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** These routines work just like the corresponding
** [sqlite3_column_blob | sqlite3_column_* routines] except that
** these routines take a single [protected sqlite3_value] object pointer
** instead of an [sqlite3_stmt*] pointer and an integer column number.
**
** The sqlite3_value_text16() interface extracts a UTF16 string
** in the native byte-order of the host machine. The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF16 strings as big-endian and little-endian respectively.
**
** The sqlite3_value_numeric_type() interface attempts to apply
** numeric affinity to the value. This means that an attempt is
** made to convert the value to an integer or floating point. If
** such a conversion is possible without loss of information (in other
** words if the value is a string that looks like a number)
** then the conversion is done. Otherwise no conversion occurs. The
** [SQLITE_INTEGER | datatype] after conversion is returned.
**
** Please pay particular attention to the fact that the pointer that
** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].
**
** These routines must be called from the same thread as
** the SQL function that supplied the [sqlite3_value*] parameters.
**
**
** INVARIANTS:
**
** {F15103} The [sqlite3_value_blob(V)] interface converts the
** [protected sqlite3_value] object V into a blob and then returns a
** pointer to the converted value.
**
** {F15106} The [sqlite3_value_bytes(V)] interface returns the
** number of bytes in the blob or string (exclusive of the
** zero terminator on the string) that was returned by the
** most recent call to [sqlite3_value_blob(V)] or
** [sqlite3_value_text(V)].
**
** {F15109} The [sqlite3_value_bytes16(V)] interface returns the
** number of bytes in the string (exclusive of the
** zero terminator on the string) that was returned by the
** most recent call to [sqlite3_value_text16(V)],
** [sqlite3_value_text16be(V)], or [sqlite3_value_text16le(V)].
**
** {F15112} The [sqlite3_value_double(V)] interface converts the
** [protected sqlite3_value] object V into a floating point value and
** returns a copy of that value.
**
** {F15115} The [sqlite3_value_int(V)] interface converts the
** [protected sqlite3_value] object V into a 64-bit signed integer and
** returns the lower 32 bits of that integer.
**
** {F15118} The [sqlite3_value_int64(V)] interface converts the
** [protected sqlite3_value] object V into a 64-bit signed integer and
** returns a copy of that integer.
**
** {F15121} The [sqlite3_value_text(V)] interface converts the
** [protected sqlite3_value] object V into a zero-terminated UTF-8
** string and returns a pointer to that string.
**
** {F15124} The [sqlite3_value_text16(V)] interface converts the
** [protected sqlite3_value] object V into a zero-terminated 2-byte
** aligned UTF-16 native byte order
** string and returns a pointer to that string.
**
** {F15127} The [sqlite3_value_text16be(V)] interface converts the
** [protected sqlite3_value] object V into a zero-terminated 2-byte
** aligned UTF-16 big-endian
** string and returns a pointer to that string.
**
** {F15130} The [sqlite3_value_text16le(V)] interface converts the
** [protected sqlite3_value] object V into a zero-terminated 2-byte
** aligned UTF-16 little-endian
** string and returns a pointer to that string.
**
** {F15133} The [sqlite3_value_type(V)] interface returns
** one of [SQLITE_NULL], [SQLITE_INTEGER], [SQLITE_FLOAT],
** [SQLITE_TEXT], or [SQLITE_BLOB] as appropriate for
** the [sqlite3_value] object V.
**
** {F15136} The [sqlite3_value_numeric_type(V)] interface converts
** the [protected sqlite3_value] object V into either an integer or
** a floating point value if it can do so without loss of
** information, and returns one of [SQLITE_NULL],
** [SQLITE_INTEGER], [SQLITE_FLOAT], [SQLITE_TEXT], or
** [SQLITE_BLOB] as appropriate for
** the [protected sqlite3_value] object V after the conversion attempt.
*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);
/*
** CAPI3REF: Obtain Aggregate Function Context {F16210}
**
** The implementation of aggregate SQL functions use this routine to allocate
** a structure for storing their state.
** The first time the sqlite3_aggregate_context() routine is
** is called for a particular aggregate, SQLite allocates nBytes of memory
** zeros that memory, and returns a pointer to it.
** On second and subsequent calls to sqlite3_aggregate_context()
** for the same aggregate function index, the same buffer is returned.
** The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** SQLite automatically frees the allocated buffer when the aggregate
** query concludes.
**
** The first parameter should be a copy of the
** [sqlite3_context | SQL function context] that is the first
** parameter to the callback routine that implements the aggregate
** function.
**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.
**
** INVARIANTS:
**
** {F16211} The first invocation of [sqlite3_aggregate_context(C,N)] for
** a particular instance of an aggregate function (for a particular
** context C) causes SQLite to allocation N bytes of memory,
** zero that memory, and return a pointer to the allocationed
** memory.
**
** {F16213} If a memory allocation error occurs during
** [sqlite3_aggregate_context(C,N)] then the function returns 0.
**
** {F16215} Second and subsequent invocations of
** [sqlite3_aggregate_context(C,N)] for the same context pointer C
** ignore the N parameter and return a pointer to the same
** block of memory returned by the first invocation.
**
** {F16217} The memory allocated by [sqlite3_aggregate_context(C,N)] is
** automatically freed on the next call to [sqlite3_reset()]
** or [sqlite3_finalize()] for the [prepared statement] containing
** the aggregate function associated with context C.
*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
/*
** CAPI3REF: User Data For Functions {F16240}
**
** The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function. {END}
**
** This routine must be called from the same thread in which
** the application-defined function is running.
**
** INVARIANTS:
**
** {F16243} The [sqlite3_user_data(C)] interface returns a copy of the
** P pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
** registered the SQL function associated with
** [sqlite3_context] C.
*/
void *sqlite3_user_data(sqlite3_context*);
/*
** CAPI3REF: Database Connection For Functions {F16250}
**
** The sqlite3_context_db_handle() interface returns a copy of
** the pointer to the [database connection] (the 1st parameter)
** of the the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.
**
** INVARIANTS:
**
** {F16253} The [sqlite3_context_db_handle(C)] interface returns a copy of the
** D pointer from the [sqlite3_create_function(D,X,N,E,P,F,S,L)]
** or [sqlite3_create_function16(D,X,N,E,P,F,S,L)] call that
** registered the SQL function associated with
** [sqlite3_context] C.
*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
/*
** CAPI3REF: Function Auxiliary Data {F16270}
**
** The following two functions may be used by scalar SQL functions to
** associate meta-data with argument values. If the same value is passed to
** multiple invocations of the same SQL function during query execution, under
** some circumstances the associated meta-data may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** meta-data associated with the SQL value passed as the regular expression
** pattern. The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**
** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function.
** If no meta-data has been ever been set for the Nth
** argument of the function, or if the cooresponding function parameter
** has changed since the meta-data was set, then sqlite3_get_auxdata()
** returns a NULL pointer.
**
** The sqlite3_set_auxdata() interface saves the meta-data
** pointed to by its 3rd parameter as the meta-data for the N-th
** argument of the application-defined function. Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed.
** If it is not NULL, SQLite will invoke the destructor
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the meta-data when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first.
**
** SQLite is free to call the destructor and drop meta-data on
** any parameter of any function at any time. The only guarantee
** is that the destructor will be called before the metadata is
** dropped.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
**
** INVARIANTS:
**
** {F16272} The [sqlite3_get_auxdata(C,N)] interface returns a pointer
** to metadata associated with the Nth parameter of the SQL function
** whose context is C, or NULL if there is no metadata associated
** with that parameter.
**
** {F16274} The [sqlite3_set_auxdata(C,N,P,D)] interface assigns a metadata
** pointer P to the Nth parameter of the SQL function with context
** C.
**
** {F16276} SQLite will invoke the destructor D with a single argument
** which is the metadata pointer P following a call to
** [sqlite3_set_auxdata(C,N,P,D)] when SQLite ceases to hold
** the metadata.
**
** {F16277} SQLite ceases to hold metadata for an SQL function parameter
** when the value of that parameter changes.
**
** {F16278} When [sqlite3_set_auxdata(C,N,P,D)] is invoked, the destructor
** is called for any prior metadata associated with the same function
** context C and parameter N.
**
** {F16279} SQLite will call destructors for any metadata it is holding
** in a particular [prepared statement] S when either
** [sqlite3_reset(S)] or [sqlite3_finalize(S)] is called.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int N);
void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
/*
** CAPI3REF: Constants Defining Special Destructor Behavior {F10280}
**
** These are special value for the destructor that is passed in as the
** final argument to routines like [sqlite3_result_blob()]. If the destructor
** argument is SQLITE_STATIC, it means that the content pointer is constant
** and will never change. It does not need to be destroyed. The
** SQLITE_TRANSIENT value means that the content will likely change in
** the near future and that SQLite should make its own private copy of
** the content before returning.
**
** The typedef is necessary to work around problems in certain
** C++ compilers. See ticket #2191.
*/
typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
/*
** CAPI3REF: Setting The Result Of An SQL Function {F16400}
**
** These routines are used by the xFunc or xFinal callbacks that
** implement SQL functions and aggregates. See
** [sqlite3_create_function()] and [sqlite3_create_function16()]
** for additional information.
**
** These functions work very much like the
** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
** to bind values to host parameters in prepared statements.
** Refer to the
** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
** additional information.
**
** The sqlite3_result_blob() interface sets the result from
** an application defined function to be the BLOB whose content is pointed
** to by the second parameter and which is N bytes long where N is the
** third parameter.
** The sqlite3_result_zeroblob() inerfaces set the result of
** the application defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** The sqlite3_result_double() interface sets the result from
** an application defined function to be a floating point value specified
** by its 2nd argument.
**
** The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** SQLite uses the string pointed to by the
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
** as the text of an error message. SQLite interprets the error
** message string from sqlite3_result_error() as UTF8. SQLite
** interprets the string from sqlite3_result_error16() as UTF16 in native
** byte order. If the third parameter to sqlite3_result_error()
** or sqlite3_result_error16() is negative then SQLite takes as the error
** message all text up through the first zero character.
** If the third parameter to sqlite3_result_error() or
** sqlite3_result_error16() is non-negative then SQLite takes that many
** bytes (not characters) from the 2nd parameter as the error message.
** The sqlite3_result_error() and sqlite3_result_error16()
** routines make a copy private copy of the error message text before
** they return. Hence, the calling function can deallocate or
** modify the text after they return without harm.
** The sqlite3_result_error_code() function changes the error code
** returned by SQLite as a result of an error in a function. By default,
** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error()
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
**
** The sqlite3_result_toobig() interface causes SQLite
** to throw an error indicating that a string or BLOB is to long
** to represent. The sqlite3_result_nomem() interface
** causes SQLite to throw an exception indicating that the a
** memory allocation failed.
**
** The sqlite3_result_int() interface sets the return value
** of the application-defined function to be the 32-bit signed integer
** value given in the 2nd argument.
** The sqlite3_result_int64() interface sets the return value
** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** The sqlite3_result_text(), sqlite3_result_text16(),
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter
** through the first zero character.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text
** pointed to by the 2nd parameter are taken as the application-defined
** function result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
** function as the destructor on the text or blob result when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_STATIC, then
** SQLite assumes that the text or blob result is constant space and
** does not copy the space or call a destructor when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the
** [unprotected sqlite3_value] object specified by the 2nd parameter. The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread
** than the one containing the application-defined function that recieved
** the [sqlite3_context] pointer, the results are undefined.
**
** INVARIANTS:
**
** {F16403} The default return value from any SQL function is NULL.
**
** {F16406} The [sqlite3_result_blob(C,V,N,D)] interface changes the
** return value of function C to be a blob that is N bytes
** in length and with content pointed to by V.
**
** {F16409} The [sqlite3_result_double(C,V)] interface changes the
** return value of function C to be the floating point value V.
**
** {F16412} The [sqlite3_result_error(C,V,N)] interface changes the return
** value of function C to be an exception with error code
** [SQLITE_ERROR] and a UTF8 error message copied from V up to the
** first zero byte or until N bytes are read if N is positive.
**
** {F16415} The [sqlite3_result_error16(C,V,N)] interface changes the return
** value of function C to be an exception with error code
** [SQLITE_ERROR] and a UTF16 native byte order error message
** copied from V up to the first zero terminator or until N bytes
** are read if N is positive.
**
** {F16418} The [sqlite3_result_error_toobig(C)] interface changes the return
** value of the function C to be an exception with error code
** [SQLITE_TOOBIG] and an appropriate error message.
**
** {F16421} The [sqlite3_result_error_nomem(C)] interface changes the return
** value of the function C to be an exception with error code
** [SQLITE_NOMEM] and an appropriate error message.
**
** {F16424} The [sqlite3_result_error_code(C,E)] interface changes the return
** value of the function C to be an exception with error code E.
** The error message text is unchanged.
**
** {F16427} The [sqlite3_result_int(C,V)] interface changes the
** return value of function C to be the 32-bit integer value V.
**
** {F16430} The [sqlite3_result_int64(C,V)] interface changes the
** return value of function C to be the 64-bit integer value V.
**
** {F16433} The [sqlite3_result_null(C)] interface changes the
** return value of function C to be NULL.
**
** {F16436} The [sqlite3_result_text(C,V,N,D)] interface changes the
** return value of function C to be the UTF8 string
** V up the first zero if N is negative
** or the first N bytes of V if N is non-negative.
**
** {F16439} The [sqlite3_result_text16(C,V,N,D)] interface changes the
** return value of function C to be the UTF16 native byte order
** string V up to the first zero if N is
** negative or the first N bytes of V if N is non-negative.
**
** {F16442} The [sqlite3_result_text16be(C,V,N,D)] interface changes the
** return value of function C to be the UTF16 big-endian
** string V up to the first zero if N is
** is negative or the first N bytes or V if N is non-negative.
**
** {F16445} The [sqlite3_result_text16le(C,V,N,D)] interface changes the
** return value of function C to be the UTF16 little-endian
** string V up to the first zero if N is
** negative or the first N bytes of V if N is non-negative.
**
** {F16448} The [sqlite3_result_value(C,V)] interface changes the
** return value of function C to be [unprotected sqlite3_value]
** object V.
**
** {F16451} The [sqlite3_result_zeroblob(C,N)] interface changes the
** return value of function C to be an N-byte blob of all zeros.
**
** {F16454} The [sqlite3_result_error()] and [sqlite3_result_error16()]
** interfaces make a copy of their error message strings before
** returning.
**
** {F16457} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
** [sqlite3_result_text16be(C,V,N,D)], or
** [sqlite3_result_text16le(C,V,N,D)] is the constant [SQLITE_STATIC]
** then no destructor is ever called on the pointer V and SQLite
** assumes that V is immutable.
**
** {F16460} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
** [sqlite3_result_text16be(C,V,N,D)], or
** [sqlite3_result_text16le(C,V,N,D)] is the constant
** [SQLITE_TRANSIENT] then the interfaces makes a copy of the
** content of V and retains the copy.
**
** {F16463} If the D destructor parameter to [sqlite3_result_blob(C,V,N,D)],
** [sqlite3_result_text(C,V,N,D)], [sqlite3_result_text16(C,V,N,D)],
** [sqlite3_result_text16be(C,V,N,D)], or
** [sqlite3_result_text16le(C,V,N,D)] is some value other than
** the constants [SQLITE_STATIC] and [SQLITE_TRANSIENT] then
** SQLite will invoke the destructor D with V as its only argument
** when it has finished with the V value.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
void sqlite3_result_error_code(sqlite3_context*, int);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);
/*
** CAPI3REF: Define New Collating Sequences {F16600}
**
** These functions are used to add new collation sequences to the
** [sqlite3*] handle specified as the first argument.
**
** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). In all cases
** the name is passed as the second function argument.
**
** The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian or UTF-16 big-endian respectively. The
** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that
** the routine expects pointers to 16-bit word aligned strings
** of UTF16 in the native byte order of the host computer.
**
** A pointer to the user supplied routine must be passed as the fifth
** argument. If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** Each time the application
** supplied function is invoked, it is passed a copy of the void* passed as
** the fourth argument to sqlite3_create_collation() or
** sqlite3_create_collation16() as its first parameter.
**
** The remaining arguments to the application-supplied routine are two strings,
** each represented by a (length, data) pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered. {END} The application defined collation routine should
** return negative, zero or positive if
** the first string is less than, equal to, or greater than the second
** string. i.e. (STRING1 - STRING2).
**
** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** excapt that it takes an extra argument which is a destructor for
** the collation. The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** Collations are destroyed when
** they are overridden by later calls to the collation creation functions
** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
**
** INVARIANTS:
**
** {F16603} A successful call to the
** [sqlite3_create_collation_v2(B,X,E,P,F,D)] interface
** registers function F as the comparison function used to
** implement collation X on [database connection] B for
** databases having encoding E.
**
** {F16604} SQLite understands the X parameter to
** [sqlite3_create_collation_v2(B,X,E,P,F,D)] as a zero-terminated
** UTF-8 string in which case is ignored for ASCII characters and
** is significant for non-ASCII characters.
**
** {F16606} Successive calls to [sqlite3_create_collation_v2(B,X,E,P,F,D)]
** with the same values for B, X, and E, override prior values
** of P, F, and D.
**
** {F16609} The destructor D in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
** is not NULL then it is called with argument P when the
** collating function is dropped by SQLite.
**
** {F16612} A collating function is dropped when it is overloaded.
**
** {F16615} A collating function is dropped when the database connection
** is closed using [sqlite3_close()].
**
** {F16618} The pointer P in [sqlite3_create_collation_v2(B,X,E,P,F,D)]
** is passed through as the first parameter to the comparison
** function F for all subsequent invocations of F.
**
** {F16621} A call to [sqlite3_create_collation(B,X,E,P,F)] is exactly
** the same as a call to [sqlite3_create_collation_v2()] with
** the same parameters and a NULL destructor.
**
** {F16624} Following a [sqlite3_create_collation_v2(B,X,E,P,F,D)],
** SQLite uses the comparison function F for all text comparison
** operations on [database connection] B on text values that
** use the collating sequence name X.
**
** {F16627} The [sqlite3_create_collation16(B,X,E,P,F)] works the same
** as [sqlite3_create_collation(B,X,E,P,F)] except that the
** collation name X is understood as UTF-16 in native byte order
** instead of UTF-8.
**
** {F16630} When multiple comparison functions are available for the same
** collating sequence, SQLite chooses the one whose text encoding
** requires the least amount of conversion from the default
** text encoding of the database.
*/
int sqlite3_create_collation(
sqlite3*,
const char *zName,
int eTextRep,
void*,
int(*xCompare)(void*,int,const void*,int,const void*)
);
int sqlite3_create_collation_v2(
sqlite3*,
const char *zName,
int eTextRep,
void*,
int(*xCompare)(void*,int,const void*,int,const void*),
void(*xDestroy)(void*)
);
int sqlite3_create_collation16(
sqlite3*,
const char *zName,
int eTextRep,
void*,
int(*xCompare)(void*,int,const void*,int,const void*)
);
/*
** CAPI3REF: Collation Needed Callbacks {F16700}
**
** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** database handle to be called whenever an undefined collation sequence is
** required.
**
** If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names
** are passed as UTF-16 in machine native byte order. A call to either
** function replaces any existing callback.
**
** When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16(). The second argument is the database
** handle. The third argument is one of [SQLITE_UTF8],
** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most
** desirable form of the collation sequence function required.
** The fourth parameter is the name of the
** required collation sequence.
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
**
** INVARIANTS:
**
** {F16702} A successful call to [sqlite3_collation_needed(D,P,F)]
** or [sqlite3_collation_needed16(D,P,F)] causes
** the [database connection] D to invoke callback F with first
** parameter P whenever it needs a comparison function for a
** collating sequence that it does not know about.
**
** {F16704} Each successful call to [sqlite3_collation_needed()] or
** [sqlite3_collation_needed16()] overrides the callback registered
** on the same [database connection] by prior calls to either
** interface.
**
** {F16706} The name of the requested collating function passed in the
** 4th parameter to the callback is in UTF-8 if the callback
** was registered using [sqlite3_collation_needed()] and
** is in UTF-16 native byte order if the callback was
** registered using [sqlite3_collation_needed16()].
**
**
*/
int sqlite3_collation_needed(
sqlite3*,
void*,
void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(
sqlite3*,
void*,
void(*)(void*,sqlite3*,int eTextRep,const void*)
);
/*
** Specify the key for an encrypted database. This routine should be
** called right after sqlite3_open().
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
int sqlite3_key(
sqlite3 *db, /* Database to be rekeyed */
const void *pKey, int nKey /* The key */
);
/*
** Change the key on an open database. If the current database is not
** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
** database is decrypted.
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
int sqlite3_rekey(
sqlite3 *db, /* Database to be rekeyed */
const void *pKey, int nKey /* The new key */
);
/*
** CAPI3REF: Suspend Execution For A Short Time {F10530}
**
** The sqlite3_sleep() function
** causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** If the operating system does not support sleep requests with
** millisecond time resolution, then the time will be rounded up to
** the nearest second. The number of milliseconds of sleep actually
** requested from the operating system is returned.
**
** SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.
**
** INVARIANTS:
**
** {F10533} The [sqlite3_sleep(M)] interface invokes the xSleep
** method of the default [sqlite3_vfs|VFS] in order to
** suspend execution of the current thread for at least
** M milliseconds.
**
** {F10536} The [sqlite3_sleep(M)] interface returns the number of
** milliseconds of sleep actually requested of the operating
** system, which might be larger than the parameter M.
*/
int sqlite3_sleep(int);
/*
** CAPI3REF: Name Of The Folder Holding Temporary Files {F10310}
**
** If this global variable is made to point to a string which is
** the name of a folder (a.ka. directory), then all temporary files
** created by SQLite will be placed in that directory. If this variable
** is NULL pointer, then SQLite does a search for an appropriate temporary
** file directory.
**
** It is not safe to modify this variable once a database connection
** has been opened. It is intended that this variable be set once
** as part of process initialization and before any SQLite interface
** routines have been call and remain unchanged thereafter.
*/
SQLITE_EXTERN char *sqlite3_temp_directory;
/*
** CAPI3REF: Test To See If The Database Is In Auto-Commit Mode {F12930}
**
** The sqlite3_get_autocommit() interfaces returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively. Autocommit mode is on
** by default. Autocommit mode is disabled by a [BEGIN] statement.
** Autocommit mode is reenabled by a [COMMIT] or [ROLLBACK].
**
** If certain kinds of errors occur on a statement within a multi-statement
** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR],
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically. The only way to
** find out if SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** INVARIANTS:
**
** {F12931} The [sqlite3_get_autocommit(D)] interface returns non-zero or
** zero if the [database connection] D is or is not in autocommit
** mode, respectively.
**
** {F12932} Autocommit mode is on by default.
**
** {F12933} Autocommit mode is disabled by a successful [BEGIN] statement.
**
** {F12934} Autocommit mode is enabled by a successful [COMMIT] or [ROLLBACK]
** statement.
**
**
** LIMITATIONS:
***
** {U12936} If another thread changes the autocommit status of the database
** connection while this routine is running, then the return value
** is undefined.
*/
int sqlite3_get_autocommit(sqlite3*);
/*
** CAPI3REF: Find The Database Handle Of A Prepared Statement {F13120}
**
** The sqlite3_db_handle interface
** returns the [sqlite3*] database handle to which a
** [prepared statement] belongs.
** The database handle returned by sqlite3_db_handle
** is the same database handle that was
** the first argument to the [sqlite3_prepare_v2()] or its variants
** that was used to create the statement in the first place.
**
** INVARIANTS:
**
** {F13123} The [sqlite3_db_handle(S)] interface returns a pointer
** to the [database connection] associated with
** [prepared statement] S.
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
/*
** CAPI3REF: Commit And Rollback Notification Callbacks {F12950}
**
** The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is committed.
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The pArg argument is passed through
** to the callback. If the callback on a commit hook function
** returns non-zero, then the commit is converted into a rollback.
**
** If another function was previously registered, its
** pArg value is returned. Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
** For the purposes of this API, a transaction is said to have been
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo>
**
** These are experimental interfaces and are subject to change.
**
** INVARIANTS:
**
** {F12951} The [sqlite3_commit_hook(D,F,P)] interface registers the
** callback function F to be invoked with argument P whenever
** a transaction commits on [database connection] D.
**
** {F12952} The [sqlite3_commit_hook(D,F,P)] interface returns the P
** argument from the previous call with the same
** [database connection ] D , or NULL on the first call
** for a particular [database connection] D.
**
** {F12953} Each call to [sqlite3_commit_hook()] overwrites the callback
** registered by prior calls.
**
** {F12954} If the F argument to [sqlite3_commit_hook(D,F,P)] is NULL
** then the commit hook callback is cancelled and no callback
** is invoked when a transaction commits.
**
** {F12955} If the commit callback returns non-zero then the commit is
** converted into a rollback.
**
** {F12961} The [sqlite3_rollback_hook(D,F,P)] interface registers the
** callback function F to be invoked with argument P whenever
** a transaction rolls back on [database connection] D.
**
** {F12962} The [sqlite3_rollback_hook(D,F,P)] interface returns the P
** argument from the previous call with the same
** [database connection ] D , or NULL on the first call
** for a particular [database connection] D.
**
** {F12963} Each call to [sqlite3_rollback_hook()] overwrites the callback
** registered by prior calls.
**
** {F12964} If the F argument to [sqlite3_rollback_hook(D,F,P)] is NULL
** then the rollback hook callback is cancelled and no callback
** is invoked when a transaction rolls back.
*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
/*
** CAPI3REF: Data Change Notification Callbacks {F12970}
**
** The sqlite3_update_hook() interface
** registers a callback function with the database connection identified by the
** first argument to be invoked whenever a row is updated, inserted or deleted.
** Any callback set by a previous call to this function for the same
** database connection is overridden.
**
** The second argument is a pointer to the function to invoke when a
** row is updated, inserted or deleted.
** The first argument to the callback is
** a copy of the third argument to sqlite3_update_hook().
** The second callback
** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
** depending on the operation that caused the callback to be invoked.
** The third and
** fourth arguments to the callback contain pointers to the database and
** table name containing the affected row.
** The final callback parameter is
** the rowid of the row.
** In the case of an update, this is the rowid after
** the update takes place.
**
** The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** If another function was previously registered, its pArg value
** is returned. Otherwise NULL is returned.
**
** INVARIANTS:
**
** {F12971} The [sqlite3_update_hook(D,F,P)] interface causes callback
** function F to be invoked with first parameter P whenever
** a table row is modified, inserted, or deleted on
** [database connection] D.
**
** {F12973} The [sqlite3_update_hook(D,F,P)] interface returns the value
** of P for the previous call on the same [database connection] D,
** or NULL for the first call.
**
** {F12975} If the update hook callback F in [sqlite3_update_hook(D,F,P)]
** is NULL then the no update callbacks are made.
**
** {F12977} Each call to [sqlite3_update_hook(D,F,P)] overrides prior calls
** to the same interface on the same [database connection] D.
**
** {F12979} The update hook callback is not invoked when internal system
** tables such as sqlite_master and sqlite_sequence are modified.
**
** {F12981} The second parameter to the update callback
** is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
** depending on the operation that caused the callback to be invoked.
**
** {F12983} The third and fourth arguments to the callback contain pointers
** to zero-terminated UTF-8 strings which are the names of the
** database and table that is being updated.
** {F12985} The final callback parameter is the rowid of the row after
** the change occurs.
*/
void *sqlite3_update_hook(
sqlite3*,
void(*)(void *,int ,char const *,char const *,sqlite3_int64),
void*
);
/*
** CAPI3REF: Enable Or Disable Shared Pager Cache {F10330}
**
** This routine enables or disables the sharing of the database cache
** and schema data structures between connections to the same database.
** Sharing is enabled if the argument is true and disabled if the argument
** is false.
**
** Cache sharing is enabled and disabled
** for an entire process. {END} This is a change as of SQLite version 3.5.0.
** In prior versions of SQLite, sharing was
** enabled or disabled for each thread separately.
**
** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.
**
** Virtual tables cannot be used with a shared cache. When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error.
**
** This routine returns [SQLITE_OK] if shared cache was
** enabled or disabled successfully. An [error code]
** is returned otherwise.
**
** Shared cache is disabled by default. But this might change in
** future releases of SQLite. Applications that care about shared
** cache setting should set it explicitly.
**
** INVARIANTS:
**
** {F10331} A successful invocation of [sqlite3_enable_shared_cache(B)]
** will enable or disable shared cache mode for any subsequently
** created [database connection] in the same process.
**
** {F10336} When shared cache is enabled, the [sqlite3_create_module()]
** interface will always return an error.
**
** {F10337} The [sqlite3_enable_shared_cache(B)] interface returns
** [SQLITE_OK] if shared cache was enabled or disabled successfully.
**
** {F10339} Shared cache is disabled by default.
*/
int sqlite3_enable_shared_cache(int);
/*
** CAPI3REF: Attempt To Free Heap Memory {F17340}
**
** The sqlite3_release_memory() interface attempts to
** free N bytes of heap memory by deallocating non-essential memory
** allocations held by the database labrary. {END} Memory used
** to cache database pages to improve performance is an example of
** non-essential memory. Sqlite3_release_memory() returns
** the number of bytes actually freed, which might be more or less
** than the amount requested.
**
** INVARIANTS:
**
** {F17341} The [sqlite3_release_memory(N)] interface attempts to
** free N bytes of heap memory by deallocating non-essential
** memory allocations held by the database labrary.
**
** {F16342} The [sqlite3_release_memory(N)] returns the number
** of bytes actually freed, which might be more or less
** than the amount requested.
*/
int sqlite3_release_memory(int);
/*
** CAPI3REF: Impose A Limit On Heap Size {F17350}
**
** The sqlite3_soft_heap_limit() interface
** places a "soft" limit on the amount of heap memory that may be allocated
** by SQLite. If an internal allocation is requested
** that would exceed the soft heap limit, [sqlite3_release_memory()] is
** invoked one or more times to free up some space before the allocation
** is made.
**
** The limit is called "soft", because if
** [sqlite3_release_memory()] cannot
** free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.
** But if the soft heap limit cannot honored, execution will
** continue without error or notification. This is why the limit is
** called a "soft" limit. It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs. Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.
**
** INVARIANTS:
**
** {F16351} The [sqlite3_soft_heap_limit(N)] interface places a soft limit
** of N bytes on the amount of heap memory that may be allocated
** using [sqlite3_malloc()] or [sqlite3_realloc()] at any point
** in time.
**
** {F16352} If a call to [sqlite3_malloc()] or [sqlite3_realloc()] would
** cause the total amount of allocated memory to exceed the
** soft heap limit, then [sqlite3_release_memory()] is invoked
** in an attempt to reduce the memory usage prior to proceeding
** with the memory allocation attempt.
**
** {F16353} Calls to [sqlite3_malloc()] or [sqlite3_realloc()] that trigger
** attempts to reduce memory usage through the soft heap limit
** mechanism continue even if the attempt to reduce memory
** usage is unsuccessful.
**
** {F16354} A negative or zero value for N in a call to
** [sqlite3_soft_heap_limit(N)] means that there is no soft
** heap limit and [sqlite3_release_memory()] will only be
** called when memory is completely exhausted.
**
** {F16355} The default value for the soft heap limit is zero.
**
** {F16358} Each call to [sqlite3_soft_heap_limit(N)] overrides the
** values set by all prior calls.
*/
void sqlite3_soft_heap_limit(int);
/*
** CAPI3REF: Extract Metadata About A Column Of A Table {F12850}
**
** This routine
** returns meta-data about a specific column of a specific database
** table accessible using the connection handle passed as the first function
** argument.
**
** The column is identified by the second, third and fourth parameters to
** this function. The second parameter is either the name of the database
** (i.e. "main", "temp" or an attached database) containing the specified
** table or NULL. If it is NULL, then all attached databases are searched
** for the table using the same algorithm as the database engine uses to
** resolve unqualified table references.
**
** The third and fourth parameters to this function are the table and column
** name of the desired column, respectively. Neither of these parameters
** may be NULL.
**
** Meta information is returned by writing to the memory locations passed as
** the 5th and subsequent parameters to this function. Any of these
** arguments may be NULL, in which case the corresponding element of meta
** information is ommitted.
**
** <pre>
** Parameter Output Type Description
** -----------------------------------
**
** 5th const char* Data type
** 6th const char* Name of the default collation sequence
** 7th int True if the column has a NOT NULL constraint
** 8th int True if the column is part of the PRIMARY KEY
** 9th int True if the column is AUTOINCREMENT
** </pre>
**
**
** The memory pointed to by the character pointers returned for the
** declaration type and collation sequence is valid only until the next
** call to any sqlite API function.
**
** If the specified table is actually a view, then an error is returned.
**
** If the specified column is "rowid", "oid" or "_rowid_" and an
** INTEGER PRIMARY KEY column has been explicitly declared, then the output
** parameters are set for the explicitly declared column. If there is no
** explicitly declared IPK column, then the output parameters are set as
** follows:
**
** <pre>
** data type: "INTEGER"
** collation sequence: "BINARY"
** not null: 0
** primary key: 1
** auto increment: 0
** </pre>
**
** This function may load one or more schemas from database files. If an
** error occurs during this process, or if the requested table or column
** cannot be found, an SQLITE error code is returned and an error message
** left in the database handle (to be retrieved using sqlite3_errmsg()).
**
** This API is only available if the library was compiled with the
** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
*/
int sqlite3_table_column_metadata(
sqlite3 *db, /* Connection handle */
const char *zDbName, /* Database name or NULL */
const char *zTableName, /* Table name */
const char *zColumnName, /* Column name */
char const **pzDataType, /* OUTPUT: Declared data type */
char const **pzCollSeq, /* OUTPUT: Collation sequence name */
int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
int *pPrimaryKey, /* OUTPUT: True if column part of PK */
int *pAutoinc /* OUTPUT: True if column is auto-increment */
);
/*
** CAPI3REF: Load An Extension {F12600}
**
** {F12601} The sqlite3_load_extension() interface
** attempts to load an SQLite extension library contained in the file
** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0
** in which case the name of the entry point defaults
** to "sqlite3_extension_init".
**
** {F12604} The sqlite3_load_extension() interface shall
** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
**
** {F12605}
** If an error occurs and pzErrMsg is not 0, then the
** sqlite3_load_extension() interface shall attempt to fill *pzErrMsg with
** error message text stored in memory obtained from [sqlite3_malloc()].
** {END} The calling function should free this memory
** by calling [sqlite3_free()].
**
** {F12606}
** Extension loading must be enabled using [sqlite3_enable_load_extension()]
** prior to calling this API or an error will be returned.
*/
int sqlite3_load_extension(
sqlite3 *db, /* Load the extension into this database connection */
const char *zFile, /* Name of the shared library containing extension */
const char *zProc, /* Entry point. Derived from zFile if 0 */
char **pzErrMsg /* Put error message here if not 0 */
);
/*
** CAPI3REF: Enable Or Disable Extension Loading {F12620}
**
** So as not to open security holes in older applications that are
** unprepared to deal with extension loading, and as a means of disabling
** extension loading while evaluating user-entered SQL, the following
** API is provided to turn the [sqlite3_load_extension()] mechanism on and
** off. {F12622} It is off by default. {END} See ticket #1863.
**
** {F12621} Call the sqlite3_enable_load_extension() routine
** with onoff==1 to turn extension loading on
** and call it with onoff==0 to turn it back off again. {END}
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
/*
** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640}
**
** {F12641} This function
** registers an extension entry point that is automatically invoked
** whenever a new database connection is opened using
** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END}
**
** This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new database connections.
**
** {F12642} Duplicate extensions are detected so calling this routine multiple
** times with the same extension is harmless.
**
** {F12643} This routine stores a pointer to the extension in an array
** that is obtained from sqlite_malloc(). {END} If you run a memory leak
** checker on your program and it reports a leak because of this
** array, then invoke [sqlite3_reset_auto_extension()] prior
** to shutdown to free the memory.
**
** {F12644} Automatic extensions apply across all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
int sqlite3_auto_extension(void *xEntryPoint);
/*
** CAPI3REF: Reset Automatic Extension Loading {F12660}
**
** {F12661} This function disables all previously registered
** automatic extensions. {END} This
** routine undoes the effect of all prior [sqlite3_auto_extension()]
** calls.
**
** {F12662} This call disabled automatic extensions in all threads. {END}
**
** This interface is experimental and is subject to change or
** removal in future releases of SQLite.
*/
void sqlite3_reset_auto_extension(void);
/*
****** EXPERIMENTAL - subject to change without notice **************
**
** The interface to the virtual-table mechanism is currently considered
** to be experimental. The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.
**
** When the virtual-table mechanism stablizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
*/
/*
** Structures used by the virtual table interface
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;
/*
** CAPI3REF: Virtual Table Object {F18000}
** KEYWORDS: sqlite3_module
**
** A module is a class of virtual tables. Each module is defined
** by an instance of the following structure. This structure consists
** mostly of methods for the module.
*/
struct sqlite3_module {
int iVersion;
int (*xCreate)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xConnect)(sqlite3*, void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVTab, char**);
int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
int (*xDisconnect)(sqlite3_vtab *pVTab);
int (*xDestroy)(sqlite3_vtab *pVTab);
int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
int (*xClose)(sqlite3_vtab_cursor*);
int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
int argc, sqlite3_value **argv);
int (*xNext)(sqlite3_vtab_cursor*);
int (*xEof)(sqlite3_vtab_cursor*);
int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
int (*xBegin)(sqlite3_vtab *pVTab);
int (*xSync)(sqlite3_vtab *pVTab);
int (*xCommit)(sqlite3_vtab *pVTab);
int (*xRollback)(sqlite3_vtab *pVTab);
int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
void **ppArg);
int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};
/*
** CAPI3REF: Virtual Table Indexing Information {F18100}
** KEYWORDS: sqlite3_index_info
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the xBestIndex
** method of an sqlite3_module. The fields under **Inputs** are the
** inputs to xBestIndex and are read-only. xBestIndex inserts its
** results into the **Outputs** fields.
**
** The aConstraint[] array records WHERE clause constraints of the
** form:
**
** column OP expr
**
** Where OP is =, <, <=, >, or >=.
** The particular operator is stored
** in aConstraint[].op. The index of the column is stored in
** aConstraint[].iColumn. aConstraint[].usable is TRUE if the
** expr on the right-hand side can be evaluated (and thus the constraint
** is usable) and false if it cannot.
**
** The optimizer automatically inverts terms of the form "expr OP column"
** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** The aConstraint[] array only reports WHERE clause terms in the correct
** form that refer to the particular virtual table being queried.
**
** Information about the ORDER BY clause is stored in aOrderBy[].
** Each term of aOrderBy records a column of the ORDER BY clause.
**
** The xBestIndex method must fill aConstraintUsage[] with information
** about what parameters to pass to xFilter. If argvIndex>0 then
** the right-hand side of the corresponding aConstraint[] is evaluated
** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit
** is true, then the constraint is assumed to be fully handled by the
** virtual table and is not checked again by SQLite.
**
** The idxNum and idxPtr values are recorded and passed into xFilter.
** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
**
** The orderByConsumed means that output from xFilter will occur in
** the correct order to satisfy the ORDER BY clause so that no separate
** sorting step is required.
**
** The estimatedCost value is an estimate of the cost of doing the
** particular lookup. A full scan of a table with N entries should have
** a cost of N. A binary search of a table of N entries should have a
** cost of approximately log(N).
*/
struct sqlite3_index_info {
/* Inputs */
int nConstraint; /* Number of entries in aConstraint */
struct sqlite3_index_constraint {
int iColumn; /* Column on left-hand side of constraint */
unsigned char op; /* Constraint operator */
unsigned char usable; /* True if this constraint is usable */
int iTermOffset; /* Used internally - xBestIndex should ignore */
} *aConstraint; /* Table of WHERE clause constraints */
int nOrderBy; /* Number of terms in the ORDER BY clause */
struct sqlite3_index_orderby {
int iColumn; /* Column number */
unsigned char desc; /* True for DESC. False for ASC. */
} *aOrderBy; /* The ORDER BY clause */
/* Outputs */
struct sqlite3_index_constraint_usage {
int argvIndex; /* if >0, constraint is part of argv to xFilter */
unsigned char omit; /* Do not code a test for this constraint */
} *aConstraintUsage;
int idxNum; /* Number used to identify the index */
char *idxStr; /* String, possibly obtained from sqlite3_malloc */
int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
int orderByConsumed; /* True if output is already ordered */
double estimatedCost; /* Estimated cost of using this index */
};
#define SQLITE_INDEX_CONSTRAINT_EQ 2
#define SQLITE_INDEX_CONSTRAINT_GT 4
#define SQLITE_INDEX_CONSTRAINT_LE 8
#define SQLITE_INDEX_CONSTRAINT_LT 16
#define SQLITE_INDEX_CONSTRAINT_GE 32
#define SQLITE_INDEX_CONSTRAINT_MATCH 64
/*
** CAPI3REF: Register A Virtual Table Implementation {F18200}
**
** This routine is used to register a new module name with an SQLite
** connection. Module names must be registered before creating new
** virtual tables on the module, or before using preexisting virtual
** tables of the module.
*/
int sqlite3_create_module(
sqlite3 *db, /* SQLite connection to register module with */
const char *zName, /* Name of the module */
const sqlite3_module *, /* Methods for the module */
void * /* Client data for xCreate/xConnect */
);
/*
** CAPI3REF: Register A Virtual Table Implementation {F18210}
**
** This routine is identical to the sqlite3_create_module() method above,
** except that it allows a destructor function to be specified. It is
** even more experimental than the rest of the virtual tables API.
*/
int sqlite3_create_module_v2(
sqlite3 *db, /* SQLite connection to register module with */
const char *zName, /* Name of the module */
const sqlite3_module *, /* Methods for the module */
void *, /* Client data for xCreate/xConnect */
void(*xDestroy)(void*) /* Module destructor function */
);
/*
** CAPI3REF: Virtual Table Instance Object {F18010}
** KEYWORDS: sqlite3_vtab
**
** Every module implementation uses a subclass of the following structure
** to describe a particular instance of the module. Each subclass will
** be tailored to the specific needs of the module implementation. The
** purpose of this superclass is to define certain fields that are common
** to all module implementations.
**
** Virtual tables methods can set an error message by assigning a
** string obtained from sqlite3_mprintf() to zErrMsg. The method should
** take care that any prior string is freed by a call to sqlite3_free()
** prior to assigning a new string to zErrMsg. After the error message
** is delivered up to the client application, the string will be automatically
** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note
** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
** since virtual tables are commonly implemented in loadable extensions which
** do not have access to sqlite3MPrintf() or sqlite3Free().
*/
struct sqlite3_vtab {
const sqlite3_module *pModule; /* The module for this virtual table */
int nRef; /* Used internally */
char *zErrMsg; /* Error message from sqlite3_mprintf() */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Virtual Table Cursor Object {F18020}
** KEYWORDS: sqlite3_vtab_cursor
**
** Every module implementation uses a subclass of the following structure
** to describe cursors that point into the virtual table and are used
** to loop through the virtual table. Cursors are created using the
** xOpen method of the module. Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
sqlite3_vtab *pVtab; /* Virtual table of this cursor */
/* Virtual table implementations will typically add additional fields */
};
/*
** CAPI3REF: Declare The Schema Of A Virtual Table {F18280}
**
** The xCreate and xConnect methods of a module use the following API
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
/*
** CAPI3REF: Overload A Function For A Virtual Table {F18300}
**
** Virtual tables can provide alternative implementations of functions
** using the xFindFunction method. But global versions of those functions
** must exist in order to be overloaded.
**
** This API makes sure a global version of a function with a particular
** name and number of parameters exists. If no such function exists
** before this API is called, a new function is created. The implementation
** of the new function always causes an exception to be thrown. So
** the new function is not good for anything by itself. Its only
** purpose is to be a place-holder function that can be overloaded
** by virtual tables.
**
** This API should be considered part of the virtual table interface,
** which is experimental and subject to change.
*/
int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
/*
** The interface to the virtual-table mechanism defined above (back up
** to a comment remarkably similar to this one) is currently considered
** to be experimental. The interface might change in incompatible ways.
** If this is a problem for you, do not use the interface at this time.
**
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
**
****** EXPERIMENTAL - subject to change without notice **************
*/
/*
** CAPI3REF: A Handle To An Open BLOB {F17800}
**
** An instance of this object represents an open BLOB on which
** incremental I/O can be preformed.
** Objects of this type are created by
** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the blob.
** The [sqlite3_blob_bytes()] interface returns the size of the
** blob in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;
/*
** CAPI3REF: Open A BLOB For Incremental I/O {F17810}
**
** This interfaces opens a handle to the blob located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same blob that would be selected by:
**
** <pre>
** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
** </pre> {END}
**
** If the flags parameter is non-zero, the blob is opened for
** read and write access. If it is zero, the blob is opened for read
** access.
**
** Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** is assigned 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
** [sqlite3_blob | blob handle] is written to *ppBlob.
** Otherwise an error code is returned and
** any value written to *ppBlob should not be used by the caller.
** This function sets the database-handle error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
**
** INVARIANTS:
**
** {F17813} A successful invocation of the [sqlite3_blob_open(D,B,T,C,R,F,P)]
** interface opens an [sqlite3_blob] object P on the blob
** in column C of table T in database B on [database connection] D.
**
** {F17814} A successful invocation of [sqlite3_blob_open(D,...)] starts
** a new transaction on [database connection] D if that connection
** is not already in a transaction.
**
** {F17816} The [sqlite3_blob_open(D,B,T,C,R,F,P)] interface opens the blob
** for read and write access if and only if the F parameter
** is non-zero.
**
** {F17819} The [sqlite3_blob_open()] interface returns [SQLITE_OK] on
** success and an appropriate [error code] on failure.
**
** {F17821} If an error occurs during evaluation of [sqlite3_blob_open(D,...)]
** then subsequent calls to [sqlite3_errcode(D)],
** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
** information approprate for that error.
*/
int sqlite3_blob_open(
sqlite3*,
const char *zDb,
const char *zTable,
const char *zColumn,
sqlite3_int64 iRow,
int flags,
sqlite3_blob **ppBlob
);
/*
** CAPI3REF: Close A BLOB Handle {F17830}
**
** Close an open [sqlite3_blob | 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. {END}
** 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. {F17833} Any errors that occur during
** closing are reported as a non-zero return value.
**
** The BLOB is closed unconditionally. Even if this routine returns
** an error code, the BLOB is still closed.
**
** INVARIANTS:
**
** {F17833} The [sqlite3_blob_close(P)] interface closes an
** [sqlite3_blob] object P previously opened using
** [sqlite3_blob_open()].
**
** {F17836} Closing an [sqlite3_blob] object using
** [sqlite3_blob_close()] shall cause the current transaction to
** commit if there are no other open [sqlite3_blob] objects
** or [prepared statements] on the same [database connection] and
** the [database connection] is in
** [sqlite3_get_autocommit | autocommit mode].
**
** {F17839} The [sqlite3_blob_close(P)] interfaces closes the
** [sqlite3_blob] object P unconditionally, even if
** [sqlite3_blob_close(P)] returns something other than [SQLITE_OK].
**
*/
int sqlite3_blob_close(sqlite3_blob *);
/*
** CAPI3REF: Return The Size Of An Open BLOB {F17840}
**
** Return the size in bytes of the blob accessible via the open
** [sqlite3_blob] object in its only argument.
**
** INVARIANTS:
**
** {F17843} The [sqlite3_blob_bytes(P)] interface returns the size
** in bytes of the BLOB that the [sqlite3_blob] object P
** refers to.
*/
int sqlite3_blob_bytes(sqlite3_blob *);
/*
** CAPI3REF: Read Data From A BLOB Incrementally {F17850}
**
** This function is used to read data from an open
** [sqlite3_blob | blob-handle] into a caller supplied buffer.
** N bytes of data are copied into buffer
** Z from the open blob, starting at offset iOffset.
**
** If offset iOffset is less than N bytes from the end of the blob,
** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is
** less than zero [SQLITE_ERROR] is returned and no data is read.
**
** On success, SQLITE_OK is returned. Otherwise, an
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17853} The [sqlite3_blob_read(P,Z,N,X)] interface reads N bytes
** beginning at offset X from
** the blob that [sqlite3_blob] object P refers to
** and writes those N bytes into buffer Z.
**
** {F17856} In [sqlite3_blob_read(P,Z,N,X)] if the size of the blob
** is less than N+X bytes, then the function returns [SQLITE_ERROR]
** and nothing is read from the blob.
**
** {F17859} In [sqlite3_blob_read(P,Z,N,X)] if X or N is less than zero
** then the function returns [SQLITE_ERROR]
** and nothing is read from the blob.
**
** {F17862} The [sqlite3_blob_read(P,Z,N,X)] interface returns [SQLITE_OK]
** if N bytes where successfully read into buffer Z.
**
** {F17865} If the requested read could not be completed,
** the [sqlite3_blob_read(P,Z,N,X)] interface returns an
** appropriate [error code] or [extended error code].
**
** {F17868} If an error occurs during evaluation of [sqlite3_blob_read(D,...)]
** then subsequent calls to [sqlite3_errcode(D)],
** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
** information approprate for that error.
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
/*
** CAPI3REF: Write Data Into A BLOB Incrementally {F17870}
**
** This function is used to write data into an open
** [sqlite3_blob | blob-handle] from a user supplied buffer.
** n bytes of data are copied from the buffer
** pointed to by z into the open blob, starting at offset iOffset.
**
** If the [sqlite3_blob | 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
** 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.
**
** On success, SQLITE_OK is returned. Otherwise, an
** [error code] or an [extended error code] is returned.
**
** INVARIANTS:
**
** {F17873} The [sqlite3_blob_write(P,Z,N,X)] interface writes N bytes
** from buffer Z into
** the blob that [sqlite3_blob] object P refers to
** beginning at an offset of X into the blob.
**
** {F17875} The [sqlite3_blob_write(P,Z,N,X)] interface returns
** [SQLITE_READONLY] if the [sqlite3_blob] object P was
** [sqlite3_blob_open | opened] for reading only.
**
** {F17876} In [sqlite3_blob_write(P,Z,N,X)] if the size of the blob
** is less than N+X bytes, then the function returns [SQLITE_ERROR]
** and nothing is written into the blob.
**
** {F17879} In [sqlite3_blob_write(P,Z,N,X)] if X or N is less than zero
** then the function returns [SQLITE_ERROR]
** and nothing is written into the blob.
**
** {F17882} The [sqlite3_blob_write(P,Z,N,X)] interface returns [SQLITE_OK]
** if N bytes where successfully written into blob.
**
** {F17885} If the requested write could not be completed,
** the [sqlite3_blob_write(P,Z,N,X)] interface returns an
** appropriate [error code] or [extended error code].
**
** {F17888} If an error occurs during evaluation of [sqlite3_blob_write(D,...)]
** then subsequent calls to [sqlite3_errcode(D)],
** [sqlite3_errmsg(D)], and [sqlite3_errmsg16(D)] will return
** information approprate for that error.
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
/*
** CAPI3REF: Virtual File System Objects {F11200}
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system. Most SQLite builds come with a
** single default VFS that is appropriate for the host computer.
** New VFSes can be registered and existing VFSes can be unregistered.
** The following interfaces are provided.
**
** The sqlite3_vfs_find() interface returns a pointer to
** a VFS given its name. Names are case sensitive.
** Names are zero-terminated UTF-8 strings.
** If there is no match, a NULL
** pointer is returned. If zVfsName is NULL then the default
** VFS is returned.
**
** New VFSes are registered with sqlite3_vfs_register().
** Each new VFS becomes the default VFS if the makeDflt flag is set.
** The same VFS can be registered multiple times without injury.
** To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set. If two different VFSes with the
** same name are registered, the behavior is undefined. If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
**
** Unregister a VFS with the sqlite3_vfs_unregister() interface.
** If the default VFS is unregistered, another VFS is chosen as
** the default. The choice for the new VFS is arbitrary.
**
** INVARIANTS:
**
** {F11203} The [sqlite3_vfs_find(N)] interface returns a pointer to the
** registered [sqlite3_vfs] object whose name exactly matches
** the zero-terminated UTF-8 string N, or it returns NULL if
** there is no match.
**
** {F11206} If the N parameter to [sqlite3_vfs_find(N)] is NULL then
** the function returns a pointer to the default [sqlite3_vfs]
** object if there is one, or NULL if there is no default
** [sqlite3_vfs] object.
**
** {F11209} The [sqlite3_vfs_register(P,F)] interface registers the
** well-formed [sqlite3_vfs] object P using the name given
** by the zName field of the object.
**
** {F11212} Using the [sqlite3_vfs_register(P,F)] interface to register
** the same [sqlite3_vfs] object multiple times is a harmless no-op.
**
** {F11215} The [sqlite3_vfs_register(P,F)] interface makes the
** the [sqlite3_vfs] object P the default [sqlite3_vfs] object
** if F is non-zero.
**
** {F11218} The [sqlite3_vfs_unregister(P)] interface unregisters the
** [sqlite3_vfs] object P so that it is no longer returned by
** subsequent calls to [sqlite3_vfs_find()].
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);
/*
** CAPI3REF: Mutexes {F17000}
**
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations
** of these mutex routines. An appropriate implementation
** is selected automatically at compile-time. The following
** implementations are available in the SQLite core:
**
** <ul>
** <li> SQLITE_MUTEX_OS2
** <li> SQLITE_MUTEX_PTHREAD
** <li> SQLITE_MUTEX_W32
** <li> SQLITE_MUTEX_NOOP
** </ul>
**
** The SQLITE_MUTEX_NOOP implementation is a set of routines
** that does no real locking and is appropriate for use in
** a single-threaded application. The SQLITE_MUTEX_OS2,
** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
** are appropriate for use on os/2, unix, and windows.
**
** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. The
** mutex interface routines defined here become external
** references in the SQLite library for which implementations
** must be provided by the application. This facility allows an
** application that links against SQLite to provide its own mutex
** implementation without having to modify the SQLite core.
**
** {F17011} The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. {F17012} If it returns NULL
** that means that a mutex could not be allocated. {F17013} SQLite
** will unwind its stack and return an error. {F17014} The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li> SQLITE_MUTEX_FAST
** <li> SQLITE_MUTEX_RECURSIVE
** <li> SQLITE_MUTEX_STATIC_MASTER
** <li> SQLITE_MUTEX_STATIC_MEM
** <li> SQLITE_MUTEX_STATIC_MEM2
** <li> SQLITE_MUTEX_STATIC_PRNG
** <li> SQLITE_MUTEX_STATIC_LRU
** <li> SQLITE_MUTEX_STATIC_LRU2
** </ul> {END}
**
** {F17015} The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to. {F17016} But SQLite will only request a recursive mutex in
** cases where it really needs one. {END} If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return
** a pointer to a static preexisting mutex. {END} Four static mutexes are
** used by the current version of SQLite. Future versions of SQLite
** may add additional static mutexes. Static mutexes are for internal
** use by SQLite only. Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** {F17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call. {F17034} But for the static
** mutex types, the same mutex is returned on every call that has
** the same type number. {END}
**
** {F17019} The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every
** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in
** use when they are deallocated. {U17022} Attempting to deallocate a static
** mutex results in undefined behavior. {F17023} SQLite never deallocates
** a static mutex. {END}
**
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. {F17024} If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. {F17025} The sqlite3_mutex_try() interface returns SQLITE_OK
** upon successful entry. {F17026} Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** {F17027} In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter. {U17028} If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** {F17029} SQLite will never exhibit
** such behavior in its own use of mutexes. {END}
**
** Some systems (ex: windows95) do not the operation implemented by
** sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() will
** always return SQLITE_BUSY. {F17030} The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END}
**
** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread. {U17032} The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated. {F17033} SQLite will
** never do either. {END}
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
sqlite3_mutex *sqlite3_mutex_alloc(int);
void sqlite3_mutex_free(sqlite3_mutex*);
void sqlite3_mutex_enter(sqlite3_mutex*);
int sqlite3_mutex_try(sqlite3_mutex*);
void sqlite3_mutex_leave(sqlite3_mutex*);
/*
** CAPI3REF: Mutex Verifcation Routines {F17080}
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements. {F17081} The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core. {F17082} The core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag. {U17087} External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** {F17083} These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread. {END}
**
** {X17084} The implementation is not required to provided versions of these
** routines that actually work.
** If the implementation does not provide working
** versions of these routines, it should at least provide stubs
** that always return true so that one does not get spurious
** assertion failures. {END}
**
** {F17085} If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1. {END} This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist. But the
** the reason the mutex does not exist is because the build is not
** using mutexes. And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do. {F17086} The sqlite3_mutex_notheld()
** interface should also return 1 when given a NULL pointer.
*/
int sqlite3_mutex_held(sqlite3_mutex*);
int sqlite3_mutex_notheld(sqlite3_mutex*);
/*
** CAPI3REF: Mutex Types {F17001}
**
** {F17002} The [sqlite3_mutex_alloc()] interface takes a single argument
** which is one of these integer constants. {END}
*/
#define SQLITE_MUTEX_FAST 0
#define SQLITE_MUTEX_RECURSIVE 1
#define SQLITE_MUTEX_STATIC_MASTER 2
#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */
#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */
/*
** CAPI3REF: Low-Level Control Of Database Files {F11300}
**
** {F11301} The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. {F11302} The
** name of the database is the name assigned to the database by the
** <a href="lang_attach.html">ATTACH</a> SQL command that opened the
** database. {F11303} To control the main database file, use the name "main"
** or a NULL pointer. {F11304} The third and fourth parameters to this routine
** are passed directly through to the second and third parameters of
** the xFileControl method. {F11305} The return value of the xFileControl
** method becomes the return value of this routine.
**
** {F11306} If the second parameter (zDbName) does not match the name of any
** open database file, then SQLITE_ERROR is returned. {F11307} This error
** code is not remembered and will not be recalled by [sqlite3_errcode()]
** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might
** also return SQLITE_ERROR. {U11309} There is no way to distinguish between
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
** xFileControl method. {END}
**
** See also: [SQLITE_FCNTL_LOCKSTATE]
*/
int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
/*
** CAPI3REF: Testing Interface {F11400}
**
** The sqlite3_test_control() interface is used to read out internal
** state of SQLite and to inject faults into SQLite for testing
** purposes. The first parameter a operation code that determines
** the number, meaning, and operation of all subsequent parameters.
**
** This interface is not for use by applications. It exists solely
** for verifying the correct operation of the SQLite library. Depending
** on how the SQLite library is compiled, this interface might not exist.
**
** The details of the operation codes, their meanings, the parameters
** they take, and what they do are all subject to change without notice.
** Unlike most of the SQLite API, this function is not guaranteed to
** operate consistently from one release to the next.
*/
int sqlite3_test_control(int op, ...);
/*
** CAPI3REF: Testing Interface Operation Codes {F11410}
**
** These constants are the valid operation code parameters used
** as the first argument to [sqlite3_test_control()].
**
** These parameters and their meansing are subject to change
** without notice. These values are for testing purposes only.
** Applications should not use any of these parameters or the
** [sqlite3_test_control()] interface.
*/
#define SQLITE_TESTCTRL_FAULT_CONFIG 1
#define SQLITE_TESTCTRL_FAULT_FAILURES 2
#define SQLITE_TESTCTRL_FAULT_BENIGN_FAILURES 3
#define SQLITE_TESTCTRL_FAULT_PENDING 4
#define SQLITE_TESTCTRL_PRNG_SAVE 5
#define SQLITE_TESTCTRL_PRNG_RESTORE 6
#define SQLITE_TESTCTRL_PRNG_RESET 7
#define SQLITE_TESTCTRL_BITVEC_TEST 8
/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif
#ifdef __cplusplus
} /* End of the 'extern "C"' block */
#endif
#endif