3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
28 * Base interface for all DBMS-specific code. At a bare minimum, all of the
29 * following must be implemented to support MediaWiki
34 interface DatabaseType
{
36 * Get the type of the DBMS, as it appears in $wgDBtype.
43 * Open a connection to the database. Usually aborts on failure
45 * @param string $server database server host
46 * @param string $user database user name
47 * @param string $password database user password
48 * @param string $dbName database name
50 * @throws DBConnectionError
52 function open( $server, $user, $password, $dbName );
55 * Fetch the next row from the given result object, in object form.
56 * Fields can be retrieved with $row->fieldname, with fields acting like
58 * If no more rows are available, false is returned.
60 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
62 * @throws DBUnexpectedError Thrown if the database returns an error
64 function fetchObject( $res );
67 * Fetch the next row from the given result object, in associative array
68 * form. Fields are retrieved with $row['fieldname'].
69 * If no more rows are available, false is returned.
71 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
73 * @throws DBUnexpectedError Thrown if the database returns an error
75 function fetchRow( $res );
78 * Get the number of rows in a result object
80 * @param $res Mixed: A SQL result
83 function numRows( $res );
86 * Get the number of fields in a result object
87 * @see http://www.php.net/mysql_num_fields
89 * @param $res Mixed: A SQL result
92 function numFields( $res );
95 * Get a field name in a result object
96 * @see http://www.php.net/mysql_field_name
98 * @param $res Mixed: A SQL result
102 function fieldName( $res, $n );
105 * Get the inserted value of an auto-increment row
107 * The value inserted should be fetched from nextSequenceValue()
110 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
111 * $dbw->insert( 'page', array( 'page_id' => $id ) );
112 * $id = $dbw->insertId();
119 * Change the position of the cursor in a result object
120 * @see http://www.php.net/mysql_data_seek
122 * @param $res Mixed: A SQL result
123 * @param $row Mixed: Either MySQL row or ResultWrapper
125 function dataSeek( $res, $row );
128 * Get the last error number
129 * @see http://www.php.net/mysql_errno
133 function lastErrno();
136 * Get a description of the last error
137 * @see http://www.php.net/mysql_error
141 function lastError();
144 * mysql_fetch_field() wrapper
145 * Returns false if the field doesn't exist
147 * @param string $table table name
148 * @param string $field field name
152 function fieldInfo( $table, $field );
155 * Get information about an index into an object
156 * @param string $table Table name
157 * @param string $index Index name
158 * @param string $fname Calling function name
159 * @return Mixed: Database-specific index description class or false if the index does not exist
161 function indexInfo( $table, $index, $fname = __METHOD__
);
164 * Get the number of rows affected by the last write query
165 * @see http://www.php.net/mysql_affected_rows
169 function affectedRows();
172 * Wrapper for addslashes()
174 * @param string $s to be slashed.
175 * @return string: slashed string.
177 function strencode( $s );
180 * Returns a wikitext link to the DB's website, e.g.,
181 * return "[http://www.mysql.com/ MySQL]";
182 * Should at least contain plain text, if for some reason
183 * your database has no website.
185 * @return string: wikitext of a link to the server software's web site
187 static function getSoftwareLink();
190 * A string describing the current software version, like from
191 * mysql_get_server_info().
193 * @return string: Version information from the database server.
195 function getServerVersion();
198 * A string describing the current software version, and possibly
199 * other details in a user-friendly way. Will be listed on Special:Version, etc.
200 * Use getServerVersion() to get machine-friendly information.
202 * @return string: Version information from the database server
204 function getServerInfo();
208 * Database abstraction object
211 abstract class DatabaseBase
implements DatabaseType
{
212 /** Number of times to re-try an operation in case of deadlock */
213 const DEADLOCK_TRIES
= 4;
214 /** Minimum time to wait before retry, in microseconds */
215 const DEADLOCK_DELAY_MIN
= 500000;
216 /** Maximum time to wait before retry */
217 const DEADLOCK_DELAY_MAX
= 1500000;
219 # ------------------------------------------------------------------------------
221 # ------------------------------------------------------------------------------
223 protected $mLastQuery = '';
224 protected $mDoneWrites = false;
225 protected $mPHPError = false;
227 protected $mServer, $mUser, $mPassword, $mDBname;
229 protected $mConn = null;
230 protected $mOpened = false;
232 /** @var array of Closure */
233 protected $mTrxIdleCallbacks = array();
234 /** @var array of Closure */
235 protected $mTrxPreCommitCallbacks = array();
237 protected $mTablePrefix;
240 protected $mTrxLevel = 0;
241 protected $mErrorCount = 0;
242 protected $mLBInfo = array();
243 protected $mFakeSlaveLag = null, $mFakeMaster = false;
244 protected $mDefaultBigSelects = null;
245 protected $mSchemaVars = false;
247 protected $preparedArgs;
249 protected $htmlErrors;
251 protected $delimiter = ';';
254 * Remembers the function name given for starting the most recent transaction via begin().
255 * Used to provide additional context for error reporting.
258 * @see DatabaseBase::mTrxLevel
260 private $mTrxFname = null;
263 * Record if possible write queries were done in the last transaction started
266 * @see DatabaseBase::mTrxLevel
268 private $mTrxDoneWrites = false;
271 * Record if the current transaction was started implicitly due to DBO_TRX being set.
274 * @see DatabaseBase::mTrxLevel
276 private $mTrxAutomatic = false;
280 * @var file handle for upgrade
282 protected $fileHandle = null;
284 # ------------------------------------------------------------------------------
286 # ------------------------------------------------------------------------------
287 # These optionally set a variable and return the previous state
290 * A string describing the current software version, and possibly
291 * other details in a user-friendly way. Will be listed on Special:Version, etc.
292 * Use getServerVersion() to get machine-friendly information.
294 * @return string: Version information from the database server
296 public function getServerInfo() {
297 return $this->getServerVersion();
301 * @return string: command delimiter used by this database engine
303 public function getDelimiter() {
304 return $this->delimiter
;
308 * Boolean, controls output of large amounts of debug information.
309 * @param $debug bool|null
310 * - true to enable debugging
311 * - false to disable debugging
312 * - omitted or null to do nothing
314 * @return bool|null previous value of the flag
316 public function debug( $debug = null ) {
317 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
321 * Turns buffering of SQL result sets on (true) or off (false). Default is
324 * Unbuffered queries are very troublesome in MySQL:
326 * - If another query is executed while the first query is being read
327 * out, the first query is killed. This means you can't call normal
328 * MediaWiki functions while you are reading an unbuffered query result
329 * from a normal wfGetDB() connection.
331 * - Unbuffered queries cause the MySQL server to use large amounts of
332 * memory and to hold broad locks which block other queries.
334 * If you want to limit client-side memory, it's almost always better to
335 * split up queries into batches using a LIMIT clause than to switch off
338 * @param $buffer null|bool
340 * @return null|bool The previous value of the flag
342 public function bufferResults( $buffer = null ) {
343 if ( is_null( $buffer ) ) {
344 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
346 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
351 * Turns on (false) or off (true) the automatic generation and sending
352 * of a "we're sorry, but there has been a database error" page on
353 * database errors. Default is on (false). When turned off, the
354 * code should use lastErrno() and lastError() to handle the
355 * situation as appropriate.
357 * @param $ignoreErrors bool|null
359 * @return bool The previous value of the flag.
361 public function ignoreErrors( $ignoreErrors = null ) {
362 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
366 * Gets or sets the current transaction level.
368 * Historically, transactions were allowed to be "nested". This is no
369 * longer supported, so this function really only returns a boolean.
371 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
372 * @return int The previous value
374 public function trxLevel( $level = null ) {
375 return wfSetVar( $this->mTrxLevel
, $level );
379 * Get/set the number of errors logged. Only useful when errors are ignored
380 * @param int $count The count to set, or omitted to leave it unchanged.
381 * @return int The error count
383 public function errorCount( $count = null ) {
384 return wfSetVar( $this->mErrorCount
, $count );
388 * Get/set the table prefix.
389 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
390 * @return string The previous table prefix.
392 public function tablePrefix( $prefix = null ) {
393 return wfSetVar( $this->mTablePrefix
, $prefix );
397 * Set the filehandle to copy write statements to.
399 * @param $fh filehandle
401 public function setFileHandle( $fh ) {
402 $this->fileHandle
= $fh;
406 * Get properties passed down from the server info array of the load
409 * @param string $name The entry of the info array to get, or null to get the
412 * @return LoadBalancer|null
414 public function getLBInfo( $name = null ) {
415 if ( is_null( $name ) ) {
416 return $this->mLBInfo
;
418 if ( array_key_exists( $name, $this->mLBInfo
) ) {
419 return $this->mLBInfo
[$name];
427 * Set the LB info array, or a member of it. If called with one parameter,
428 * the LB info array is set to that parameter. If it is called with two
429 * parameters, the member with the given name is set to the given value.
434 public function setLBInfo( $name, $value = null ) {
435 if ( is_null( $value ) ) {
436 $this->mLBInfo
= $name;
438 $this->mLBInfo
[$name] = $value;
443 * Set lag time in seconds for a fake slave
447 public function setFakeSlaveLag( $lag ) {
448 $this->mFakeSlaveLag
= $lag;
452 * Make this connection a fake master
454 * @param $enabled bool
456 public function setFakeMaster( $enabled = true ) {
457 $this->mFakeMaster
= $enabled;
461 * Returns true if this database supports (and uses) cascading deletes
465 public function cascadingDeletes() {
470 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
474 public function cleanupTriggers() {
479 * Returns true if this database is strict about what can be put into an IP field.
480 * Specifically, it uses a NULL value instead of an empty string.
484 public function strictIPs() {
489 * Returns true if this database uses timestamps rather than integers
493 public function realTimestamps() {
498 * Returns true if this database does an implicit sort when doing GROUP BY
502 public function implicitGroupby() {
507 * Returns true if this database does an implicit order by when the column has an index
508 * For example: SELECT page_title FROM page LIMIT 1
512 public function implicitOrderby() {
517 * Returns true if this database can do a native search on IP columns
518 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
522 public function searchableIPs() {
527 * Returns true if this database can use functional indexes
531 public function functionalIndexes() {
536 * Return the last query that went through DatabaseBase::query()
539 public function lastQuery() {
540 return $this->mLastQuery
;
544 * Returns true if the connection may have been used for write queries.
545 * Should return true if unsure.
549 public function doneWrites() {
550 return $this->mDoneWrites
;
554 * Returns true if there is a transaction open with possible write
555 * queries or transaction pre-commit/idle callbacks waiting on it to finish.
559 public function writesOrCallbacksPending() {
560 return $this->mTrxLevel
&& (
561 $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks ||
$this->mTrxPreCommitCallbacks
566 * Is a connection to the database open?
569 public function isOpen() {
570 return $this->mOpened
;
574 * Set a flag for this connection
576 * @param $flag Integer: DBO_* constants from Defines.php:
577 * - DBO_DEBUG: output some debug info (same as debug())
578 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
579 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
580 * - DBO_TRX: automatically start transactions
581 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
582 * and removes it in command line mode
583 * - DBO_PERSISTENT: use persistant database connection
585 public function setFlag( $flag ) {
586 global $wgDebugDBTransactions;
587 $this->mFlags |
= $flag;
588 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
589 wfDebug( "Implicit transactions are now disabled.\n" );
594 * Clear a flag for this connection
596 * @param $flag: same as setFlag()'s $flag param
598 public function clearFlag( $flag ) {
599 global $wgDebugDBTransactions;
600 $this->mFlags
&= ~
$flag;
601 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
602 wfDebug( "Implicit transactions are now disabled.\n" );
607 * Returns a boolean whether the flag $flag is set for this connection
609 * @param $flag: same as setFlag()'s $flag param
612 public function getFlag( $flag ) {
613 return !!( $this->mFlags
& $flag );
617 * General read-only accessor
619 * @param $name string
623 public function getProperty( $name ) {
630 public function getWikiID() {
631 if ( $this->mTablePrefix
) {
632 return "{$this->mDBname}-{$this->mTablePrefix}";
634 return $this->mDBname
;
639 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
643 public function getSchemaPath() {
645 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
646 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
648 return "$IP/maintenance/tables.sql";
652 # ------------------------------------------------------------------------------
654 # ------------------------------------------------------------------------------
658 * @param string $server database server host
659 * @param string $user database user name
660 * @param string $password database user password
661 * @param string $dbName database name
663 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
664 * @param bool $foreign disable some operations specific to local databases
666 function __construct( $server = false, $user = false, $password = false, $dbName = false,
667 $flags = 0, $tablePrefix = 'get from global', $foreign = false
669 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
671 $this->mFlags
= $flags;
673 if ( $this->mFlags
& DBO_DEFAULT
) {
674 if ( $wgCommandLineMode ) {
675 $this->mFlags
&= ~DBO_TRX
;
676 if ( $wgDebugDBTransactions ) {
677 wfDebug( "Implicit transaction open disabled.\n" );
680 $this->mFlags |
= DBO_TRX
;
681 if ( $wgDebugDBTransactions ) {
682 wfDebug( "Implicit transaction open enabled.\n" );
687 /** Get the default table prefix*/
688 if ( $tablePrefix == 'get from global' ) {
689 $this->mTablePrefix
= $wgDBprefix;
691 $this->mTablePrefix
= $tablePrefix;
694 $this->mForeign
= $foreign;
697 $this->open( $server, $user, $password, $dbName );
702 * Called by serialize. Throw an exception when DB connection is serialized.
703 * This causes problems on some database engines because the connection is
704 * not restored on unserialize.
706 public function __sleep() {
707 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
711 * Given a DB type, construct the name of the appropriate child class of
712 * DatabaseBase. This is designed to replace all of the manual stuff like:
713 * $class = 'Database' . ucfirst( strtolower( $type ) );
714 * as well as validate against the canonical list of DB types we have
716 * This factory function is mostly useful for when you need to connect to a
717 * database other than the MediaWiki default (such as for external auth,
718 * an extension, et cetera). Do not use this to connect to the MediaWiki
719 * database. Example uses in core:
720 * @see LoadBalancer::reallyOpenConnection()
721 * @see ForeignDBRepo::getMasterDB()
722 * @see WebInstaller_DBConnect::execute()
726 * @param string $dbType A possible DB type
727 * @param array $p An array of options to pass to the constructor.
728 * Valid options are: host, user, password, dbname, flags, tablePrefix
729 * @return DatabaseBase subclass or null
731 final public static function factory( $dbType, $p = array() ) {
732 $canonicalDBTypes = array(
733 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
735 $dbType = strtolower( $dbType );
736 $class = 'Database' . ucfirst( $dbType );
738 if ( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
740 isset( $p['host'] ) ?
$p['host'] : false,
741 isset( $p['user'] ) ?
$p['user'] : false,
742 isset( $p['password'] ) ?
$p['password'] : false,
743 isset( $p['dbname'] ) ?
$p['dbname'] : false,
744 isset( $p['flags'] ) ?
$p['flags'] : 0,
745 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global',
746 isset( $p['foreign'] ) ?
$p['foreign'] : false
753 protected function installErrorHandler() {
754 $this->mPHPError
= false;
755 $this->htmlErrors
= ini_set( 'html_errors', '0' );
756 set_error_handler( array( $this, 'connectionErrorHandler' ) );
760 * @return bool|string
762 protected function restoreErrorHandler() {
763 restore_error_handler();
764 if ( $this->htmlErrors
!== false ) {
765 ini_set( 'html_errors', $this->htmlErrors
);
767 if ( $this->mPHPError
) {
768 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
769 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
781 public function connectionErrorHandler( $errno, $errstr ) {
782 $this->mPHPError
= $errstr;
786 * Closes a database connection.
787 * if it is open : commits any open transactions
789 * @throws MWException
790 * @return Bool operation success. true if already closed.
792 public function close() {
793 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
794 throw new MWException( "Transaction idle callbacks still pending." );
796 $this->mOpened
= false;
797 if ( $this->mConn
) {
798 if ( $this->trxLevel() ) {
799 if ( !$this->mTrxAutomatic
) {
800 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
801 " performing implicit commit before closing connection!" );
804 $this->commit( __METHOD__
, 'flush' );
807 $ret = $this->closeConnection();
808 $this->mConn
= false;
816 * Closes underlying database connection
818 * @return bool: Whether connection was closed successfully
820 abstract protected function closeConnection();
823 * @param string $error fallback error message, used if none is given by DB
824 * @throws DBConnectionError
826 function reportConnectionError( $error = 'Unknown error' ) {
827 $myError = $this->lastError();
833 throw new DBConnectionError( $this, $error );
837 * The DBMS-dependent part of query()
839 * @param $sql String: SQL query.
840 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
842 abstract protected function doQuery( $sql );
845 * Determine whether a query writes to the DB.
846 * Should return true if unsure.
852 public function isWriteQuery( $sql ) {
853 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
857 * Run an SQL query and return the result. Normally throws a DBQueryError
858 * on failure. If errors are ignored, returns false instead.
860 * In new code, the query wrappers select(), insert(), update(), delete(),
861 * etc. should be used where possible, since they give much better DBMS
862 * independence and automatically quote or validate user input in a variety
863 * of contexts. This function is generally only useful for queries which are
864 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
867 * However, the query wrappers themselves should call this function.
869 * @param $sql String: SQL query
870 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
871 * comment (you can use __METHOD__ or add some extra info)
872 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
873 * maybe best to catch the exception instead?
874 * @throws MWException
875 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
876 * for a successful read query, or false on failure if $tempIgnore set
878 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
879 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
880 if ( !Profiler
::instance()->isStub() ) {
881 # generalizeSQL will probably cut down the query to reasonable
882 # logging size most of the time. The substr is really just a sanity check.
885 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
886 $totalProf = 'DatabaseBase::query-master';
888 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
889 $totalProf = 'DatabaseBase::query';
892 wfProfileIn( $totalProf );
893 wfProfileIn( $queryProf );
896 $this->mLastQuery
= $sql;
897 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
898 # Set a flag indicating that writes have been done
899 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
900 $this->mDoneWrites
= true;
903 # Add a comment for easy SHOW PROCESSLIST interpretation
905 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
906 $userName = $wgUser->getName();
907 if ( mb_strlen( $userName ) > 15 ) {
908 $userName = mb_substr( $userName, 0, 15 ) . '...';
910 $userName = str_replace( '/', '', $userName );
915 // Add trace comment to the begin of the sql string, right after the operator.
916 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
917 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
919 # If DBO_TRX is set, start a transaction
920 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
921 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
923 # Avoid establishing transactions for SHOW and SET statements too -
924 # that would delay transaction initializations to once connection
925 # is really used by application
926 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
927 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
928 global $wgDebugDBTransactions;
929 if ( $wgDebugDBTransactions ) {
930 wfDebug( "Implicit transaction start.\n" );
932 $this->begin( __METHOD__
. " ($fname)" );
933 $this->mTrxAutomatic
= true;
937 # Keep track of whether the transaction has write queries pending
938 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
939 $this->mTrxDoneWrites
= true;
942 if ( $this->debug() ) {
946 $sqlx = substr( $commentedSql, 0, 500 );
947 $sqlx = strtr( $sqlx, "\t\n", ' ' );
949 $master = $isMaster ?
'master' : 'slave';
950 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
953 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
955 # Do the query and handle errors
956 $ret = $this->doQuery( $commentedSql );
958 MWDebug
::queryTime( $queryId );
960 # Try reconnecting if the connection was lost
961 if ( false === $ret && $this->wasErrorReissuable() ) {
962 # Transaction is gone, like it or not
963 $this->mTrxLevel
= 0;
964 $this->mTrxIdleCallbacks
= array(); // cancel
965 $this->mTrxPreCommitCallbacks
= array(); // cancel
966 wfDebug( "Connection lost, reconnecting...\n" );
968 if ( $this->ping() ) {
969 wfDebug( "Reconnected\n" );
970 $sqlx = substr( $commentedSql, 0, 500 );
971 $sqlx = strtr( $sqlx, "\t\n", ' ' );
972 global $wgRequestTime;
973 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
974 if ( $elapsed < 300 ) {
975 # Not a database error to lose a transaction after a minute or two
976 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
978 $ret = $this->doQuery( $commentedSql );
980 wfDebug( "Failed\n" );
984 if ( false === $ret ) {
985 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
988 if ( !Profiler
::instance()->isStub() ) {
989 wfProfileOut( $queryProf );
990 wfProfileOut( $totalProf );
993 return $this->resultObject( $ret );
997 * Report a query error. Log the error, and if neither the object ignore
998 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1000 * @param $error String
1001 * @param $errno Integer
1002 * @param $sql String
1003 * @param $fname String
1004 * @param $tempIgnore Boolean
1005 * @throws DBQueryError
1007 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1008 # Ignore errors during error handling to avoid infinite recursion
1009 $ignore = $this->ignoreErrors( true );
1010 ++
$this->mErrorCount
;
1012 if ( $ignore ||
$tempIgnore ) {
1013 wfDebug( "SQL ERROR (ignored): $error\n" );
1014 $this->ignoreErrors( $ignore );
1016 $sql1line = str_replace( "\n", "\\n", $sql );
1017 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1018 wfDebug( "SQL ERROR: " . $error . "\n" );
1019 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1024 * Intended to be compatible with the PEAR::DB wrapper functions.
1025 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1027 * ? = scalar value, quoted as necessary
1028 * ! = raw SQL bit (a function for instance)
1029 * & = filename; reads the file and inserts as a blob
1030 * (we don't use this though...)
1032 * @param $sql string
1033 * @param $func string
1037 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1038 /* MySQL doesn't support prepared statements (yet), so just
1039 pack up the query for reference. We'll manually replace
1041 return array( 'query' => $sql, 'func' => $func );
1045 * Free a prepared query, generated by prepare().
1048 protected function freePrepared( $prepared ) {
1049 /* No-op by default */
1053 * Execute a prepared query with the various arguments
1054 * @param string $prepared the prepared sql
1055 * @param $args Mixed: Either an array here, or put scalars as varargs
1057 * @return ResultWrapper
1059 public function execute( $prepared, $args = null ) {
1060 if ( !is_array( $args ) ) {
1062 $args = func_get_args();
1063 array_shift( $args );
1066 $sql = $this->fillPrepared( $prepared['query'], $args );
1068 return $this->query( $sql, $prepared['func'] );
1072 * For faking prepared SQL statements on DBs that don't support it directly.
1074 * @param string $preparedQuery a 'preparable' SQL statement
1075 * @param array $args of arguments to fill it with
1076 * @return string executable SQL
1078 public function fillPrepared( $preparedQuery, $args ) {
1080 $this->preparedArgs
=& $args;
1082 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1083 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1087 * preg_callback func for fillPrepared()
1088 * The arguments should be in $this->preparedArgs and must not be touched
1089 * while we're doing this.
1091 * @param $matches Array
1092 * @throws DBUnexpectedError
1095 protected function fillPreparedArg( $matches ) {
1096 switch ( $matches[1] ) {
1105 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1107 switch ( $matches[1] ) {
1109 return $this->addQuotes( $arg );
1113 # return $this->addQuotes( file_get_contents( $arg ) );
1114 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1116 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1121 * Free a result object returned by query() or select(). It's usually not
1122 * necessary to call this, just use unset() or let the variable holding
1123 * the result object go out of scope.
1125 * @param $res Mixed: A SQL result
1127 public function freeResult( $res ) {
1131 * A SELECT wrapper which returns a single field from a single result row.
1133 * Usually throws a DBQueryError on failure. If errors are explicitly
1134 * ignored, returns false on failure.
1136 * If no result rows are returned from the query, false is returned.
1138 * @param string|array $table Table name. See DatabaseBase::select() for details.
1139 * @param string $var The field name to select. This must be a valid SQL
1140 * fragment: do not use unvalidated user input.
1141 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1142 * @param string $fname The function name of the caller.
1143 * @param string|array $options The query options. See DatabaseBase::select() for details.
1145 * @return bool|mixed The value from the field, or false on failure.
1147 public function selectField( $table, $var, $cond = '', $fname = __METHOD__
,
1150 if ( !is_array( $options ) ) {
1151 $options = array( $options );
1154 $options['LIMIT'] = 1;
1156 $res = $this->select( $table, $var, $cond, $fname, $options );
1158 if ( $res === false ||
!$this->numRows( $res ) ) {
1162 $row = $this->fetchRow( $res );
1164 if ( $row !== false ) {
1165 return reset( $row );
1172 * Returns an optional USE INDEX clause to go after the table, and a
1173 * string to go at the end of the query.
1175 * @param array $options associative array of options to be turned into
1176 * an SQL query, valid keys are listed in the function.
1178 * @see DatabaseBase::select()
1180 public function makeSelectOptions( $options ) {
1181 $preLimitTail = $postLimitTail = '';
1184 $noKeyOptions = array();
1186 foreach ( $options as $key => $option ) {
1187 if ( is_numeric( $key ) ) {
1188 $noKeyOptions[$option] = true;
1192 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1194 $preLimitTail .= $this->makeOrderBy( $options );
1196 // if (isset($options['LIMIT'])) {
1197 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1198 // isset($options['OFFSET']) ? $options['OFFSET']
1202 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1203 $postLimitTail .= ' FOR UPDATE';
1206 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1207 $postLimitTail .= ' LOCK IN SHARE MODE';
1210 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1211 $startOpts .= 'DISTINCT';
1214 # Various MySQL extensions
1215 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1216 $startOpts .= ' /*! STRAIGHT_JOIN */';
1219 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1220 $startOpts .= ' HIGH_PRIORITY';
1223 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1224 $startOpts .= ' SQL_BIG_RESULT';
1227 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1228 $startOpts .= ' SQL_BUFFER_RESULT';
1231 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1232 $startOpts .= ' SQL_SMALL_RESULT';
1235 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1236 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1239 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1240 $startOpts .= ' SQL_CACHE';
1243 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1244 $startOpts .= ' SQL_NO_CACHE';
1247 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1248 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1253 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1257 * Returns an optional GROUP BY with an optional HAVING
1259 * @param array $options associative array of options
1261 * @see DatabaseBase::select()
1264 public function makeGroupByWithHaving( $options ) {
1266 if ( isset( $options['GROUP BY'] ) ) {
1267 $gb = is_array( $options['GROUP BY'] )
1268 ?
implode( ',', $options['GROUP BY'] )
1269 : $options['GROUP BY'];
1270 $sql .= ' GROUP BY ' . $gb;
1272 if ( isset( $options['HAVING'] ) ) {
1273 $having = is_array( $options['HAVING'] )
1274 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1275 : $options['HAVING'];
1276 $sql .= ' HAVING ' . $having;
1282 * Returns an optional ORDER BY
1284 * @param array $options associative array of options
1286 * @see DatabaseBase::select()
1289 public function makeOrderBy( $options ) {
1290 if ( isset( $options['ORDER BY'] ) ) {
1291 $ob = is_array( $options['ORDER BY'] )
1292 ?
implode( ',', $options['ORDER BY'] )
1293 : $options['ORDER BY'];
1294 return ' ORDER BY ' . $ob;
1300 * Execute a SELECT query constructed using the various parameters provided.
1301 * See below for full details of the parameters.
1303 * @param string|array $table Table name
1304 * @param string|array $vars Field names
1305 * @param string|array $conds Conditions
1306 * @param string $fname Caller function name
1307 * @param array $options Query options
1308 * @param $join_conds Array Join conditions
1310 * @param $table string|array
1312 * May be either an array of table names, or a single string holding a table
1313 * name. If an array is given, table aliases can be specified, for example:
1315 * array( 'a' => 'user' )
1317 * This includes the user table in the query, with the alias "a" available
1318 * for use in field names (e.g. a.user_name).
1320 * All of the table names given here are automatically run through
1321 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1322 * added, and various other table name mappings to be performed.
1325 * @param $vars string|array
1327 * May be either a field name or an array of field names. The field names
1328 * can be complete fragments of SQL, for direct inclusion into the SELECT
1329 * query. If an array is given, field aliases can be specified, for example:
1331 * array( 'maxrev' => 'MAX(rev_id)' )
1333 * This includes an expression with the alias "maxrev" in the query.
1335 * If an expression is given, care must be taken to ensure that it is
1339 * @param $conds string|array
1341 * May be either a string containing a single condition, or an array of
1342 * conditions. If an array is given, the conditions constructed from each
1343 * element are combined with AND.
1345 * Array elements may take one of two forms:
1347 * - Elements with a numeric key are interpreted as raw SQL fragments.
1348 * - Elements with a string key are interpreted as equality conditions,
1349 * where the key is the field name.
1350 * - If the value of such an array element is a scalar (such as a
1351 * string), it will be treated as data and thus quoted appropriately.
1352 * If it is null, an IS NULL clause will be added.
1353 * - If the value is an array, an IN(...) clause will be constructed,
1354 * such that the field name may match any of the elements in the
1355 * array. The elements of the array will be quoted.
1357 * Note that expressions are often DBMS-dependent in their syntax.
1358 * DBMS-independent wrappers are provided for constructing several types of
1359 * expression commonly used in condition queries. See:
1360 * - DatabaseBase::buildLike()
1361 * - DatabaseBase::conditional()
1364 * @param $options string|array
1366 * Optional: Array of query options. Boolean options are specified by
1367 * including them in the array as a string value with a numeric key, for
1370 * array( 'FOR UPDATE' )
1372 * The supported options are:
1374 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1375 * with LIMIT can theoretically be used for paging through a result set,
1376 * but this is discouraged in MediaWiki for performance reasons.
1378 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1379 * and then the first rows are taken until the limit is reached. LIMIT
1380 * is applied to a result set after OFFSET.
1382 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1383 * changed until the next COMMIT.
1385 * - DISTINCT: Boolean: return only unique result rows.
1387 * - GROUP BY: May be either an SQL fragment string naming a field or
1388 * expression to group by, or an array of such SQL fragments.
1390 * - HAVING: May be either an string containing a HAVING clause or an array of
1391 * conditions building the HAVING clause. If an array is given, the conditions
1392 * constructed from each element are combined with AND.
1394 * - ORDER BY: May be either an SQL fragment giving a field name or
1395 * expression to order by, or an array of such SQL fragments.
1397 * - USE INDEX: This may be either a string giving the index name to use
1398 * for the query, or an array. If it is an associative array, each key
1399 * gives the table name (or alias), each value gives the index name to
1400 * use for that table. All strings are SQL fragments and so should be
1401 * validated by the caller.
1403 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1404 * instead of SELECT.
1406 * And also the following boolean MySQL extensions, see the MySQL manual
1407 * for documentation:
1409 * - LOCK IN SHARE MODE
1413 * - SQL_BUFFER_RESULT
1414 * - SQL_SMALL_RESULT
1415 * - SQL_CALC_FOUND_ROWS
1420 * @param $join_conds string|array
1422 * Optional associative array of table-specific join conditions. In the
1423 * most common case, this is unnecessary, since the join condition can be
1424 * in $conds. However, it is useful for doing a LEFT JOIN.
1426 * The key of the array contains the table name or alias. The value is an
1427 * array with two elements, numbered 0 and 1. The first gives the type of
1428 * join, the second is an SQL fragment giving the join condition for that
1429 * table. For example:
1431 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1433 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1434 * with no rows in it will be returned. If there was a query error, a
1435 * DBQueryError exception will be thrown, except if the "ignore errors"
1436 * option was set, in which case false will be returned.
1438 public function select( $table, $vars, $conds = '', $fname = __METHOD__
,
1439 $options = array(), $join_conds = array() ) {
1440 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1442 return $this->query( $sql, $fname );
1446 * The equivalent of DatabaseBase::select() except that the constructed SQL
1447 * is returned, instead of being immediately executed. This can be useful for
1448 * doing UNION queries, where the SQL text of each query is needed. In general,
1449 * however, callers outside of Database classes should just use select().
1451 * @param string|array $table Table name
1452 * @param string|array $vars Field names
1453 * @param string|array $conds Conditions
1454 * @param string $fname Caller function name
1455 * @param string|array $options Query options
1456 * @param $join_conds string|array Join conditions
1458 * @return string SQL query string.
1459 * @see DatabaseBase::select()
1461 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1462 $options = array(), $join_conds = array() )
1464 if ( is_array( $vars ) ) {
1465 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1468 $options = (array)$options;
1470 if ( is_array( $table ) ) {
1471 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1472 ?
$options['USE INDEX']
1474 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1476 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1478 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1480 } elseif ( $table != '' ) {
1481 if ( $table[0] == ' ' ) {
1482 $from = ' FROM ' . $table;
1484 $from = ' FROM ' . $this->tableName( $table );
1490 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1492 if ( !empty( $conds ) ) {
1493 if ( is_array( $conds ) ) {
1494 $conds = $this->makeList( $conds, LIST_AND
);
1496 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1498 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1501 if ( isset( $options['LIMIT'] ) ) {
1502 $sql = $this->limitResult( $sql, $options['LIMIT'],
1503 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1505 $sql = "$sql $postLimitTail";
1507 if ( isset( $options['EXPLAIN'] ) ) {
1508 $sql = 'EXPLAIN ' . $sql;
1515 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1516 * that a single row object is returned. If the query returns no rows,
1517 * false is returned.
1519 * @param string|array $table Table name
1520 * @param string|array $vars Field names
1521 * @param array $conds Conditions
1522 * @param string $fname Caller function name
1523 * @param string|array $options Query options
1524 * @param $join_conds array|string Join conditions
1526 * @return object|bool
1528 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1529 $options = array(), $join_conds = array() )
1531 $options = (array)$options;
1532 $options['LIMIT'] = 1;
1533 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1535 if ( $res === false ) {
1539 if ( !$this->numRows( $res ) ) {
1543 $obj = $this->fetchObject( $res );
1549 * Estimate rows in dataset.
1551 * MySQL allows you to estimate the number of rows that would be returned
1552 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1553 * index cardinality statistics, and is notoriously inaccurate, especially
1554 * when large numbers of rows have recently been added or deleted.
1556 * For DBMSs that don't support fast result size estimation, this function
1557 * will actually perform the SELECT COUNT(*).
1559 * Takes the same arguments as DatabaseBase::select().
1561 * @param string $table table name
1562 * @param array|string $vars : unused
1563 * @param array|string $conds : filters on the table
1564 * @param string $fname function name for profiling
1565 * @param array $options options for select
1566 * @return Integer: row count
1568 public function estimateRowCount( $table, $vars = '*', $conds = '',
1569 $fname = __METHOD__
, $options = array() )
1572 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1575 $row = $this->fetchRow( $res );
1576 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1583 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1584 * It's only slightly flawed. Don't use for anything important.
1586 * @param string $sql A SQL Query
1590 static function generalizeSQL( $sql ) {
1591 # This does the same as the regexp below would do, but in such a way
1592 # as to avoid crashing php on some large strings.
1593 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1595 $sql = str_replace( "\\\\", '', $sql );
1596 $sql = str_replace( "\\'", '', $sql );
1597 $sql = str_replace( "\\\"", '', $sql );
1598 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1599 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1601 # All newlines, tabs, etc replaced by single space
1602 $sql = preg_replace( '/\s+/', ' ', $sql );
1605 $sql = preg_replace( '/-?[0-9]+/s', 'N', $sql );
1611 * Determines whether a field exists in a table
1613 * @param string $table table name
1614 * @param string $field filed to check on that table
1615 * @param string $fname calling function name (optional)
1616 * @return Boolean: whether $table has filed $field
1618 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1619 $info = $this->fieldInfo( $table, $field );
1625 * Determines whether an index exists
1626 * Usually throws a DBQueryError on failure
1627 * If errors are explicitly ignored, returns NULL on failure
1631 * @param $fname string
1635 public function indexExists( $table, $index, $fname = __METHOD__
) {
1636 if ( !$this->tableExists( $table ) ) {
1640 $info = $this->indexInfo( $table, $index, $fname );
1641 if ( is_null( $info ) ) {
1644 return $info !== false;
1649 * Query whether a given table exists
1651 * @param $table string
1652 * @param $fname string
1656 public function tableExists( $table, $fname = __METHOD__
) {
1657 $table = $this->tableName( $table );
1658 $old = $this->ignoreErrors( true );
1659 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1660 $this->ignoreErrors( $old );
1666 * mysql_field_type() wrapper
1671 public function fieldType( $res, $index ) {
1672 if ( $res instanceof ResultWrapper
) {
1673 $res = $res->result
;
1676 return mysql_field_type( $res, $index );
1680 * Determines if a given index is unique
1682 * @param $table string
1683 * @param $index string
1687 public function indexUnique( $table, $index ) {
1688 $indexInfo = $this->indexInfo( $table, $index );
1690 if ( !$indexInfo ) {
1694 return !$indexInfo[0]->Non_unique
;
1698 * Helper for DatabaseBase::insert().
1700 * @param $options array
1703 protected function makeInsertOptions( $options ) {
1704 return implode( ' ', $options );
1708 * INSERT wrapper, inserts an array into a table.
1712 * - A single associative array. The array keys are the field names, and
1713 * the values are the values to insert. The values are treated as data
1714 * and will be quoted appropriately. If NULL is inserted, this will be
1715 * converted to a database NULL.
1716 * - An array with numeric keys, holding a list of associative arrays.
1717 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1718 * each subarray must be identical to each other, and in the same order.
1720 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1723 * $options is an array of options, with boolean options encoded as values
1724 * with numeric keys, in the same style as $options in
1725 * DatabaseBase::select(). Supported options are:
1727 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1728 * any rows which cause duplicate key errors are not inserted. It's
1729 * possible to determine how many rows were successfully inserted using
1730 * DatabaseBase::affectedRows().
1732 * @param $table String Table name. This will be passed through
1733 * DatabaseBase::tableName().
1734 * @param $a Array of rows to insert
1735 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1736 * @param array $options of options
1740 public function insert( $table, $a, $fname = __METHOD__
, $options = array() ) {
1741 # No rows to insert, easy just return now
1742 if ( !count( $a ) ) {
1746 $table = $this->tableName( $table );
1748 if ( !is_array( $options ) ) {
1749 $options = array( $options );
1753 if ( isset( $options['fileHandle'] ) ) {
1754 $fh = $options['fileHandle'];
1756 $options = $this->makeInsertOptions( $options );
1758 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1760 $keys = array_keys( $a[0] );
1763 $keys = array_keys( $a );
1766 $sql = 'INSERT ' . $options .
1767 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1771 foreach ( $a as $row ) {
1777 $sql .= '(' . $this->makeList( $row ) . ')';
1780 $sql .= '(' . $this->makeList( $a ) . ')';
1783 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1785 } elseif ( $fh !== null ) {
1789 return (bool)$this->query( $sql, $fname );
1793 * Make UPDATE options for the DatabaseBase::update function
1795 * @param array $options The options passed to DatabaseBase::update
1798 protected function makeUpdateOptions( $options ) {
1799 if ( !is_array( $options ) ) {
1800 $options = array( $options );
1805 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1806 $opts[] = $this->lowPriorityOption();
1809 if ( in_array( 'IGNORE', $options ) ) {
1813 return implode( ' ', $opts );
1817 * UPDATE wrapper. Takes a condition array and a SET array.
1819 * @param $table String name of the table to UPDATE. This will be passed through
1820 * DatabaseBase::tableName().
1822 * @param array $values An array of values to SET. For each array element,
1823 * the key gives the field name, and the value gives the data
1824 * to set that field to. The data will be quoted by
1825 * DatabaseBase::addQuotes().
1827 * @param $conds Array: An array of conditions (WHERE). See
1828 * DatabaseBase::select() for the details of the format of
1829 * condition arrays. Use '*' to update all rows.
1831 * @param $fname String: The function name of the caller (from __METHOD__),
1832 * for logging and profiling.
1834 * @param array $options An array of UPDATE options, can be:
1835 * - IGNORE: Ignore unique key conflicts
1836 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1839 function update( $table, $values, $conds, $fname = __METHOD__
, $options = array() ) {
1840 $table = $this->tableName( $table );
1841 $opts = $this->makeUpdateOptions( $options );
1842 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1844 if ( $conds !== array() && $conds !== '*' ) {
1845 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1848 return $this->query( $sql, $fname );
1852 * Makes an encoded list of strings from an array
1853 * @param array $a containing the data
1854 * @param int $mode Constant
1855 * - LIST_COMMA: comma separated, no field names
1856 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1857 * the documentation for $conds in DatabaseBase::select().
1858 * - LIST_OR: ORed WHERE clause (without the WHERE)
1859 * - LIST_SET: comma separated with field names, like a SET clause
1860 * - LIST_NAMES: comma separated field names
1862 * @throws MWException|DBUnexpectedError
1865 public function makeList( $a, $mode = LIST_COMMA
) {
1866 if ( !is_array( $a ) ) {
1867 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1873 foreach ( $a as $field => $value ) {
1875 if ( $mode == LIST_AND
) {
1877 } elseif ( $mode == LIST_OR
) {
1886 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1887 $list .= "($value)";
1888 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1890 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1891 if ( count( $value ) == 0 ) {
1892 throw new MWException( __METHOD__
. ": empty input for field $field" );
1893 } elseif ( count( $value ) == 1 ) {
1894 // Special-case single values, as IN isn't terribly efficient
1895 // Don't necessarily assume the single key is 0; we don't
1896 // enforce linear numeric ordering on other arrays here.
1897 $value = array_values( $value );
1898 $list .= $field . " = " . $this->addQuotes( $value[0] );
1900 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1902 } elseif ( $value === null ) {
1903 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1904 $list .= "$field IS ";
1905 } elseif ( $mode == LIST_SET
) {
1906 $list .= "$field = ";
1910 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1911 $list .= "$field = ";
1913 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1921 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1922 * The keys on each level may be either integers or strings.
1924 * @param array $data organized as 2-d
1925 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1926 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1927 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1928 * @return Mixed: string SQL fragment, or false if no items in array.
1930 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1933 foreach ( $data as $base => $sub ) {
1934 if ( count( $sub ) ) {
1935 $conds[] = $this->makeList(
1936 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1942 return $this->makeList( $conds, LIST_OR
);
1944 // Nothing to search for...
1950 * Return aggregated value alias
1953 * @param $valuename string
1957 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1965 public function bitNot( $field ) {
1971 * @param $fieldRight
1974 public function bitAnd( $fieldLeft, $fieldRight ) {
1975 return "($fieldLeft & $fieldRight)";
1980 * @param $fieldRight
1983 public function bitOr( $fieldLeft, $fieldRight ) {
1984 return "($fieldLeft | $fieldRight)";
1988 * Build a concatenation list to feed into a SQL query
1989 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
1992 public function buildConcat( $stringList ) {
1993 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1997 * Change the current database
1999 * @todo Explain what exactly will fail if this is not overridden.
2003 * @return bool Success or failure
2005 public function selectDB( $db ) {
2006 # Stub. Shouldn't cause serious problems if it's not overridden, but
2007 # if your database engine supports a concept similar to MySQL's
2008 # databases you may as well.
2009 $this->mDBname
= $db;
2014 * Get the current DB name
2016 public function getDBname() {
2017 return $this->mDBname
;
2021 * Get the server hostname or IP address
2023 public function getServer() {
2024 return $this->mServer
;
2028 * Format a table name ready for use in constructing an SQL query
2030 * This does two important things: it quotes the table names to clean them up,
2031 * and it adds a table prefix if only given a table name with no quotes.
2033 * All functions of this object which require a table name call this function
2034 * themselves. Pass the canonical name to such functions. This is only needed
2035 * when calling query() directly.
2037 * @param string $name database table name
2038 * @param string $format One of:
2039 * quoted - Automatically pass the table name through addIdentifierQuotes()
2040 * so that it can be used in a query.
2041 * raw - Do not add identifier quotes to the table name
2042 * @return String: full database name
2044 public function tableName( $name, $format = 'quoted' ) {
2045 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2046 # Skip the entire process when we have a string quoted on both ends.
2047 # Note that we check the end so that we will still quote any use of
2048 # use of `database`.table. But won't break things if someone wants
2049 # to query a database table with a dot in the name.
2050 if ( $this->isQuotedIdentifier( $name ) ) {
2054 # Lets test for any bits of text that should never show up in a table
2055 # name. Basically anything like JOIN or ON which are actually part of
2056 # SQL queries, but may end up inside of the table value to combine
2057 # sql. Such as how the API is doing.
2058 # Note that we use a whitespace test rather than a \b test to avoid
2059 # any remote case where a word like on may be inside of a table name
2060 # surrounded by symbols which may be considered word breaks.
2061 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2065 # Split database and table into proper variables.
2066 # We reverse the explode so that database.table and table both output
2067 # the correct table.
2068 $dbDetails = explode( '.', $name, 2 );
2069 if ( count( $dbDetails ) == 2 ) {
2070 list( $database, $table ) = $dbDetails;
2071 # We don't want any prefix added in this case
2074 list( $table ) = $dbDetails;
2075 if ( $wgSharedDB !== null # We have a shared database
2076 && $this->mForeign
== false # We're not working on a foreign database
2077 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2078 && in_array( $table, $wgSharedTables ) # A shared table is selected
2080 $database = $wgSharedDB;
2081 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
2084 $prefix = $this->mTablePrefix
; # Default prefix
2088 # Quote $table and apply the prefix if not quoted.
2089 $tableName = "{$prefix}{$table}";
2090 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2091 $tableName = $this->addIdentifierQuotes( $tableName );
2094 # Quote $database and merge it with the table name if needed
2095 if ( $database !== null ) {
2096 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2097 $database = $this->addIdentifierQuotes( $database );
2099 $tableName = $database . '.' . $tableName;
2106 * Fetch a number of table names into an array
2107 * This is handy when you need to construct SQL for joins
2110 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2111 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2112 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2116 public function tableNames() {
2117 $inArray = func_get_args();
2120 foreach ( $inArray as $name ) {
2121 $retVal[$name] = $this->tableName( $name );
2128 * Fetch a number of table names into an zero-indexed numerical array
2129 * This is handy when you need to construct SQL for joins
2132 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2133 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2134 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2138 public function tableNamesN() {
2139 $inArray = func_get_args();
2142 foreach ( $inArray as $name ) {
2143 $retVal[] = $this->tableName( $name );
2150 * Get an aliased table name
2151 * e.g. tableName AS newTableName
2153 * @param string $name Table name, see tableName()
2154 * @param string|bool $alias Alias (optional)
2155 * @return string SQL name for aliased table. Will not alias a table to its own name
2157 public function tableNameWithAlias( $name, $alias = false ) {
2158 if ( !$alias ||
$alias == $name ) {
2159 return $this->tableName( $name );
2161 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2166 * Gets an array of aliased table names
2168 * @param $tables array( [alias] => table )
2169 * @return array of strings, see tableNameWithAlias()
2171 public function tableNamesWithAlias( $tables ) {
2173 foreach ( $tables as $alias => $table ) {
2174 if ( is_numeric( $alias ) ) {
2177 $retval[] = $this->tableNameWithAlias( $table, $alias );
2183 * Get an aliased field name
2184 * e.g. fieldName AS newFieldName
2186 * @param string $name Field name
2187 * @param string|bool $alias Alias (optional)
2188 * @return string SQL name for aliased field. Will not alias a field to its own name
2190 public function fieldNameWithAlias( $name, $alias = false ) {
2191 if ( !$alias ||
(string)$alias === (string)$name ) {
2194 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2199 * Gets an array of aliased field names
2201 * @param $fields array( [alias] => field )
2202 * @return array of strings, see fieldNameWithAlias()
2204 public function fieldNamesWithAlias( $fields ) {
2206 foreach ( $fields as $alias => $field ) {
2207 if ( is_numeric( $alias ) ) {
2210 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2216 * Get the aliased table name clause for a FROM clause
2217 * which might have a JOIN and/or USE INDEX clause
2219 * @param array $tables ( [alias] => table )
2220 * @param $use_index array Same as for select()
2221 * @param $join_conds array Same as for select()
2224 protected function tableNamesWithUseIndexOrJOIN(
2225 $tables, $use_index = array(), $join_conds = array()
2229 $use_index = (array)$use_index;
2230 $join_conds = (array)$join_conds;
2232 foreach ( $tables as $alias => $table ) {
2233 if ( !is_string( $alias ) ) {
2234 // No alias? Set it equal to the table name
2237 // Is there a JOIN clause for this table?
2238 if ( isset( $join_conds[$alias] ) ) {
2239 list( $joinType, $conds ) = $join_conds[$alias];
2240 $tableClause = $joinType;
2241 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2242 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2243 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2245 $tableClause .= ' ' . $use;
2248 $on = $this->makeList( (array)$conds, LIST_AND
);
2250 $tableClause .= ' ON (' . $on . ')';
2253 $retJOIN[] = $tableClause;
2254 // Is there an INDEX clause for this table?
2255 } elseif ( isset( $use_index[$alias] ) ) {
2256 $tableClause = $this->tableNameWithAlias( $table, $alias );
2257 $tableClause .= ' ' . $this->useIndexClause(
2258 implode( ',', (array)$use_index[$alias] ) );
2260 $ret[] = $tableClause;
2262 $tableClause = $this->tableNameWithAlias( $table, $alias );
2264 $ret[] = $tableClause;
2268 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2269 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2270 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2272 // Compile our final table clause
2273 return implode( ' ', array( $straightJoins, $otherJoins ) );
2277 * Get the name of an index in a given table
2283 protected function indexName( $index ) {
2284 // Backwards-compatibility hack
2286 'ar_usertext_timestamp' => 'usertext_timestamp',
2287 'un_user_id' => 'user_id',
2288 'un_user_ip' => 'user_ip',
2291 if ( isset( $renamed[$index] ) ) {
2292 return $renamed[$index];
2299 * If it's a string, adds quotes and backslashes
2300 * Otherwise returns as-is
2306 public function addQuotes( $s ) {
2307 if ( $s === null ) {
2310 # This will also quote numeric values. This should be harmless,
2311 # and protects against weird problems that occur when they really
2312 # _are_ strings such as article titles and string->number->string
2313 # conversion is not 1:1.
2314 return "'" . $this->strencode( $s ) . "'";
2319 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2320 * MySQL uses `backticks` while basically everything else uses double quotes.
2321 * Since MySQL is the odd one out here the double quotes are our generic
2322 * and we implement backticks in DatabaseMysql.
2328 public function addIdentifierQuotes( $s ) {
2329 return '"' . str_replace( '"', '""', $s ) . '"';
2333 * Returns if the given identifier looks quoted or not according to
2334 * the database convention for quoting identifiers .
2336 * @param $name string
2340 public function isQuotedIdentifier( $name ) {
2341 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2348 protected function escapeLikeInternal( $s ) {
2349 $s = str_replace( '\\', '\\\\', $s );
2350 $s = $this->strencode( $s );
2351 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2357 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2358 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2359 * Alternatively, the function could be provided with an array of aforementioned parameters.
2361 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2362 * for subpages of 'My page title'.
2363 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2366 * @return String: fully built LIKE statement
2368 public function buildLike() {
2369 $params = func_get_args();
2371 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2372 $params = $params[0];
2377 foreach ( $params as $value ) {
2378 if ( $value instanceof LikeMatch
) {
2379 $s .= $value->toString();
2381 $s .= $this->escapeLikeInternal( $value );
2385 return " LIKE '" . $s . "' ";
2389 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2393 public function anyChar() {
2394 return new LikeMatch( '_' );
2398 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2402 public function anyString() {
2403 return new LikeMatch( '%' );
2407 * Returns an appropriately quoted sequence value for inserting a new row.
2408 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2409 * subclass will return an integer, and save the value for insertId()
2411 * Any implementation of this function should *not* involve reusing
2412 * sequence numbers created for rolled-back transactions.
2413 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2414 * @param $seqName string
2417 public function nextSequenceValue( $seqName ) {
2422 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2423 * is only needed because a) MySQL must be as efficient as possible due to
2424 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2425 * which index to pick. Anyway, other databases might have different
2426 * indexes on a given table. So don't bother overriding this unless you're
2431 public function useIndexClause( $index ) {
2436 * REPLACE query wrapper.
2438 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2439 * except that when there is a duplicate key error, the old row is deleted
2440 * and the new row is inserted in its place.
2442 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2443 * perform the delete, we need to know what the unique indexes are so that
2444 * we know how to find the conflicting rows.
2446 * It may be more efficient to leave off unique indexes which are unlikely
2447 * to collide. However if you do this, you run the risk of encountering
2448 * errors which wouldn't have occurred in MySQL.
2450 * @param string $table The table to replace the row(s) in.
2451 * @param array $rows Can be either a single row to insert, or multiple rows,
2452 * in the same format as for DatabaseBase::insert()
2453 * @param array $uniqueIndexes is an array of indexes. Each element may be either
2454 * a field name or an array of field names
2455 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2457 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2458 $quotedTable = $this->tableName( $table );
2460 if ( count( $rows ) == 0 ) {
2465 if ( !is_array( reset( $rows ) ) ) {
2466 $rows = array( $rows );
2469 foreach ( $rows as $row ) {
2470 # Delete rows which collide
2471 if ( $uniqueIndexes ) {
2472 $sql = "DELETE FROM $quotedTable WHERE ";
2474 foreach ( $uniqueIndexes as $index ) {
2481 if ( is_array( $index ) ) {
2483 foreach ( $index as $col ) {
2489 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2492 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2496 $this->query( $sql, $fname );
2499 # Now insert the row
2500 $this->insert( $table, $row, $fname );
2505 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2508 * @param string $table Table name
2509 * @param array $rows Rows to insert
2510 * @param string $fname Caller function name
2512 * @return ResultWrapper
2514 protected function nativeReplace( $table, $rows, $fname ) {
2515 $table = $this->tableName( $table );
2518 if ( !is_array( reset( $rows ) ) ) {
2519 $rows = array( $rows );
2522 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2525 foreach ( $rows as $row ) {
2532 $sql .= '(' . $this->makeList( $row ) . ')';
2535 return $this->query( $sql, $fname );
2539 * DELETE where the condition is a join.
2541 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2542 * we use sub-selects
2544 * For safety, an empty $conds will not delete everything. If you want to
2545 * delete all rows where the join condition matches, set $conds='*'.
2547 * DO NOT put the join condition in $conds.
2549 * @param $delTable String: The table to delete from.
2550 * @param $joinTable String: The other table.
2551 * @param $delVar String: The variable to join on, in the first table.
2552 * @param $joinVar String: The variable to join on, in the second table.
2553 * @param $conds Array: Condition array of field names mapped to variables,
2554 * ANDed together in the WHERE clause
2555 * @param $fname String: Calling function name (use __METHOD__) for
2557 * @throws DBUnexpectedError
2559 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2560 $fname = __METHOD__
)
2563 throw new DBUnexpectedError( $this,
2564 'DatabaseBase::deleteJoin() called with empty $conds' );
2567 $delTable = $this->tableName( $delTable );
2568 $joinTable = $this->tableName( $joinTable );
2569 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2570 if ( $conds != '*' ) {
2571 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2575 $this->query( $sql, $fname );
2579 * Returns the size of a text field, or -1 for "unlimited"
2581 * @param $table string
2582 * @param $field string
2586 public function textFieldSize( $table, $field ) {
2587 $table = $this->tableName( $table );
2588 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2589 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2590 $row = $this->fetchObject( $res );
2594 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2604 * A string to insert into queries to show that they're low-priority, like
2605 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2606 * string and nothing bad should happen.
2608 * @return string Returns the text of the low priority option if it is
2609 * supported, or a blank string otherwise
2611 public function lowPriorityOption() {
2616 * DELETE query wrapper.
2618 * @param array $table Table name
2619 * @param string|array $conds of conditions. See $conds in DatabaseBase::select() for
2620 * the format. Use $conds == "*" to delete all rows
2621 * @param string $fname name of the calling function
2623 * @throws DBUnexpectedError
2624 * @return bool|ResultWrapper
2626 public function delete( $table, $conds, $fname = __METHOD__
) {
2628 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2631 $table = $this->tableName( $table );
2632 $sql = "DELETE FROM $table";
2634 if ( $conds != '*' ) {
2635 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2638 return $this->query( $sql, $fname );
2642 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2643 * into another table.
2645 * @param string $destTable The table name to insert into
2646 * @param string|array $srcTable May be either a table name, or an array of table names
2647 * to include in a join.
2649 * @param array $varMap must be an associative array of the form
2650 * array( 'dest1' => 'source1', ...). Source items may be literals
2651 * rather than field names, but strings should be quoted with
2652 * DatabaseBase::addQuotes()
2654 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
2655 * the details of the format of condition arrays. May be "*" to copy the
2658 * @param string $fname The function name of the caller, from __METHOD__
2660 * @param array $insertOptions Options for the INSERT part of the query, see
2661 * DatabaseBase::insert() for details.
2662 * @param array $selectOptions Options for the SELECT part of the query, see
2663 * DatabaseBase::select() for details.
2665 * @return ResultWrapper
2667 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2668 $fname = __METHOD__
,
2669 $insertOptions = array(), $selectOptions = array() )
2671 $destTable = $this->tableName( $destTable );
2673 if ( is_array( $insertOptions ) ) {
2674 $insertOptions = implode( ' ', $insertOptions );
2677 if ( !is_array( $selectOptions ) ) {
2678 $selectOptions = array( $selectOptions );
2681 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2683 if ( is_array( $srcTable ) ) {
2684 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2686 $srcTable = $this->tableName( $srcTable );
2689 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2690 " SELECT $startOpts " . implode( ',', $varMap ) .
2691 " FROM $srcTable $useIndex ";
2693 if ( $conds != '*' ) {
2694 if ( is_array( $conds ) ) {
2695 $conds = $this->makeList( $conds, LIST_AND
);
2697 $sql .= " WHERE $conds";
2700 $sql .= " $tailOpts";
2702 return $this->query( $sql, $fname );
2706 * Construct a LIMIT query with optional offset. This is used for query
2707 * pages. The SQL should be adjusted so that only the first $limit rows
2708 * are returned. If $offset is provided as well, then the first $offset
2709 * rows should be discarded, and the next $limit rows should be returned.
2710 * If the result of the query is not ordered, then the rows to be returned
2711 * are theoretically arbitrary.
2713 * $sql is expected to be a SELECT, if that makes a difference.
2715 * The version provided by default works in MySQL and SQLite. It will very
2716 * likely need to be overridden for most other DBMSes.
2718 * @param string $sql SQL query we will append the limit too
2719 * @param $limit Integer the SQL limit
2720 * @param $offset Integer|bool the SQL offset (default false)
2722 * @throws DBUnexpectedError
2725 public function limitResult( $sql, $limit, $offset = false ) {
2726 if ( !is_numeric( $limit ) ) {
2727 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2729 return "$sql LIMIT "
2730 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2735 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2736 * within the UNION construct.
2739 public function unionSupportsOrderAndLimit() {
2740 return true; // True for almost every DB supported
2744 * Construct a UNION query
2745 * This is used for providing overload point for other DB abstractions
2746 * not compatible with the MySQL syntax.
2747 * @param array $sqls SQL statements to combine
2748 * @param $all Boolean: use UNION ALL
2749 * @return String: SQL fragment
2751 public function unionQueries( $sqls, $all ) {
2752 $glue = $all ?
') UNION ALL (' : ') UNION (';
2753 return '(' . implode( $glue, $sqls ) . ')';
2757 * Returns an SQL expression for a simple conditional. This doesn't need
2758 * to be overridden unless CASE isn't supported in your DBMS.
2760 * @param string|array $cond SQL expression which will result in a boolean value
2761 * @param string $trueVal SQL expression to return if true
2762 * @param string $falseVal SQL expression to return if false
2763 * @return String: SQL fragment
2765 public function conditional( $cond, $trueVal, $falseVal ) {
2766 if ( is_array( $cond ) ) {
2767 $cond = $this->makeList( $cond, LIST_AND
);
2769 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2773 * Returns a comand for str_replace function in SQL query.
2774 * Uses REPLACE() in MySQL
2776 * @param string $orig column to modify
2777 * @param string $old column to seek
2778 * @param string $new column to replace with
2782 public function strreplace( $orig, $old, $new ) {
2783 return "REPLACE({$orig}, {$old}, {$new})";
2787 * Determines how long the server has been up
2792 public function getServerUptime() {
2797 * Determines if the last failure was due to a deadlock
2802 public function wasDeadlock() {
2807 * Determines if the last failure was due to a lock timeout
2812 public function wasLockTimeout() {
2817 * Determines if the last query error was something that should be dealt
2818 * with by pinging the connection and reissuing the query.
2823 public function wasErrorReissuable() {
2828 * Determines if the last failure was due to the database being read-only.
2833 public function wasReadOnlyError() {
2838 * Perform a deadlock-prone transaction.
2840 * This function invokes a callback function to perform a set of write
2841 * queries. If a deadlock occurs during the processing, the transaction
2842 * will be rolled back and the callback function will be called again.
2845 * $dbw->deadlockLoop( callback, ... );
2847 * Extra arguments are passed through to the specified callback function.
2849 * Returns whatever the callback function returned on its successful,
2850 * iteration, or false on error, for example if the retry limit was
2855 public function deadlockLoop() {
2856 $this->begin( __METHOD__
);
2857 $args = func_get_args();
2858 $function = array_shift( $args );
2859 $oldIgnore = $this->ignoreErrors( true );
2860 $tries = self
::DEADLOCK_TRIES
;
2862 if ( is_array( $function ) ) {
2863 $fname = $function[0];
2869 $retVal = call_user_func_array( $function, $args );
2870 $error = $this->lastError();
2871 $errno = $this->lastErrno();
2872 $sql = $this->lastQuery();
2875 if ( $this->wasDeadlock() ) {
2877 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
2879 $this->reportQueryError( $error, $errno, $sql, $fname );
2882 } while ( $this->wasDeadlock() && --$tries > 0 );
2884 $this->ignoreErrors( $oldIgnore );
2886 if ( $tries <= 0 ) {
2887 $this->rollback( __METHOD__
);
2888 $this->reportQueryError( $error, $errno, $sql, $fname );
2891 $this->commit( __METHOD__
);
2897 * Wait for the slave to catch up to a given master position.
2899 * @param $pos DBMasterPos object
2900 * @param $timeout Integer: the maximum number of seconds to wait for
2903 * @return integer: zero if the slave was past that position already,
2904 * greater than zero if we waited for some period of time, less than
2905 * zero if we timed out.
2907 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2908 wfProfileIn( __METHOD__
);
2910 if ( !is_null( $this->mFakeSlaveLag
) ) {
2911 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2913 if ( $wait > $timeout * 1e6
) {
2914 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2915 wfProfileOut( __METHOD__
);
2917 } elseif ( $wait > 0 ) {
2918 wfDebug( "Fake slave waiting $wait us\n" );
2920 wfProfileOut( __METHOD__
);
2923 wfDebug( "Fake slave up to date ($wait us)\n" );
2924 wfProfileOut( __METHOD__
);
2929 wfProfileOut( __METHOD__
);
2931 # Real waits are implemented in the subclass.
2936 * Get the replication position of this slave
2938 * @return DBMasterPos, or false if this is not a slave.
2940 public function getSlavePos() {
2941 if ( !is_null( $this->mFakeSlaveLag
) ) {
2942 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2943 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2952 * Get the position of this master
2954 * @return DBMasterPos, or false if this is not a master
2956 public function getMasterPos() {
2957 if ( $this->mFakeMaster
) {
2958 return new MySQLMasterPos( 'fake', microtime( true ) );
2965 * Run an anonymous function as soon as there is no transaction pending.
2966 * If there is a transaction and it is rolled back, then the callback is cancelled.
2967 * Queries in the function will run in AUTO-COMMIT mode unless there are begin() calls.
2968 * Callbacks must commit any transactions that they begin.
2970 * This is useful for updates to different systems or when separate transactions are needed.
2971 * For example, one might want to enqueue jobs into a system outside the database, but only
2972 * after the database is updated so that the jobs will see the data when they actually run.
2973 * It can also be used for updates that easily cause deadlocks if locks are held too long.
2975 * @param Closure $callback
2978 final public function onTransactionIdle( Closure
$callback ) {
2979 $this->mTrxIdleCallbacks
[] = $callback;
2980 if ( !$this->mTrxLevel
) {
2981 $this->runOnTransactionIdleCallbacks();
2986 * Run an anonymous function before the current transaction commits or now if there is none.
2987 * If there is a transaction and it is rolled back, then the callback is cancelled.
2988 * Callbacks must not start nor commit any transactions.
2990 * This is useful for updates that easily cause deadlocks if locks are held too long
2991 * but where atomicity is strongly desired for these updates and some related updates.
2993 * @param Closure $callback
2996 final public function onTransactionPreCommitOrIdle( Closure
$callback ) {
2997 if ( $this->mTrxLevel
) {
2998 $this->mTrxPreCommitCallbacks
[] = $callback;
3000 $this->onTransactionIdle( $callback ); // this will trigger immediately
3005 * Actually any "on transaction idle" callbacks.
3009 protected function runOnTransactionIdleCallbacks() {
3010 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
3012 $e = null; // last exception
3013 do { // callbacks may add callbacks :)
3014 $callbacks = $this->mTrxIdleCallbacks
;
3015 $this->mTrxIdleCallbacks
= array(); // recursion guard
3016 foreach ( $callbacks as $callback ) {
3018 $this->clearFlag( DBO_TRX
); // make each query its own transaction
3020 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
3021 } catch ( Exception
$e ) {
3024 } while ( count( $this->mTrxIdleCallbacks
) );
3026 if ( $e instanceof Exception
) {
3027 throw $e; // re-throw any last exception
3032 * Actually any "on transaction pre-commit" callbacks.
3036 protected function runOnTransactionPreCommitCallbacks() {
3037 $e = null; // last exception
3038 do { // callbacks may add callbacks :)
3039 $callbacks = $this->mTrxPreCommitCallbacks
;
3040 $this->mTrxPreCommitCallbacks
= array(); // recursion guard
3041 foreach ( $callbacks as $callback ) {
3044 } catch ( Exception
$e ) {}
3046 } while ( count( $this->mTrxPreCommitCallbacks
) );
3048 if ( $e instanceof Exception
) {
3049 throw $e; // re-throw any last exception
3054 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3055 * new transaction is started.
3057 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3058 * any previous database query will have started a transaction automatically.
3060 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3061 * transaction was started automatically because of the DBO_TRX flag.
3063 * @param $fname string
3065 final public function begin( $fname = __METHOD__
) {
3066 global $wgDebugDBTransactions;
3068 if ( $this->mTrxLevel
) { // implicit commit
3069 if ( !$this->mTrxAutomatic
) {
3070 // We want to warn about inadvertently nested begin/commit pairs, but not about
3071 // auto-committing implicit transactions that were started by query() via DBO_TRX
3072 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3073 " performing implicit commit!";
3075 wfLogDBError( $msg );
3077 // if the transaction was automatic and has done write operations,
3078 // log it if $wgDebugDBTransactions is enabled.
3079 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3080 wfDebug( "$fname: Automatic transaction with writes in progress" .
3081 " (from {$this->mTrxFname}), performing implicit commit!\n"
3086 $this->runOnTransactionPreCommitCallbacks();
3087 $this->doCommit( $fname );
3088 $this->runOnTransactionIdleCallbacks();
3091 $this->doBegin( $fname );
3092 $this->mTrxFname
= $fname;
3093 $this->mTrxDoneWrites
= false;
3094 $this->mTrxAutomatic
= false;
3098 * Issues the BEGIN command to the database server.
3100 * @see DatabaseBase::begin()
3101 * @param type $fname
3103 protected function doBegin( $fname ) {
3104 $this->query( 'BEGIN', $fname );
3105 $this->mTrxLevel
= 1;
3109 * Commits a transaction previously started using begin().
3110 * If no transaction is in progress, a warning is issued.
3112 * Nesting of transactions is not supported.
3114 * @param $fname string
3115 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3116 * transactions, or calling commit when no transaction is in progress.
3117 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3118 * that it is safe to ignore these warnings in your context.
3120 final public function commit( $fname = __METHOD__
, $flush = '' ) {
3121 if ( $flush != 'flush' ) {
3122 if ( !$this->mTrxLevel
) {
3123 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3124 } elseif ( $this->mTrxAutomatic
) {
3125 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3128 if ( !$this->mTrxLevel
) {
3129 return; // nothing to do
3130 } elseif ( !$this->mTrxAutomatic
) {
3131 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3135 $this->runOnTransactionPreCommitCallbacks();
3136 $this->doCommit( $fname );
3137 $this->runOnTransactionIdleCallbacks();
3141 * Issues the COMMIT command to the database server.
3143 * @see DatabaseBase::commit()
3144 * @param type $fname
3146 protected function doCommit( $fname ) {
3147 if ( $this->mTrxLevel
) {
3148 $this->query( 'COMMIT', $fname );
3149 $this->mTrxLevel
= 0;
3154 * Rollback a transaction previously started using begin().
3155 * If no transaction is in progress, a warning is issued.
3157 * No-op on non-transactional databases.
3159 * @param $fname string
3161 final public function rollback( $fname = __METHOD__
) {
3162 if ( !$this->mTrxLevel
) {
3163 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3165 $this->doRollback( $fname );
3166 $this->mTrxIdleCallbacks
= array(); // cancel
3167 $this->mTrxPreCommitCallbacks
= array(); // cancel
3171 * Issues the ROLLBACK command to the database server.
3173 * @see DatabaseBase::rollback()
3174 * @param type $fname
3176 protected function doRollback( $fname ) {
3177 if ( $this->mTrxLevel
) {
3178 $this->query( 'ROLLBACK', $fname, true );
3179 $this->mTrxLevel
= 0;
3184 * Creates a new table with structure copied from existing table
3185 * Note that unlike most database abstraction functions, this function does not
3186 * automatically append database prefix, because it works at a lower
3187 * abstraction level.
3188 * The table names passed to this function shall not be quoted (this
3189 * function calls addIdentifierQuotes when needed).
3191 * @param string $oldName name of table whose structure should be copied
3192 * @param string $newName name of table to be created
3193 * @param $temporary Boolean: whether the new table should be temporary
3194 * @param string $fname calling function name
3195 * @throws MWException
3196 * @return Boolean: true if operation was successful
3198 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3201 throw new MWException(
3202 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3206 * List all tables on the database
3208 * @param string $prefix Only show tables with this prefix, e.g. mw_
3209 * @param string $fname calling function name
3210 * @throws MWException
3212 function listTables( $prefix = null, $fname = __METHOD__
) {
3213 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3217 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3218 * to the format used for inserting into timestamp fields in this DBMS.
3220 * The result is unquoted, and needs to be passed through addQuotes()
3221 * before it can be included in raw SQL.
3223 * @param $ts string|int
3227 public function timestamp( $ts = 0 ) {
3228 return wfTimestamp( TS_MW
, $ts );
3232 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3233 * to the format used for inserting into timestamp fields in this DBMS. If
3234 * NULL is input, it is passed through, allowing NULL values to be inserted
3235 * into timestamp fields.
3237 * The result is unquoted, and needs to be passed through addQuotes()
3238 * before it can be included in raw SQL.
3240 * @param $ts string|int
3244 public function timestampOrNull( $ts = null ) {
3245 if ( is_null( $ts ) ) {
3248 return $this->timestamp( $ts );
3253 * Take the result from a query, and wrap it in a ResultWrapper if
3254 * necessary. Boolean values are passed through as is, to indicate success
3255 * of write queries or failure.
3257 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3258 * resource, and it was necessary to call this function to convert it to
3259 * a wrapper. Nowadays, raw database objects are never exposed to external
3260 * callers, so this is unnecessary in external code. For compatibility with
3261 * old code, ResultWrapper objects are passed through unaltered.
3263 * @param $result bool|ResultWrapper
3265 * @return bool|ResultWrapper
3267 public function resultObject( $result ) {
3268 if ( empty( $result ) ) {
3270 } elseif ( $result instanceof ResultWrapper
) {
3272 } elseif ( $result === true ) {
3273 // Successful write query
3276 return new ResultWrapper( $this, $result );
3281 * Ping the server and try to reconnect if it there is no connection
3283 * @return bool Success or failure
3285 public function ping() {
3286 # Stub. Not essential to override.
3291 * Get slave lag. Currently supported only by MySQL.
3293 * Note that this function will generate a fatal error on many
3294 * installations. Most callers should use LoadBalancer::safeGetLag()
3297 * @return int Database replication lag in seconds
3299 public function getLag() {
3300 return intval( $this->mFakeSlaveLag
);
3304 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3308 function maxListLen() {
3313 * Some DBMSs have a special format for inserting into blob fields, they
3314 * don't allow simple quoted strings to be inserted. To insert into such
3315 * a field, pass the data through this function before passing it to
3316 * DatabaseBase::insert().
3320 public function encodeBlob( $b ) {
3325 * Some DBMSs return a special placeholder object representing blob fields
3326 * in result objects. Pass the object through this function to return the
3331 public function decodeBlob( $b ) {
3336 * Override database's default behavior. $options include:
3337 * 'connTimeout' : Set the connection timeout value in seconds.
3338 * May be useful for very long batch queries such as
3339 * full-wiki dumps, where a single query reads out over
3342 * @param $options Array
3345 public function setSessionOptions( array $options ) {
3349 * Read and execute SQL commands from a file.
3351 * Returns true on success, error string or exception on failure (depending
3352 * on object's error ignore settings).
3354 * @param string $filename File name to open
3355 * @param bool|callable $lineCallback Optional function called before reading each line
3356 * @param bool|callable $resultCallback Optional function called for each MySQL result
3357 * @param bool|string $fname Calling function name or false if name should be
3358 * generated dynamically using $filename
3359 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3360 * @throws MWException
3361 * @throws Exception|MWException
3362 * @return bool|string
3364 public function sourceFile(
3365 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3367 wfSuppressWarnings();
3368 $fp = fopen( $filename, 'r' );
3369 wfRestoreWarnings();
3371 if ( false === $fp ) {
3372 throw new MWException( "Could not open \"{$filename}\".\n" );
3376 $fname = __METHOD__
. "( $filename )";
3380 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3382 catch ( MWException
$e ) {
3393 * Get the full path of a patch file. Originally based on archive()
3394 * from updaters.inc. Keep in mind this always returns a patch, as
3395 * it fails back to MySQL if no DB-specific patch can be found
3397 * @param string $patch The name of the patch, like patch-something.sql
3398 * @return String Full path to patch file
3400 public function patchPath( $patch ) {
3403 $dbType = $this->getType();
3404 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3405 return "$IP/maintenance/$dbType/archives/$patch";
3407 return "$IP/maintenance/archives/$patch";
3412 * Set variables to be used in sourceFile/sourceStream, in preference to the
3413 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3414 * all. If it's set to false, $GLOBALS will be used.
3416 * @param bool|array $vars mapping variable name to value.
3418 public function setSchemaVars( $vars ) {
3419 $this->mSchemaVars
= $vars;
3423 * Read and execute commands from an open file handle.
3425 * Returns true on success, error string or exception on failure (depending
3426 * on object's error ignore settings).
3428 * @param $fp Resource: File handle
3429 * @param $lineCallback Callback: Optional function called before reading each query
3430 * @param $resultCallback Callback: Optional function called for each MySQL result
3431 * @param string $fname Calling function name
3432 * @param $inputCallback Callback: Optional function called for each complete query sent
3433 * @return bool|string
3435 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3436 $fname = __METHOD__
, $inputCallback = false )
3440 while ( !feof( $fp ) ) {
3441 if ( $lineCallback ) {
3442 call_user_func( $lineCallback );
3445 $line = trim( fgets( $fp ) );
3447 if ( $line == '' ) {
3451 if ( '-' == $line[0] && '-' == $line[1] ) {
3459 $done = $this->streamStatementEnd( $cmd, $line );
3463 if ( $done ||
feof( $fp ) ) {
3464 $cmd = $this->replaceVars( $cmd );
3466 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3467 $res = $this->query( $cmd, $fname );
3469 if ( $resultCallback ) {
3470 call_user_func( $resultCallback, $res, $this );
3473 if ( false === $res ) {
3474 $err = $this->lastError();
3475 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3486 * Called by sourceStream() to check if we've reached a statement end
3488 * @param string $sql SQL assembled so far
3489 * @param string $newLine New line about to be added to $sql
3490 * @return Bool Whether $newLine contains end of the statement
3492 public function streamStatementEnd( &$sql, &$newLine ) {
3493 if ( $this->delimiter
) {
3495 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3496 if ( $newLine != $prev ) {
3504 * Database independent variable replacement. Replaces a set of variables
3505 * in an SQL statement with their contents as given by $this->getSchemaVars().
3507 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3509 * - '{$var}' should be used for text and is passed through the database's
3511 * - `{$var}` should be used for identifiers (eg: table and database names),
3512 * it is passed through the database's addIdentifierQuotes method which
3513 * can be overridden if the database uses something other than backticks.
3514 * - / *$var* / is just encoded, besides traditional table prefix and
3515 * table options its use should be avoided.
3517 * @param string $ins SQL statement to replace variables in
3518 * @return String The new SQL statement with variables replaced
3520 protected function replaceSchemaVars( $ins ) {
3521 $vars = $this->getSchemaVars();
3522 foreach ( $vars as $var => $value ) {
3524 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3526 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3528 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3534 * Replace variables in sourced SQL
3536 * @param $ins string
3540 protected function replaceVars( $ins ) {
3541 $ins = $this->replaceSchemaVars( $ins );
3544 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3545 array( $this, 'tableNameCallback' ), $ins );
3548 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3549 array( $this, 'indexNameCallback' ), $ins );
3555 * Get schema variables. If none have been set via setSchemaVars(), then
3556 * use some defaults from the current object.
3560 protected function getSchemaVars() {
3561 if ( $this->mSchemaVars
) {
3562 return $this->mSchemaVars
;
3564 return $this->getDefaultSchemaVars();
3569 * Get schema variables to use if none have been set via setSchemaVars().
3571 * Override this in derived classes to provide variables for tables.sql
3572 * and SQL patch files.
3576 protected function getDefaultSchemaVars() {
3581 * Table name callback
3583 * @param $matches array
3587 protected function tableNameCallback( $matches ) {
3588 return $this->tableName( $matches[1] );
3592 * Index name callback
3594 * @param $matches array
3598 protected function indexNameCallback( $matches ) {
3599 return $this->indexName( $matches[1] );
3603 * Check to see if a named lock is available. This is non-blocking.
3605 * @param string $lockName name of lock to poll
3606 * @param string $method name of method calling us
3610 public function lockIsFree( $lockName, $method ) {
3615 * Acquire a named lock
3617 * Abstracted from Filestore::lock() so child classes can implement for
3620 * @param string $lockName name of lock to aquire
3621 * @param string $method name of method calling us
3622 * @param $timeout Integer: timeout
3625 public function lock( $lockName, $method, $timeout = 5 ) {
3632 * @param string $lockName Name of lock to release
3633 * @param string $method Name of method calling us
3635 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3636 * by this thread (in which case the lock is not released), and NULL if the named
3637 * lock did not exist
3639 public function unlock( $lockName, $method ) {
3644 * Lock specific tables
3646 * @param array $read of tables to lock for read access
3647 * @param array $write of tables to lock for write access
3648 * @param string $method name of caller
3649 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3653 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3658 * Unlock specific tables
3660 * @param string $method the caller
3664 public function unlockTables( $method ) {
3670 * @param $tableName string
3671 * @param $fName string
3672 * @return bool|ResultWrapper
3675 public function dropTable( $tableName, $fName = __METHOD__
) {
3676 if ( !$this->tableExists( $tableName, $fName ) ) {
3679 $sql = "DROP TABLE " . $this->tableName( $tableName );
3680 if ( $this->cascadingDeletes() ) {
3683 return $this->query( $sql, $fName );
3687 * Get search engine class. All subclasses of this need to implement this
3688 * if they wish to use searching.
3692 public function getSearchEngine() {
3693 return 'SearchEngineDummy';
3697 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3698 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3699 * because "i" sorts after all numbers.
3703 public function getInfinity() {
3708 * Encode an expiry time into the DBMS dependent format
3710 * @param string $expiry timestamp for expiry, or the 'infinity' string
3713 public function encodeExpiry( $expiry ) {
3714 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3715 ?
$this->getInfinity()
3716 : $this->timestamp( $expiry );
3720 * Decode an expiry time into a DBMS independent format
3722 * @param string $expiry DB timestamp field value for expiry
3723 * @param $format integer: TS_* constant, defaults to TS_MW
3726 public function decodeExpiry( $expiry, $format = TS_MW
) {
3727 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3729 : wfTimestamp( $format, $expiry );
3733 * Allow or deny "big selects" for this session only. This is done by setting
3734 * the sql_big_selects session variable.
3736 * This is a MySQL-specific feature.
3738 * @param $value Mixed: true for allow, false for deny, or "default" to
3739 * restore the initial value
3741 public function setBigSelects( $value = true ) {
3748 public function __toString() {
3749 return (string)$this->mConn
;
3752 public function __destruct() {
3753 if ( count( $this->mTrxIdleCallbacks
) ||
count( $this->mTrxPreCommitCallbacks
) ) {
3754 trigger_error( "Transaction idle or pre-commit callbacks still pending." ); // sanity