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
27 /** Number of times to re-try an operation in case of deadlock */
28 define( 'DEADLOCK_TRIES', 4 );
29 /** Minimum time to wait before retry, in microseconds */
30 define( 'DEADLOCK_DELAY_MIN', 500000 );
31 /** Maximum time to wait before retry */
32 define( 'DEADLOCK_DELAY_MAX', 1500000 );
35 * Base interface for all DBMS-specific code. At a bare minimum, all of the
36 * following must be implemented to support MediaWiki
41 interface DatabaseType
{
43 * Get the type of the DBMS, as it appears in $wgDBtype.
50 * Open a connection to the database. Usually aborts on failure
52 * @param string $server database server host
53 * @param string $user database user name
54 * @param string $password database user password
55 * @param string $dbName database name
57 * @throws DBConnectionError
59 function open( $server, $user, $password, $dbName );
62 * Fetch the next row from the given result object, in object form.
63 * Fields can be retrieved with $row->fieldname, with fields acting like
65 * If no more rows are available, false is returned.
67 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
69 * @throws DBUnexpectedError Thrown if the database returns an error
71 function fetchObject( $res );
74 * Fetch the next row from the given result object, in associative array
75 * form. Fields are retrieved with $row['fieldname'].
76 * If no more rows are available, false is returned.
78 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
80 * @throws DBUnexpectedError Thrown if the database returns an error
82 function fetchRow( $res );
85 * Get the number of rows in a result object
87 * @param $res Mixed: A SQL result
90 function numRows( $res );
93 * Get the number of fields in a result object
94 * @see http://www.php.net/mysql_num_fields
96 * @param $res Mixed: A SQL result
99 function numFields( $res );
102 * Get a field name in a result object
103 * @see http://www.php.net/mysql_field_name
105 * @param $res Mixed: A SQL result
109 function fieldName( $res, $n );
112 * Get the inserted value of an auto-increment row
114 * The value inserted should be fetched from nextSequenceValue()
117 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
118 * $dbw->insert( 'page', array( 'page_id' => $id ) );
119 * $id = $dbw->insertId();
126 * Change the position of the cursor in a result object
127 * @see http://www.php.net/mysql_data_seek
129 * @param $res Mixed: A SQL result
130 * @param $row Mixed: Either MySQL row or ResultWrapper
132 function dataSeek( $res, $row );
135 * Get the last error number
136 * @see http://www.php.net/mysql_errno
140 function lastErrno();
143 * Get a description of the last error
144 * @see http://www.php.net/mysql_error
148 function lastError();
151 * mysql_fetch_field() wrapper
152 * Returns false if the field doesn't exist
154 * @param string $table table name
155 * @param string $field field name
159 function fieldInfo( $table, $field );
162 * Get information about an index into an object
163 * @param string $table Table name
164 * @param string $index Index name
165 * @param string $fname Calling function name
166 * @return Mixed: Database-specific index description class or false if the index does not exist
168 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
171 * Get the number of rows affected by the last write query
172 * @see http://www.php.net/mysql_affected_rows
176 function affectedRows();
179 * Wrapper for addslashes()
181 * @param string $s to be slashed.
182 * @return string: slashed string.
184 function strencode( $s );
187 * Returns a wikitext link to the DB's website, e.g.,
188 * return "[http://www.mysql.com/ MySQL]";
189 * Should at least contain plain text, if for some reason
190 * your database has no website.
192 * @return string: wikitext of a link to the server software's web site
194 static function getSoftwareLink();
197 * A string describing the current software version, like from
198 * mysql_get_server_info().
200 * @return string: Version information from the database server.
202 function getServerVersion();
205 * A string describing the current software version, and possibly
206 * other details in a user-friendly way. Will be listed on Special:Version, etc.
207 * Use getServerVersion() to get machine-friendly information.
209 * @return string: Version information from the database server
211 function getServerInfo();
215 * Database abstraction object
218 abstract class DatabaseBase
implements DatabaseType
{
220 # ------------------------------------------------------------------------------
222 # ------------------------------------------------------------------------------
224 protected $mLastQuery = '';
225 protected $mDoneWrites = false;
226 protected $mPHPError = false;
228 protected $mServer, $mUser, $mPassword, $mDBname;
230 protected $mConn = null;
231 protected $mOpened = false;
235 * @var array of Closure
237 protected $mTrxIdleCallbacks = array();
239 protected $mTablePrefix;
241 protected $mTrxLevel = 0;
242 protected $mErrorCount = 0;
243 protected $mLBInfo = array();
244 protected $mFakeSlaveLag = null, $mFakeMaster = false;
245 protected $mDefaultBigSelects = null;
246 protected $mSchemaVars = false;
248 protected $preparedArgs;
250 protected $htmlErrors;
252 protected $delimiter = ';';
255 * Remembers the function name given for starting the most recent transaction via begin().
256 * Used to provide additional context for error reporting.
259 * @see DatabaseBase::mTrxLevel
261 private $mTrxFname = null;
264 * Record if possible write queries were done in the last transaction started
267 * @see DatabaseBase::mTrxLevel
269 private $mTrxDoneWrites = false;
272 * Record if the current transaction was started implicitly due to DBO_TRX being set.
275 * @see DatabaseBase::mTrxLevel
277 private $mTrxAutomatic = false;
281 * @var file handle for upgrade
283 protected $fileHandle = null;
285 # ------------------------------------------------------------------------------
287 # ------------------------------------------------------------------------------
288 # These optionally set a variable and return the previous state
291 * A string describing the current software version, and possibly
292 * other details in a user-friendly way. Will be listed on Special:Version, etc.
293 * Use getServerVersion() to get machine-friendly information.
295 * @return string: Version information from the database server
297 public function getServerInfo() {
298 return $this->getServerVersion();
302 * @return string: command delimiter used by this database engine
304 public function getDelimiter() {
305 return $this->delimiter
;
309 * Boolean, controls output of large amounts of debug information.
310 * @param $debug bool|null
311 * - true to enable debugging
312 * - false to disable debugging
313 * - omitted or null to do nothing
315 * @return bool|null previous value of the flag
317 public function debug( $debug = null ) {
318 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
322 * Turns buffering of SQL result sets on (true) or off (false). Default is
325 * Unbuffered queries are very troublesome in MySQL:
327 * - If another query is executed while the first query is being read
328 * out, the first query is killed. This means you can't call normal
329 * MediaWiki functions while you are reading an unbuffered query result
330 * from a normal wfGetDB() connection.
332 * - Unbuffered queries cause the MySQL server to use large amounts of
333 * memory and to hold broad locks which block other queries.
335 * If you want to limit client-side memory, it's almost always better to
336 * split up queries into batches using a LIMIT clause than to switch off
339 * @param $buffer null|bool
341 * @return null|bool The previous value of the flag
343 public function bufferResults( $buffer = null ) {
344 if ( is_null( $buffer ) ) {
345 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
347 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
352 * Turns on (false) or off (true) the automatic generation and sending
353 * of a "we're sorry, but there has been a database error" page on
354 * database errors. Default is on (false). When turned off, the
355 * code should use lastErrno() and lastError() to handle the
356 * situation as appropriate.
358 * @param $ignoreErrors bool|null
360 * @return bool The previous value of the flag.
362 public function ignoreErrors( $ignoreErrors = null ) {
363 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
367 * Gets or sets the current transaction level.
369 * Historically, transactions were allowed to be "nested". This is no
370 * longer supported, so this function really only returns a boolean.
372 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
373 * @return int The previous value
375 public function trxLevel( $level = null ) {
376 return wfSetVar( $this->mTrxLevel
, $level );
380 * Get/set the number of errors logged. Only useful when errors are ignored
381 * @param int $count The count to set, or omitted to leave it unchanged.
382 * @return int The error count
384 public function errorCount( $count = null ) {
385 return wfSetVar( $this->mErrorCount
, $count );
389 * Get/set the table prefix.
390 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
391 * @return string The previous table prefix.
393 public function tablePrefix( $prefix = null ) {
394 return wfSetVar( $this->mTablePrefix
, $prefix );
398 * Set the filehandle to copy write statements to.
400 * @param $fh filehandle
402 public function setFileHandle( $fh ) {
403 $this->fileHandle
= $fh;
407 * Get properties passed down from the server info array of the load
410 * @param string $name The entry of the info array to get, or null to get the
413 * @return LoadBalancer|null
415 public function getLBInfo( $name = null ) {
416 if ( is_null( $name ) ) {
417 return $this->mLBInfo
;
419 if ( array_key_exists( $name, $this->mLBInfo
) ) {
420 return $this->mLBInfo
[$name];
428 * Set the LB info array, or a member of it. If called with one parameter,
429 * the LB info array is set to that parameter. If it is called with two
430 * parameters, the member with the given name is set to the given value.
435 public function setLBInfo( $name, $value = null ) {
436 if ( is_null( $value ) ) {
437 $this->mLBInfo
= $name;
439 $this->mLBInfo
[$name] = $value;
444 * Set lag time in seconds for a fake slave
448 public function setFakeSlaveLag( $lag ) {
449 $this->mFakeSlaveLag
= $lag;
453 * Make this connection a fake master
455 * @param $enabled bool
457 public function setFakeMaster( $enabled = true ) {
458 $this->mFakeMaster
= $enabled;
462 * Returns true if this database supports (and uses) cascading deletes
466 public function cascadingDeletes() {
471 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
475 public function cleanupTriggers() {
480 * Returns true if this database is strict about what can be put into an IP field.
481 * Specifically, it uses a NULL value instead of an empty string.
485 public function strictIPs() {
490 * Returns true if this database uses timestamps rather than integers
494 public function realTimestamps() {
499 * Returns true if this database does an implicit sort when doing GROUP BY
503 public function implicitGroupby() {
508 * Returns true if this database does an implicit order by when the column has an index
509 * For example: SELECT page_title FROM page LIMIT 1
513 public function implicitOrderby() {
518 * Returns true if this database can do a native search on IP columns
519 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
523 public function searchableIPs() {
528 * Returns true if this database can use functional indexes
532 public function functionalIndexes() {
537 * Return the last query that went through DatabaseBase::query()
540 public function lastQuery() {
541 return $this->mLastQuery
;
545 * Returns true if the connection may have been used for write queries.
546 * Should return true if unsure.
550 public function doneWrites() {
551 return $this->mDoneWrites
;
555 * Returns true if there is a transaction open with possible write
556 * queries or transaction idle callbacks waiting on it to finish.
560 public function writesOrCallbacksPending() {
561 return $this->mTrxLevel
&& ( $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks
);
565 * Is a connection to the database open?
568 public function isOpen() {
569 return $this->mOpened
;
573 * Set a flag for this connection
575 * @param $flag Integer: DBO_* constants from Defines.php:
576 * - DBO_DEBUG: output some debug info (same as debug())
577 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
578 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
579 * - DBO_TRX: automatically start transactions
580 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
581 * and removes it in command line mode
582 * - DBO_PERSISTENT: use persistant database connection
584 public function setFlag( $flag ) {
585 global $wgDebugDBTransactions;
586 $this->mFlags |
= $flag;
587 if ( ( $flag & DBO_TRX
) & $wgDebugDBTransactions ) {
588 wfDebug( "Implicit transactions are now disabled.\n" );
593 * Clear a flag for this connection
595 * @param $flag: same as setFlag()'s $flag param
597 public function clearFlag( $flag ) {
598 global $wgDebugDBTransactions;
599 $this->mFlags
&= ~
$flag;
600 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
601 wfDebug( "Implicit transactions are now disabled.\n" );
606 * Returns a boolean whether the flag $flag is set for this connection
608 * @param $flag: same as setFlag()'s $flag param
611 public function getFlag( $flag ) {
612 return !!( $this->mFlags
& $flag );
616 * General read-only accessor
618 * @param $name string
622 public function getProperty( $name ) {
629 public function getWikiID() {
630 if ( $this->mTablePrefix
) {
631 return "{$this->mDBname}-{$this->mTablePrefix}";
633 return $this->mDBname
;
638 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
642 public function getSchemaPath() {
644 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
645 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
647 return "$IP/maintenance/tables.sql";
651 # ------------------------------------------------------------------------------
653 # ------------------------------------------------------------------------------
657 * @param string $server database server host
658 * @param string $user database user name
659 * @param string $password database user password
660 * @param string $dbName database name
662 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
664 function __construct( $server = false, $user = false, $password = false, $dbName = false,
665 $flags = 0, $tablePrefix = 'get from global'
667 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
669 $this->mFlags
= $flags;
671 if ( $this->mFlags
& DBO_DEFAULT
) {
672 if ( $wgCommandLineMode ) {
673 $this->mFlags
&= ~DBO_TRX
;
674 if ( $wgDebugDBTransactions ) {
675 wfDebug( "Implicit transaction open disabled.\n" );
678 $this->mFlags |
= DBO_TRX
;
679 if ( $wgDebugDBTransactions ) {
680 wfDebug( "Implicit transaction open enabled.\n" );
685 /** Get the default table prefix*/
686 if ( $tablePrefix == 'get from global' ) {
687 $this->mTablePrefix
= $wgDBprefix;
689 $this->mTablePrefix
= $tablePrefix;
693 $this->open( $server, $user, $password, $dbName );
698 * Called by serialize. Throw an exception when DB connection is serialized.
699 * This causes problems on some database engines because the connection is
700 * not restored on unserialize.
702 public function __sleep() {
703 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
707 * Given a DB type, construct the name of the appropriate child class of
708 * DatabaseBase. This is designed to replace all of the manual stuff like:
709 * $class = 'Database' . ucfirst( strtolower( $type ) );
710 * as well as validate against the canonical list of DB types we have
712 * This factory function is mostly useful for when you need to connect to a
713 * database other than the MediaWiki default (such as for external auth,
714 * an extension, et cetera). Do not use this to connect to the MediaWiki
715 * database. Example uses in core:
716 * @see LoadBalancer::reallyOpenConnection()
717 * @see ForeignDBRepo::getMasterDB()
718 * @see WebInstaller_DBConnect::execute()
722 * @param string $dbType A possible DB type
723 * @param array $p An array of options to pass to the constructor.
724 * Valid options are: host, user, password, dbname, flags, tablePrefix
725 * @return DatabaseBase subclass or null
727 final public static function factory( $dbType, $p = array() ) {
728 $canonicalDBTypes = array(
729 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
731 $dbType = strtolower( $dbType );
732 $class = 'Database' . ucfirst( $dbType );
734 if( in_array( $dbType, $canonicalDBTypes ) ||
( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
736 isset( $p['host'] ) ?
$p['host'] : false,
737 isset( $p['user'] ) ?
$p['user'] : false,
738 isset( $p['password'] ) ?
$p['password'] : false,
739 isset( $p['dbname'] ) ?
$p['dbname'] : false,
740 isset( $p['flags'] ) ?
$p['flags'] : 0,
741 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
748 protected function installErrorHandler() {
749 $this->mPHPError
= false;
750 $this->htmlErrors
= ini_set( 'html_errors', '0' );
751 set_error_handler( array( $this, 'connectionErrorHandler' ) );
755 * @return bool|string
757 protected function restoreErrorHandler() {
758 restore_error_handler();
759 if ( $this->htmlErrors
!== false ) {
760 ini_set( 'html_errors', $this->htmlErrors
);
762 if ( $this->mPHPError
) {
763 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
764 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
775 protected function connectionErrorHandler( $errno, $errstr ) {
776 $this->mPHPError
= $errstr;
780 * Closes a database connection.
781 * if it is open : commits any open transactions
783 * @throws MWException
784 * @return Bool operation success. true if already closed.
786 public function close() {
787 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
788 throw new MWException( "Transaction idle callbacks still pending." );
790 $this->mOpened
= false;
791 if ( $this->mConn
) {
792 if ( $this->trxLevel() ) {
793 if ( !$this->mTrxAutomatic
) {
794 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
795 " performing implicit commit before closing connection!" );
798 $this->commit( __METHOD__
, 'flush' );
801 $ret = $this->closeConnection();
802 $this->mConn
= false;
810 * Closes underlying database connection
812 * @return bool: Whether connection was closed successfully
814 abstract protected function closeConnection();
817 * @param string $error fallback error message, used if none is given by DB
818 * @throws DBConnectionError
820 function reportConnectionError( $error = 'Unknown error' ) {
821 $myError = $this->lastError();
827 throw new DBConnectionError( $this, $error );
831 * The DBMS-dependent part of query()
833 * @param $sql String: SQL query.
834 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
836 abstract protected function doQuery( $sql );
839 * Determine whether a query writes to the DB.
840 * Should return true if unsure.
846 public function isWriteQuery( $sql ) {
847 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
851 * Run an SQL query and return the result. Normally throws a DBQueryError
852 * on failure. If errors are ignored, returns false instead.
854 * In new code, the query wrappers select(), insert(), update(), delete(),
855 * etc. should be used where possible, since they give much better DBMS
856 * independence and automatically quote or validate user input in a variety
857 * of contexts. This function is generally only useful for queries which are
858 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
861 * However, the query wrappers themselves should call this function.
863 * @param $sql String: SQL query
864 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
865 * comment (you can use __METHOD__ or add some extra info)
866 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
867 * maybe best to catch the exception instead?
868 * @throws MWException
869 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
870 * for a successful read query, or false on failure if $tempIgnore set
872 public function query( $sql, $fname = '', $tempIgnore = false ) {
873 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
874 if ( !Profiler
::instance()->isStub() ) {
875 # generalizeSQL will probably cut down the query to reasonable
876 # logging size most of the time. The substr is really just a sanity check.
879 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
880 $totalProf = 'DatabaseBase::query-master';
882 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
883 $totalProf = 'DatabaseBase::query';
886 wfProfileIn( $totalProf );
887 wfProfileIn( $queryProf );
890 $this->mLastQuery
= $sql;
891 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
892 # Set a flag indicating that writes have been done
893 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
894 $this->mDoneWrites
= true;
897 # Add a comment for easy SHOW PROCESSLIST interpretation
899 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
900 $userName = $wgUser->getName();
901 if ( mb_strlen( $userName ) > 15 ) {
902 $userName = mb_substr( $userName, 0, 15 ) . '...';
904 $userName = str_replace( '/', '', $userName );
909 // Add trace comment to the begin of the sql string, right after the operator.
910 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
911 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
913 # If DBO_TRX is set, start a transaction
914 if ( ( $this->mFlags
& DBO_TRX
) && !$this->mTrxLevel
&&
915 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
917 # Avoid establishing transactions for SHOW and SET statements too -
918 # that would delay transaction initializations to once connection
919 # is really used by application
920 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
921 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
922 global $wgDebugDBTransactions;
923 if ( $wgDebugDBTransactions ) {
924 wfDebug( "Implicit transaction start.\n" );
926 $this->begin( __METHOD__
. " ($fname)" );
927 $this->mTrxAutomatic
= true;
931 # Keep track of whether the transaction has write queries pending
932 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $this->isWriteQuery( $sql ) ) {
933 $this->mTrxDoneWrites
= true;
936 if ( $this->debug() ) {
940 $sqlx = substr( $commentedSql, 0, 500 );
941 $sqlx = strtr( $sqlx, "\t\n", ' ' );
943 $master = $isMaster ?
'master' : 'slave';
944 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
947 if ( istainted( $sql ) & TC_MYSQL
) {
948 if ( !Profiler
::instance()->isStub() ) {
949 wfProfileOut( $queryProf );
950 wfProfileOut( $totalProf );
952 throw new MWException( 'Tainted query found' );
955 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
957 # Do the query and handle errors
958 $ret = $this->doQuery( $commentedSql );
960 MWDebug
::queryTime( $queryId );
962 # Try reconnecting if the connection was lost
963 if ( false === $ret && $this->wasErrorReissuable() ) {
964 # Transaction is gone, like it or not
965 $this->mTrxLevel
= 0;
966 $this->mTrxIdleCallbacks
= array(); // cancel
967 wfDebug( "Connection lost, reconnecting...\n" );
969 if ( $this->ping() ) {
970 wfDebug( "Reconnected\n" );
971 $sqlx = substr( $commentedSql, 0, 500 );
972 $sqlx = strtr( $sqlx, "\t\n", ' ' );
973 global $wgRequestTime;
974 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
975 if ( $elapsed < 300 ) {
976 # Not a database error to lose a transaction after a minute or two
977 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
979 $ret = $this->doQuery( $commentedSql );
981 wfDebug( "Failed\n" );
985 if ( false === $ret ) {
986 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
989 if ( !Profiler
::instance()->isStub() ) {
990 wfProfileOut( $queryProf );
991 wfProfileOut( $totalProf );
994 return $this->resultObject( $ret );
998 * Report a query error. Log the error, and if neither the object ignore
999 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1001 * @param $error String
1002 * @param $errno Integer
1003 * @param $sql String
1004 * @param $fname String
1005 * @param $tempIgnore Boolean
1006 * @throws DBQueryError
1008 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1009 # Ignore errors during error handling to avoid infinite recursion
1010 $ignore = $this->ignoreErrors( true );
1011 ++
$this->mErrorCount
;
1013 if ( $ignore ||
$tempIgnore ) {
1014 wfDebug( "SQL ERROR (ignored): $error\n" );
1015 $this->ignoreErrors( $ignore );
1017 $sql1line = str_replace( "\n", "\\n", $sql );
1018 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1019 wfDebug( "SQL ERROR: " . $error . "\n" );
1020 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1025 * Intended to be compatible with the PEAR::DB wrapper functions.
1026 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1028 * ? = scalar value, quoted as necessary
1029 * ! = raw SQL bit (a function for instance)
1030 * & = filename; reads the file and inserts as a blob
1031 * (we don't use this though...)
1033 * @param $sql string
1034 * @param $func string
1038 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1039 /* MySQL doesn't support prepared statements (yet), so just
1040 pack up the query for reference. We'll manually replace
1042 return array( 'query' => $sql, 'func' => $func );
1046 * Free a prepared query, generated by prepare().
1049 protected function freePrepared( $prepared ) {
1050 /* No-op by default */
1054 * Execute a prepared query with the various arguments
1055 * @param string $prepared the prepared sql
1056 * @param $args Mixed: Either an array here, or put scalars as varargs
1058 * @return ResultWrapper
1060 public function execute( $prepared, $args = null ) {
1061 if ( !is_array( $args ) ) {
1063 $args = func_get_args();
1064 array_shift( $args );
1067 $sql = $this->fillPrepared( $prepared['query'], $args );
1069 return $this->query( $sql, $prepared['func'] );
1073 * For faking prepared SQL statements on DBs that don't support it directly.
1075 * @param string $preparedQuery a 'preparable' SQL statement
1076 * @param array $args of arguments to fill it with
1077 * @return string executable SQL
1079 public function fillPrepared( $preparedQuery, $args ) {
1081 $this->preparedArgs
=& $args;
1083 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1084 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1088 * preg_callback func for fillPrepared()
1089 * The arguments should be in $this->preparedArgs and must not be touched
1090 * while we're doing this.
1092 * @param $matches Array
1093 * @throws DBUnexpectedError
1096 protected function fillPreparedArg( $matches ) {
1097 switch ( $matches[1] ) {
1106 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1108 switch ( $matches[1] ) {
1110 return $this->addQuotes( $arg );
1114 # return $this->addQuotes( file_get_contents( $arg ) );
1115 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1117 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1122 * Free a result object returned by query() or select(). It's usually not
1123 * necessary to call this, just use unset() or let the variable holding
1124 * the result object go out of scope.
1126 * @param $res Mixed: A SQL result
1128 public function freeResult( $res ) {
1132 * A SELECT wrapper which returns a single field from a single result row.
1134 * Usually throws a DBQueryError on failure. If errors are explicitly
1135 * ignored, returns false on failure.
1137 * If no result rows are returned from the query, false is returned.
1139 * @param string|array $table Table name. See DatabaseBase::select() for details.
1140 * @param string $var The field name to select. This must be a valid SQL
1141 * fragment: do not use unvalidated user input.
1142 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1143 * @param string $fname The function name of the caller.
1144 * @param string|array $options The query options. See DatabaseBase::select() for details.
1146 * @return bool|mixed The value from the field, or false on failure.
1148 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1151 if ( !is_array( $options ) ) {
1152 $options = array( $options );
1155 $options['LIMIT'] = 1;
1157 $res = $this->select( $table, $var, $cond, $fname, $options );
1159 if ( $res === false ||
!$this->numRows( $res ) ) {
1163 $row = $this->fetchRow( $res );
1165 if ( $row !== false ) {
1166 return reset( $row );
1173 * Returns an optional USE INDEX clause to go after the table, and a
1174 * string to go at the end of the query.
1176 * @param array $options associative array of options to be turned into
1177 * an SQL query, valid keys are listed in the function.
1179 * @see DatabaseBase::select()
1181 public function makeSelectOptions( $options ) {
1182 $preLimitTail = $postLimitTail = '';
1185 $noKeyOptions = array();
1187 foreach ( $options as $key => $option ) {
1188 if ( is_numeric( $key ) ) {
1189 $noKeyOptions[$option] = true;
1193 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1195 $preLimitTail .= $this->makeOrderBy( $options );
1197 // if (isset($options['LIMIT'])) {
1198 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1199 // isset($options['OFFSET']) ? $options['OFFSET']
1203 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1204 $postLimitTail .= ' FOR UPDATE';
1207 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1208 $postLimitTail .= ' LOCK IN SHARE MODE';
1211 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1212 $startOpts .= 'DISTINCT';
1215 # Various MySQL extensions
1216 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1217 $startOpts .= ' /*! STRAIGHT_JOIN */';
1220 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1221 $startOpts .= ' HIGH_PRIORITY';
1224 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1225 $startOpts .= ' SQL_BIG_RESULT';
1228 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1229 $startOpts .= ' SQL_BUFFER_RESULT';
1232 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1233 $startOpts .= ' SQL_SMALL_RESULT';
1236 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1237 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1240 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1241 $startOpts .= ' SQL_CACHE';
1244 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1245 $startOpts .= ' SQL_NO_CACHE';
1248 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1249 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1254 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1258 * Returns an optional GROUP BY with an optional HAVING
1260 * @param array $options associative array of options
1262 * @see DatabaseBase::select()
1265 public function makeGroupByWithHaving( $options ) {
1267 if ( isset( $options['GROUP BY'] ) ) {
1268 $gb = is_array( $options['GROUP BY'] )
1269 ?
implode( ',', $options['GROUP BY'] )
1270 : $options['GROUP BY'];
1271 $sql .= ' GROUP BY ' . $gb;
1273 if ( isset( $options['HAVING'] ) ) {
1274 $having = is_array( $options['HAVING'] )
1275 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1276 : $options['HAVING'];
1277 $sql .= ' HAVING ' . $having;
1283 * Returns an optional ORDER BY
1285 * @param array $options associative array of options
1287 * @see DatabaseBase::select()
1290 public function makeOrderBy( $options ) {
1291 if ( isset( $options['ORDER BY'] ) ) {
1292 $ob = is_array( $options['ORDER BY'] )
1293 ?
implode( ',', $options['ORDER BY'] )
1294 : $options['ORDER BY'];
1295 return ' ORDER BY ' . $ob;
1301 * Execute a SELECT query constructed using the various parameters provided.
1302 * See below for full details of the parameters.
1304 * @param string|array $table Table name
1305 * @param string|array $vars Field names
1306 * @param string|array $conds Conditions
1307 * @param string $fname Caller function name
1308 * @param array $options Query options
1309 * @param $join_conds Array Join conditions
1311 * @param $table string|array
1313 * May be either an array of table names, or a single string holding a table
1314 * name. If an array is given, table aliases can be specified, for example:
1316 * array( 'a' => 'user' )
1318 * This includes the user table in the query, with the alias "a" available
1319 * for use in field names (e.g. a.user_name).
1321 * All of the table names given here are automatically run through
1322 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1323 * added, and various other table name mappings to be performed.
1326 * @param $vars string|array
1328 * May be either a field name or an array of field names. The field names
1329 * can be complete fragments of SQL, for direct inclusion into the SELECT
1330 * query. If an array is given, field aliases can be specified, for example:
1332 * array( 'maxrev' => 'MAX(rev_id)' )
1334 * This includes an expression with the alias "maxrev" in the query.
1336 * If an expression is given, care must be taken to ensure that it is
1340 * @param $conds string|array
1342 * May be either a string containing a single condition, or an array of
1343 * conditions. If an array is given, the conditions constructed from each
1344 * element are combined with AND.
1346 * Array elements may take one of two forms:
1348 * - Elements with a numeric key are interpreted as raw SQL fragments.
1349 * - Elements with a string key are interpreted as equality conditions,
1350 * where the key is the field name.
1351 * - If the value of such an array element is a scalar (such as a
1352 * string), it will be treated as data and thus quoted appropriately.
1353 * If it is null, an IS NULL clause will be added.
1354 * - If the value is an array, an IN(...) clause will be constructed,
1355 * such that the field name may match any of the elements in the
1356 * array. The elements of the array will be quoted.
1358 * Note that expressions are often DBMS-dependent in their syntax.
1359 * DBMS-independent wrappers are provided for constructing several types of
1360 * expression commonly used in condition queries. See:
1361 * - DatabaseBase::buildLike()
1362 * - DatabaseBase::conditional()
1365 * @param $options string|array
1367 * Optional: Array of query options. Boolean options are specified by
1368 * including them in the array as a string value with a numeric key, for
1371 * array( 'FOR UPDATE' )
1373 * The supported options are:
1375 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1376 * with LIMIT can theoretically be used for paging through a result set,
1377 * but this is discouraged in MediaWiki for performance reasons.
1379 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1380 * and then the first rows are taken until the limit is reached. LIMIT
1381 * is applied to a result set after OFFSET.
1383 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1384 * changed until the next COMMIT.
1386 * - DISTINCT: Boolean: return only unique result rows.
1388 * - GROUP BY: May be either an SQL fragment string naming a field or
1389 * expression to group by, or an array of such SQL fragments.
1391 * - HAVING: May be either an string containing a HAVING clause or an array of
1392 * conditions building the HAVING clause. If an array is given, the conditions
1393 * constructed from each element are combined with AND.
1395 * - ORDER BY: May be either an SQL fragment giving a field name or
1396 * expression to order by, or an array of such SQL fragments.
1398 * - USE INDEX: This may be either a string giving the index name to use
1399 * for the query, or an array. If it is an associative array, each key
1400 * gives the table name (or alias), each value gives the index name to
1401 * use for that table. All strings are SQL fragments and so should be
1402 * validated by the caller.
1404 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1405 * instead of SELECT.
1407 * And also the following boolean MySQL extensions, see the MySQL manual
1408 * for documentation:
1410 * - LOCK IN SHARE MODE
1414 * - SQL_BUFFER_RESULT
1415 * - SQL_SMALL_RESULT
1416 * - SQL_CALC_FOUND_ROWS
1421 * @param $join_conds string|array
1423 * Optional associative array of table-specific join conditions. In the
1424 * most common case, this is unnecessary, since the join condition can be
1425 * in $conds. However, it is useful for doing a LEFT JOIN.
1427 * The key of the array contains the table name or alias. The value is an
1428 * array with two elements, numbered 0 and 1. The first gives the type of
1429 * join, the second is an SQL fragment giving the join condition for that
1430 * table. For example:
1432 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1434 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1435 * with no rows in it will be returned. If there was a query error, a
1436 * DBQueryError exception will be thrown, except if the "ignore errors"
1437 * option was set, in which case false will be returned.
1439 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1440 $options = array(), $join_conds = array() ) {
1441 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1443 return $this->query( $sql, $fname );
1447 * The equivalent of DatabaseBase::select() except that the constructed SQL
1448 * is returned, instead of being immediately executed. This can be useful for
1449 * doing UNION queries, where the SQL text of each query is needed. In general,
1450 * however, callers outside of Database classes should just use select().
1452 * @param string|array $table Table name
1453 * @param string|array $vars Field names
1454 * @param string|array $conds Conditions
1455 * @param string $fname Caller function name
1456 * @param string|array $options Query options
1457 * @param $join_conds string|array Join conditions
1459 * @return string SQL query string.
1460 * @see DatabaseBase::select()
1462 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1463 $options = array(), $join_conds = array() )
1465 if ( is_array( $vars ) ) {
1466 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1469 $options = (array)$options;
1471 if ( is_array( $table ) ) {
1472 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1473 ?
$options['USE INDEX']
1475 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1477 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1479 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1481 } elseif ( $table != '' ) {
1482 if ( $table[0] == ' ' ) {
1483 $from = ' FROM ' . $table;
1485 $from = ' FROM ' . $this->tableName( $table );
1491 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1493 if ( !empty( $conds ) ) {
1494 if ( is_array( $conds ) ) {
1495 $conds = $this->makeList( $conds, LIST_AND
);
1497 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1499 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1502 if ( isset( $options['LIMIT'] ) ) {
1503 $sql = $this->limitResult( $sql, $options['LIMIT'],
1504 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1506 $sql = "$sql $postLimitTail";
1508 if ( isset( $options['EXPLAIN'] ) ) {
1509 $sql = 'EXPLAIN ' . $sql;
1516 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1517 * that a single row object is returned. If the query returns no rows,
1518 * false is returned.
1520 * @param string|array $table Table name
1521 * @param string|array $vars Field names
1522 * @param array $conds Conditions
1523 * @param string $fname Caller function name
1524 * @param string|array $options Query options
1525 * @param $join_conds array|string Join conditions
1527 * @return object|bool
1529 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1530 $options = array(), $join_conds = array() )
1532 $options = (array)$options;
1533 $options['LIMIT'] = 1;
1534 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1536 if ( $res === false ) {
1540 if ( !$this->numRows( $res ) ) {
1544 $obj = $this->fetchObject( $res );
1550 * Estimate rows in dataset.
1552 * MySQL allows you to estimate the number of rows that would be returned
1553 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1554 * index cardinality statistics, and is notoriously inaccurate, especially
1555 * when large numbers of rows have recently been added or deleted.
1557 * For DBMSs that don't support fast result size estimation, this function
1558 * will actually perform the SELECT COUNT(*).
1560 * Takes the same arguments as DatabaseBase::select().
1562 * @param string $table table name
1563 * @param array|string $vars : unused
1564 * @param array|string $conds : filters on the table
1565 * @param string $fname function name for profiling
1566 * @param array $options options for select
1567 * @return Integer: row count
1569 public function estimateRowCount( $table, $vars = '*', $conds = '',
1570 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1573 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1576 $row = $this->fetchRow( $res );
1577 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1584 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1585 * It's only slightly flawed. Don't use for anything important.
1587 * @param string $sql A SQL Query
1591 static function generalizeSQL( $sql ) {
1592 # This does the same as the regexp below would do, but in such a way
1593 # as to avoid crashing php on some large strings.
1594 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1596 $sql = str_replace( "\\\\", '', $sql );
1597 $sql = str_replace( "\\'", '', $sql );
1598 $sql = str_replace( "\\\"", '', $sql );
1599 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1600 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1602 # All newlines, tabs, etc replaced by single space
1603 $sql = preg_replace( '/\s+/', ' ', $sql );
1606 $sql = preg_replace( '/-?[0-9]+/s', 'N', $sql );
1612 * Determines whether a field exists in a table
1614 * @param string $table table name
1615 * @param string $field filed to check on that table
1616 * @param string $fname calling function name (optional)
1617 * @return Boolean: whether $table has filed $field
1619 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1620 $info = $this->fieldInfo( $table, $field );
1626 * Determines whether an index exists
1627 * Usually throws a DBQueryError on failure
1628 * If errors are explicitly ignored, returns NULL on failure
1632 * @param $fname string
1636 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1637 if( !$this->tableExists( $table ) ) {
1641 $info = $this->indexInfo( $table, $index, $fname );
1642 if ( is_null( $info ) ) {
1645 return $info !== false;
1650 * Query whether a given table exists
1652 * @param $table string
1653 * @param $fname string
1657 public function tableExists( $table, $fname = __METHOD__
) {
1658 $table = $this->tableName( $table );
1659 $old = $this->ignoreErrors( true );
1660 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1661 $this->ignoreErrors( $old );
1667 * mysql_field_type() wrapper
1672 public function fieldType( $res, $index ) {
1673 if ( $res instanceof ResultWrapper
) {
1674 $res = $res->result
;
1677 return mysql_field_type( $res, $index );
1681 * Determines if a given index is unique
1683 * @param $table string
1684 * @param $index string
1688 public function indexUnique( $table, $index ) {
1689 $indexInfo = $this->indexInfo( $table, $index );
1691 if ( !$indexInfo ) {
1695 return !$indexInfo[0]->Non_unique
;
1699 * Helper for DatabaseBase::insert().
1701 * @param $options array
1704 protected function makeInsertOptions( $options ) {
1705 return implode( ' ', $options );
1709 * INSERT wrapper, inserts an array into a table.
1713 * - A single associative array. The array keys are the field names, and
1714 * the values are the values to insert. The values are treated as data
1715 * and will be quoted appropriately. If NULL is inserted, this will be
1716 * converted to a database NULL.
1717 * - An array with numeric keys, holding a list of associative arrays.
1718 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1719 * each subarray must be identical to each other, and in the same order.
1721 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1724 * $options is an array of options, with boolean options encoded as values
1725 * with numeric keys, in the same style as $options in
1726 * DatabaseBase::select(). Supported options are:
1728 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1729 * any rows which cause duplicate key errors are not inserted. It's
1730 * possible to determine how many rows were successfully inserted using
1731 * DatabaseBase::affectedRows().
1733 * @param $table String Table name. This will be passed through
1734 * DatabaseBase::tableName().
1735 * @param $a Array of rows to insert
1736 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1737 * @param array $options of options
1741 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1742 # No rows to insert, easy just return now
1743 if ( !count( $a ) ) {
1747 $table = $this->tableName( $table );
1749 if ( !is_array( $options ) ) {
1750 $options = array( $options );
1754 if ( isset( $options['fileHandle'] ) ) {
1755 $fh = $options['fileHandle'];
1757 $options = $this->makeInsertOptions( $options );
1759 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1761 $keys = array_keys( $a[0] );
1764 $keys = array_keys( $a );
1767 $sql = 'INSERT ' . $options .
1768 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1772 foreach ( $a as $row ) {
1778 $sql .= '(' . $this->makeList( $row ) . ')';
1781 $sql .= '(' . $this->makeList( $a ) . ')';
1784 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1786 } elseif ( $fh !== null ) {
1790 return (bool)$this->query( $sql, $fname );
1794 * Make UPDATE options for the DatabaseBase::update function
1796 * @param array $options The options passed to DatabaseBase::update
1799 protected function makeUpdateOptions( $options ) {
1800 if ( !is_array( $options ) ) {
1801 $options = array( $options );
1806 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1807 $opts[] = $this->lowPriorityOption();
1810 if ( in_array( 'IGNORE', $options ) ) {
1814 return implode( ' ', $opts );
1818 * UPDATE wrapper. Takes a condition array and a SET array.
1820 * @param $table String name of the table to UPDATE. This will be passed through
1821 * DatabaseBase::tableName().
1823 * @param array $values An array of values to SET. For each array element,
1824 * the key gives the field name, and the value gives the data
1825 * to set that field to. The data will be quoted by
1826 * DatabaseBase::addQuotes().
1828 * @param $conds Array: An array of conditions (WHERE). See
1829 * DatabaseBase::select() for the details of the format of
1830 * condition arrays. Use '*' to update all rows.
1832 * @param $fname String: The function name of the caller (from __METHOD__),
1833 * for logging and profiling.
1835 * @param array $options An array of UPDATE options, can be:
1836 * - IGNORE: Ignore unique key conflicts
1837 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1840 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1841 $table = $this->tableName( $table );
1842 $opts = $this->makeUpdateOptions( $options );
1843 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1845 if ( $conds !== array() && $conds !== '*' ) {
1846 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1849 return $this->query( $sql, $fname );
1853 * Makes an encoded list of strings from an array
1854 * @param array $a containing the data
1855 * @param int $mode Constant
1856 * - LIST_COMMA: comma separated, no field names
1857 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1858 * the documentation for $conds in DatabaseBase::select().
1859 * - LIST_OR: ORed WHERE clause (without the WHERE)
1860 * - LIST_SET: comma separated with field names, like a SET clause
1861 * - LIST_NAMES: comma separated field names
1863 * @throws MWException|DBUnexpectedError
1866 public function makeList( $a, $mode = LIST_COMMA
) {
1867 if ( !is_array( $a ) ) {
1868 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1874 foreach ( $a as $field => $value ) {
1876 if ( $mode == LIST_AND
) {
1878 } elseif ( $mode == LIST_OR
) {
1887 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1888 $list .= "($value)";
1889 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1891 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1892 if ( count( $value ) == 0 ) {
1893 throw new MWException( __METHOD__
. ": empty input for field $field" );
1894 } elseif ( count( $value ) == 1 ) {
1895 // Special-case single values, as IN isn't terribly efficient
1896 // Don't necessarily assume the single key is 0; we don't
1897 // enforce linear numeric ordering on other arrays here.
1898 $value = array_values( $value );
1899 $list .= $field . " = " . $this->addQuotes( $value[0] );
1901 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1903 } elseif ( $value === null ) {
1904 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1905 $list .= "$field IS ";
1906 } elseif ( $mode == LIST_SET
) {
1907 $list .= "$field = ";
1911 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1912 $list .= "$field = ";
1914 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1922 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1923 * The keys on each level may be either integers or strings.
1925 * @param array $data organized as 2-d
1926 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1927 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1928 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1929 * @return Mixed: string SQL fragment, or false if no items in array.
1931 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1934 foreach ( $data as $base => $sub ) {
1935 if ( count( $sub ) ) {
1936 $conds[] = $this->makeList(
1937 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1943 return $this->makeList( $conds, LIST_OR
);
1945 // Nothing to search for...
1951 * Return aggregated value alias
1954 * @param $valuename string
1958 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1966 public function bitNot( $field ) {
1972 * @param $fieldRight
1975 public function bitAnd( $fieldLeft, $fieldRight ) {
1976 return "($fieldLeft & $fieldRight)";
1981 * @param $fieldRight
1984 public function bitOr( $fieldLeft, $fieldRight ) {
1985 return "($fieldLeft | $fieldRight)";
1989 * Build a concatenation list to feed into a SQL query
1990 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
1993 public function buildConcat( $stringList ) {
1994 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1998 * Change the current database
2000 * @todo Explain what exactly will fail if this is not overridden.
2004 * @return bool Success or failure
2006 public function selectDB( $db ) {
2007 # Stub. Shouldn't cause serious problems if it's not overridden, but
2008 # if your database engine supports a concept similar to MySQL's
2009 # databases you may as well.
2010 $this->mDBname
= $db;
2015 * Get the current DB name
2017 public function getDBname() {
2018 return $this->mDBname
;
2022 * Get the server hostname or IP address
2024 public function getServer() {
2025 return $this->mServer
;
2029 * Format a table name ready for use in constructing an SQL query
2031 * This does two important things: it quotes the table names to clean them up,
2032 * and it adds a table prefix if only given a table name with no quotes.
2034 * All functions of this object which require a table name call this function
2035 * themselves. Pass the canonical name to such functions. This is only needed
2036 * when calling query() directly.
2038 * @param string $name database table name
2039 * @param string $format One of:
2040 * quoted - Automatically pass the table name through addIdentifierQuotes()
2041 * so that it can be used in a query.
2042 * raw - Do not add identifier quotes to the table name
2043 * @return String: full database name
2045 public function tableName( $name, $format = 'quoted' ) {
2046 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2047 # Skip the entire process when we have a string quoted on both ends.
2048 # Note that we check the end so that we will still quote any use of
2049 # use of `database`.table. But won't break things if someone wants
2050 # to query a database table with a dot in the name.
2051 if ( $this->isQuotedIdentifier( $name ) ) {
2055 # Lets test for any bits of text that should never show up in a table
2056 # name. Basically anything like JOIN or ON which are actually part of
2057 # SQL queries, but may end up inside of the table value to combine
2058 # sql. Such as how the API is doing.
2059 # Note that we use a whitespace test rather than a \b test to avoid
2060 # any remote case where a word like on may be inside of a table name
2061 # surrounded by symbols which may be considered word breaks.
2062 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2066 # Split database and table into proper variables.
2067 # We reverse the explode so that database.table and table both output
2068 # the correct table.
2069 $dbDetails = explode( '.', $name, 2 );
2070 if ( count( $dbDetails ) == 2 ) {
2071 list( $database, $table ) = $dbDetails;
2072 # We don't want any prefix added in this case
2075 list( $table ) = $dbDetails;
2076 if ( $wgSharedDB !== null # We have a shared database
2077 && !$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 = 'DatabaseBase::replace' ) {
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 = 'DatabaseBase::deleteJoin' )
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 = 'DatabaseBase::delete' ) {
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 = 'DatabaseBase::insertSelect',
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 = 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( DEADLOCK_DELAY_MIN
, 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 * Callbacks must commit any transactions that they begin.
2969 * This is useful for updates to different systems or separate transactions are needed.
2973 * @param Closure $callback
2975 final public function onTransactionIdle( Closure
$callback ) {
2976 if ( $this->mTrxLevel
) {
2977 $this->mTrxIdleCallbacks
[] = $callback;
2984 * Actually run the "on transaction idle" callbacks.
2988 protected function runOnTransactionIdleCallbacks() {
2989 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
2991 $e = null; // last exception
2992 do { // callbacks may add callbacks :)
2993 $callbacks = $this->mTrxIdleCallbacks
;
2994 $this->mTrxIdleCallbacks
= array(); // recursion guard
2995 foreach ( $callbacks as $callback ) {
2997 $this->clearFlag( DBO_TRX
); // make each query its own transaction
2999 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
3000 } catch ( Exception
$e ) {
3003 } while ( count( $this->mTrxIdleCallbacks
) );
3005 if ( $e instanceof Exception
) {
3006 throw $e; // re-throw any last exception
3011 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3012 * new transaction is started.
3014 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3015 * any previous database query will have started a transaction automatically.
3017 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3018 * transaction was started automatically because of the DBO_TRX flag.
3020 * @param $fname string
3022 final public function begin( $fname = 'DatabaseBase::begin' ) {
3023 global $wgDebugDBTransactions;
3025 if ( $this->mTrxLevel
) { // implicit commit
3026 if ( !$this->mTrxAutomatic
) {
3027 // We want to warn about inadvertently nested begin/commit pairs, but not about
3028 // auto-committing implicit transactions that were started by query() via DBO_TRX
3029 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3030 " performing implicit commit!";
3032 wfLogDBError( $msg );
3034 // if the transaction was automatic and has done write operations,
3035 // log it if $wgDebugDBTransactions is enabled.
3036 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3037 wfDebug( "$fname: Automatic transaction with writes in progress" .
3038 " (from {$this->mTrxFname}), performing implicit commit!\n"
3043 $this->doCommit( $fname );
3044 $this->runOnTransactionIdleCallbacks();
3047 $this->doBegin( $fname );
3048 $this->mTrxFname
= $fname;
3049 $this->mTrxDoneWrites
= false;
3050 $this->mTrxAutomatic
= false;
3054 * Issues the BEGIN command to the database server.
3056 * @see DatabaseBase::begin()
3057 * @param type $fname
3059 protected function doBegin( $fname ) {
3060 $this->query( 'BEGIN', $fname );
3061 $this->mTrxLevel
= 1;
3065 * Commits a transaction previously started using begin().
3066 * If no transaction is in progress, a warning is issued.
3068 * Nesting of transactions is not supported.
3070 * @param $fname string
3071 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3072 * transactions, or calling commit when no transaction is in progress.
3073 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3074 * that it is safe to ignore these warnings in your context.
3076 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3077 if ( $flush != 'flush' ) {
3078 if ( !$this->mTrxLevel
) {
3079 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3080 } elseif( $this->mTrxAutomatic
) {
3081 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3084 if ( !$this->mTrxLevel
) {
3085 return; // nothing to do
3086 } elseif( !$this->mTrxAutomatic
) {
3087 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3091 $this->doCommit( $fname );
3092 $this->runOnTransactionIdleCallbacks();
3096 * Issues the COMMIT command to the database server.
3098 * @see DatabaseBase::commit()
3099 * @param type $fname
3101 protected function doCommit( $fname ) {
3102 if ( $this->mTrxLevel
) {
3103 $this->query( 'COMMIT', $fname );
3104 $this->mTrxLevel
= 0;
3109 * Rollback a transaction previously started using begin().
3110 * If no transaction is in progress, a warning is issued.
3112 * No-op on non-transactional databases.
3114 * @param $fname string
3116 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3117 if ( !$this->mTrxLevel
) {
3118 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3120 $this->doRollback( $fname );
3121 $this->mTrxIdleCallbacks
= array(); // cancel
3125 * Issues the ROLLBACK command to the database server.
3127 * @see DatabaseBase::rollback()
3128 * @param type $fname
3130 protected function doRollback( $fname ) {
3131 if ( $this->mTrxLevel
) {
3132 $this->query( 'ROLLBACK', $fname, true );
3133 $this->mTrxLevel
= 0;
3138 * Creates a new table with structure copied from existing table
3139 * Note that unlike most database abstraction functions, this function does not
3140 * automatically append database prefix, because it works at a lower
3141 * abstraction level.
3142 * The table names passed to this function shall not be quoted (this
3143 * function calls addIdentifierQuotes when needed).
3145 * @param string $oldName name of table whose structure should be copied
3146 * @param string $newName name of table to be created
3147 * @param $temporary Boolean: whether the new table should be temporary
3148 * @param string $fname calling function name
3149 * @throws MWException
3150 * @return Boolean: true if operation was successful
3152 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3153 $fname = 'DatabaseBase::duplicateTableStructure'
3155 throw new MWException(
3156 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3160 * List all tables on the database
3162 * @param string $prefix Only show tables with this prefix, e.g. mw_
3163 * @param string $fname calling function name
3164 * @throws MWException
3166 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3167 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3171 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3172 * to the format used for inserting into timestamp fields in this DBMS.
3174 * The result is unquoted, and needs to be passed through addQuotes()
3175 * before it can be included in raw SQL.
3177 * @param $ts string|int
3181 public function timestamp( $ts = 0 ) {
3182 return wfTimestamp( TS_MW
, $ts );
3186 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3187 * to the format used for inserting into timestamp fields in this DBMS. If
3188 * NULL is input, it is passed through, allowing NULL values to be inserted
3189 * into timestamp fields.
3191 * The result is unquoted, and needs to be passed through addQuotes()
3192 * before it can be included in raw SQL.
3194 * @param $ts string|int
3198 public function timestampOrNull( $ts = null ) {
3199 if ( is_null( $ts ) ) {
3202 return $this->timestamp( $ts );
3207 * Take the result from a query, and wrap it in a ResultWrapper if
3208 * necessary. Boolean values are passed through as is, to indicate success
3209 * of write queries or failure.
3211 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3212 * resource, and it was necessary to call this function to convert it to
3213 * a wrapper. Nowadays, raw database objects are never exposed to external
3214 * callers, so this is unnecessary in external code. For compatibility with
3215 * old code, ResultWrapper objects are passed through unaltered.
3217 * @param $result bool|ResultWrapper
3219 * @return bool|ResultWrapper
3221 public function resultObject( $result ) {
3222 if ( empty( $result ) ) {
3224 } elseif ( $result instanceof ResultWrapper
) {
3226 } elseif ( $result === true ) {
3227 // Successful write query
3230 return new ResultWrapper( $this, $result );
3235 * Ping the server and try to reconnect if it there is no connection
3237 * @return bool Success or failure
3239 public function ping() {
3240 # Stub. Not essential to override.
3245 * Get slave lag. Currently supported only by MySQL.
3247 * Note that this function will generate a fatal error on many
3248 * installations. Most callers should use LoadBalancer::safeGetLag()
3251 * @return int Database replication lag in seconds
3253 public function getLag() {
3254 return intval( $this->mFakeSlaveLag
);
3258 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3262 function maxListLen() {
3267 * Some DBMSs have a special format for inserting into blob fields, they
3268 * don't allow simple quoted strings to be inserted. To insert into such
3269 * a field, pass the data through this function before passing it to
3270 * DatabaseBase::insert().
3274 public function encodeBlob( $b ) {
3279 * Some DBMSs return a special placeholder object representing blob fields
3280 * in result objects. Pass the object through this function to return the
3285 public function decodeBlob( $b ) {
3290 * Override database's default behavior. $options include:
3291 * 'connTimeout' : Set the connection timeout value in seconds.
3292 * May be useful for very long batch queries such as
3293 * full-wiki dumps, where a single query reads out over
3296 * @param $options Array
3299 public function setSessionOptions( array $options ) {
3303 * Read and execute SQL commands from a file.
3305 * Returns true on success, error string or exception on failure (depending
3306 * on object's error ignore settings).
3308 * @param string $filename File name to open
3309 * @param bool|callable $lineCallback Optional function called before reading each line
3310 * @param bool|callable $resultCallback Optional function called for each MySQL result
3311 * @param bool|string $fname Calling function name or false if name should be
3312 * generated dynamically using $filename
3313 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3314 * @throws MWException
3315 * @throws Exception|MWException
3316 * @return bool|string
3318 public function sourceFile(
3319 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3321 wfSuppressWarnings();
3322 $fp = fopen( $filename, 'r' );
3323 wfRestoreWarnings();
3325 if ( false === $fp ) {
3326 throw new MWException( "Could not open \"{$filename}\".\n" );
3330 $fname = __METHOD__
. "( $filename )";
3334 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3336 catch ( MWException
$e ) {
3347 * Get the full path of a patch file. Originally based on archive()
3348 * from updaters.inc. Keep in mind this always returns a patch, as
3349 * it fails back to MySQL if no DB-specific patch can be found
3351 * @param string $patch The name of the patch, like patch-something.sql
3352 * @return String Full path to patch file
3354 public function patchPath( $patch ) {
3357 $dbType = $this->getType();
3358 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3359 return "$IP/maintenance/$dbType/archives/$patch";
3361 return "$IP/maintenance/archives/$patch";
3366 * Set variables to be used in sourceFile/sourceStream, in preference to the
3367 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3368 * all. If it's set to false, $GLOBALS will be used.
3370 * @param bool|array $vars mapping variable name to value.
3372 public function setSchemaVars( $vars ) {
3373 $this->mSchemaVars
= $vars;
3377 * Read and execute commands from an open file handle.
3379 * Returns true on success, error string or exception on failure (depending
3380 * on object's error ignore settings).
3382 * @param $fp Resource: File handle
3383 * @param $lineCallback Callback: Optional function called before reading each query
3384 * @param $resultCallback Callback: Optional function called for each MySQL result
3385 * @param string $fname Calling function name
3386 * @param $inputCallback Callback: Optional function called for each complete query sent
3387 * @return bool|string
3389 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3390 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3394 while ( !feof( $fp ) ) {
3395 if ( $lineCallback ) {
3396 call_user_func( $lineCallback );
3399 $line = trim( fgets( $fp ) );
3401 if ( $line == '' ) {
3405 if ( '-' == $line[0] && '-' == $line[1] ) {
3413 $done = $this->streamStatementEnd( $cmd, $line );
3417 if ( $done ||
feof( $fp ) ) {
3418 $cmd = $this->replaceVars( $cmd );
3420 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3421 $res = $this->query( $cmd, $fname );
3423 if ( $resultCallback ) {
3424 call_user_func( $resultCallback, $res, $this );
3427 if ( false === $res ) {
3428 $err = $this->lastError();
3429 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3440 * Called by sourceStream() to check if we've reached a statement end
3442 * @param string $sql SQL assembled so far
3443 * @param string $newLine New line about to be added to $sql
3444 * @return Bool Whether $newLine contains end of the statement
3446 public function streamStatementEnd( &$sql, &$newLine ) {
3447 if ( $this->delimiter
) {
3449 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3450 if ( $newLine != $prev ) {
3458 * Database independent variable replacement. Replaces a set of variables
3459 * in an SQL statement with their contents as given by $this->getSchemaVars().
3461 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3463 * - '{$var}' should be used for text and is passed through the database's
3465 * - `{$var}` should be used for identifiers (eg: table and database names),
3466 * it is passed through the database's addIdentifierQuotes method which
3467 * can be overridden if the database uses something other than backticks.
3468 * - / *$var* / is just encoded, besides traditional table prefix and
3469 * table options its use should be avoided.
3471 * @param string $ins SQL statement to replace variables in
3472 * @return String The new SQL statement with variables replaced
3474 protected function replaceSchemaVars( $ins ) {
3475 $vars = $this->getSchemaVars();
3476 foreach ( $vars as $var => $value ) {
3478 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3480 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3482 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3488 * Replace variables in sourced SQL
3490 * @param $ins string
3494 protected function replaceVars( $ins ) {
3495 $ins = $this->replaceSchemaVars( $ins );
3498 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3499 array( $this, 'tableNameCallback' ), $ins );
3502 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3503 array( $this, 'indexNameCallback' ), $ins );
3509 * Get schema variables. If none have been set via setSchemaVars(), then
3510 * use some defaults from the current object.
3514 protected function getSchemaVars() {
3515 if ( $this->mSchemaVars
) {
3516 return $this->mSchemaVars
;
3518 return $this->getDefaultSchemaVars();
3523 * Get schema variables to use if none have been set via setSchemaVars().
3525 * Override this in derived classes to provide variables for tables.sql
3526 * and SQL patch files.
3530 protected function getDefaultSchemaVars() {
3535 * Table name callback
3537 * @param $matches array
3541 protected function tableNameCallback( $matches ) {
3542 return $this->tableName( $matches[1] );
3546 * Index name callback
3548 * @param $matches array
3552 protected function indexNameCallback( $matches ) {
3553 return $this->indexName( $matches[1] );
3557 * Check to see if a named lock is available. This is non-blocking.
3559 * @param string $lockName name of lock to poll
3560 * @param string $method name of method calling us
3564 public function lockIsFree( $lockName, $method ) {
3569 * Acquire a named lock
3571 * Abstracted from Filestore::lock() so child classes can implement for
3574 * @param string $lockName name of lock to aquire
3575 * @param string $method name of method calling us
3576 * @param $timeout Integer: timeout
3579 public function lock( $lockName, $method, $timeout = 5 ) {
3586 * @param string $lockName Name of lock to release
3587 * @param string $method Name of method calling us
3589 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3590 * by this thread (in which case the lock is not released), and NULL if the named
3591 * lock did not exist
3593 public function unlock( $lockName, $method ) {
3598 * Lock specific tables
3600 * @param array $read of tables to lock for read access
3601 * @param array $write of tables to lock for write access
3602 * @param string $method name of caller
3603 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3607 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3612 * Unlock specific tables
3614 * @param string $method the caller
3618 public function unlockTables( $method ) {
3624 * @param $tableName string
3625 * @param $fName string
3626 * @return bool|ResultWrapper
3629 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3630 if( !$this->tableExists( $tableName, $fName ) ) {
3633 $sql = "DROP TABLE " . $this->tableName( $tableName );
3634 if( $this->cascadingDeletes() ) {
3637 return $this->query( $sql, $fName );
3641 * Get search engine class. All subclasses of this need to implement this
3642 * if they wish to use searching.
3646 public function getSearchEngine() {
3647 return 'SearchEngineDummy';
3651 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3652 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3653 * because "i" sorts after all numbers.
3657 public function getInfinity() {
3662 * Encode an expiry time into the DBMS dependent format
3664 * @param string $expiry timestamp for expiry, or the 'infinity' string
3667 public function encodeExpiry( $expiry ) {
3668 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3669 ?
$this->getInfinity()
3670 : $this->timestamp( $expiry );
3674 * Decode an expiry time into a DBMS independent format
3676 * @param string $expiry DB timestamp field value for expiry
3677 * @param $format integer: TS_* constant, defaults to TS_MW
3680 public function decodeExpiry( $expiry, $format = TS_MW
) {
3681 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
3683 : wfTimestamp( $format, $expiry );
3687 * Allow or deny "big selects" for this session only. This is done by setting
3688 * the sql_big_selects session variable.
3690 * This is a MySQL-specific feature.
3692 * @param $value Mixed: true for allow, false for deny, or "default" to
3693 * restore the initial value
3695 public function setBigSelects( $value = true ) {
3702 public function __toString() {
3703 return (string)$this->mConn
;
3706 public function __destruct() {
3707 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
3708 trigger_error( "Transaction idle callbacks still pending." );