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[mediawiki.git] / includes / db / Database.php
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1 <?php
2 /**
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
23 * @file
24 * @ingroup Database
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 );
34 /**
35 * Base interface for all DBMS-specific code. At a bare minimum, all of the
36 * following must be implemented to support MediaWiki
38 * @file
39 * @ingroup Database
41 interface DatabaseType {
42 /**
43 * Get the type of the DBMS, as it appears in $wgDBtype.
45 * @return string
47 function getType();
49 /**
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
56 * @return bool
57 * @throws DBConnectionError
59 function open( $server, $user, $password, $dbName );
61 /**
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
64 * member variables.
65 * If no more rows are available, false is returned.
67 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
68 * @return object|bool
69 * @throws DBUnexpectedError Thrown if the database returns an error
71 function fetchObject( $res );
73 /**
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.
79 * @return array|bool
80 * @throws DBUnexpectedError Thrown if the database returns an error
82 function fetchRow( $res );
84 /**
85 * Get the number of rows in a result object
87 * @param $res Mixed: A SQL result
88 * @return int
90 function numRows( $res );
92 /**
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
97 * @return int
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
106 * @param $n Integer
107 * @return string
109 function fieldName( $res, $n );
112 * Get the inserted value of an auto-increment row
114 * The value inserted should be fetched from nextSequenceValue()
116 * Example:
117 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
118 * $dbw->insert( 'page', array( 'page_id' => $id ) );
119 * $id = $dbw->insertId();
121 * @return int
123 function 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
138 * @return int
140 function lastErrno();
143 * Get a description of the last error
144 * @see http://www.php.net/mysql_error
146 * @return string
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
157 * @return Field
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
174 * @return int
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
216 * @ingroup Database
218 abstract class DatabaseBase implements DatabaseType {
220 # ------------------------------------------------------------------------------
221 # Variables
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;
233 /** @var array of Closure */
234 protected $mTrxIdleCallbacks = array();
235 /** @var array of Closure */
236 protected $mTrxPreCommitCallbacks = array();
238 protected $mTablePrefix;
239 protected $mFlags;
240 protected $mTrxLevel = 0;
241 protected $mErrorCount = 0;
242 protected $mLBInfo = array();
243 protected $mFakeSlaveLag = null, $mFakeMaster = false;
244 protected $mDefaultBigSelects = null;
245 protected $mSchemaVars = false;
247 protected $preparedArgs;
249 protected $htmlErrors;
251 protected $delimiter = ';';
254 * Remembers the function name given for starting the most recent transaction via begin().
255 * Used to provide additional context for error reporting.
257 * @var String
258 * @see DatabaseBase::mTrxLevel
260 private $mTrxFname = null;
263 * Record if possible write queries were done in the last transaction started
265 * @var Bool
266 * @see DatabaseBase::mTrxLevel
268 private $mTrxDoneWrites = false;
271 * Record if the current transaction was started implicitly due to DBO_TRX being set.
273 * @var Bool
274 * @see DatabaseBase::mTrxLevel
276 private $mTrxAutomatic = false;
279 * @since 1.21
280 * @var file handle for upgrade
282 protected $fileHandle = null;
284 # ------------------------------------------------------------------------------
285 # Accessors
286 # ------------------------------------------------------------------------------
287 # These optionally set a variable and return the previous state
290 * A string describing the current software version, and possibly
291 * other details in a user-friendly way. Will be listed on Special:Version, etc.
292 * Use getServerVersion() to get machine-friendly information.
294 * @return string: Version information from the database server
296 public function getServerInfo() {
297 return $this->getServerVersion();
301 * @return string: command delimiter used by this database engine
303 public function getDelimiter() {
304 return $this->delimiter;
308 * Boolean, controls output of large amounts of debug information.
309 * @param $debug bool|null
310 * - true to enable debugging
311 * - false to disable debugging
312 * - omitted or null to do nothing
314 * @return bool|null previous value of the flag
316 public function debug( $debug = null ) {
317 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
321 * Turns buffering of SQL result sets on (true) or off (false). Default is
322 * "on".
324 * Unbuffered queries are very troublesome in MySQL:
326 * - If another query is executed while the first query is being read
327 * out, the first query is killed. This means you can't call normal
328 * MediaWiki functions while you are reading an unbuffered query result
329 * from a normal wfGetDB() connection.
331 * - Unbuffered queries cause the MySQL server to use large amounts of
332 * memory and to hold broad locks which block other queries.
334 * If you want to limit client-side memory, it's almost always better to
335 * split up queries into batches using a LIMIT clause than to switch off
336 * buffering.
338 * @param $buffer null|bool
340 * @return null|bool The previous value of the flag
342 public function bufferResults( $buffer = null ) {
343 if ( is_null( $buffer ) ) {
344 return !(bool)( $this->mFlags & DBO_NOBUFFER );
345 } else {
346 return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
351 * Turns on (false) or off (true) the automatic generation and sending
352 * of a "we're sorry, but there has been a database error" page on
353 * database errors. Default is on (false). When turned off, the
354 * code should use lastErrno() and lastError() to handle the
355 * situation as appropriate.
357 * @param $ignoreErrors bool|null
359 * @return bool The previous value of the flag.
361 public function ignoreErrors( $ignoreErrors = null ) {
362 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
366 * Gets or sets the current transaction level.
368 * Historically, transactions were allowed to be "nested". This is no
369 * longer supported, so this function really only returns a boolean.
371 * @param int $level An integer (0 or 1), or omitted to leave it unchanged.
372 * @return int The previous value
374 public function trxLevel( $level = null ) {
375 return wfSetVar( $this->mTrxLevel, $level );
379 * Get/set the number of errors logged. Only useful when errors are ignored
380 * @param int $count The count to set, or omitted to leave it unchanged.
381 * @return int The error count
383 public function errorCount( $count = null ) {
384 return wfSetVar( $this->mErrorCount, $count );
388 * Get/set the table prefix.
389 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
390 * @return string The previous table prefix.
392 public function tablePrefix( $prefix = null ) {
393 return wfSetVar( $this->mTablePrefix, $prefix );
397 * Set the filehandle to copy write statements to.
399 * @param $fh filehandle
401 public function setFileHandle( $fh ) {
402 $this->fileHandle = $fh;
406 * Get properties passed down from the server info array of the load
407 * balancer.
409 * @param string $name The entry of the info array to get, or null to get the
410 * whole array
412 * @return LoadBalancer|null
414 public function getLBInfo( $name = null ) {
415 if ( is_null( $name ) ) {
416 return $this->mLBInfo;
417 } else {
418 if ( array_key_exists( $name, $this->mLBInfo ) ) {
419 return $this->mLBInfo[$name];
420 } else {
421 return null;
427 * Set the LB info array, or a member of it. If called with one parameter,
428 * the LB info array is set to that parameter. If it is called with two
429 * parameters, the member with the given name is set to the given value.
431 * @param $name
432 * @param $value
434 public function setLBInfo( $name, $value = null ) {
435 if ( is_null( $value ) ) {
436 $this->mLBInfo = $name;
437 } else {
438 $this->mLBInfo[$name] = $value;
443 * Set lag time in seconds for a fake slave
445 * @param $lag int
447 public function setFakeSlaveLag( $lag ) {
448 $this->mFakeSlaveLag = $lag;
452 * Make this connection a fake master
454 * @param $enabled bool
456 public function setFakeMaster( $enabled = true ) {
457 $this->mFakeMaster = $enabled;
461 * Returns true if this database supports (and uses) cascading deletes
463 * @return bool
465 public function cascadingDeletes() {
466 return false;
470 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
472 * @return bool
474 public function cleanupTriggers() {
475 return false;
479 * Returns true if this database is strict about what can be put into an IP field.
480 * Specifically, it uses a NULL value instead of an empty string.
482 * @return bool
484 public function strictIPs() {
485 return false;
489 * Returns true if this database uses timestamps rather than integers
491 * @return bool
493 public function realTimestamps() {
494 return false;
498 * Returns true if this database does an implicit sort when doing GROUP BY
500 * @return bool
502 public function implicitGroupby() {
503 return true;
507 * Returns true if this database does an implicit order by when the column has an index
508 * For example: SELECT page_title FROM page LIMIT 1
510 * @return bool
512 public function implicitOrderby() {
513 return true;
517 * Returns true if this database can do a native search on IP columns
518 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
520 * @return bool
522 public function searchableIPs() {
523 return false;
527 * Returns true if this database can use functional indexes
529 * @return bool
531 public function functionalIndexes() {
532 return false;
536 * Return the last query that went through DatabaseBase::query()
537 * @return String
539 public function lastQuery() {
540 return $this->mLastQuery;
544 * Returns true if the connection may have been used for write queries.
545 * Should return true if unsure.
547 * @return bool
549 public function doneWrites() {
550 return $this->mDoneWrites;
554 * Returns true if there is a transaction open with possible write
555 * queries or transaction pre-commit/idle callbacks waiting on it to finish.
557 * @return bool
559 public function writesOrCallbacksPending() {
560 return $this->mTrxLevel && (
561 $this->mTrxDoneWrites || $this->mTrxIdleCallbacks || $this->mTrxPreCommitCallbacks
566 * Is a connection to the database open?
567 * @return Boolean
569 public function isOpen() {
570 return $this->mOpened;
574 * Set a flag for this connection
576 * @param $flag Integer: DBO_* constants from Defines.php:
577 * - DBO_DEBUG: output some debug info (same as debug())
578 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
579 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
580 * - DBO_TRX: automatically start transactions
581 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
582 * and removes it in command line mode
583 * - DBO_PERSISTENT: use persistant database connection
585 public function setFlag( $flag ) {
586 global $wgDebugDBTransactions;
587 $this->mFlags |= $flag;
588 if ( ( $flag & DBO_TRX ) & $wgDebugDBTransactions ) {
589 wfDebug( "Implicit transactions are now disabled.\n" );
594 * Clear a flag for this connection
596 * @param $flag: same as setFlag()'s $flag param
598 public function clearFlag( $flag ) {
599 global $wgDebugDBTransactions;
600 $this->mFlags &= ~$flag;
601 if ( ( $flag & DBO_TRX ) && $wgDebugDBTransactions ) {
602 wfDebug( "Implicit transactions are now disabled.\n" );
607 * Returns a boolean whether the flag $flag is set for this connection
609 * @param $flag: same as setFlag()'s $flag param
610 * @return Boolean
612 public function getFlag( $flag ) {
613 return !!( $this->mFlags & $flag );
617 * General read-only accessor
619 * @param $name string
621 * @return string
623 public function getProperty( $name ) {
624 return $this->$name;
628 * @return string
630 public function getWikiID() {
631 if ( $this->mTablePrefix ) {
632 return "{$this->mDBname}-{$this->mTablePrefix}";
633 } else {
634 return $this->mDBname;
639 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
641 * @return string
643 public function getSchemaPath() {
644 global $IP;
645 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
646 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
647 } else {
648 return "$IP/maintenance/tables.sql";
652 # ------------------------------------------------------------------------------
653 # Other functions
654 # ------------------------------------------------------------------------------
657 * Constructor.
658 * @param string $server database server host
659 * @param string $user database user name
660 * @param string $password database user password
661 * @param string $dbName database name
662 * @param $flags
663 * @param string $tablePrefix database table prefixes. By default use the prefix gave in LocalSettings.php
665 function __construct( $server = false, $user = false, $password = false, $dbName = false,
666 $flags = 0, $tablePrefix = 'get from global'
668 global $wgDBprefix, $wgCommandLineMode, $wgDebugDBTransactions;
670 $this->mFlags = $flags;
672 if ( $this->mFlags & DBO_DEFAULT ) {
673 if ( $wgCommandLineMode ) {
674 $this->mFlags &= ~DBO_TRX;
675 if ( $wgDebugDBTransactions ) {
676 wfDebug( "Implicit transaction open disabled.\n" );
678 } else {
679 $this->mFlags |= DBO_TRX;
680 if ( $wgDebugDBTransactions ) {
681 wfDebug( "Implicit transaction open enabled.\n" );
686 /** Get the default table prefix*/
687 if ( $tablePrefix == 'get from global' ) {
688 $this->mTablePrefix = $wgDBprefix;
689 } else {
690 $this->mTablePrefix = $tablePrefix;
693 if ( $user ) {
694 $this->open( $server, $user, $password, $dbName );
699 * Called by serialize. Throw an exception when DB connection is serialized.
700 * This causes problems on some database engines because the connection is
701 * not restored on unserialize.
703 public function __sleep() {
704 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
708 * Given a DB type, construct the name of the appropriate child class of
709 * DatabaseBase. This is designed to replace all of the manual stuff like:
710 * $class = 'Database' . ucfirst( strtolower( $type ) );
711 * as well as validate against the canonical list of DB types we have
713 * This factory function is mostly useful for when you need to connect to a
714 * database other than the MediaWiki default (such as for external auth,
715 * an extension, et cetera). Do not use this to connect to the MediaWiki
716 * database. Example uses in core:
717 * @see LoadBalancer::reallyOpenConnection()
718 * @see ForeignDBRepo::getMasterDB()
719 * @see WebInstaller_DBConnect::execute()
721 * @since 1.18
723 * @param string $dbType A possible DB type
724 * @param array $p An array of options to pass to the constructor.
725 * Valid options are: host, user, password, dbname, flags, tablePrefix
726 * @return DatabaseBase subclass or null
728 final public static function factory( $dbType, $p = array() ) {
729 $canonicalDBTypes = array(
730 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql'
732 $dbType = strtolower( $dbType );
733 $class = 'Database' . ucfirst( $dbType );
735 if ( in_array( $dbType, $canonicalDBTypes ) || ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) ) {
736 return new $class(
737 isset( $p['host'] ) ? $p['host'] : false,
738 isset( $p['user'] ) ? $p['user'] : false,
739 isset( $p['password'] ) ? $p['password'] : false,
740 isset( $p['dbname'] ) ? $p['dbname'] : false,
741 isset( $p['flags'] ) ? $p['flags'] : 0,
742 isset( $p['tablePrefix'] ) ? $p['tablePrefix'] : 'get from global'
744 } else {
745 return null;
749 protected function installErrorHandler() {
750 $this->mPHPError = false;
751 $this->htmlErrors = ini_set( 'html_errors', '0' );
752 set_error_handler( array( $this, 'connectionErrorHandler' ) );
756 * @return bool|string
758 protected function restoreErrorHandler() {
759 restore_error_handler();
760 if ( $this->htmlErrors !== false ) {
761 ini_set( 'html_errors', $this->htmlErrors );
763 if ( $this->mPHPError ) {
764 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
765 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
766 return $error;
767 } else {
768 return false;
773 * @param $errno
774 * @param $errstr
775 * @access private
777 public function connectionErrorHandler( $errno, $errstr ) {
778 $this->mPHPError = $errstr;
782 * Closes a database connection.
783 * if it is open : commits any open transactions
785 * @throws MWException
786 * @return Bool operation success. true if already closed.
788 public function close() {
789 if ( count( $this->mTrxIdleCallbacks ) ) { // sanity
790 throw new MWException( "Transaction idle callbacks still pending." );
792 $this->mOpened = false;
793 if ( $this->mConn ) {
794 if ( $this->trxLevel() ) {
795 if ( !$this->mTrxAutomatic ) {
796 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
797 " performing implicit commit before closing connection!" );
800 $this->commit( __METHOD__, 'flush' );
803 $ret = $this->closeConnection();
804 $this->mConn = false;
805 return $ret;
806 } else {
807 return true;
812 * Closes underlying database connection
813 * @since 1.20
814 * @return bool: Whether connection was closed successfully
816 abstract protected function closeConnection();
819 * @param string $error fallback error message, used if none is given by DB
820 * @throws DBConnectionError
822 function reportConnectionError( $error = 'Unknown error' ) {
823 $myError = $this->lastError();
824 if ( $myError ) {
825 $error = $myError;
828 # New method
829 throw new DBConnectionError( $this, $error );
833 * The DBMS-dependent part of query()
835 * @param $sql String: SQL query.
836 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
838 abstract protected function doQuery( $sql );
841 * Determine whether a query writes to the DB.
842 * Should return true if unsure.
844 * @param $sql string
846 * @return bool
848 public function isWriteQuery( $sql ) {
849 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
853 * Run an SQL query and return the result. Normally throws a DBQueryError
854 * on failure. If errors are ignored, returns false instead.
856 * In new code, the query wrappers select(), insert(), update(), delete(),
857 * etc. should be used where possible, since they give much better DBMS
858 * independence and automatically quote or validate user input in a variety
859 * of contexts. This function is generally only useful for queries which are
860 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
861 * as CREATE TABLE.
863 * However, the query wrappers themselves should call this function.
865 * @param $sql String: SQL query
866 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
867 * comment (you can use __METHOD__ or add some extra info)
868 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
869 * maybe best to catch the exception instead?
870 * @throws MWException
871 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
872 * for a successful read query, or false on failure if $tempIgnore set
874 public function query( $sql, $fname = '', $tempIgnore = false ) {
875 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
876 if ( !Profiler::instance()->isStub() ) {
877 # generalizeSQL will probably cut down the query to reasonable
878 # logging size most of the time. The substr is really just a sanity check.
880 if ( $isMaster ) {
881 $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
882 $totalProf = 'DatabaseBase::query-master';
883 } else {
884 $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
885 $totalProf = 'DatabaseBase::query';
888 wfProfileIn( $totalProf );
889 wfProfileIn( $queryProf );
892 $this->mLastQuery = $sql;
893 if ( !$this->mDoneWrites && $this->isWriteQuery( $sql ) ) {
894 # Set a flag indicating that writes have been done
895 wfDebug( __METHOD__ . ": Writes done: $sql\n" );
896 $this->mDoneWrites = true;
899 # Add a comment for easy SHOW PROCESSLIST interpretation
900 global $wgUser;
901 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
902 $userName = $wgUser->getName();
903 if ( mb_strlen( $userName ) > 15 ) {
904 $userName = mb_substr( $userName, 0, 15 ) . '...';
906 $userName = str_replace( '/', '', $userName );
907 } else {
908 $userName = '';
911 // Add trace comment to the begin of the sql string, right after the operator.
912 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
913 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
915 # If DBO_TRX is set, start a transaction
916 if ( ( $this->mFlags & DBO_TRX ) && !$this->mTrxLevel &&
917 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' )
919 # Avoid establishing transactions for SHOW and SET statements too -
920 # that would delay transaction initializations to once connection
921 # is really used by application
922 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
923 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 ) {
924 global $wgDebugDBTransactions;
925 if ( $wgDebugDBTransactions ) {
926 wfDebug( "Implicit transaction start.\n" );
928 $this->begin( __METHOD__ . " ($fname)" );
929 $this->mTrxAutomatic = true;
933 # Keep track of whether the transaction has write queries pending
934 if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $this->isWriteQuery( $sql ) ) {
935 $this->mTrxDoneWrites = true;
938 if ( $this->debug() ) {
939 static $cnt = 0;
941 $cnt++;
942 $sqlx = substr( $commentedSql, 0, 500 );
943 $sqlx = strtr( $sqlx, "\t\n", ' ' );
945 $master = $isMaster ? 'master' : 'slave';
946 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
949 if ( istainted( $sql ) & TC_MYSQL ) {
950 if ( !Profiler::instance()->isStub() ) {
951 wfProfileOut( $queryProf );
952 wfProfileOut( $totalProf );
954 throw new MWException( 'Tainted query found' );
957 $queryId = MWDebug::query( $sql, $fname, $isMaster );
959 # Do the query and handle errors
960 $ret = $this->doQuery( $commentedSql );
962 MWDebug::queryTime( $queryId );
964 # Try reconnecting if the connection was lost
965 if ( false === $ret && $this->wasErrorReissuable() ) {
966 # Transaction is gone, like it or not
967 $this->mTrxLevel = 0;
968 $this->mTrxIdleCallbacks = array(); // cancel
969 $this->mTrxPreCommitCallbacks = array(); // cancel
970 wfDebug( "Connection lost, reconnecting...\n" );
972 if ( $this->ping() ) {
973 wfDebug( "Reconnected\n" );
974 $sqlx = substr( $commentedSql, 0, 500 );
975 $sqlx = strtr( $sqlx, "\t\n", ' ' );
976 global $wgRequestTime;
977 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
978 if ( $elapsed < 300 ) {
979 # Not a database error to lose a transaction after a minute or two
980 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
982 $ret = $this->doQuery( $commentedSql );
983 } else {
984 wfDebug( "Failed\n" );
988 if ( false === $ret ) {
989 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
992 if ( !Profiler::instance()->isStub() ) {
993 wfProfileOut( $queryProf );
994 wfProfileOut( $totalProf );
997 return $this->resultObject( $ret );
1001 * Report a query error. Log the error, and if neither the object ignore
1002 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1004 * @param $error String
1005 * @param $errno Integer
1006 * @param $sql String
1007 * @param $fname String
1008 * @param $tempIgnore Boolean
1009 * @throws DBQueryError
1011 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1012 # Ignore errors during error handling to avoid infinite recursion
1013 $ignore = $this->ignoreErrors( true );
1014 ++$this->mErrorCount;
1016 if ( $ignore || $tempIgnore ) {
1017 wfDebug( "SQL ERROR (ignored): $error\n" );
1018 $this->ignoreErrors( $ignore );
1019 } else {
1020 $sql1line = str_replace( "\n", "\\n", $sql );
1021 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
1022 wfDebug( "SQL ERROR: " . $error . "\n" );
1023 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1028 * Intended to be compatible with the PEAR::DB wrapper functions.
1029 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1031 * ? = scalar value, quoted as necessary
1032 * ! = raw SQL bit (a function for instance)
1033 * & = filename; reads the file and inserts as a blob
1034 * (we don't use this though...)
1036 * @param $sql string
1037 * @param $func string
1039 * @return array
1041 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1042 /* MySQL doesn't support prepared statements (yet), so just
1043 pack up the query for reference. We'll manually replace
1044 the bits later. */
1045 return array( 'query' => $sql, 'func' => $func );
1049 * Free a prepared query, generated by prepare().
1050 * @param $prepared
1052 protected function freePrepared( $prepared ) {
1053 /* No-op by default */
1057 * Execute a prepared query with the various arguments
1058 * @param string $prepared the prepared sql
1059 * @param $args Mixed: Either an array here, or put scalars as varargs
1061 * @return ResultWrapper
1063 public function execute( $prepared, $args = null ) {
1064 if ( !is_array( $args ) ) {
1065 # Pull the var args
1066 $args = func_get_args();
1067 array_shift( $args );
1070 $sql = $this->fillPrepared( $prepared['query'], $args );
1072 return $this->query( $sql, $prepared['func'] );
1076 * For faking prepared SQL statements on DBs that don't support it directly.
1078 * @param string $preparedQuery a 'preparable' SQL statement
1079 * @param array $args of arguments to fill it with
1080 * @return string executable SQL
1082 public function fillPrepared( $preparedQuery, $args ) {
1083 reset( $args );
1084 $this->preparedArgs =& $args;
1086 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1087 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1091 * preg_callback func for fillPrepared()
1092 * The arguments should be in $this->preparedArgs and must not be touched
1093 * while we're doing this.
1095 * @param $matches Array
1096 * @throws DBUnexpectedError
1097 * @return String
1099 protected function fillPreparedArg( $matches ) {
1100 switch ( $matches[1] ) {
1101 case '\\?':
1102 return '?';
1103 case '\\!':
1104 return '!';
1105 case '\\&':
1106 return '&';
1109 list( /* $n */, $arg ) = each( $this->preparedArgs );
1111 switch ( $matches[1] ) {
1112 case '?':
1113 return $this->addQuotes( $arg );
1114 case '!':
1115 return $arg;
1116 case '&':
1117 # return $this->addQuotes( file_get_contents( $arg ) );
1118 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1119 default:
1120 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1125 * Free a result object returned by query() or select(). It's usually not
1126 * necessary to call this, just use unset() or let the variable holding
1127 * the result object go out of scope.
1129 * @param $res Mixed: A SQL result
1131 public function freeResult( $res ) {
1135 * A SELECT wrapper which returns a single field from a single result row.
1137 * Usually throws a DBQueryError on failure. If errors are explicitly
1138 * ignored, returns false on failure.
1140 * If no result rows are returned from the query, false is returned.
1142 * @param string|array $table Table name. See DatabaseBase::select() for details.
1143 * @param string $var The field name to select. This must be a valid SQL
1144 * fragment: do not use unvalidated user input.
1145 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1146 * @param string $fname The function name of the caller.
1147 * @param string|array $options The query options. See DatabaseBase::select() for details.
1149 * @return bool|mixed The value from the field, or false on failure.
1151 public function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1152 $options = array()
1154 if ( !is_array( $options ) ) {
1155 $options = array( $options );
1158 $options['LIMIT'] = 1;
1160 $res = $this->select( $table, $var, $cond, $fname, $options );
1162 if ( $res === false || !$this->numRows( $res ) ) {
1163 return false;
1166 $row = $this->fetchRow( $res );
1168 if ( $row !== false ) {
1169 return reset( $row );
1170 } else {
1171 return false;
1176 * Returns an optional USE INDEX clause to go after the table, and a
1177 * string to go at the end of the query.
1179 * @param array $options associative array of options to be turned into
1180 * an SQL query, valid keys are listed in the function.
1181 * @return Array
1182 * @see DatabaseBase::select()
1184 public function makeSelectOptions( $options ) {
1185 $preLimitTail = $postLimitTail = '';
1186 $startOpts = '';
1188 $noKeyOptions = array();
1190 foreach ( $options as $key => $option ) {
1191 if ( is_numeric( $key ) ) {
1192 $noKeyOptions[$option] = true;
1196 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1198 $preLimitTail .= $this->makeOrderBy( $options );
1200 // if (isset($options['LIMIT'])) {
1201 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1202 // isset($options['OFFSET']) ? $options['OFFSET']
1203 // : false);
1204 // }
1206 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1207 $postLimitTail .= ' FOR UPDATE';
1210 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1211 $postLimitTail .= ' LOCK IN SHARE MODE';
1214 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1215 $startOpts .= 'DISTINCT';
1218 # Various MySQL extensions
1219 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1220 $startOpts .= ' /*! STRAIGHT_JOIN */';
1223 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1224 $startOpts .= ' HIGH_PRIORITY';
1227 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1228 $startOpts .= ' SQL_BIG_RESULT';
1231 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1232 $startOpts .= ' SQL_BUFFER_RESULT';
1235 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1236 $startOpts .= ' SQL_SMALL_RESULT';
1239 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1240 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1243 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1244 $startOpts .= ' SQL_CACHE';
1247 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1248 $startOpts .= ' SQL_NO_CACHE';
1251 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1252 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1253 } else {
1254 $useIndex = '';
1257 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1261 * Returns an optional GROUP BY with an optional HAVING
1263 * @param array $options associative array of options
1264 * @return string
1265 * @see DatabaseBase::select()
1266 * @since 1.21
1268 public function makeGroupByWithHaving( $options ) {
1269 $sql = '';
1270 if ( isset( $options['GROUP BY'] ) ) {
1271 $gb = is_array( $options['GROUP BY'] )
1272 ? implode( ',', $options['GROUP BY'] )
1273 : $options['GROUP BY'];
1274 $sql .= ' GROUP BY ' . $gb;
1276 if ( isset( $options['HAVING'] ) ) {
1277 $having = is_array( $options['HAVING'] )
1278 ? $this->makeList( $options['HAVING'], LIST_AND )
1279 : $options['HAVING'];
1280 $sql .= ' HAVING ' . $having;
1282 return $sql;
1286 * Returns an optional ORDER BY
1288 * @param array $options associative array of options
1289 * @return string
1290 * @see DatabaseBase::select()
1291 * @since 1.21
1293 public function makeOrderBy( $options ) {
1294 if ( isset( $options['ORDER BY'] ) ) {
1295 $ob = is_array( $options['ORDER BY'] )
1296 ? implode( ',', $options['ORDER BY'] )
1297 : $options['ORDER BY'];
1298 return ' ORDER BY ' . $ob;
1300 return '';
1304 * Execute a SELECT query constructed using the various parameters provided.
1305 * See below for full details of the parameters.
1307 * @param string|array $table Table name
1308 * @param string|array $vars Field names
1309 * @param string|array $conds Conditions
1310 * @param string $fname Caller function name
1311 * @param array $options Query options
1312 * @param $join_conds Array Join conditions
1314 * @param $table string|array
1316 * May be either an array of table names, or a single string holding a table
1317 * name. If an array is given, table aliases can be specified, for example:
1319 * array( 'a' => 'user' )
1321 * This includes the user table in the query, with the alias "a" available
1322 * for use in field names (e.g. a.user_name).
1324 * All of the table names given here are automatically run through
1325 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1326 * added, and various other table name mappings to be performed.
1329 * @param $vars string|array
1331 * May be either a field name or an array of field names. The field names
1332 * can be complete fragments of SQL, for direct inclusion into the SELECT
1333 * query. If an array is given, field aliases can be specified, for example:
1335 * array( 'maxrev' => 'MAX(rev_id)' )
1337 * This includes an expression with the alias "maxrev" in the query.
1339 * If an expression is given, care must be taken to ensure that it is
1340 * DBMS-independent.
1343 * @param $conds string|array
1345 * May be either a string containing a single condition, or an array of
1346 * conditions. If an array is given, the conditions constructed from each
1347 * element are combined with AND.
1349 * Array elements may take one of two forms:
1351 * - Elements with a numeric key are interpreted as raw SQL fragments.
1352 * - Elements with a string key are interpreted as equality conditions,
1353 * where the key is the field name.
1354 * - If the value of such an array element is a scalar (such as a
1355 * string), it will be treated as data and thus quoted appropriately.
1356 * If it is null, an IS NULL clause will be added.
1357 * - If the value is an array, an IN(...) clause will be constructed,
1358 * such that the field name may match any of the elements in the
1359 * array. The elements of the array will be quoted.
1361 * Note that expressions are often DBMS-dependent in their syntax.
1362 * DBMS-independent wrappers are provided for constructing several types of
1363 * expression commonly used in condition queries. See:
1364 * - DatabaseBase::buildLike()
1365 * - DatabaseBase::conditional()
1368 * @param $options string|array
1370 * Optional: Array of query options. Boolean options are specified by
1371 * including them in the array as a string value with a numeric key, for
1372 * example:
1374 * array( 'FOR UPDATE' )
1376 * The supported options are:
1378 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1379 * with LIMIT can theoretically be used for paging through a result set,
1380 * but this is discouraged in MediaWiki for performance reasons.
1382 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1383 * and then the first rows are taken until the limit is reached. LIMIT
1384 * is applied to a result set after OFFSET.
1386 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1387 * changed until the next COMMIT.
1389 * - DISTINCT: Boolean: return only unique result rows.
1391 * - GROUP BY: May be either an SQL fragment string naming a field or
1392 * expression to group by, or an array of such SQL fragments.
1394 * - HAVING: May be either an string containing a HAVING clause or an array of
1395 * conditions building the HAVING clause. If an array is given, the conditions
1396 * constructed from each element are combined with AND.
1398 * - ORDER BY: May be either an SQL fragment giving a field name or
1399 * expression to order by, or an array of such SQL fragments.
1401 * - USE INDEX: This may be either a string giving the index name to use
1402 * for the query, or an array. If it is an associative array, each key
1403 * gives the table name (or alias), each value gives the index name to
1404 * use for that table. All strings are SQL fragments and so should be
1405 * validated by the caller.
1407 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1408 * instead of SELECT.
1410 * And also the following boolean MySQL extensions, see the MySQL manual
1411 * for documentation:
1413 * - LOCK IN SHARE MODE
1414 * - STRAIGHT_JOIN
1415 * - HIGH_PRIORITY
1416 * - SQL_BIG_RESULT
1417 * - SQL_BUFFER_RESULT
1418 * - SQL_SMALL_RESULT
1419 * - SQL_CALC_FOUND_ROWS
1420 * - SQL_CACHE
1421 * - SQL_NO_CACHE
1424 * @param $join_conds string|array
1426 * Optional associative array of table-specific join conditions. In the
1427 * most common case, this is unnecessary, since the join condition can be
1428 * in $conds. However, it is useful for doing a LEFT JOIN.
1430 * The key of the array contains the table name or alias. The value is an
1431 * array with two elements, numbered 0 and 1. The first gives the type of
1432 * join, the second is an SQL fragment giving the join condition for that
1433 * table. For example:
1435 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1437 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1438 * with no rows in it will be returned. If there was a query error, a
1439 * DBQueryError exception will be thrown, except if the "ignore errors"
1440 * option was set, in which case false will be returned.
1442 public function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1443 $options = array(), $join_conds = array() ) {
1444 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1446 return $this->query( $sql, $fname );
1450 * The equivalent of DatabaseBase::select() except that the constructed SQL
1451 * is returned, instead of being immediately executed. This can be useful for
1452 * doing UNION queries, where the SQL text of each query is needed. In general,
1453 * however, callers outside of Database classes should just use select().
1455 * @param string|array $table Table name
1456 * @param string|array $vars Field names
1457 * @param string|array $conds Conditions
1458 * @param string $fname Caller function name
1459 * @param string|array $options Query options
1460 * @param $join_conds string|array Join conditions
1462 * @return string SQL query string.
1463 * @see DatabaseBase::select()
1465 public function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1466 $options = array(), $join_conds = array() )
1468 if ( is_array( $vars ) ) {
1469 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1472 $options = (array)$options;
1474 if ( is_array( $table ) ) {
1475 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1476 ? $options['USE INDEX']
1477 : array();
1478 if ( count( $join_conds ) || count( $useIndex ) ) {
1479 $from = ' FROM ' .
1480 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1481 } else {
1482 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1484 } elseif ( $table != '' ) {
1485 if ( $table[0] == ' ' ) {
1486 $from = ' FROM ' . $table;
1487 } else {
1488 $from = ' FROM ' . $this->tableName( $table );
1490 } else {
1491 $from = '';
1494 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1496 if ( !empty( $conds ) ) {
1497 if ( is_array( $conds ) ) {
1498 $conds = $this->makeList( $conds, LIST_AND );
1500 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1501 } else {
1502 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1505 if ( isset( $options['LIMIT'] ) ) {
1506 $sql = $this->limitResult( $sql, $options['LIMIT'],
1507 isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
1509 $sql = "$sql $postLimitTail";
1511 if ( isset( $options['EXPLAIN'] ) ) {
1512 $sql = 'EXPLAIN ' . $sql;
1515 return $sql;
1519 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1520 * that a single row object is returned. If the query returns no rows,
1521 * false is returned.
1523 * @param string|array $table Table name
1524 * @param string|array $vars Field names
1525 * @param array $conds Conditions
1526 * @param string $fname Caller function name
1527 * @param string|array $options Query options
1528 * @param $join_conds array|string Join conditions
1530 * @return object|bool
1532 public function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1533 $options = array(), $join_conds = array() )
1535 $options = (array)$options;
1536 $options['LIMIT'] = 1;
1537 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1539 if ( $res === false ) {
1540 return false;
1543 if ( !$this->numRows( $res ) ) {
1544 return false;
1547 $obj = $this->fetchObject( $res );
1549 return $obj;
1553 * Estimate rows in dataset.
1555 * MySQL allows you to estimate the number of rows that would be returned
1556 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1557 * index cardinality statistics, and is notoriously inaccurate, especially
1558 * when large numbers of rows have recently been added or deleted.
1560 * For DBMSs that don't support fast result size estimation, this function
1561 * will actually perform the SELECT COUNT(*).
1563 * Takes the same arguments as DatabaseBase::select().
1565 * @param string $table table name
1566 * @param array|string $vars : unused
1567 * @param array|string $conds : filters on the table
1568 * @param string $fname function name for profiling
1569 * @param array $options options for select
1570 * @return Integer: row count
1572 public function estimateRowCount( $table, $vars = '*', $conds = '',
1573 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1575 $rows = 0;
1576 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1578 if ( $res ) {
1579 $row = $this->fetchRow( $res );
1580 $rows = ( isset( $row['rowcount'] ) ) ? $row['rowcount'] : 0;
1583 return $rows;
1587 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1588 * It's only slightly flawed. Don't use for anything important.
1590 * @param string $sql A SQL Query
1592 * @return string
1594 static function generalizeSQL( $sql ) {
1595 # This does the same as the regexp below would do, but in such a way
1596 # as to avoid crashing php on some large strings.
1597 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1599 $sql = str_replace( "\\\\", '', $sql );
1600 $sql = str_replace( "\\'", '', $sql );
1601 $sql = str_replace( "\\\"", '', $sql );
1602 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1603 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1605 # All newlines, tabs, etc replaced by single space
1606 $sql = preg_replace( '/\s+/', ' ', $sql );
1608 # All numbers => N
1609 $sql = preg_replace( '/-?[0-9]+/s', 'N', $sql );
1611 return $sql;
1615 * Determines whether a field exists in a table
1617 * @param string $table table name
1618 * @param string $field filed to check on that table
1619 * @param string $fname calling function name (optional)
1620 * @return Boolean: whether $table has filed $field
1622 public function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1623 $info = $this->fieldInfo( $table, $field );
1625 return (bool)$info;
1629 * Determines whether an index exists
1630 * Usually throws a DBQueryError on failure
1631 * If errors are explicitly ignored, returns NULL on failure
1633 * @param $table
1634 * @param $index
1635 * @param $fname string
1637 * @return bool|null
1639 public function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1640 if ( !$this->tableExists( $table ) ) {
1641 return null;
1644 $info = $this->indexInfo( $table, $index, $fname );
1645 if ( is_null( $info ) ) {
1646 return null;
1647 } else {
1648 return $info !== false;
1653 * Query whether a given table exists
1655 * @param $table string
1656 * @param $fname string
1658 * @return bool
1660 public function tableExists( $table, $fname = __METHOD__ ) {
1661 $table = $this->tableName( $table );
1662 $old = $this->ignoreErrors( true );
1663 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1664 $this->ignoreErrors( $old );
1666 return (bool)$res;
1670 * mysql_field_type() wrapper
1671 * @param $res
1672 * @param $index
1673 * @return string
1675 public function fieldType( $res, $index ) {
1676 if ( $res instanceof ResultWrapper ) {
1677 $res = $res->result;
1680 return mysql_field_type( $res, $index );
1684 * Determines if a given index is unique
1686 * @param $table string
1687 * @param $index string
1689 * @return bool
1691 public function indexUnique( $table, $index ) {
1692 $indexInfo = $this->indexInfo( $table, $index );
1694 if ( !$indexInfo ) {
1695 return null;
1698 return !$indexInfo[0]->Non_unique;
1702 * Helper for DatabaseBase::insert().
1704 * @param $options array
1705 * @return string
1707 protected function makeInsertOptions( $options ) {
1708 return implode( ' ', $options );
1712 * INSERT wrapper, inserts an array into a table.
1714 * $a may be either:
1716 * - A single associative array. The array keys are the field names, and
1717 * the values are the values to insert. The values are treated as data
1718 * and will be quoted appropriately. If NULL is inserted, this will be
1719 * converted to a database NULL.
1720 * - An array with numeric keys, holding a list of associative arrays.
1721 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1722 * each subarray must be identical to each other, and in the same order.
1724 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1725 * returns success.
1727 * $options is an array of options, with boolean options encoded as values
1728 * with numeric keys, in the same style as $options in
1729 * DatabaseBase::select(). Supported options are:
1731 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1732 * any rows which cause duplicate key errors are not inserted. It's
1733 * possible to determine how many rows were successfully inserted using
1734 * DatabaseBase::affectedRows().
1736 * @param $table String Table name. This will be passed through
1737 * DatabaseBase::tableName().
1738 * @param $a Array of rows to insert
1739 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1740 * @param array $options of options
1742 * @return bool
1744 public function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1745 # No rows to insert, easy just return now
1746 if ( !count( $a ) ) {
1747 return true;
1750 $table = $this->tableName( $table );
1752 if ( !is_array( $options ) ) {
1753 $options = array( $options );
1756 $fh = null;
1757 if ( isset( $options['fileHandle'] ) ) {
1758 $fh = $options['fileHandle'];
1760 $options = $this->makeInsertOptions( $options );
1762 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1763 $multi = true;
1764 $keys = array_keys( $a[0] );
1765 } else {
1766 $multi = false;
1767 $keys = array_keys( $a );
1770 $sql = 'INSERT ' . $options .
1771 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1773 if ( $multi ) {
1774 $first = true;
1775 foreach ( $a as $row ) {
1776 if ( $first ) {
1777 $first = false;
1778 } else {
1779 $sql .= ',';
1781 $sql .= '(' . $this->makeList( $row ) . ')';
1783 } else {
1784 $sql .= '(' . $this->makeList( $a ) . ')';
1787 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1788 return false;
1789 } elseif ( $fh !== null ) {
1790 return true;
1793 return (bool)$this->query( $sql, $fname );
1797 * Make UPDATE options for the DatabaseBase::update function
1799 * @param array $options The options passed to DatabaseBase::update
1800 * @return string
1802 protected function makeUpdateOptions( $options ) {
1803 if ( !is_array( $options ) ) {
1804 $options = array( $options );
1807 $opts = array();
1809 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1810 $opts[] = $this->lowPriorityOption();
1813 if ( in_array( 'IGNORE', $options ) ) {
1814 $opts[] = 'IGNORE';
1817 return implode( ' ', $opts );
1821 * UPDATE wrapper. Takes a condition array and a SET array.
1823 * @param $table String name of the table to UPDATE. This will be passed through
1824 * DatabaseBase::tableName().
1826 * @param array $values An array of values to SET. For each array element,
1827 * the key gives the field name, and the value gives the data
1828 * to set that field to. The data will be quoted by
1829 * DatabaseBase::addQuotes().
1831 * @param $conds Array: An array of conditions (WHERE). See
1832 * DatabaseBase::select() for the details of the format of
1833 * condition arrays. Use '*' to update all rows.
1835 * @param $fname String: The function name of the caller (from __METHOD__),
1836 * for logging and profiling.
1838 * @param array $options An array of UPDATE options, can be:
1839 * - IGNORE: Ignore unique key conflicts
1840 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1841 * @return Boolean
1843 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1844 $table = $this->tableName( $table );
1845 $opts = $this->makeUpdateOptions( $options );
1846 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1848 if ( $conds !== array() && $conds !== '*' ) {
1849 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1852 return $this->query( $sql, $fname );
1856 * Makes an encoded list of strings from an array
1857 * @param array $a containing the data
1858 * @param int $mode Constant
1859 * - LIST_COMMA: comma separated, no field names
1860 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1861 * the documentation for $conds in DatabaseBase::select().
1862 * - LIST_OR: ORed WHERE clause (without the WHERE)
1863 * - LIST_SET: comma separated with field names, like a SET clause
1864 * - LIST_NAMES: comma separated field names
1866 * @throws MWException|DBUnexpectedError
1867 * @return string
1869 public function makeList( $a, $mode = LIST_COMMA ) {
1870 if ( !is_array( $a ) ) {
1871 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1874 $first = true;
1875 $list = '';
1877 foreach ( $a as $field => $value ) {
1878 if ( !$first ) {
1879 if ( $mode == LIST_AND ) {
1880 $list .= ' AND ';
1881 } elseif ( $mode == LIST_OR ) {
1882 $list .= ' OR ';
1883 } else {
1884 $list .= ',';
1886 } else {
1887 $first = false;
1890 if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
1891 $list .= "($value)";
1892 } elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
1893 $list .= "$value";
1894 } elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
1895 if ( count( $value ) == 0 ) {
1896 throw new MWException( __METHOD__ . ": empty input for field $field" );
1897 } elseif ( count( $value ) == 1 ) {
1898 // Special-case single values, as IN isn't terribly efficient
1899 // Don't necessarily assume the single key is 0; we don't
1900 // enforce linear numeric ordering on other arrays here.
1901 $value = array_values( $value );
1902 $list .= $field . " = " . $this->addQuotes( $value[0] );
1903 } else {
1904 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1906 } elseif ( $value === null ) {
1907 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1908 $list .= "$field IS ";
1909 } elseif ( $mode == LIST_SET ) {
1910 $list .= "$field = ";
1912 $list .= 'NULL';
1913 } else {
1914 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1915 $list .= "$field = ";
1917 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1921 return $list;
1925 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1926 * The keys on each level may be either integers or strings.
1928 * @param array $data organized as 2-d
1929 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
1930 * @param string $baseKey field name to match the base-level keys to (eg 'pl_namespace')
1931 * @param string $subKey field name to match the sub-level keys to (eg 'pl_title')
1932 * @return Mixed: string SQL fragment, or false if no items in array.
1934 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1935 $conds = array();
1937 foreach ( $data as $base => $sub ) {
1938 if ( count( $sub ) ) {
1939 $conds[] = $this->makeList(
1940 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1941 LIST_AND );
1945 if ( $conds ) {
1946 return $this->makeList( $conds, LIST_OR );
1947 } else {
1948 // Nothing to search for...
1949 return false;
1954 * Return aggregated value alias
1956 * @param $valuedata
1957 * @param $valuename string
1959 * @return string
1961 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1962 return $valuename;
1966 * @param $field
1967 * @return string
1969 public function bitNot( $field ) {
1970 return "(~$field)";
1974 * @param $fieldLeft
1975 * @param $fieldRight
1976 * @return string
1978 public function bitAnd( $fieldLeft, $fieldRight ) {
1979 return "($fieldLeft & $fieldRight)";
1983 * @param $fieldLeft
1984 * @param $fieldRight
1985 * @return string
1987 public function bitOr( $fieldLeft, $fieldRight ) {
1988 return "($fieldLeft | $fieldRight)";
1992 * Build a concatenation list to feed into a SQL query
1993 * @param array $stringList list of raw SQL expressions; caller is responsible for any quoting
1994 * @return String
1996 public function buildConcat( $stringList ) {
1997 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2001 * Change the current database
2003 * @todo Explain what exactly will fail if this is not overridden.
2005 * @param $db
2007 * @return bool Success or failure
2009 public function selectDB( $db ) {
2010 # Stub. Shouldn't cause serious problems if it's not overridden, but
2011 # if your database engine supports a concept similar to MySQL's
2012 # databases you may as well.
2013 $this->mDBname = $db;
2014 return true;
2018 * Get the current DB name
2020 public function getDBname() {
2021 return $this->mDBname;
2025 * Get the server hostname or IP address
2027 public function getServer() {
2028 return $this->mServer;
2032 * Format a table name ready for use in constructing an SQL query
2034 * This does two important things: it quotes the table names to clean them up,
2035 * and it adds a table prefix if only given a table name with no quotes.
2037 * All functions of this object which require a table name call this function
2038 * themselves. Pass the canonical name to such functions. This is only needed
2039 * when calling query() directly.
2041 * @param string $name database table name
2042 * @param string $format One of:
2043 * quoted - Automatically pass the table name through addIdentifierQuotes()
2044 * so that it can be used in a query.
2045 * raw - Do not add identifier quotes to the table name
2046 * @return String: full database name
2048 public function tableName( $name, $format = 'quoted' ) {
2049 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
2050 # Skip the entire process when we have a string quoted on both ends.
2051 # Note that we check the end so that we will still quote any use of
2052 # use of `database`.table. But won't break things if someone wants
2053 # to query a database table with a dot in the name.
2054 if ( $this->isQuotedIdentifier( $name ) ) {
2055 return $name;
2058 # Lets test for any bits of text that should never show up in a table
2059 # name. Basically anything like JOIN or ON which are actually part of
2060 # SQL queries, but may end up inside of the table value to combine
2061 # sql. Such as how the API is doing.
2062 # Note that we use a whitespace test rather than a \b test to avoid
2063 # any remote case where a word like on may be inside of a table name
2064 # surrounded by symbols which may be considered word breaks.
2065 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2066 return $name;
2069 # Split database and table into proper variables.
2070 # We reverse the explode so that database.table and table both output
2071 # the correct table.
2072 $dbDetails = explode( '.', $name, 2 );
2073 if ( count( $dbDetails ) == 2 ) {
2074 list( $database, $table ) = $dbDetails;
2075 # We don't want any prefix added in this case
2076 $prefix = '';
2077 } else {
2078 list( $table ) = $dbDetails;
2079 if ( $wgSharedDB !== null # We have a shared database
2080 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
2081 && in_array( $table, $wgSharedTables ) # A shared table is selected
2083 $database = $wgSharedDB;
2084 $prefix = $wgSharedPrefix === null ? $this->mTablePrefix : $wgSharedPrefix;
2085 } else {
2086 $database = null;
2087 $prefix = $this->mTablePrefix; # Default prefix
2091 # Quote $table and apply the prefix if not quoted.
2092 $tableName = "{$prefix}{$table}";
2093 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) ) {
2094 $tableName = $this->addIdentifierQuotes( $tableName );
2097 # Quote $database and merge it with the table name if needed
2098 if ( $database !== null ) {
2099 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2100 $database = $this->addIdentifierQuotes( $database );
2102 $tableName = $database . '.' . $tableName;
2105 return $tableName;
2109 * Fetch a number of table names into an array
2110 * This is handy when you need to construct SQL for joins
2112 * Example:
2113 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2114 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2115 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2117 * @return array
2119 public function tableNames() {
2120 $inArray = func_get_args();
2121 $retVal = array();
2123 foreach ( $inArray as $name ) {
2124 $retVal[$name] = $this->tableName( $name );
2127 return $retVal;
2131 * Fetch a number of table names into an zero-indexed numerical array
2132 * This is handy when you need to construct SQL for joins
2134 * Example:
2135 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2136 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2137 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2139 * @return array
2141 public function tableNamesN() {
2142 $inArray = func_get_args();
2143 $retVal = array();
2145 foreach ( $inArray as $name ) {
2146 $retVal[] = $this->tableName( $name );
2149 return $retVal;
2153 * Get an aliased table name
2154 * e.g. tableName AS newTableName
2156 * @param string $name Table name, see tableName()
2157 * @param string|bool $alias Alias (optional)
2158 * @return string SQL name for aliased table. Will not alias a table to its own name
2160 public function tableNameWithAlias( $name, $alias = false ) {
2161 if ( !$alias || $alias == $name ) {
2162 return $this->tableName( $name );
2163 } else {
2164 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2169 * Gets an array of aliased table names
2171 * @param $tables array( [alias] => table )
2172 * @return array of strings, see tableNameWithAlias()
2174 public function tableNamesWithAlias( $tables ) {
2175 $retval = array();
2176 foreach ( $tables as $alias => $table ) {
2177 if ( is_numeric( $alias ) ) {
2178 $alias = $table;
2180 $retval[] = $this->tableNameWithAlias( $table, $alias );
2182 return $retval;
2186 * Get an aliased field name
2187 * e.g. fieldName AS newFieldName
2189 * @param string $name Field name
2190 * @param string|bool $alias Alias (optional)
2191 * @return string SQL name for aliased field. Will not alias a field to its own name
2193 public function fieldNameWithAlias( $name, $alias = false ) {
2194 if ( !$alias || (string)$alias === (string)$name ) {
2195 return $name;
2196 } else {
2197 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2202 * Gets an array of aliased field names
2204 * @param $fields array( [alias] => field )
2205 * @return array of strings, see fieldNameWithAlias()
2207 public function fieldNamesWithAlias( $fields ) {
2208 $retval = array();
2209 foreach ( $fields as $alias => $field ) {
2210 if ( is_numeric( $alias ) ) {
2211 $alias = $field;
2213 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2215 return $retval;
2219 * Get the aliased table name clause for a FROM clause
2220 * which might have a JOIN and/or USE INDEX clause
2222 * @param array $tables ( [alias] => table )
2223 * @param $use_index array Same as for select()
2224 * @param $join_conds array Same as for select()
2225 * @return string
2227 protected function tableNamesWithUseIndexOrJOIN(
2228 $tables, $use_index = array(), $join_conds = array()
2230 $ret = array();
2231 $retJOIN = array();
2232 $use_index = (array)$use_index;
2233 $join_conds = (array)$join_conds;
2235 foreach ( $tables as $alias => $table ) {
2236 if ( !is_string( $alias ) ) {
2237 // No alias? Set it equal to the table name
2238 $alias = $table;
2240 // Is there a JOIN clause for this table?
2241 if ( isset( $join_conds[$alias] ) ) {
2242 list( $joinType, $conds ) = $join_conds[$alias];
2243 $tableClause = $joinType;
2244 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2245 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2246 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2247 if ( $use != '' ) {
2248 $tableClause .= ' ' . $use;
2251 $on = $this->makeList( (array)$conds, LIST_AND );
2252 if ( $on != '' ) {
2253 $tableClause .= ' ON (' . $on . ')';
2256 $retJOIN[] = $tableClause;
2257 // Is there an INDEX clause for this table?
2258 } elseif ( isset( $use_index[$alias] ) ) {
2259 $tableClause = $this->tableNameWithAlias( $table, $alias );
2260 $tableClause .= ' ' . $this->useIndexClause(
2261 implode( ',', (array)$use_index[$alias] ) );
2263 $ret[] = $tableClause;
2264 } else {
2265 $tableClause = $this->tableNameWithAlias( $table, $alias );
2267 $ret[] = $tableClause;
2271 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2272 $straightJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
2273 $otherJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
2275 // Compile our final table clause
2276 return implode( ' ', array( $straightJoins, $otherJoins ) );
2280 * Get the name of an index in a given table
2282 * @param $index
2284 * @return string
2286 protected function indexName( $index ) {
2287 // Backwards-compatibility hack
2288 $renamed = array(
2289 'ar_usertext_timestamp' => 'usertext_timestamp',
2290 'un_user_id' => 'user_id',
2291 'un_user_ip' => 'user_ip',
2294 if ( isset( $renamed[$index] ) ) {
2295 return $renamed[$index];
2296 } else {
2297 return $index;
2302 * If it's a string, adds quotes and backslashes
2303 * Otherwise returns as-is
2305 * @param $s string
2307 * @return string
2309 public function addQuotes( $s ) {
2310 if ( $s === null ) {
2311 return 'NULL';
2312 } else {
2313 # This will also quote numeric values. This should be harmless,
2314 # and protects against weird problems that occur when they really
2315 # _are_ strings such as article titles and string->number->string
2316 # conversion is not 1:1.
2317 return "'" . $this->strencode( $s ) . "'";
2322 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2323 * MySQL uses `backticks` while basically everything else uses double quotes.
2324 * Since MySQL is the odd one out here the double quotes are our generic
2325 * and we implement backticks in DatabaseMysql.
2327 * @param $s string
2329 * @return string
2331 public function addIdentifierQuotes( $s ) {
2332 return '"' . str_replace( '"', '""', $s ) . '"';
2336 * Returns if the given identifier looks quoted or not according to
2337 * the database convention for quoting identifiers .
2339 * @param $name string
2341 * @return boolean
2343 public function isQuotedIdentifier( $name ) {
2344 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2348 * @param $s string
2349 * @return string
2351 protected function escapeLikeInternal( $s ) {
2352 $s = str_replace( '\\', '\\\\', $s );
2353 $s = $this->strencode( $s );
2354 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2356 return $s;
2360 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2361 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2362 * Alternatively, the function could be provided with an array of aforementioned parameters.
2364 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2365 * for subpages of 'My page title'.
2366 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2368 * @since 1.16
2369 * @return String: fully built LIKE statement
2371 public function buildLike() {
2372 $params = func_get_args();
2374 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2375 $params = $params[0];
2378 $s = '';
2380 foreach ( $params as $value ) {
2381 if ( $value instanceof LikeMatch ) {
2382 $s .= $value->toString();
2383 } else {
2384 $s .= $this->escapeLikeInternal( $value );
2388 return " LIKE '" . $s . "' ";
2392 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2394 * @return LikeMatch
2396 public function anyChar() {
2397 return new LikeMatch( '_' );
2401 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2403 * @return LikeMatch
2405 public function anyString() {
2406 return new LikeMatch( '%' );
2410 * Returns an appropriately quoted sequence value for inserting a new row.
2411 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2412 * subclass will return an integer, and save the value for insertId()
2414 * Any implementation of this function should *not* involve reusing
2415 * sequence numbers created for rolled-back transactions.
2416 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2417 * @param $seqName string
2418 * @return null
2420 public function nextSequenceValue( $seqName ) {
2421 return null;
2425 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2426 * is only needed because a) MySQL must be as efficient as possible due to
2427 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2428 * which index to pick. Anyway, other databases might have different
2429 * indexes on a given table. So don't bother overriding this unless you're
2430 * MySQL.
2431 * @param $index
2432 * @return string
2434 public function useIndexClause( $index ) {
2435 return '';
2439 * REPLACE query wrapper.
2441 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2442 * except that when there is a duplicate key error, the old row is deleted
2443 * and the new row is inserted in its place.
2445 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2446 * perform the delete, we need to know what the unique indexes are so that
2447 * we know how to find the conflicting rows.
2449 * It may be more efficient to leave off unique indexes which are unlikely
2450 * to collide. However if you do this, you run the risk of encountering
2451 * errors which wouldn't have occurred in MySQL.
2453 * @param string $table The table to replace the row(s) in.
2454 * @param array $rows Can be either a single row to insert, or multiple rows,
2455 * in the same format as for DatabaseBase::insert()
2456 * @param array $uniqueIndexes is an array of indexes. Each element may be either
2457 * a field name or an array of field names
2458 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2460 public function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2461 $quotedTable = $this->tableName( $table );
2463 if ( count( $rows ) == 0 ) {
2464 return;
2467 # Single row case
2468 if ( !is_array( reset( $rows ) ) ) {
2469 $rows = array( $rows );
2472 foreach ( $rows as $row ) {
2473 # Delete rows which collide
2474 if ( $uniqueIndexes ) {
2475 $sql = "DELETE FROM $quotedTable WHERE ";
2476 $first = true;
2477 foreach ( $uniqueIndexes as $index ) {
2478 if ( $first ) {
2479 $first = false;
2480 $sql .= '( ';
2481 } else {
2482 $sql .= ' ) OR ( ';
2484 if ( is_array( $index ) ) {
2485 $first2 = true;
2486 foreach ( $index as $col ) {
2487 if ( $first2 ) {
2488 $first2 = false;
2489 } else {
2490 $sql .= ' AND ';
2492 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2494 } else {
2495 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2498 $sql .= ' )';
2499 $this->query( $sql, $fname );
2502 # Now insert the row
2503 $this->insert( $table, $row, $fname );
2508 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2509 * statement.
2511 * @param string $table Table name
2512 * @param array $rows Rows to insert
2513 * @param string $fname Caller function name
2515 * @return ResultWrapper
2517 protected function nativeReplace( $table, $rows, $fname ) {
2518 $table = $this->tableName( $table );
2520 # Single row case
2521 if ( !is_array( reset( $rows ) ) ) {
2522 $rows = array( $rows );
2525 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2526 $first = true;
2528 foreach ( $rows as $row ) {
2529 if ( $first ) {
2530 $first = false;
2531 } else {
2532 $sql .= ',';
2535 $sql .= '(' . $this->makeList( $row ) . ')';
2538 return $this->query( $sql, $fname );
2542 * DELETE where the condition is a join.
2544 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2545 * we use sub-selects
2547 * For safety, an empty $conds will not delete everything. If you want to
2548 * delete all rows where the join condition matches, set $conds='*'.
2550 * DO NOT put the join condition in $conds.
2552 * @param $delTable String: The table to delete from.
2553 * @param $joinTable String: The other table.
2554 * @param $delVar String: The variable to join on, in the first table.
2555 * @param $joinVar String: The variable to join on, in the second table.
2556 * @param $conds Array: Condition array of field names mapped to variables,
2557 * ANDed together in the WHERE clause
2558 * @param $fname String: Calling function name (use __METHOD__) for
2559 * logs/profiling
2560 * @throws DBUnexpectedError
2562 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2563 $fname = 'DatabaseBase::deleteJoin' )
2565 if ( !$conds ) {
2566 throw new DBUnexpectedError( $this,
2567 'DatabaseBase::deleteJoin() called with empty $conds' );
2570 $delTable = $this->tableName( $delTable );
2571 $joinTable = $this->tableName( $joinTable );
2572 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2573 if ( $conds != '*' ) {
2574 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
2576 $sql .= ')';
2578 $this->query( $sql, $fname );
2582 * Returns the size of a text field, or -1 for "unlimited"
2584 * @param $table string
2585 * @param $field string
2587 * @return int
2589 public function textFieldSize( $table, $field ) {
2590 $table = $this->tableName( $table );
2591 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2592 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2593 $row = $this->fetchObject( $res );
2595 $m = array();
2597 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
2598 $size = $m[1];
2599 } else {
2600 $size = -1;
2603 return $size;
2607 * A string to insert into queries to show that they're low-priority, like
2608 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2609 * string and nothing bad should happen.
2611 * @return string Returns the text of the low priority option if it is
2612 * supported, or a blank string otherwise
2614 public function lowPriorityOption() {
2615 return '';
2619 * DELETE query wrapper.
2621 * @param array $table Table name
2622 * @param string|array $conds of conditions. See $conds in DatabaseBase::select() for
2623 * the format. Use $conds == "*" to delete all rows
2624 * @param string $fname name of the calling function
2626 * @throws DBUnexpectedError
2627 * @return bool|ResultWrapper
2629 public function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2630 if ( !$conds ) {
2631 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2634 $table = $this->tableName( $table );
2635 $sql = "DELETE FROM $table";
2637 if ( $conds != '*' ) {
2638 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
2641 return $this->query( $sql, $fname );
2645 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2646 * into another table.
2648 * @param string $destTable The table name to insert into
2649 * @param string|array $srcTable May be either a table name, or an array of table names
2650 * to include in a join.
2652 * @param array $varMap must be an associative array of the form
2653 * array( 'dest1' => 'source1', ...). Source items may be literals
2654 * rather than field names, but strings should be quoted with
2655 * DatabaseBase::addQuotes()
2657 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
2658 * the details of the format of condition arrays. May be "*" to copy the
2659 * whole table.
2661 * @param string $fname The function name of the caller, from __METHOD__
2663 * @param array $insertOptions Options for the INSERT part of the query, see
2664 * DatabaseBase::insert() for details.
2665 * @param array $selectOptions Options for the SELECT part of the query, see
2666 * DatabaseBase::select() for details.
2668 * @return ResultWrapper
2670 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
2671 $fname = 'DatabaseBase::insertSelect',
2672 $insertOptions = array(), $selectOptions = array() )
2674 $destTable = $this->tableName( $destTable );
2676 if ( is_array( $insertOptions ) ) {
2677 $insertOptions = implode( ' ', $insertOptions );
2680 if ( !is_array( $selectOptions ) ) {
2681 $selectOptions = array( $selectOptions );
2684 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2686 if ( is_array( $srcTable ) ) {
2687 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2688 } else {
2689 $srcTable = $this->tableName( $srcTable );
2692 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2693 " SELECT $startOpts " . implode( ',', $varMap ) .
2694 " FROM $srcTable $useIndex ";
2696 if ( $conds != '*' ) {
2697 if ( is_array( $conds ) ) {
2698 $conds = $this->makeList( $conds, LIST_AND );
2700 $sql .= " WHERE $conds";
2703 $sql .= " $tailOpts";
2705 return $this->query( $sql, $fname );
2709 * Construct a LIMIT query with optional offset. This is used for query
2710 * pages. The SQL should be adjusted so that only the first $limit rows
2711 * are returned. If $offset is provided as well, then the first $offset
2712 * rows should be discarded, and the next $limit rows should be returned.
2713 * If the result of the query is not ordered, then the rows to be returned
2714 * are theoretically arbitrary.
2716 * $sql is expected to be a SELECT, if that makes a difference.
2718 * The version provided by default works in MySQL and SQLite. It will very
2719 * likely need to be overridden for most other DBMSes.
2721 * @param string $sql SQL query we will append the limit too
2722 * @param $limit Integer the SQL limit
2723 * @param $offset Integer|bool the SQL offset (default false)
2725 * @throws DBUnexpectedError
2726 * @return string
2728 public function limitResult( $sql, $limit, $offset = false ) {
2729 if ( !is_numeric( $limit ) ) {
2730 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2732 return "$sql LIMIT "
2733 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
2734 . "{$limit} ";
2738 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2739 * within the UNION construct.
2740 * @return Boolean
2742 public function unionSupportsOrderAndLimit() {
2743 return true; // True for almost every DB supported
2747 * Construct a UNION query
2748 * This is used for providing overload point for other DB abstractions
2749 * not compatible with the MySQL syntax.
2750 * @param array $sqls SQL statements to combine
2751 * @param $all Boolean: use UNION ALL
2752 * @return String: SQL fragment
2754 public function unionQueries( $sqls, $all ) {
2755 $glue = $all ? ') UNION ALL (' : ') UNION (';
2756 return '(' . implode( $glue, $sqls ) . ')';
2760 * Returns an SQL expression for a simple conditional. This doesn't need
2761 * to be overridden unless CASE isn't supported in your DBMS.
2763 * @param string|array $cond SQL expression which will result in a boolean value
2764 * @param string $trueVal SQL expression to return if true
2765 * @param string $falseVal SQL expression to return if false
2766 * @return String: SQL fragment
2768 public function conditional( $cond, $trueVal, $falseVal ) {
2769 if ( is_array( $cond ) ) {
2770 $cond = $this->makeList( $cond, LIST_AND );
2772 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2776 * Returns a comand for str_replace function in SQL query.
2777 * Uses REPLACE() in MySQL
2779 * @param string $orig column to modify
2780 * @param string $old column to seek
2781 * @param string $new column to replace with
2783 * @return string
2785 public function strreplace( $orig, $old, $new ) {
2786 return "REPLACE({$orig}, {$old}, {$new})";
2790 * Determines how long the server has been up
2791 * STUB
2793 * @return int
2795 public function getServerUptime() {
2796 return 0;
2800 * Determines if the last failure was due to a deadlock
2801 * STUB
2803 * @return bool
2805 public function wasDeadlock() {
2806 return false;
2810 * Determines if the last failure was due to a lock timeout
2811 * STUB
2813 * @return bool
2815 public function wasLockTimeout() {
2816 return false;
2820 * Determines if the last query error was something that should be dealt
2821 * with by pinging the connection and reissuing the query.
2822 * STUB
2824 * @return bool
2826 public function wasErrorReissuable() {
2827 return false;
2831 * Determines if the last failure was due to the database being read-only.
2832 * STUB
2834 * @return bool
2836 public function wasReadOnlyError() {
2837 return false;
2841 * Perform a deadlock-prone transaction.
2843 * This function invokes a callback function to perform a set of write
2844 * queries. If a deadlock occurs during the processing, the transaction
2845 * will be rolled back and the callback function will be called again.
2847 * Usage:
2848 * $dbw->deadlockLoop( callback, ... );
2850 * Extra arguments are passed through to the specified callback function.
2852 * Returns whatever the callback function returned on its successful,
2853 * iteration, or false on error, for example if the retry limit was
2854 * reached.
2856 * @return bool
2858 public function deadlockLoop() {
2859 $this->begin( __METHOD__ );
2860 $args = func_get_args();
2861 $function = array_shift( $args );
2862 $oldIgnore = $this->ignoreErrors( true );
2863 $tries = DEADLOCK_TRIES;
2865 if ( is_array( $function ) ) {
2866 $fname = $function[0];
2867 } else {
2868 $fname = $function;
2871 do {
2872 $retVal = call_user_func_array( $function, $args );
2873 $error = $this->lastError();
2874 $errno = $this->lastErrno();
2875 $sql = $this->lastQuery();
2877 if ( $errno ) {
2878 if ( $this->wasDeadlock() ) {
2879 # Retry
2880 usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
2881 } else {
2882 $this->reportQueryError( $error, $errno, $sql, $fname );
2885 } while ( $this->wasDeadlock() && --$tries > 0 );
2887 $this->ignoreErrors( $oldIgnore );
2889 if ( $tries <= 0 ) {
2890 $this->rollback( __METHOD__ );
2891 $this->reportQueryError( $error, $errno, $sql, $fname );
2892 return false;
2893 } else {
2894 $this->commit( __METHOD__ );
2895 return $retVal;
2900 * Wait for the slave to catch up to a given master position.
2902 * @param $pos DBMasterPos object
2903 * @param $timeout Integer: the maximum number of seconds to wait for
2904 * synchronisation
2906 * @return integer: zero if the slave was past that position already,
2907 * greater than zero if we waited for some period of time, less than
2908 * zero if we timed out.
2910 public function masterPosWait( DBMasterPos $pos, $timeout ) {
2911 wfProfileIn( __METHOD__ );
2913 if ( !is_null( $this->mFakeSlaveLag ) ) {
2914 $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
2916 if ( $wait > $timeout * 1e6 ) {
2917 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2918 wfProfileOut( __METHOD__ );
2919 return -1;
2920 } elseif ( $wait > 0 ) {
2921 wfDebug( "Fake slave waiting $wait us\n" );
2922 usleep( $wait );
2923 wfProfileOut( __METHOD__ );
2924 return 1;
2925 } else {
2926 wfDebug( "Fake slave up to date ($wait us)\n" );
2927 wfProfileOut( __METHOD__ );
2928 return 0;
2932 wfProfileOut( __METHOD__ );
2934 # Real waits are implemented in the subclass.
2935 return 0;
2939 * Get the replication position of this slave
2941 * @return DBMasterPos, or false if this is not a slave.
2943 public function getSlavePos() {
2944 if ( !is_null( $this->mFakeSlaveLag ) ) {
2945 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
2946 wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
2947 return $pos;
2948 } else {
2949 # Stub
2950 return false;
2955 * Get the position of this master
2957 * @return DBMasterPos, or false if this is not a master
2959 public function getMasterPos() {
2960 if ( $this->mFakeMaster ) {
2961 return new MySQLMasterPos( 'fake', microtime( true ) );
2962 } else {
2963 return false;
2968 * Run an anonymous function as soon as there is no transaction pending.
2969 * If there is a transaction and it is rolled back, then the callback is cancelled.
2970 * Queries in the function will run in AUTO-COMMIT mode unless there are begin() calls.
2971 * Callbacks must commit any transactions that they begin.
2973 * This is useful for updates to different systems or when separate transactions are needed.
2974 * For example, one might want to enqueue jobs into a system outside the database, but only
2975 * after the database is updated so that the jobs will see the data when they actually run.
2976 * It can also be used for updates that easily cause deadlocks if locks are held too long.
2978 * @param Closure $callback
2979 * @since 1.20
2981 final public function onTransactionIdle( Closure $callback ) {
2982 $this->mTrxIdleCallbacks[] = $callback;
2983 if ( !$this->mTrxLevel ) {
2984 $this->runOnTransactionIdleCallbacks();
2989 * Run an anonymous function before the current transaction commits or now if there is none.
2990 * If there is a transaction and it is rolled back, then the callback is cancelled.
2991 * Callbacks must not start nor commit any transactions.
2993 * This is useful for updates that easily cause deadlocks if locks are held too long
2994 * but where atomicity is strongly desired for these updates and some related updates.
2996 * @param Closure $callback
2997 * @since 1.22
2999 final public function onTransactionPreCommitOrIdle( Closure $callback ) {
3000 if ( $this->mTrxLevel ) {
3001 $this->mTrxPreCommitCallbacks[] = $callback;
3002 } else {
3003 $this->onTransactionIdle( $callback ); // this will trigger immediately
3008 * Actually any "on transaction idle" callbacks.
3010 * @since 1.20
3012 protected function runOnTransactionIdleCallbacks() {
3013 $autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
3015 $e = null; // last exception
3016 do { // callbacks may add callbacks :)
3017 $callbacks = $this->mTrxIdleCallbacks;
3018 $this->mTrxIdleCallbacks = array(); // recursion guard
3019 foreach ( $callbacks as $callback ) {
3020 try {
3021 $this->clearFlag( DBO_TRX ); // make each query its own transaction
3022 $callback();
3023 $this->setFlag( $autoTrx ? DBO_TRX : 0 ); // restore automatic begin()
3024 } catch ( Exception $e ) {
3027 } while ( count( $this->mTrxIdleCallbacks ) );
3029 if ( $e instanceof Exception ) {
3030 throw $e; // re-throw any last exception
3035 * Actually any "on transaction pre-commit" callbacks.
3037 * @since 1.22
3039 protected function runOnTransactionPreCommitCallbacks() {
3040 $e = null; // last exception
3041 do { // callbacks may add callbacks :)
3042 $callbacks = $this->mTrxPreCommitCallbacks;
3043 $this->mTrxPreCommitCallbacks = array(); // recursion guard
3044 foreach ( $callbacks as $callback ) {
3045 try {
3046 $callback();
3047 } catch ( Exception $e ) {}
3049 } while ( count( $this->mTrxPreCommitCallbacks ) );
3051 if ( $e instanceof Exception ) {
3052 throw $e; // re-throw any last exception
3057 * Begin a transaction. If a transaction is already in progress, that transaction will be committed before the
3058 * new transaction is started.
3060 * Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts),
3061 * any previous database query will have started a transaction automatically.
3063 * Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current
3064 * transaction was started automatically because of the DBO_TRX flag.
3066 * @param $fname string
3068 final public function begin( $fname = 'DatabaseBase::begin' ) {
3069 global $wgDebugDBTransactions;
3071 if ( $this->mTrxLevel ) { // implicit commit
3072 if ( !$this->mTrxAutomatic ) {
3073 // We want to warn about inadvertently nested begin/commit pairs, but not about
3074 // auto-committing implicit transactions that were started by query() via DBO_TRX
3075 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3076 " performing implicit commit!";
3077 wfWarn( $msg );
3078 wfLogDBError( $msg );
3079 } else {
3080 // if the transaction was automatic and has done write operations,
3081 // log it if $wgDebugDBTransactions is enabled.
3082 if ( $this->mTrxDoneWrites && $wgDebugDBTransactions ) {
3083 wfDebug( "$fname: Automatic transaction with writes in progress" .
3084 " (from {$this->mTrxFname}), performing implicit commit!\n"
3089 $this->runOnTransactionPreCommitCallbacks();
3090 $this->doCommit( $fname );
3091 $this->runOnTransactionIdleCallbacks();
3094 $this->doBegin( $fname );
3095 $this->mTrxFname = $fname;
3096 $this->mTrxDoneWrites = false;
3097 $this->mTrxAutomatic = false;
3101 * Issues the BEGIN command to the database server.
3103 * @see DatabaseBase::begin()
3104 * @param type $fname
3106 protected function doBegin( $fname ) {
3107 $this->query( 'BEGIN', $fname );
3108 $this->mTrxLevel = 1;
3112 * Commits a transaction previously started using begin().
3113 * If no transaction is in progress, a warning is issued.
3115 * Nesting of transactions is not supported.
3117 * @param $fname string
3118 * @param string $flush Flush flag, set to 'flush' to disable warnings about explicitly committing implicit
3119 * transactions, or calling commit when no transaction is in progress.
3120 * This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure
3121 * that it is safe to ignore these warnings in your context.
3123 final public function commit( $fname = 'DatabaseBase::commit', $flush = '' ) {
3124 if ( $flush != 'flush' ) {
3125 if ( !$this->mTrxLevel ) {
3126 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3127 } elseif ( $this->mTrxAutomatic ) {
3128 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3130 } else {
3131 if ( !$this->mTrxLevel ) {
3132 return; // nothing to do
3133 } elseif ( !$this->mTrxAutomatic ) {
3134 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3138 $this->runOnTransactionPreCommitCallbacks();
3139 $this->doCommit( $fname );
3140 $this->runOnTransactionIdleCallbacks();
3144 * Issues the COMMIT command to the database server.
3146 * @see DatabaseBase::commit()
3147 * @param type $fname
3149 protected function doCommit( $fname ) {
3150 if ( $this->mTrxLevel ) {
3151 $this->query( 'COMMIT', $fname );
3152 $this->mTrxLevel = 0;
3157 * Rollback a transaction previously started using begin().
3158 * If no transaction is in progress, a warning is issued.
3160 * No-op on non-transactional databases.
3162 * @param $fname string
3164 final public function rollback( $fname = 'DatabaseBase::rollback' ) {
3165 if ( !$this->mTrxLevel ) {
3166 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3168 $this->doRollback( $fname );
3169 $this->mTrxIdleCallbacks = array(); // cancel
3170 $this->mTrxPreCommitCallbacks = array(); // cancel
3174 * Issues the ROLLBACK command to the database server.
3176 * @see DatabaseBase::rollback()
3177 * @param type $fname
3179 protected function doRollback( $fname ) {
3180 if ( $this->mTrxLevel ) {
3181 $this->query( 'ROLLBACK', $fname, true );
3182 $this->mTrxLevel = 0;
3187 * Creates a new table with structure copied from existing table
3188 * Note that unlike most database abstraction functions, this function does not
3189 * automatically append database prefix, because it works at a lower
3190 * abstraction level.
3191 * The table names passed to this function shall not be quoted (this
3192 * function calls addIdentifierQuotes when needed).
3194 * @param string $oldName name of table whose structure should be copied
3195 * @param string $newName name of table to be created
3196 * @param $temporary Boolean: whether the new table should be temporary
3197 * @param string $fname calling function name
3198 * @throws MWException
3199 * @return Boolean: true if operation was successful
3201 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3202 $fname = 'DatabaseBase::duplicateTableStructure'
3204 throw new MWException(
3205 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3209 * List all tables on the database
3211 * @param string $prefix Only show tables with this prefix, e.g. mw_
3212 * @param string $fname calling function name
3213 * @throws MWException
3215 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
3216 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3220 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3221 * to the format used for inserting into timestamp fields in this DBMS.
3223 * The result is unquoted, and needs to be passed through addQuotes()
3224 * before it can be included in raw SQL.
3226 * @param $ts string|int
3228 * @return string
3230 public function timestamp( $ts = 0 ) {
3231 return wfTimestamp( TS_MW, $ts );
3235 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3236 * to the format used for inserting into timestamp fields in this DBMS. If
3237 * NULL is input, it is passed through, allowing NULL values to be inserted
3238 * into timestamp fields.
3240 * The result is unquoted, and needs to be passed through addQuotes()
3241 * before it can be included in raw SQL.
3243 * @param $ts string|int
3245 * @return string
3247 public function timestampOrNull( $ts = null ) {
3248 if ( is_null( $ts ) ) {
3249 return null;
3250 } else {
3251 return $this->timestamp( $ts );
3256 * Take the result from a query, and wrap it in a ResultWrapper if
3257 * necessary. Boolean values are passed through as is, to indicate success
3258 * of write queries or failure.
3260 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3261 * resource, and it was necessary to call this function to convert it to
3262 * a wrapper. Nowadays, raw database objects are never exposed to external
3263 * callers, so this is unnecessary in external code. For compatibility with
3264 * old code, ResultWrapper objects are passed through unaltered.
3266 * @param $result bool|ResultWrapper
3268 * @return bool|ResultWrapper
3270 public function resultObject( $result ) {
3271 if ( empty( $result ) ) {
3272 return false;
3273 } elseif ( $result instanceof ResultWrapper ) {
3274 return $result;
3275 } elseif ( $result === true ) {
3276 // Successful write query
3277 return $result;
3278 } else {
3279 return new ResultWrapper( $this, $result );
3284 * Ping the server and try to reconnect if it there is no connection
3286 * @return bool Success or failure
3288 public function ping() {
3289 # Stub. Not essential to override.
3290 return true;
3294 * Get slave lag. Currently supported only by MySQL.
3296 * Note that this function will generate a fatal error on many
3297 * installations. Most callers should use LoadBalancer::safeGetLag()
3298 * instead.
3300 * @return int Database replication lag in seconds
3302 public function getLag() {
3303 return intval( $this->mFakeSlaveLag );
3307 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3309 * @return int
3311 function maxListLen() {
3312 return 0;
3316 * Some DBMSs have a special format for inserting into blob fields, they
3317 * don't allow simple quoted strings to be inserted. To insert into such
3318 * a field, pass the data through this function before passing it to
3319 * DatabaseBase::insert().
3320 * @param $b string
3321 * @return string
3323 public function encodeBlob( $b ) {
3324 return $b;
3328 * Some DBMSs return a special placeholder object representing blob fields
3329 * in result objects. Pass the object through this function to return the
3330 * original string.
3331 * @param $b string
3332 * @return string
3334 public function decodeBlob( $b ) {
3335 return $b;
3339 * Override database's default behavior. $options include:
3340 * 'connTimeout' : Set the connection timeout value in seconds.
3341 * May be useful for very long batch queries such as
3342 * full-wiki dumps, where a single query reads out over
3343 * hours or days.
3345 * @param $options Array
3346 * @return void
3348 public function setSessionOptions( array $options ) {
3352 * Read and execute SQL commands from a file.
3354 * Returns true on success, error string or exception on failure (depending
3355 * on object's error ignore settings).
3357 * @param string $filename File name to open
3358 * @param bool|callable $lineCallback Optional function called before reading each line
3359 * @param bool|callable $resultCallback Optional function called for each MySQL result
3360 * @param bool|string $fname Calling function name or false if name should be
3361 * generated dynamically using $filename
3362 * @param bool|callable $inputCallback Callback: Optional function called for each complete line sent
3363 * @throws MWException
3364 * @throws Exception|MWException
3365 * @return bool|string
3367 public function sourceFile(
3368 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3370 wfSuppressWarnings();
3371 $fp = fopen( $filename, 'r' );
3372 wfRestoreWarnings();
3374 if ( false === $fp ) {
3375 throw new MWException( "Could not open \"{$filename}\".\n" );
3378 if ( !$fname ) {
3379 $fname = __METHOD__ . "( $filename )";
3382 try {
3383 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3385 catch ( MWException $e ) {
3386 fclose( $fp );
3387 throw $e;
3390 fclose( $fp );
3392 return $error;
3396 * Get the full path of a patch file. Originally based on archive()
3397 * from updaters.inc. Keep in mind this always returns a patch, as
3398 * it fails back to MySQL if no DB-specific patch can be found
3400 * @param string $patch The name of the patch, like patch-something.sql
3401 * @return String Full path to patch file
3403 public function patchPath( $patch ) {
3404 global $IP;
3406 $dbType = $this->getType();
3407 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3408 return "$IP/maintenance/$dbType/archives/$patch";
3409 } else {
3410 return "$IP/maintenance/archives/$patch";
3415 * Set variables to be used in sourceFile/sourceStream, in preference to the
3416 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3417 * all. If it's set to false, $GLOBALS will be used.
3419 * @param bool|array $vars mapping variable name to value.
3421 public function setSchemaVars( $vars ) {
3422 $this->mSchemaVars = $vars;
3426 * Read and execute commands from an open file handle.
3428 * Returns true on success, error string or exception on failure (depending
3429 * on object's error ignore settings).
3431 * @param $fp Resource: File handle
3432 * @param $lineCallback Callback: Optional function called before reading each query
3433 * @param $resultCallback Callback: Optional function called for each MySQL result
3434 * @param string $fname Calling function name
3435 * @param $inputCallback Callback: Optional function called for each complete query sent
3436 * @return bool|string
3438 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3439 $fname = 'DatabaseBase::sourceStream', $inputCallback = false )
3441 $cmd = '';
3443 while ( !feof( $fp ) ) {
3444 if ( $lineCallback ) {
3445 call_user_func( $lineCallback );
3448 $line = trim( fgets( $fp ) );
3450 if ( $line == '' ) {
3451 continue;
3454 if ( '-' == $line[0] && '-' == $line[1] ) {
3455 continue;
3458 if ( $cmd != '' ) {
3459 $cmd .= ' ';
3462 $done = $this->streamStatementEnd( $cmd, $line );
3464 $cmd .= "$line\n";
3466 if ( $done || feof( $fp ) ) {
3467 $cmd = $this->replaceVars( $cmd );
3469 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) || !$inputCallback ) {
3470 $res = $this->query( $cmd, $fname );
3472 if ( $resultCallback ) {
3473 call_user_func( $resultCallback, $res, $this );
3476 if ( false === $res ) {
3477 $err = $this->lastError();
3478 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3481 $cmd = '';
3485 return true;
3489 * Called by sourceStream() to check if we've reached a statement end
3491 * @param string $sql SQL assembled so far
3492 * @param string $newLine New line about to be added to $sql
3493 * @return Bool Whether $newLine contains end of the statement
3495 public function streamStatementEnd( &$sql, &$newLine ) {
3496 if ( $this->delimiter ) {
3497 $prev = $newLine;
3498 $newLine = preg_replace( '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
3499 if ( $newLine != $prev ) {
3500 return true;
3503 return false;
3507 * Database independent variable replacement. Replaces a set of variables
3508 * in an SQL statement with their contents as given by $this->getSchemaVars().
3510 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3512 * - '{$var}' should be used for text and is passed through the database's
3513 * addQuotes method.
3514 * - `{$var}` should be used for identifiers (eg: table and database names),
3515 * it is passed through the database's addIdentifierQuotes method which
3516 * can be overridden if the database uses something other than backticks.
3517 * - / *$var* / is just encoded, besides traditional table prefix and
3518 * table options its use should be avoided.
3520 * @param string $ins SQL statement to replace variables in
3521 * @return String The new SQL statement with variables replaced
3523 protected function replaceSchemaVars( $ins ) {
3524 $vars = $this->getSchemaVars();
3525 foreach ( $vars as $var => $value ) {
3526 // replace '{$var}'
3527 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3528 // replace `{$var}`
3529 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3530 // replace /*$var*/
3531 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ), $ins );
3533 return $ins;
3537 * Replace variables in sourced SQL
3539 * @param $ins string
3541 * @return string
3543 protected function replaceVars( $ins ) {
3544 $ins = $this->replaceSchemaVars( $ins );
3546 // Table prefixes
3547 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3548 array( $this, 'tableNameCallback' ), $ins );
3550 // Index names
3551 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3552 array( $this, 'indexNameCallback' ), $ins );
3554 return $ins;
3558 * Get schema variables. If none have been set via setSchemaVars(), then
3559 * use some defaults from the current object.
3561 * @return array
3563 protected function getSchemaVars() {
3564 if ( $this->mSchemaVars ) {
3565 return $this->mSchemaVars;
3566 } else {
3567 return $this->getDefaultSchemaVars();
3572 * Get schema variables to use if none have been set via setSchemaVars().
3574 * Override this in derived classes to provide variables for tables.sql
3575 * and SQL patch files.
3577 * @return array
3579 protected function getDefaultSchemaVars() {
3580 return array();
3584 * Table name callback
3586 * @param $matches array
3588 * @return string
3590 protected function tableNameCallback( $matches ) {
3591 return $this->tableName( $matches[1] );
3595 * Index name callback
3597 * @param $matches array
3599 * @return string
3601 protected function indexNameCallback( $matches ) {
3602 return $this->indexName( $matches[1] );
3606 * Check to see if a named lock is available. This is non-blocking.
3608 * @param string $lockName name of lock to poll
3609 * @param string $method name of method calling us
3610 * @return Boolean
3611 * @since 1.20
3613 public function lockIsFree( $lockName, $method ) {
3614 return true;
3618 * Acquire a named lock
3620 * Abstracted from Filestore::lock() so child classes can implement for
3621 * their own needs.
3623 * @param string $lockName name of lock to aquire
3624 * @param string $method name of method calling us
3625 * @param $timeout Integer: timeout
3626 * @return Boolean
3628 public function lock( $lockName, $method, $timeout = 5 ) {
3629 return true;
3633 * Release a lock.
3635 * @param string $lockName Name of lock to release
3636 * @param string $method Name of method calling us
3638 * @return int Returns 1 if the lock was released, 0 if the lock was not established
3639 * by this thread (in which case the lock is not released), and NULL if the named
3640 * lock did not exist
3642 public function unlock( $lockName, $method ) {
3643 return true;
3647 * Lock specific tables
3649 * @param array $read of tables to lock for read access
3650 * @param array $write of tables to lock for write access
3651 * @param string $method name of caller
3652 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3654 * @return bool
3656 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3657 return true;
3661 * Unlock specific tables
3663 * @param string $method the caller
3665 * @return bool
3667 public function unlockTables( $method ) {
3668 return true;
3672 * Delete a table
3673 * @param $tableName string
3674 * @param $fName string
3675 * @return bool|ResultWrapper
3676 * @since 1.18
3678 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3679 if ( !$this->tableExists( $tableName, $fName ) ) {
3680 return false;
3682 $sql = "DROP TABLE " . $this->tableName( $tableName );
3683 if ( $this->cascadingDeletes() ) {
3684 $sql .= " CASCADE";
3686 return $this->query( $sql, $fName );
3690 * Get search engine class. All subclasses of this need to implement this
3691 * if they wish to use searching.
3693 * @return String
3695 public function getSearchEngine() {
3696 return 'SearchEngineDummy';
3700 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3701 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3702 * because "i" sorts after all numbers.
3704 * @return String
3706 public function getInfinity() {
3707 return 'infinity';
3711 * Encode an expiry time into the DBMS dependent format
3713 * @param string $expiry timestamp for expiry, or the 'infinity' string
3714 * @return String
3716 public function encodeExpiry( $expiry ) {
3717 return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
3718 ? $this->getInfinity()
3719 : $this->timestamp( $expiry );
3723 * Decode an expiry time into a DBMS independent format
3725 * @param string $expiry DB timestamp field value for expiry
3726 * @param $format integer: TS_* constant, defaults to TS_MW
3727 * @return String
3729 public function decodeExpiry( $expiry, $format = TS_MW ) {
3730 return ( $expiry == '' || $expiry == $this->getInfinity() )
3731 ? 'infinity'
3732 : wfTimestamp( $format, $expiry );
3736 * Allow or deny "big selects" for this session only. This is done by setting
3737 * the sql_big_selects session variable.
3739 * This is a MySQL-specific feature.
3741 * @param $value Mixed: true for allow, false for deny, or "default" to
3742 * restore the initial value
3744 public function setBigSelects( $value = true ) {
3745 // no-op
3749 * @since 1.19
3751 public function __toString() {
3752 return (string)$this->mConn;
3755 public function __destruct() {
3756 if ( count( $this->mTrxIdleCallbacks ) || count( $this->mTrxPreCommitCallbacks ) ) {
3757 trigger_error( "Transaction idle or pre-commit callbacks still pending." ); // sanity