4 * @defgroup Database Database
6 * This file deals with database interface functions
7 * and query specifics/optimisations.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22 * http://www.gnu.org/copyleft/gpl.html
29 * Interface for classes that implement or wrap DatabaseBase
36 * Database abstraction object
39 abstract class DatabaseBase
implements IDatabase
{
40 /** Number of times to re-try an operation in case of deadlock */
41 const DEADLOCK_TRIES
= 4;
43 /** Minimum time to wait before retry, in microseconds */
44 const DEADLOCK_DELAY_MIN
= 500000;
46 /** Maximum time to wait before retry */
47 const DEADLOCK_DELAY_MAX
= 1500000;
49 protected $mLastQuery = '';
50 protected $mDoneWrites = false;
51 protected $mPHPError = false;
53 protected $mServer, $mUser, $mPassword, $mDBname;
55 /** @var resource Database connection */
56 protected $mConn = null;
57 protected $mOpened = false;
59 /** @var callable[] */
60 protected $mTrxIdleCallbacks = array();
61 /** @var callable[] */
62 protected $mTrxPreCommitCallbacks = array();
64 protected $mTablePrefix;
68 protected $mErrorCount = 0;
69 protected $mLBInfo = array();
70 protected $mDefaultBigSelects = null;
71 protected $mSchemaVars = false;
73 protected $preparedArgs;
75 protected $htmlErrors;
77 protected $delimiter = ';';
80 * Either 1 if a transaction is active or 0 otherwise.
81 * The other Trx fields may not be meaningfull if this is 0.
85 protected $mTrxLevel = 0;
88 * Either a short hexidecimal string if a transaction is active or ""
91 * @see DatabaseBase::mTrxLevel
93 protected $mTrxShortId = '';
96 * The UNIX time that the transaction started. Callers can assume that if
97 * snapshot isolation is used, then the data is *at least* up to date to that
98 * point (possibly more up-to-date since the first SELECT defines the snapshot).
101 * @see DatabaseBase::mTrxLevel
103 private $mTrxTimestamp = null;
106 * Remembers the function name given for starting the most recent transaction via begin().
107 * Used to provide additional context for error reporting.
110 * @see DatabaseBase::mTrxLevel
112 private $mTrxFname = null;
115 * Record if possible write queries were done in the last transaction started
118 * @see DatabaseBase::mTrxLevel
120 private $mTrxDoneWrites = false;
123 * Record if the current transaction was started implicitly due to DBO_TRX being set.
126 * @see DatabaseBase::mTrxLevel
128 private $mTrxAutomatic = false;
131 * Array of levels of atomicity within transactions
135 private $mTrxAtomicLevels;
138 * Record if the current transaction was started implicitly by DatabaseBase::startAtomic
142 private $mTrxAutomaticAtomic = false;
146 * @var resource File handle for upgrade
148 protected $fileHandle = null;
152 * @var string[] Process cache of VIEWs names in the database
154 protected $allViews = null;
157 * A string describing the current software version, and possibly
158 * other details in a user-friendly way. Will be listed on Special:Version, etc.
159 * Use getServerVersion() to get machine-friendly information.
161 * @return string Version information from the database server
163 public function getServerInfo() {
164 return $this->getServerVersion();
168 * @return string Command delimiter used by this database engine
170 public function getDelimiter() {
171 return $this->delimiter
;
175 * Boolean, controls output of large amounts of debug information.
176 * @param bool|null $debug
177 * - true to enable debugging
178 * - false to disable debugging
179 * - omitted or null to do nothing
181 * @return bool|null Previous value of the flag
183 public function debug( $debug = null ) {
184 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
188 * Turns buffering of SQL result sets on (true) or off (false). Default is
191 * Unbuffered queries are very troublesome in MySQL:
193 * - If another query is executed while the first query is being read
194 * out, the first query is killed. This means you can't call normal
195 * MediaWiki functions while you are reading an unbuffered query result
196 * from a normal wfGetDB() connection.
198 * - Unbuffered queries cause the MySQL server to use large amounts of
199 * memory and to hold broad locks which block other queries.
201 * If you want to limit client-side memory, it's almost always better to
202 * split up queries into batches using a LIMIT clause than to switch off
205 * @param null|bool $buffer
206 * @return null|bool The previous value of the flag
208 public function bufferResults( $buffer = null ) {
209 if ( is_null( $buffer ) ) {
210 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
212 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
217 * Turns on (false) or off (true) the automatic generation and sending
218 * of a "we're sorry, but there has been a database error" page on
219 * database errors. Default is on (false). When turned off, the
220 * code should use lastErrno() and lastError() to handle the
221 * situation as appropriate.
223 * Do not use this function outside of the Database classes.
225 * @param null|bool $ignoreErrors
226 * @return bool The previous value of the flag.
228 public function ignoreErrors( $ignoreErrors = null ) {
229 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
233 * Gets the current transaction level.
235 * Historically, transactions were allowed to be "nested". This is no
236 * longer supported, so this function really only returns a boolean.
238 * @return int The previous value
240 public function trxLevel() {
241 return $this->mTrxLevel
;
245 * Get the UNIX timestamp of the time that the transaction was established
247 * This can be used to reason about the staleness of SELECT data
248 * in REPEATABLE-READ transaction isolation level.
250 * @return float|null Returns null if there is not active transaction
253 public function trxTimestamp() {
254 return $this->mTrxLevel ?
$this->mTrxTimestamp
: null;
258 * Get/set the number of errors logged. Only useful when errors are ignored
259 * @param int $count The count to set, or omitted to leave it unchanged.
260 * @return int The error count
262 public function errorCount( $count = null ) {
263 return wfSetVar( $this->mErrorCount
, $count );
267 * Get/set the table prefix.
268 * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
269 * @return string The previous table prefix.
271 public function tablePrefix( $prefix = null ) {
272 return wfSetVar( $this->mTablePrefix
, $prefix );
276 * Get/set the db schema.
277 * @param string $schema The database schema to set, or omitted to leave it unchanged.
278 * @return string The previous db schema.
280 public function dbSchema( $schema = null ) {
281 return wfSetVar( $this->mSchema
, $schema );
285 * Set the filehandle to copy write statements to.
287 * @param resource $fh File handle
289 public function setFileHandle( $fh ) {
290 $this->fileHandle
= $fh;
294 * Get properties passed down from the server info array of the load
297 * @param string $name The entry of the info array to get, or null to get the
300 * @return array|mixed|null
302 public function getLBInfo( $name = null ) {
303 if ( is_null( $name ) ) {
304 return $this->mLBInfo
;
306 if ( array_key_exists( $name, $this->mLBInfo
) ) {
307 return $this->mLBInfo
[$name];
315 * Set the LB info array, or a member of it. If called with one parameter,
316 * the LB info array is set to that parameter. If it is called with two
317 * parameters, the member with the given name is set to the given value.
319 * @param string $name
320 * @param array $value
322 public function setLBInfo( $name, $value = null ) {
323 if ( is_null( $value ) ) {
324 $this->mLBInfo
= $name;
326 $this->mLBInfo
[$name] = $value;
331 * Set lag time in seconds for a fake slave
333 * @param mixed $lag Valid values for this parameter are determined by the
334 * subclass, but should be a PHP scalar or array that would be sensible
335 * as part of $wgLBFactoryConf.
337 public function setFakeSlaveLag( $lag ) {
341 * Make this connection a fake master
343 * @param bool $enabled
345 public function setFakeMaster( $enabled = true ) {
349 * Returns true if this database supports (and uses) cascading deletes
353 public function cascadingDeletes() {
358 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
362 public function cleanupTriggers() {
367 * Returns true if this database is strict about what can be put into an IP field.
368 * Specifically, it uses a NULL value instead of an empty string.
372 public function strictIPs() {
377 * Returns true if this database uses timestamps rather than integers
381 public function realTimestamps() {
386 * Returns true if this database does an implicit sort when doing GROUP BY
390 public function implicitGroupby() {
395 * Returns true if this database does an implicit order by when the column has an index
396 * For example: SELECT page_title FROM page LIMIT 1
400 public function implicitOrderby() {
405 * Returns true if this database can do a native search on IP columns
406 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
410 public function searchableIPs() {
415 * Returns true if this database can use functional indexes
419 public function functionalIndexes() {
424 * Return the last query that went through DatabaseBase::query()
427 public function lastQuery() {
428 return $this->mLastQuery
;
432 * Returns true if the connection may have been used for write queries.
433 * Should return true if unsure.
437 public function doneWrites() {
438 return (bool)$this->mDoneWrites
;
442 * Returns the last time the connection may have been used for write queries.
443 * Should return a timestamp if unsure.
445 * @return int|float UNIX timestamp or false
448 public function lastDoneWrites() {
449 return $this->mDoneWrites ?
: false;
453 * Returns true if there is a transaction open with possible write
454 * queries or transaction pre-commit/idle callbacks waiting on it to finish.
458 public function writesOrCallbacksPending() {
459 return $this->mTrxLevel
&& (
460 $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks ||
$this->mTrxPreCommitCallbacks
465 * Is a connection to the database open?
468 public function isOpen() {
469 return $this->mOpened
;
473 * Set a flag for this connection
475 * @param int $flag DBO_* constants from Defines.php:
476 * - DBO_DEBUG: output some debug info (same as debug())
477 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
478 * - DBO_TRX: automatically start transactions
479 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
480 * and removes it in command line mode
481 * - DBO_PERSISTENT: use persistant database connection
483 public function setFlag( $flag ) {
484 global $wgDebugDBTransactions;
485 $this->mFlags |
= $flag;
486 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
487 wfDebug( "Implicit transactions are now enabled.\n" );
492 * Clear a flag for this connection
494 * @param int $flag DBO_* constants from Defines.php:
495 * - DBO_DEBUG: output some debug info (same as debug())
496 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
497 * - DBO_TRX: automatically start transactions
498 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
499 * and removes it in command line mode
500 * - DBO_PERSISTENT: use persistant database connection
502 public function clearFlag( $flag ) {
503 global $wgDebugDBTransactions;
504 $this->mFlags
&= ~
$flag;
505 if ( ( $flag & DBO_TRX
) && $wgDebugDBTransactions ) {
506 wfDebug( "Implicit transactions are now disabled.\n" );
511 * Returns a boolean whether the flag $flag is set for this connection
513 * @param int $flag DBO_* constants from Defines.php:
514 * - DBO_DEBUG: output some debug info (same as debug())
515 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
516 * - DBO_TRX: automatically start transactions
517 * - DBO_PERSISTENT: use persistant database connection
520 public function getFlag( $flag ) {
521 return !!( $this->mFlags
& $flag );
525 * General read-only accessor
527 * @param string $name
530 public function getProperty( $name ) {
537 public function getWikiID() {
538 if ( $this->mTablePrefix
) {
539 return "{$this->mDBname}-{$this->mTablePrefix}";
541 return $this->mDBname
;
546 * Return a path to the DBMS-specific SQL file if it exists,
547 * otherwise default SQL file
549 * @param string $filename
552 private function getSqlFilePath( $filename ) {
554 $dbmsSpecificFilePath = "$IP/maintenance/" . $this->getType() . "/$filename";
555 if ( file_exists( $dbmsSpecificFilePath ) ) {
556 return $dbmsSpecificFilePath;
558 return "$IP/maintenance/$filename";
563 * Return a path to the DBMS-specific schema file,
564 * otherwise default to tables.sql
568 public function getSchemaPath() {
569 return $this->getSqlFilePath( 'tables.sql' );
573 * Return a path to the DBMS-specific update key file,
574 * otherwise default to update-keys.sql
578 public function getUpdateKeysPath() {
579 return $this->getSqlFilePath( 'update-keys.sql' );
583 * Get the type of the DBMS, as it appears in $wgDBtype.
587 abstract function getType();
590 * Open a connection to the database. Usually aborts on failure
592 * @param string $server Database server host
593 * @param string $user Database user name
594 * @param string $password Database user password
595 * @param string $dbName Database name
597 * @throws DBConnectionError
599 abstract function open( $server, $user, $password, $dbName );
602 * Fetch the next row from the given result object, in object form.
603 * Fields can be retrieved with $row->fieldname, with fields acting like
605 * If no more rows are available, false is returned.
607 * @param ResultWrapper|stdClass $res Object as returned from DatabaseBase::query(), etc.
608 * @return stdClass|bool
609 * @throws DBUnexpectedError Thrown if the database returns an error
611 abstract function fetchObject( $res );
614 * Fetch the next row from the given result object, in associative array
615 * form. Fields are retrieved with $row['fieldname'].
616 * If no more rows are available, false is returned.
618 * @param ResultWrapper $res Result object as returned from DatabaseBase::query(), etc.
620 * @throws DBUnexpectedError Thrown if the database returns an error
622 abstract function fetchRow( $res );
625 * Get the number of rows in a result object
627 * @param mixed $res A SQL result
630 abstract function numRows( $res );
633 * Get the number of fields in a result object
634 * @see http://www.php.net/mysql_num_fields
636 * @param mixed $res A SQL result
639 abstract function numFields( $res );
642 * Get a field name in a result object
643 * @see http://www.php.net/mysql_field_name
645 * @param mixed $res A SQL result
649 abstract function fieldName( $res, $n );
652 * Get the inserted value of an auto-increment row
654 * The value inserted should be fetched from nextSequenceValue()
657 * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
658 * $dbw->insert( 'page', array( 'page_id' => $id ) );
659 * $id = $dbw->insertId();
663 abstract function insertId();
666 * Change the position of the cursor in a result object
667 * @see http://www.php.net/mysql_data_seek
669 * @param mixed $res A SQL result
672 abstract function dataSeek( $res, $row );
675 * Get the last error number
676 * @see http://www.php.net/mysql_errno
680 abstract function lastErrno();
683 * Get a description of the last error
684 * @see http://www.php.net/mysql_error
688 abstract function lastError();
691 * mysql_fetch_field() wrapper
692 * Returns false if the field doesn't exist
694 * @param string $table Table name
695 * @param string $field Field name
699 abstract function fieldInfo( $table, $field );
702 * Get information about an index into an object
703 * @param string $table Table name
704 * @param string $index Index name
705 * @param string $fname Calling function name
706 * @return mixed Database-specific index description class or false if the index does not exist
708 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
711 * Get the number of rows affected by the last write query
712 * @see http://www.php.net/mysql_affected_rows
716 abstract function affectedRows();
719 * Wrapper for addslashes()
721 * @param string $s String to be slashed.
722 * @return string Slashed string.
724 abstract function strencode( $s );
727 * Returns a wikitext link to the DB's website, e.g.,
728 * return "[http://www.mysql.com/ MySQL]";
729 * Should at least contain plain text, if for some reason
730 * your database has no website.
732 * @return string Wikitext of a link to the server software's web site
734 abstract function getSoftwareLink();
737 * A string describing the current software version, like from
738 * mysql_get_server_info().
740 * @return string Version information from the database server.
742 abstract function getServerVersion();
747 * FIXME: It is possible to construct a Database object with no associated
748 * connection object, by specifying no parameters to __construct(). This
749 * feature is deprecated and should be removed.
751 * DatabaseBase subclasses should not be constructed directly in external
752 * code. DatabaseBase::factory() should be used instead.
754 * @param array $params Parameters passed from DatabaseBase::factory()
756 function __construct( $params = null ) {
757 global $wgDBprefix, $wgDBmwschema, $wgCommandLineMode, $wgDebugDBTransactions;
759 $this->mTrxAtomicLevels
= new SplStack
;
761 if ( is_array( $params ) ) { // MW 1.22
762 $server = $params['host'];
763 $user = $params['user'];
764 $password = $params['password'];
765 $dbName = $params['dbname'];
766 $flags = $params['flags'];
767 $tablePrefix = $params['tablePrefix'];
768 $schema = $params['schema'];
769 $foreign = $params['foreign'];
770 } else { // legacy calling pattern
771 wfDeprecated( __METHOD__
. " method called without parameter array.", "1.23" );
772 $args = func_get_args();
773 $server = isset( $args[0] ) ?
$args[0] : false;
774 $user = isset( $args[1] ) ?
$args[1] : false;
775 $password = isset( $args[2] ) ?
$args[2] : false;
776 $dbName = isset( $args[3] ) ?
$args[3] : false;
777 $flags = isset( $args[4] ) ?
$args[4] : 0;
778 $tablePrefix = isset( $args[5] ) ?
$args[5] : 'get from global';
779 $schema = 'get from global';
780 $foreign = isset( $args[6] ) ?
$args[6] : false;
783 $this->mFlags
= $flags;
784 if ( $this->mFlags
& DBO_DEFAULT
) {
785 if ( $wgCommandLineMode ) {
786 $this->mFlags
&= ~DBO_TRX
;
787 if ( $wgDebugDBTransactions ) {
788 wfDebug( "Implicit transaction open disabled.\n" );
791 $this->mFlags |
= DBO_TRX
;
792 if ( $wgDebugDBTransactions ) {
793 wfDebug( "Implicit transaction open enabled.\n" );
798 /** Get the default table prefix*/
799 if ( $tablePrefix == 'get from global' ) {
800 $this->mTablePrefix
= $wgDBprefix;
802 $this->mTablePrefix
= $tablePrefix;
805 /** Get the database schema*/
806 if ( $schema == 'get from global' ) {
807 $this->mSchema
= $wgDBmwschema;
809 $this->mSchema
= $schema;
812 $this->mForeign
= $foreign;
815 $this->open( $server, $user, $password, $dbName );
818 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
819 $trxProf = Profiler
::instance()->getTransactionProfiler();
820 $trxProf->recordConnection( $this->mServer
, $this->mDBname
, $isMaster );
824 * Called by serialize. Throw an exception when DB connection is serialized.
825 * This causes problems on some database engines because the connection is
826 * not restored on unserialize.
828 public function __sleep() {
829 throw new MWException( 'Database serialization may cause problems, since ' .
830 'the connection is not restored on wakeup.' );
834 * Given a DB type, construct the name of the appropriate child class of
835 * DatabaseBase. This is designed to replace all of the manual stuff like:
836 * $class = 'Database' . ucfirst( strtolower( $dbType ) );
837 * as well as validate against the canonical list of DB types we have
839 * This factory function is mostly useful for when you need to connect to a
840 * database other than the MediaWiki default (such as for external auth,
841 * an extension, et cetera). Do not use this to connect to the MediaWiki
842 * database. Example uses in core:
843 * @see LoadBalancer::reallyOpenConnection()
844 * @see ForeignDBRepo::getMasterDB()
845 * @see WebInstallerDBConnect::execute()
849 * @param string $dbType A possible DB type
850 * @param array $p An array of options to pass to the constructor.
851 * Valid options are: host, user, password, dbname, flags, tablePrefix, schema, driver
852 * @throws MWException If the database driver or extension cannot be found
853 * @return DatabaseBase|null DatabaseBase subclass or null
855 final public static function factory( $dbType, $p = array() ) {
856 $canonicalDBTypes = array(
857 'mysql' => array( 'mysqli', 'mysql' ),
858 'postgres' => array(),
865 $dbType = strtolower( $dbType );
866 if ( isset( $canonicalDBTypes[$dbType] ) && $canonicalDBTypes[$dbType] ) {
867 $possibleDrivers = $canonicalDBTypes[$dbType];
868 if ( !empty( $p['driver'] ) ) {
869 if ( in_array( $p['driver'], $possibleDrivers ) ) {
870 $driver = $p['driver'];
872 throw new MWException( __METHOD__
.
873 " cannot construct Database with type '$dbType' and driver '{$p['driver']}'" );
876 foreach ( $possibleDrivers as $posDriver ) {
877 if ( extension_loaded( $posDriver ) ) {
878 $driver = $posDriver;
886 if ( $driver === false ) {
887 throw new MWException( __METHOD__
.
888 " no viable database extension found for type '$dbType'" );
891 // Determine schema defaults. Currently Microsoft SQL Server uses $wgDBmwschema,
892 // and everything else doesn't use a schema (e.g. null)
893 // Although postgres and oracle support schemas, we don't use them (yet)
894 // to maintain backwards compatibility
895 $defaultSchemas = array(
900 'mssql' => 'get from global',
903 $class = 'Database' . ucfirst( $driver );
904 if ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) {
906 'host' => isset( $p['host'] ) ?
$p['host'] : false,
907 'user' => isset( $p['user'] ) ?
$p['user'] : false,
908 'password' => isset( $p['password'] ) ?
$p['password'] : false,
909 'dbname' => isset( $p['dbname'] ) ?
$p['dbname'] : false,
910 'flags' => isset( $p['flags'] ) ?
$p['flags'] : 0,
911 'tablePrefix' => isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global',
912 'schema' => isset( $p['schema'] ) ?
$p['schema'] : $defaultSchemas[$dbType],
913 'foreign' => isset( $p['foreign'] ) ?
$p['foreign'] : false
916 return new $class( $params );
922 protected function installErrorHandler() {
923 $this->mPHPError
= false;
924 $this->htmlErrors
= ini_set( 'html_errors', '0' );
925 set_error_handler( array( $this, 'connectionErrorHandler' ) );
929 * @return bool|string
931 protected function restoreErrorHandler() {
932 restore_error_handler();
933 if ( $this->htmlErrors
!== false ) {
934 ini_set( 'html_errors', $this->htmlErrors
);
936 if ( $this->mPHPError
) {
937 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
938 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
948 * @param string $errstr
950 public function connectionErrorHandler( $errno, $errstr ) {
951 $this->mPHPError
= $errstr;
955 * Create a log context to pass to wfLogDBError or other logging functions.
957 * @param array $extras Additional data to add to context
960 protected function getLogContext( array $extras = array() ) {
963 'db_server' => $this->mServer
,
964 'db_name' => $this->mDBname
,
965 'db_user' => $this->mUser
,
972 * Closes a database connection.
973 * if it is open : commits any open transactions
975 * @throws MWException
976 * @return bool Operation success. true if already closed.
978 public function close() {
979 if ( count( $this->mTrxIdleCallbacks
) ) { // sanity
980 throw new MWException( "Transaction idle callbacks still pending." );
982 if ( $this->mConn
) {
983 if ( $this->trxLevel() ) {
984 if ( !$this->mTrxAutomatic
) {
985 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
986 " performing implicit commit before closing connection!" );
989 $this->commit( __METHOD__
, 'flush' );
992 $closed = $this->closeConnection();
993 $this->mConn
= false;
997 $this->mOpened
= false;
1003 * Closes underlying database connection
1005 * @return bool Whether connection was closed successfully
1007 abstract protected function closeConnection();
1010 * @param string $error Fallback error message, used if none is given by DB
1011 * @throws DBConnectionError
1013 function reportConnectionError( $error = 'Unknown error' ) {
1014 $myError = $this->lastError();
1020 throw new DBConnectionError( $this, $error );
1024 * The DBMS-dependent part of query()
1026 * @param string $sql SQL query.
1027 * @return ResultWrapper|bool Result object to feed to fetchObject,
1028 * fetchRow, ...; or false on failure
1030 abstract protected function doQuery( $sql );
1033 * Determine whether a query writes to the DB.
1034 * Should return true if unsure.
1036 * @param string $sql
1039 public function isWriteQuery( $sql ) {
1040 return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
1044 * Determine whether a SQL statement is sensitive to isolation level.
1045 * A SQL statement is considered transactable if its result could vary
1046 * depending on the transaction isolation level. Operational commands
1047 * such as 'SET' and 'SHOW' are not considered to be transactable.
1049 * @param string $sql
1052 public function isTransactableQuery( $sql ) {
1053 $verb = substr( $sql, 0, strcspn( $sql, " \t\r\n" ) );
1054 return !in_array( $verb, array( 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET' ) );
1058 * Run an SQL query and return the result. Normally throws a DBQueryError
1059 * on failure. If errors are ignored, returns false instead.
1061 * In new code, the query wrappers select(), insert(), update(), delete(),
1062 * etc. should be used where possible, since they give much better DBMS
1063 * independence and automatically quote or validate user input in a variety
1064 * of contexts. This function is generally only useful for queries which are
1065 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
1068 * However, the query wrappers themselves should call this function.
1070 * @param string $sql SQL query
1071 * @param string $fname Name of the calling function, for profiling/SHOW PROCESSLIST
1072 * comment (you can use __METHOD__ or add some extra info)
1073 * @param bool $tempIgnore Whether to avoid throwing an exception on errors...
1074 * maybe best to catch the exception instead?
1075 * @throws MWException
1076 * @return bool|ResultWrapper True for a successful write query, ResultWrapper object
1077 * for a successful read query, or false on failure if $tempIgnore set
1079 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
1080 global $wgUser, $wgDebugDBTransactions, $wgDebugDumpSqlLength;
1082 $this->mLastQuery
= $sql;
1084 $isWriteQuery = $this->isWriteQuery( $sql );
1085 if ( $isWriteQuery ) {
1086 if ( !$this->mDoneWrites
) {
1087 wfDebug( __METHOD__
. ': Writes done: ' .
1088 DatabaseBase
::generalizeSQL( $sql ) . "\n" );
1090 # Set a flag indicating that writes have been done
1091 $this->mDoneWrites
= microtime( true );
1094 # Add a comment for easy SHOW PROCESSLIST interpretation
1095 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
1096 $userName = $wgUser->getName();
1097 if ( mb_strlen( $userName ) > 15 ) {
1098 $userName = mb_substr( $userName, 0, 15 ) . '...';
1100 $userName = str_replace( '/', '', $userName );
1105 // Add trace comment to the begin of the sql string, right after the operator.
1106 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
1107 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
1109 if ( !$this->mTrxLevel
&& $this->getFlag( DBO_TRX
) && $this->isTransactableQuery( $sql ) ) {
1110 if ( $wgDebugDBTransactions ) {
1111 wfDebug( "Implicit transaction start.\n" );
1113 $this->begin( __METHOD__
. " ($fname)" );
1114 $this->mTrxAutomatic
= true;
1117 # Keep track of whether the transaction has write queries pending
1118 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $isWriteQuery ) {
1119 $this->mTrxDoneWrites
= true;
1120 Profiler
::instance()->getTransactionProfiler()->transactionWritingIn(
1121 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
1126 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1128 $profiler = Profiler
::instance();
1129 if ( !$profiler instanceof ProfilerStub
) {
1130 # generalizeSQL will probably cut down the query to reasonable
1131 # logging size most of the time. The substr is really just a sanity check.
1133 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
1134 $totalProf = 'DatabaseBase::query-master';
1136 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
1137 $totalProf = 'DatabaseBase::query';
1139 # Include query transaction state
1140 $queryProf .= $this->mTrxShortId ?
" [TRX#{$this->mTrxShortId}]" : "";
1142 $totalProfSection = $profiler->scopedProfileIn( $totalProf );
1143 $queryProfSection = $profiler->scopedProfileIn( $queryProf );
1146 if ( $this->debug() ) {
1150 $sqlx = $wgDebugDumpSqlLength ?
substr( $commentedSql, 0, $wgDebugDumpSqlLength )
1152 $sqlx = strtr( $sqlx, "\t\n", ' ' );
1154 $master = $isMaster ?
'master' : 'slave';
1155 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
1158 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
1160 # Avoid fatals if close() was called
1161 if ( !$this->isOpen() ) {
1162 throw new DBUnexpectedError( $this, "DB connection was already closed." );
1165 # Log the query time and feed it into the DB trx profiler
1166 if ( $queryProf != '' ) {
1168 $queryStartTime = microtime( true );
1169 $queryProfile = new ScopedCallback(
1170 function () use ( $that, $queryStartTime, $queryProf, $isMaster ) {
1171 $n = $that->affectedRows();
1172 $trxProf = Profiler
::instance()->getTransactionProfiler();
1173 $trxProf->recordQueryCompletion( $queryProf, $queryStartTime, $isMaster, $n );
1178 # Do the query and handle errors
1179 $ret = $this->doQuery( $commentedSql );
1181 MWDebug
::queryTime( $queryId );
1183 # Try reconnecting if the connection was lost
1184 if ( false === $ret && $this->wasErrorReissuable() ) {
1185 # Transaction is gone, like it or not
1186 $hadTrx = $this->mTrxLevel
; // possible lost transaction
1187 $this->mTrxLevel
= 0;
1188 $this->mTrxIdleCallbacks
= array(); // bug 65263
1189 $this->mTrxPreCommitCallbacks
= array(); // bug 65263
1190 wfDebug( "Connection lost, reconnecting...\n" );
1191 # Stash the last error values since ping() might clear them
1192 $lastError = $this->lastError();
1193 $lastErrno = $this->lastErrno();
1194 if ( $this->ping() ) {
1195 wfDebug( "Reconnected\n" );
1196 $server = $this->getServer();
1197 $msg = __METHOD__
. ": lost connection to $server; reconnected";
1198 wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
1201 # Leave $ret as false and let an error be reported.
1202 # Callers may catch the exception and continue to use the DB.
1203 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
1205 # Should be safe to silently retry (no trx and thus no callbacks)
1206 $ret = $this->doQuery( $commentedSql );
1209 wfDebug( "Failed\n" );
1213 if ( false === $ret ) {
1214 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
1217 $res = $this->resultObject( $ret );
1219 // Destroy profile sections in the opposite order to their creation
1220 $queryProfSection = false;
1221 $totalProfSection = false;
1227 * Report a query error. Log the error, and if neither the object ignore
1228 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1230 * @param string $error
1232 * @param string $sql
1233 * @param string $fname
1234 * @param bool $tempIgnore
1235 * @throws DBQueryError
1237 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1238 # Ignore errors during error handling to avoid infinite recursion
1239 $ignore = $this->ignoreErrors( true );
1240 ++
$this->mErrorCount
;
1242 if ( $ignore ||
$tempIgnore ) {
1243 wfDebug( "SQL ERROR (ignored): $error\n" );
1244 $this->ignoreErrors( $ignore );
1246 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1248 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1249 $this->getLogContext( array(
1250 'method' => __METHOD__
,
1253 'sql1line' => $sql1line,
1257 wfDebug( "SQL ERROR: " . $error . "\n" );
1258 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1263 * Intended to be compatible with the PEAR::DB wrapper functions.
1264 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1266 * ? = scalar value, quoted as necessary
1267 * ! = raw SQL bit (a function for instance)
1268 * & = filename; reads the file and inserts as a blob
1269 * (we don't use this though...)
1271 * @param string $sql
1272 * @param string $func
1276 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1277 /* MySQL doesn't support prepared statements (yet), so just
1278 * pack up the query for reference. We'll manually replace
1281 return array( 'query' => $sql, 'func' => $func );
1285 * Free a prepared query, generated by prepare().
1286 * @param string $prepared
1288 protected function freePrepared( $prepared ) {
1289 /* No-op by default */
1293 * Execute a prepared query with the various arguments
1294 * @param string $prepared The prepared sql
1295 * @param mixed $args Either an array here, or put scalars as varargs
1297 * @return ResultWrapper
1299 public function execute( $prepared, $args = null ) {
1300 if ( !is_array( $args ) ) {
1302 $args = func_get_args();
1303 array_shift( $args );
1306 $sql = $this->fillPrepared( $prepared['query'], $args );
1308 return $this->query( $sql, $prepared['func'] );
1312 * For faking prepared SQL statements on DBs that don't support it directly.
1314 * @param string $preparedQuery A 'preparable' SQL statement
1315 * @param array $args Array of Arguments to fill it with
1316 * @return string Executable SQL
1318 public function fillPrepared( $preparedQuery, $args ) {
1320 $this->preparedArgs
=& $args;
1322 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1323 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1327 * preg_callback func for fillPrepared()
1328 * The arguments should be in $this->preparedArgs and must not be touched
1329 * while we're doing this.
1331 * @param array $matches
1332 * @throws DBUnexpectedError
1335 protected function fillPreparedArg( $matches ) {
1336 switch ( $matches[1] ) {
1345 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1347 switch ( $matches[1] ) {
1349 return $this->addQuotes( $arg );
1353 # return $this->addQuotes( file_get_contents( $arg ) );
1354 throw new DBUnexpectedError(
1356 '& mode is not implemented. If it\'s really needed, uncomment the line above.'
1359 throw new DBUnexpectedError(
1361 'Received invalid match. This should never happen!'
1367 * Free a result object returned by query() or select(). It's usually not
1368 * necessary to call this, just use unset() or let the variable holding
1369 * the result object go out of scope.
1371 * @param mixed $res A SQL result
1373 public function freeResult( $res ) {
1377 * A SELECT wrapper which returns a single field from a single result row.
1379 * Usually throws a DBQueryError on failure. If errors are explicitly
1380 * ignored, returns false on failure.
1382 * If no result rows are returned from the query, false is returned.
1384 * @param string|array $table Table name. See DatabaseBase::select() for details.
1385 * @param string $var The field name to select. This must be a valid SQL
1386 * fragment: do not use unvalidated user input.
1387 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1388 * @param string $fname The function name of the caller.
1389 * @param string|array $options The query options. See DatabaseBase::select() for details.
1391 * @return bool|mixed The value from the field, or false on failure.
1393 public function selectField(
1394 $table, $var, $cond = '', $fname = __METHOD__
, $options = array()
1396 if ( $var === '*' ) { // sanity
1397 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1400 if ( !is_array( $options ) ) {
1401 $options = array( $options );
1404 $options['LIMIT'] = 1;
1406 $res = $this->select( $table, $var, $cond, $fname, $options );
1407 if ( $res === false ||
!$this->numRows( $res ) ) {
1411 $row = $this->fetchRow( $res );
1413 if ( $row !== false ) {
1414 return reset( $row );
1421 * A SELECT wrapper which returns a list of single field values from result rows.
1423 * Usually throws a DBQueryError on failure. If errors are explicitly
1424 * ignored, returns false on failure.
1426 * If no result rows are returned from the query, false is returned.
1428 * @param string|array $table Table name. See DatabaseBase::select() for details.
1429 * @param string $var The field name to select. This must be a valid SQL
1430 * fragment: do not use unvalidated user input.
1431 * @param string|array $cond The condition array. See DatabaseBase::select() for details.
1432 * @param string $fname The function name of the caller.
1433 * @param string|array $options The query options. See DatabaseBase::select() for details.
1435 * @return bool|array The values from the field, or false on failure
1438 public function selectFieldValues(
1439 $table, $var, $cond = '', $fname = __METHOD__
, $options = array()
1441 if ( $var === '*' ) { // sanity
1442 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1445 if ( !is_array( $options ) ) {
1446 $options = array( $options );
1449 $res = $this->select( $table, $var, $cond, $fname, $options );
1450 if ( $res === false ) {
1455 foreach ( $res as $row ) {
1456 $values[] = $row->$var;
1463 * Returns an optional USE INDEX clause to go after the table, and a
1464 * string to go at the end of the query.
1466 * @param array $options Associative array of options to be turned into
1467 * an SQL query, valid keys are listed in the function.
1469 * @see DatabaseBase::select()
1471 public function makeSelectOptions( $options ) {
1472 $preLimitTail = $postLimitTail = '';
1475 $noKeyOptions = array();
1477 foreach ( $options as $key => $option ) {
1478 if ( is_numeric( $key ) ) {
1479 $noKeyOptions[$option] = true;
1483 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1485 $preLimitTail .= $this->makeOrderBy( $options );
1487 // if (isset($options['LIMIT'])) {
1488 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1489 // isset($options['OFFSET']) ? $options['OFFSET']
1493 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1494 $postLimitTail .= ' FOR UPDATE';
1497 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1498 $postLimitTail .= ' LOCK IN SHARE MODE';
1501 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1502 $startOpts .= 'DISTINCT';
1505 # Various MySQL extensions
1506 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1507 $startOpts .= ' /*! STRAIGHT_JOIN */';
1510 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1511 $startOpts .= ' HIGH_PRIORITY';
1514 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1515 $startOpts .= ' SQL_BIG_RESULT';
1518 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1519 $startOpts .= ' SQL_BUFFER_RESULT';
1522 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1523 $startOpts .= ' SQL_SMALL_RESULT';
1526 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1527 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1530 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1531 $startOpts .= ' SQL_CACHE';
1534 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1535 $startOpts .= ' SQL_NO_CACHE';
1538 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1539 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1544 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1548 * Returns an optional GROUP BY with an optional HAVING
1550 * @param array $options Associative array of options
1552 * @see DatabaseBase::select()
1555 public function makeGroupByWithHaving( $options ) {
1557 if ( isset( $options['GROUP BY'] ) ) {
1558 $gb = is_array( $options['GROUP BY'] )
1559 ?
implode( ',', $options['GROUP BY'] )
1560 : $options['GROUP BY'];
1561 $sql .= ' GROUP BY ' . $gb;
1563 if ( isset( $options['HAVING'] ) ) {
1564 $having = is_array( $options['HAVING'] )
1565 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1566 : $options['HAVING'];
1567 $sql .= ' HAVING ' . $having;
1574 * Returns an optional ORDER BY
1576 * @param array $options Associative array of options
1578 * @see DatabaseBase::select()
1581 public function makeOrderBy( $options ) {
1582 if ( isset( $options['ORDER BY'] ) ) {
1583 $ob = is_array( $options['ORDER BY'] )
1584 ?
implode( ',', $options['ORDER BY'] )
1585 : $options['ORDER BY'];
1587 return ' ORDER BY ' . $ob;
1594 * Execute a SELECT query constructed using the various parameters provided.
1595 * See below for full details of the parameters.
1597 * @param string|array $table Table name
1598 * @param string|array $vars Field names
1599 * @param string|array $conds Conditions
1600 * @param string $fname Caller function name
1601 * @param array $options Query options
1602 * @param array $join_conds Join conditions
1605 * @param string|array $table
1607 * May be either an array of table names, or a single string holding a table
1608 * name. If an array is given, table aliases can be specified, for example:
1610 * array( 'a' => 'user' )
1612 * This includes the user table in the query, with the alias "a" available
1613 * for use in field names (e.g. a.user_name).
1615 * All of the table names given here are automatically run through
1616 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1617 * added, and various other table name mappings to be performed.
1620 * @param string|array $vars
1622 * May be either a field name or an array of field names. The field names
1623 * can be complete fragments of SQL, for direct inclusion into the SELECT
1624 * query. If an array is given, field aliases can be specified, for example:
1626 * array( 'maxrev' => 'MAX(rev_id)' )
1628 * This includes an expression with the alias "maxrev" in the query.
1630 * If an expression is given, care must be taken to ensure that it is
1634 * @param string|array $conds
1636 * May be either a string containing a single condition, or an array of
1637 * conditions. If an array is given, the conditions constructed from each
1638 * element are combined with AND.
1640 * Array elements may take one of two forms:
1642 * - Elements with a numeric key are interpreted as raw SQL fragments.
1643 * - Elements with a string key are interpreted as equality conditions,
1644 * where the key is the field name.
1645 * - If the value of such an array element is a scalar (such as a
1646 * string), it will be treated as data and thus quoted appropriately.
1647 * If it is null, an IS NULL clause will be added.
1648 * - If the value is an array, an IN(...) clause will be constructed,
1649 * such that the field name may match any of the elements in the
1650 * array. The elements of the array will be quoted.
1652 * Note that expressions are often DBMS-dependent in their syntax.
1653 * DBMS-independent wrappers are provided for constructing several types of
1654 * expression commonly used in condition queries. See:
1655 * - DatabaseBase::buildLike()
1656 * - DatabaseBase::conditional()
1659 * @param string|array $options
1661 * Optional: Array of query options. Boolean options are specified by
1662 * including them in the array as a string value with a numeric key, for
1665 * array( 'FOR UPDATE' )
1667 * The supported options are:
1669 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1670 * with LIMIT can theoretically be used for paging through a result set,
1671 * but this is discouraged in MediaWiki for performance reasons.
1673 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1674 * and then the first rows are taken until the limit is reached. LIMIT
1675 * is applied to a result set after OFFSET.
1677 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1678 * changed until the next COMMIT.
1680 * - DISTINCT: Boolean: return only unique result rows.
1682 * - GROUP BY: May be either an SQL fragment string naming a field or
1683 * expression to group by, or an array of such SQL fragments.
1685 * - HAVING: May be either an string containing a HAVING clause or an array of
1686 * conditions building the HAVING clause. If an array is given, the conditions
1687 * constructed from each element are combined with AND.
1689 * - ORDER BY: May be either an SQL fragment giving a field name or
1690 * expression to order by, or an array of such SQL fragments.
1692 * - USE INDEX: This may be either a string giving the index name to use
1693 * for the query, or an array. If it is an associative array, each key
1694 * gives the table name (or alias), each value gives the index name to
1695 * use for that table. All strings are SQL fragments and so should be
1696 * validated by the caller.
1698 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1699 * instead of SELECT.
1701 * And also the following boolean MySQL extensions, see the MySQL manual
1702 * for documentation:
1704 * - LOCK IN SHARE MODE
1708 * - SQL_BUFFER_RESULT
1709 * - SQL_SMALL_RESULT
1710 * - SQL_CALC_FOUND_ROWS
1715 * @param string|array $join_conds
1717 * Optional associative array of table-specific join conditions. In the
1718 * most common case, this is unnecessary, since the join condition can be
1719 * in $conds. However, it is useful for doing a LEFT JOIN.
1721 * The key of the array contains the table name or alias. The value is an
1722 * array with two elements, numbered 0 and 1. The first gives the type of
1723 * join, the second is an SQL fragment giving the join condition for that
1724 * table. For example:
1726 * array( 'page' => array( 'LEFT JOIN', 'page_latest=rev_id' ) )
1728 * @return ResultWrapper|bool If the query returned no rows, a ResultWrapper
1729 * with no rows in it will be returned. If there was a query error, a
1730 * DBQueryError exception will be thrown, except if the "ignore errors"
1731 * option was set, in which case false will be returned.
1733 public function select( $table, $vars, $conds = '', $fname = __METHOD__
,
1734 $options = array(), $join_conds = array() ) {
1735 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1737 return $this->query( $sql, $fname );
1741 * The equivalent of DatabaseBase::select() except that the constructed SQL
1742 * is returned, instead of being immediately executed. This can be useful for
1743 * doing UNION queries, where the SQL text of each query is needed. In general,
1744 * however, callers outside of Database classes should just use select().
1746 * @param string|array $table Table name
1747 * @param string|array $vars Field names
1748 * @param string|array $conds Conditions
1749 * @param string $fname Caller function name
1750 * @param string|array $options Query options
1751 * @param string|array $join_conds Join conditions
1753 * @return string SQL query string.
1754 * @see DatabaseBase::select()
1756 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1757 $options = array(), $join_conds = array()
1759 if ( is_array( $vars ) ) {
1760 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1763 $options = (array)$options;
1764 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1765 ?
$options['USE INDEX']
1768 if ( is_array( $table ) ) {
1770 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndexes, $join_conds );
1771 } elseif ( $table != '' ) {
1772 if ( $table[0] == ' ' ) {
1773 $from = ' FROM ' . $table;
1776 $this->tableNamesWithUseIndexOrJOIN( array( $table ), $useIndexes, array() );
1782 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) =
1783 $this->makeSelectOptions( $options );
1785 if ( !empty( $conds ) ) {
1786 if ( is_array( $conds ) ) {
1787 $conds = $this->makeList( $conds, LIST_AND
);
1789 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1791 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1794 if ( isset( $options['LIMIT'] ) ) {
1795 $sql = $this->limitResult( $sql, $options['LIMIT'],
1796 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1798 $sql = "$sql $postLimitTail";
1800 if ( isset( $options['EXPLAIN'] ) ) {
1801 $sql = 'EXPLAIN ' . $sql;
1808 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1809 * that a single row object is returned. If the query returns no rows,
1810 * false is returned.
1812 * @param string|array $table Table name
1813 * @param string|array $vars Field names
1814 * @param array $conds Conditions
1815 * @param string $fname Caller function name
1816 * @param string|array $options Query options
1817 * @param array|string $join_conds Join conditions
1819 * @return stdClass|bool
1821 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1822 $options = array(), $join_conds = array()
1824 $options = (array)$options;
1825 $options['LIMIT'] = 1;
1826 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1828 if ( $res === false ) {
1832 if ( !$this->numRows( $res ) ) {
1836 $obj = $this->fetchObject( $res );
1842 * Estimate the number of rows in dataset
1844 * MySQL allows you to estimate the number of rows that would be returned
1845 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1846 * index cardinality statistics, and is notoriously inaccurate, especially
1847 * when large numbers of rows have recently been added or deleted.
1849 * For DBMSs that don't support fast result size estimation, this function
1850 * will actually perform the SELECT COUNT(*).
1852 * Takes the same arguments as DatabaseBase::select().
1854 * @param string $table Table name
1855 * @param string $vars Unused
1856 * @param array|string $conds Filters on the table
1857 * @param string $fname Function name for profiling
1858 * @param array $options Options for select
1859 * @return int Row count
1861 public function estimateRowCount(
1862 $table, $vars = '*', $conds = '', $fname = __METHOD__
, $options = array()
1865 $res = $this->select( $table, array( 'rowcount' => 'COUNT(*)' ), $conds, $fname, $options );
1868 $row = $this->fetchRow( $res );
1869 $rows = ( isset( $row['rowcount'] ) ) ?
(int)$row['rowcount'] : 0;
1876 * Get the number of rows in dataset
1878 * This is useful when trying to do COUNT(*) but with a LIMIT for performance.
1880 * Takes the same arguments as DatabaseBase::select().
1882 * @param string $table Table name
1883 * @param string $vars Unused
1884 * @param array|string $conds Filters on the table
1885 * @param string $fname Function name for profiling
1886 * @param array $options Options for select
1887 * @return int Row count
1890 public function selectRowCount(
1891 $table, $vars = '*', $conds = '', $fname = __METHOD__
, $options = array()
1894 $sql = $this->selectSQLText( $table, '1', $conds, $fname, $options );
1895 $res = $this->query( "SELECT COUNT(*) AS rowcount FROM ($sql) tmp_count" );
1898 $row = $this->fetchRow( $res );
1899 $rows = ( isset( $row['rowcount'] ) ) ?
(int)$row['rowcount'] : 0;
1906 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1907 * It's only slightly flawed. Don't use for anything important.
1909 * @param string $sql A SQL Query
1913 static function generalizeSQL( $sql ) {
1914 # This does the same as the regexp below would do, but in such a way
1915 # as to avoid crashing php on some large strings.
1916 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1918 $sql = str_replace( "\\\\", '', $sql );
1919 $sql = str_replace( "\\'", '', $sql );
1920 $sql = str_replace( "\\\"", '', $sql );
1921 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1922 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1924 # All newlines, tabs, etc replaced by single space
1925 $sql = preg_replace( '/\s+/', ' ', $sql );
1928 # except the ones surrounded by characters, e.g. l10n
1929 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1930 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1936 * Determines whether a field exists in a table
1938 * @param string $table Table name
1939 * @param string $field Filed to check on that table
1940 * @param string $fname Calling function name (optional)
1941 * @return bool Whether $table has filed $field
1943 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1944 $info = $this->fieldInfo( $table, $field );
1950 * Determines whether an index exists
1951 * Usually throws a DBQueryError on failure
1952 * If errors are explicitly ignored, returns NULL on failure
1954 * @param string $table
1955 * @param string $index
1956 * @param string $fname
1959 public function indexExists( $table, $index, $fname = __METHOD__
) {
1960 if ( !$this->tableExists( $table ) ) {
1964 $info = $this->indexInfo( $table, $index, $fname );
1965 if ( is_null( $info ) ) {
1968 return $info !== false;
1973 * Query whether a given table exists
1975 * @param string $table
1976 * @param string $fname
1979 public function tableExists( $table, $fname = __METHOD__
) {
1980 $table = $this->tableName( $table );
1981 $old = $this->ignoreErrors( true );
1982 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1983 $this->ignoreErrors( $old );
1989 * Determines if a given index is unique
1991 * @param string $table
1992 * @param string $index
1996 public function indexUnique( $table, $index ) {
1997 $indexInfo = $this->indexInfo( $table, $index );
1999 if ( !$indexInfo ) {
2003 return !$indexInfo[0]->Non_unique
;
2007 * Helper for DatabaseBase::insert().
2009 * @param array $options
2012 protected function makeInsertOptions( $options ) {
2013 return implode( ' ', $options );
2017 * INSERT wrapper, inserts an array into a table.
2021 * - A single associative array. The array keys are the field names, and
2022 * the values are the values to insert. The values are treated as data
2023 * and will be quoted appropriately. If NULL is inserted, this will be
2024 * converted to a database NULL.
2025 * - An array with numeric keys, holding a list of associative arrays.
2026 * This causes a multi-row INSERT on DBMSs that support it. The keys in
2027 * each subarray must be identical to each other, and in the same order.
2029 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
2032 * $options is an array of options, with boolean options encoded as values
2033 * with numeric keys, in the same style as $options in
2034 * DatabaseBase::select(). Supported options are:
2036 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
2037 * any rows which cause duplicate key errors are not inserted. It's
2038 * possible to determine how many rows were successfully inserted using
2039 * DatabaseBase::affectedRows().
2041 * @param string $table Table name. This will be passed through
2042 * DatabaseBase::tableName().
2043 * @param array $a Array of rows to insert
2044 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2045 * @param array $options Array of options
2049 public function insert( $table, $a, $fname = __METHOD__
, $options = array() ) {
2050 # No rows to insert, easy just return now
2051 if ( !count( $a ) ) {
2055 $table = $this->tableName( $table );
2057 if ( !is_array( $options ) ) {
2058 $options = array( $options );
2062 if ( isset( $options['fileHandle'] ) ) {
2063 $fh = $options['fileHandle'];
2065 $options = $this->makeInsertOptions( $options );
2067 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2069 $keys = array_keys( $a[0] );
2072 $keys = array_keys( $a );
2075 $sql = 'INSERT ' . $options .
2076 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2080 foreach ( $a as $row ) {
2086 $sql .= '(' . $this->makeList( $row ) . ')';
2089 $sql .= '(' . $this->makeList( $a ) . ')';
2092 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
2094 } elseif ( $fh !== null ) {
2098 return (bool)$this->query( $sql, $fname );
2102 * Make UPDATE options array for DatabaseBase::makeUpdateOptions
2104 * @param array $options
2107 protected function makeUpdateOptionsArray( $options ) {
2108 if ( !is_array( $options ) ) {
2109 $options = array( $options );
2114 if ( in_array( 'LOW_PRIORITY', $options ) ) {
2115 $opts[] = $this->lowPriorityOption();
2118 if ( in_array( 'IGNORE', $options ) ) {
2126 * Make UPDATE options for the DatabaseBase::update function
2128 * @param array $options The options passed to DatabaseBase::update
2131 protected function makeUpdateOptions( $options ) {
2132 $opts = $this->makeUpdateOptionsArray( $options );
2134 return implode( ' ', $opts );
2138 * UPDATE wrapper. Takes a condition array and a SET array.
2140 * @param string $table Name of the table to UPDATE. This will be passed through
2141 * DatabaseBase::tableName().
2142 * @param array $values An array of values to SET. For each array element,
2143 * the key gives the field name, and the value gives the data to set
2144 * that field to. The data will be quoted by DatabaseBase::addQuotes().
2145 * @param array $conds An array of conditions (WHERE). See
2146 * DatabaseBase::select() for the details of the format of condition
2147 * arrays. Use '*' to update all rows.
2148 * @param string $fname The function name of the caller (from __METHOD__),
2149 * for logging and profiling.
2150 * @param array $options An array of UPDATE options, can be:
2151 * - IGNORE: Ignore unique key conflicts
2152 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
2155 function update( $table, $values, $conds, $fname = __METHOD__
, $options = array() ) {
2156 $table = $this->tableName( $table );
2157 $opts = $this->makeUpdateOptions( $options );
2158 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
2160 if ( $conds !== array() && $conds !== '*' ) {
2161 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
2164 return $this->query( $sql, $fname );
2168 * Makes an encoded list of strings from an array
2170 * @param array $a Containing the data
2171 * @param int $mode Constant
2172 * - LIST_COMMA: Comma separated, no field names
2173 * - LIST_AND: ANDed WHERE clause (without the WHERE). See the
2174 * documentation for $conds in DatabaseBase::select().
2175 * - LIST_OR: ORed WHERE clause (without the WHERE)
2176 * - LIST_SET: Comma separated with field names, like a SET clause
2177 * - LIST_NAMES: Comma separated field names
2178 * @throws MWException|DBUnexpectedError
2181 public function makeList( $a, $mode = LIST_COMMA
) {
2182 if ( !is_array( $a ) ) {
2183 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
2189 foreach ( $a as $field => $value ) {
2191 if ( $mode == LIST_AND
) {
2193 } elseif ( $mode == LIST_OR
) {
2202 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
2203 $list .= "($value)";
2204 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
2206 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
2207 // Remove null from array to be handled separately if found
2208 $includeNull = false;
2209 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2210 $includeNull = true;
2211 unset( $value[$nullKey] );
2213 if ( count( $value ) == 0 && !$includeNull ) {
2214 throw new MWException( __METHOD__
. ": empty input for field $field" );
2215 } elseif ( count( $value ) == 0 ) {
2216 // only check if $field is null
2217 $list .= "$field IS NULL";
2219 // IN clause contains at least one valid element
2220 if ( $includeNull ) {
2221 // Group subconditions to ensure correct precedence
2224 if ( count( $value ) == 1 ) {
2225 // Special-case single values, as IN isn't terribly efficient
2226 // Don't necessarily assume the single key is 0; we don't
2227 // enforce linear numeric ordering on other arrays here.
2228 $value = array_values( $value );
2229 $list .= $field . " = " . $this->addQuotes( $value[0] );
2231 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2233 // if null present in array, append IS NULL
2234 if ( $includeNull ) {
2235 $list .= " OR $field IS NULL)";
2238 } elseif ( $value === null ) {
2239 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
2240 $list .= "$field IS ";
2241 } elseif ( $mode == LIST_SET
) {
2242 $list .= "$field = ";
2246 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
2247 $list .= "$field = ";
2249 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
2257 * Build a partial where clause from a 2-d array such as used for LinkBatch.
2258 * The keys on each level may be either integers or strings.
2260 * @param array $data Organized as 2-d
2261 * array(baseKeyVal => array(subKeyVal => [ignored], ...), ...)
2262 * @param string $baseKey Field name to match the base-level keys to (eg 'pl_namespace')
2263 * @param string $subKey Field name to match the sub-level keys to (eg 'pl_title')
2264 * @return string|bool SQL fragment, or false if no items in array
2266 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2269 foreach ( $data as $base => $sub ) {
2270 if ( count( $sub ) ) {
2271 $conds[] = $this->makeList(
2272 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
2278 return $this->makeList( $conds, LIST_OR
);
2280 // Nothing to search for...
2286 * Return aggregated value alias
2288 * @param array $valuedata
2289 * @param string $valuename
2293 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2298 * @param string $field
2301 public function bitNot( $field ) {
2306 * @param string $fieldLeft
2307 * @param string $fieldRight
2310 public function bitAnd( $fieldLeft, $fieldRight ) {
2311 return "($fieldLeft & $fieldRight)";
2315 * @param string $fieldLeft
2316 * @param string $fieldRight
2319 public function bitOr( $fieldLeft, $fieldRight ) {
2320 return "($fieldLeft | $fieldRight)";
2324 * Build a concatenation list to feed into a SQL query
2325 * @param array $stringList List of raw SQL expressions; caller is
2326 * responsible for any quoting
2329 public function buildConcat( $stringList ) {
2330 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2334 * Build a GROUP_CONCAT or equivalent statement for a query.
2336 * This is useful for combining a field for several rows into a single string.
2337 * NULL values will not appear in the output, duplicated values will appear,
2338 * and the resulting delimiter-separated values have no defined sort order.
2339 * Code using the results may need to use the PHP unique() or sort() methods.
2341 * @param string $delim Glue to bind the results together
2342 * @param string|array $table Table name
2343 * @param string $field Field name
2344 * @param string|array $conds Conditions
2345 * @param string|array $join_conds Join conditions
2346 * @return string SQL text
2349 public function buildGroupConcatField(
2350 $delim, $table, $field, $conds = '', $join_conds = array()
2352 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2354 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
2358 * Change the current database
2360 * @todo Explain what exactly will fail if this is not overridden.
2364 * @return bool Success or failure
2366 public function selectDB( $db ) {
2367 # Stub. Shouldn't cause serious problems if it's not overridden, but
2368 # if your database engine supports a concept similar to MySQL's
2369 # databases you may as well.
2370 $this->mDBname
= $db;
2376 * Get the current DB name
2379 public function getDBname() {
2380 return $this->mDBname
;
2384 * Get the server hostname or IP address
2387 public function getServer() {
2388 return $this->mServer
;
2392 * Format a table name ready for use in constructing an SQL query
2394 * This does two important things: it quotes the table names to clean them up,
2395 * and it adds a table prefix if only given a table name with no quotes.
2397 * All functions of this object which require a table name call this function
2398 * themselves. Pass the canonical name to such functions. This is only needed
2399 * when calling query() directly.
2401 * @param string $name Database table name
2402 * @param string $format One of:
2403 * quoted - Automatically pass the table name through addIdentifierQuotes()
2404 * so that it can be used in a query.
2405 * raw - Do not add identifier quotes to the table name
2406 * @return string Full database name
2408 public function tableName( $name, $format = 'quoted' ) {
2409 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables, $wgSharedSchema;
2410 # Skip the entire process when we have a string quoted on both ends.
2411 # Note that we check the end so that we will still quote any use of
2412 # use of `database`.table. But won't break things if someone wants
2413 # to query a database table with a dot in the name.
2414 if ( $this->isQuotedIdentifier( $name ) ) {
2418 # Lets test for any bits of text that should never show up in a table
2419 # name. Basically anything like JOIN or ON which are actually part of
2420 # SQL queries, but may end up inside of the table value to combine
2421 # sql. Such as how the API is doing.
2422 # Note that we use a whitespace test rather than a \b test to avoid
2423 # any remote case where a word like on may be inside of a table name
2424 # surrounded by symbols which may be considered word breaks.
2425 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2429 # Split database and table into proper variables.
2430 # We reverse the explode so that database.table and table both output
2431 # the correct table.
2432 $dbDetails = explode( '.', $name, 3 );
2433 if ( count( $dbDetails ) == 3 ) {
2434 list( $database, $schema, $table ) = $dbDetails;
2435 # We don't want any prefix added in this case
2437 } elseif ( count( $dbDetails ) == 2 ) {
2438 list( $database, $table ) = $dbDetails;
2439 # We don't want any prefix added in this case
2440 # In dbs that support it, $database may actually be the schema
2441 # but that doesn't affect any of the functionality here
2445 list( $table ) = $dbDetails;
2446 if ( $wgSharedDB !== null # We have a shared database
2447 && $this->mForeign
== false # We're not working on a foreign database
2448 && !$this->isQuotedIdentifier( $table ) # Prevent shared tables listing '`table`'
2449 && in_array( $table, $wgSharedTables ) # A shared table is selected
2451 $database = $wgSharedDB;
2452 $schema = $wgSharedSchema === null ?
$this->mSchema
: $wgSharedSchema;
2453 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
2456 $schema = $this->mSchema
; # Default schema
2457 $prefix = $this->mTablePrefix
; # Default prefix
2461 # Quote $table and apply the prefix if not quoted.
2462 # $tableName might be empty if this is called from Database::replaceVars()
2463 $tableName = "{$prefix}{$table}";
2464 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) && $tableName !== '' ) {
2465 $tableName = $this->addIdentifierQuotes( $tableName );
2468 # Quote $schema and merge it with the table name if needed
2469 if ( $schema !== null ) {
2470 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $schema ) ) {
2471 $schema = $this->addIdentifierQuotes( $schema );
2473 $tableName = $schema . '.' . $tableName;
2476 # Quote $database and merge it with the table name if needed
2477 if ( $database !== null ) {
2478 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
2479 $database = $this->addIdentifierQuotes( $database );
2481 $tableName = $database . '.' . $tableName;
2488 * Fetch a number of table names into an array
2489 * This is handy when you need to construct SQL for joins
2492 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
2493 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2494 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2498 public function tableNames() {
2499 $inArray = func_get_args();
2502 foreach ( $inArray as $name ) {
2503 $retVal[$name] = $this->tableName( $name );
2510 * Fetch a number of table names into an zero-indexed numerical array
2511 * This is handy when you need to construct SQL for joins
2514 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
2515 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2516 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2520 public function tableNamesN() {
2521 $inArray = func_get_args();
2524 foreach ( $inArray as $name ) {
2525 $retVal[] = $this->tableName( $name );
2532 * Get an aliased table name
2533 * e.g. tableName AS newTableName
2535 * @param string $name Table name, see tableName()
2536 * @param string|bool $alias Alias (optional)
2537 * @return string SQL name for aliased table. Will not alias a table to its own name
2539 public function tableNameWithAlias( $name, $alias = false ) {
2540 if ( !$alias ||
$alias == $name ) {
2541 return $this->tableName( $name );
2543 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2548 * Gets an array of aliased table names
2550 * @param array $tables Array( [alias] => table )
2551 * @return string[] See tableNameWithAlias()
2553 public function tableNamesWithAlias( $tables ) {
2555 foreach ( $tables as $alias => $table ) {
2556 if ( is_numeric( $alias ) ) {
2559 $retval[] = $this->tableNameWithAlias( $table, $alias );
2566 * Get an aliased field name
2567 * e.g. fieldName AS newFieldName
2569 * @param string $name Field name
2570 * @param string|bool $alias Alias (optional)
2571 * @return string SQL name for aliased field. Will not alias a field to its own name
2573 public function fieldNameWithAlias( $name, $alias = false ) {
2574 if ( !$alias ||
(string)$alias === (string)$name ) {
2577 return $name . ' AS ' . $alias; //PostgreSQL needs AS
2582 * Gets an array of aliased field names
2584 * @param array $fields Array( [alias] => field )
2585 * @return string[] See fieldNameWithAlias()
2587 public function fieldNamesWithAlias( $fields ) {
2589 foreach ( $fields as $alias => $field ) {
2590 if ( is_numeric( $alias ) ) {
2593 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2600 * Get the aliased table name clause for a FROM clause
2601 * which might have a JOIN and/or USE INDEX clause
2603 * @param array $tables ( [alias] => table )
2604 * @param array $use_index Same as for select()
2605 * @param array $join_conds Same as for select()
2608 protected function tableNamesWithUseIndexOrJOIN(
2609 $tables, $use_index = array(), $join_conds = array()
2613 $use_index = (array)$use_index;
2614 $join_conds = (array)$join_conds;
2616 foreach ( $tables as $alias => $table ) {
2617 if ( !is_string( $alias ) ) {
2618 // No alias? Set it equal to the table name
2621 // Is there a JOIN clause for this table?
2622 if ( isset( $join_conds[$alias] ) ) {
2623 list( $joinType, $conds ) = $join_conds[$alias];
2624 $tableClause = $joinType;
2625 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2626 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2627 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2629 $tableClause .= ' ' . $use;
2632 $on = $this->makeList( (array)$conds, LIST_AND
);
2634 $tableClause .= ' ON (' . $on . ')';
2637 $retJOIN[] = $tableClause;
2638 } elseif ( isset( $use_index[$alias] ) ) {
2639 // Is there an INDEX clause for this table?
2640 $tableClause = $this->tableNameWithAlias( $table, $alias );
2641 $tableClause .= ' ' . $this->useIndexClause(
2642 implode( ',', (array)$use_index[$alias] )
2645 $ret[] = $tableClause;
2647 $tableClause = $this->tableNameWithAlias( $table, $alias );
2649 $ret[] = $tableClause;
2653 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2654 $implicitJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2655 $explicitJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2657 // Compile our final table clause
2658 return implode( ' ', array( $implicitJoins, $explicitJoins ) );
2662 * Get the name of an index in a given table.
2664 * @protected Don't use outside of DatabaseBase and childs
2665 * @param string $index
2668 public function indexName( $index ) {
2669 // @FIXME: Make this protected once we move away from PHP 5.3
2670 // Needs to be public because of usage in closure (in DatabaseBase::replaceVars)
2672 // Backwards-compatibility hack
2674 'ar_usertext_timestamp' => 'usertext_timestamp',
2675 'un_user_id' => 'user_id',
2676 'un_user_ip' => 'user_ip',
2679 if ( isset( $renamed[$index] ) ) {
2680 return $renamed[$index];
2687 * Adds quotes and backslashes.
2692 public function addQuotes( $s ) {
2693 if ( $s === null ) {
2696 # This will also quote numeric values. This should be harmless,
2697 # and protects against weird problems that occur when they really
2698 # _are_ strings such as article titles and string->number->string
2699 # conversion is not 1:1.
2700 return "'" . $this->strencode( $s ) . "'";
2705 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2706 * MySQL uses `backticks` while basically everything else uses double quotes.
2707 * Since MySQL is the odd one out here the double quotes are our generic
2708 * and we implement backticks in DatabaseMysql.
2713 public function addIdentifierQuotes( $s ) {
2714 return '"' . str_replace( '"', '""', $s ) . '"';
2718 * Returns if the given identifier looks quoted or not according to
2719 * the database convention for quoting identifiers .
2721 * @param string $name
2724 public function isQuotedIdentifier( $name ) {
2725 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2732 protected function escapeLikeInternal( $s ) {
2733 return addcslashes( $s, '\%_' );
2737 * LIKE statement wrapper, receives a variable-length argument list with
2738 * parts of pattern to match containing either string literals that will be
2739 * escaped or tokens returned by anyChar() or anyString(). Alternatively,
2740 * the function could be provided with an array of aforementioned
2743 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns
2744 * a LIKE clause that searches for subpages of 'My page title'.
2746 * $pattern = array( 'My_page_title/', $dbr->anyString() );
2747 * $query .= $dbr->buildLike( $pattern );
2750 * @return string Fully built LIKE statement
2752 public function buildLike() {
2753 $params = func_get_args();
2755 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2756 $params = $params[0];
2761 foreach ( $params as $value ) {
2762 if ( $value instanceof LikeMatch
) {
2763 $s .= $value->toString();
2765 $s .= $this->escapeLikeInternal( $value );
2769 return " LIKE {$this->addQuotes( $s )} ";
2773 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2777 public function anyChar() {
2778 return new LikeMatch( '_' );
2782 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2786 public function anyString() {
2787 return new LikeMatch( '%' );
2791 * Returns an appropriately quoted sequence value for inserting a new row.
2792 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2793 * subclass will return an integer, and save the value for insertId()
2795 * Any implementation of this function should *not* involve reusing
2796 * sequence numbers created for rolled-back transactions.
2797 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2798 * @param string $seqName
2801 public function nextSequenceValue( $seqName ) {
2806 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2807 * is only needed because a) MySQL must be as efficient as possible due to
2808 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2809 * which index to pick. Anyway, other databases might have different
2810 * indexes on a given table. So don't bother overriding this unless you're
2812 * @param string $index
2815 public function useIndexClause( $index ) {
2820 * REPLACE query wrapper.
2822 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2823 * except that when there is a duplicate key error, the old row is deleted
2824 * and the new row is inserted in its place.
2826 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2827 * perform the delete, we need to know what the unique indexes are so that
2828 * we know how to find the conflicting rows.
2830 * It may be more efficient to leave off unique indexes which are unlikely
2831 * to collide. However if you do this, you run the risk of encountering
2832 * errors which wouldn't have occurred in MySQL.
2834 * @param string $table The table to replace the row(s) in.
2835 * @param array $uniqueIndexes Is an array of indexes. Each element may be either
2836 * a field name or an array of field names
2837 * @param array $rows Can be either a single row to insert, or multiple rows,
2838 * in the same format as for DatabaseBase::insert()
2839 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2841 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2842 $quotedTable = $this->tableName( $table );
2844 if ( count( $rows ) == 0 ) {
2849 if ( !is_array( reset( $rows ) ) ) {
2850 $rows = array( $rows );
2853 foreach ( $rows as $row ) {
2854 # Delete rows which collide
2855 if ( $uniqueIndexes ) {
2856 $sql = "DELETE FROM $quotedTable WHERE ";
2858 foreach ( $uniqueIndexes as $index ) {
2865 if ( is_array( $index ) ) {
2867 foreach ( $index as $col ) {
2873 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2876 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2880 $this->query( $sql, $fname );
2883 # Now insert the row
2884 $this->insert( $table, $row, $fname );
2889 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2892 * @param string $table Table name
2893 * @param array|string $rows Row(s) to insert
2894 * @param string $fname Caller function name
2896 * @return ResultWrapper
2898 protected function nativeReplace( $table, $rows, $fname ) {
2899 $table = $this->tableName( $table );
2902 if ( !is_array( reset( $rows ) ) ) {
2903 $rows = array( $rows );
2906 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2909 foreach ( $rows as $row ) {
2916 $sql .= '(' . $this->makeList( $row ) . ')';
2919 return $this->query( $sql, $fname );
2923 * INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table.
2925 * This updates any conflicting rows (according to the unique indexes) using
2926 * the provided SET clause and inserts any remaining (non-conflicted) rows.
2928 * $rows may be either:
2929 * - A single associative array. The array keys are the field names, and
2930 * the values are the values to insert. The values are treated as data
2931 * and will be quoted appropriately. If NULL is inserted, this will be
2932 * converted to a database NULL.
2933 * - An array with numeric keys, holding a list of associative arrays.
2934 * This causes a multi-row INSERT on DBMSs that support it. The keys in
2935 * each subarray must be identical to each other, and in the same order.
2937 * It may be more efficient to leave off unique indexes which are unlikely
2938 * to collide. However if you do this, you run the risk of encountering
2939 * errors which wouldn't have occurred in MySQL.
2941 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
2946 * @param string $table Table name. This will be passed through DatabaseBase::tableName().
2947 * @param array $rows A single row or list of rows to insert
2948 * @param array $uniqueIndexes List of single field names or field name tuples
2949 * @param array $set An array of values to SET. For each array element, the
2950 * key gives the field name, and the value gives the data to set that
2951 * field to. The data will be quoted by DatabaseBase::addQuotes().
2952 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
2956 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2959 if ( !count( $rows ) ) {
2960 return true; // nothing to do
2963 if ( !is_array( reset( $rows ) ) ) {
2964 $rows = array( $rows );
2967 if ( count( $uniqueIndexes ) ) {
2968 $clauses = array(); // list WHERE clauses that each identify a single row
2969 foreach ( $rows as $row ) {
2970 foreach ( $uniqueIndexes as $index ) {
2971 $index = is_array( $index ) ?
$index : array( $index ); // columns
2972 $rowKey = array(); // unique key to this row
2973 foreach ( $index as $column ) {
2974 $rowKey[$column] = $row[$column];
2976 $clauses[] = $this->makeList( $rowKey, LIST_AND
);
2979 $where = array( $this->makeList( $clauses, LIST_OR
) );
2984 $useTrx = !$this->mTrxLevel
;
2986 $this->begin( $fname );
2989 # Update any existing conflicting row(s)
2990 if ( $where !== false ) {
2991 $ok = $this->update( $table, $set, $where, $fname );
2995 # Now insert any non-conflicting row(s)
2996 $ok = $this->insert( $table, $rows, $fname, array( 'IGNORE' ) ) && $ok;
2997 } catch ( Exception
$e ) {
2999 $this->rollback( $fname );
3004 $this->commit( $fname );
3011 * DELETE where the condition is a join.
3013 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
3014 * we use sub-selects
3016 * For safety, an empty $conds will not delete everything. If you want to
3017 * delete all rows where the join condition matches, set $conds='*'.
3019 * DO NOT put the join condition in $conds.
3021 * @param string $delTable The table to delete from.
3022 * @param string $joinTable The other table.
3023 * @param string $delVar The variable to join on, in the first table.
3024 * @param string $joinVar The variable to join on, in the second table.
3025 * @param array $conds Condition array of field names mapped to variables,
3026 * ANDed together in the WHERE clause
3027 * @param string $fname Calling function name (use __METHOD__) for logs/profiling
3028 * @throws DBUnexpectedError
3030 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
3034 throw new DBUnexpectedError( $this,
3035 'DatabaseBase::deleteJoin() called with empty $conds' );
3038 $delTable = $this->tableName( $delTable );
3039 $joinTable = $this->tableName( $joinTable );
3040 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
3041 if ( $conds != '*' ) {
3042 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
3046 $this->query( $sql, $fname );
3050 * Returns the size of a text field, or -1 for "unlimited"
3052 * @param string $table
3053 * @param string $field
3056 public function textFieldSize( $table, $field ) {
3057 $table = $this->tableName( $table );
3058 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
3059 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
3060 $row = $this->fetchObject( $res );
3064 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
3074 * A string to insert into queries to show that they're low-priority, like
3075 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
3076 * string and nothing bad should happen.
3078 * @return string Returns the text of the low priority option if it is
3079 * supported, or a blank string otherwise
3081 public function lowPriorityOption() {
3086 * DELETE query wrapper.
3088 * @param array $table Table name
3089 * @param string|array $conds Array of conditions. See $conds in DatabaseBase::select()
3090 * for the format. Use $conds == "*" to delete all rows
3091 * @param string $fname Name of the calling function
3092 * @throws DBUnexpectedError
3093 * @return bool|ResultWrapper
3095 public function delete( $table, $conds, $fname = __METHOD__
) {
3097 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
3100 $table = $this->tableName( $table );
3101 $sql = "DELETE FROM $table";
3103 if ( $conds != '*' ) {
3104 if ( is_array( $conds ) ) {
3105 $conds = $this->makeList( $conds, LIST_AND
);
3107 $sql .= ' WHERE ' . $conds;
3110 return $this->query( $sql, $fname );
3114 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
3115 * into another table.
3117 * @param string $destTable The table name to insert into
3118 * @param string|array $srcTable May be either a table name, or an array of table names
3119 * to include in a join.
3121 * @param array $varMap Must be an associative array of the form
3122 * array( 'dest1' => 'source1', ...). Source items may be literals
3123 * rather than field names, but strings should be quoted with
3124 * DatabaseBase::addQuotes()
3126 * @param array $conds Condition array. See $conds in DatabaseBase::select() for
3127 * the details of the format of condition arrays. May be "*" to copy the
3130 * @param string $fname The function name of the caller, from __METHOD__
3132 * @param array $insertOptions Options for the INSERT part of the query, see
3133 * DatabaseBase::insert() for details.
3134 * @param array $selectOptions Options for the SELECT part of the query, see
3135 * DatabaseBase::select() for details.
3137 * @return ResultWrapper
3139 public function insertSelect( $destTable, $srcTable, $varMap, $conds,
3140 $fname = __METHOD__
,
3141 $insertOptions = array(), $selectOptions = array()
3143 $destTable = $this->tableName( $destTable );
3145 if ( !is_array( $insertOptions ) ) {
3146 $insertOptions = array( $insertOptions );
3149 $insertOptions = $this->makeInsertOptions( $insertOptions );
3151 if ( !is_array( $selectOptions ) ) {
3152 $selectOptions = array( $selectOptions );
3155 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
3157 if ( is_array( $srcTable ) ) {
3158 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
3160 $srcTable = $this->tableName( $srcTable );
3163 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
3164 " SELECT $startOpts " . implode( ',', $varMap ) .
3165 " FROM $srcTable $useIndex ";
3167 if ( $conds != '*' ) {
3168 if ( is_array( $conds ) ) {
3169 $conds = $this->makeList( $conds, LIST_AND
);
3171 $sql .= " WHERE $conds";
3174 $sql .= " $tailOpts";
3176 return $this->query( $sql, $fname );
3180 * Construct a LIMIT query with optional offset. This is used for query
3181 * pages. The SQL should be adjusted so that only the first $limit rows
3182 * are returned. If $offset is provided as well, then the first $offset
3183 * rows should be discarded, and the next $limit rows should be returned.
3184 * If the result of the query is not ordered, then the rows to be returned
3185 * are theoretically arbitrary.
3187 * $sql is expected to be a SELECT, if that makes a difference.
3189 * The version provided by default works in MySQL and SQLite. It will very
3190 * likely need to be overridden for most other DBMSes.
3192 * @param string $sql SQL query we will append the limit too
3193 * @param int $limit The SQL limit
3194 * @param int|bool $offset The SQL offset (default false)
3195 * @throws DBUnexpectedError
3198 public function limitResult( $sql, $limit, $offset = false ) {
3199 if ( !is_numeric( $limit ) ) {
3200 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
3203 return "$sql LIMIT "
3204 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3209 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
3210 * within the UNION construct.
3213 public function unionSupportsOrderAndLimit() {
3214 return true; // True for almost every DB supported
3218 * Construct a UNION query
3219 * This is used for providing overload point for other DB abstractions
3220 * not compatible with the MySQL syntax.
3221 * @param array $sqls SQL statements to combine
3222 * @param bool $all Use UNION ALL
3223 * @return string SQL fragment
3225 public function unionQueries( $sqls, $all ) {
3226 $glue = $all ?
') UNION ALL (' : ') UNION (';
3228 return '(' . implode( $glue, $sqls ) . ')';
3232 * Returns an SQL expression for a simple conditional. This doesn't need
3233 * to be overridden unless CASE isn't supported in your DBMS.
3235 * @param string|array $cond SQL expression which will result in a boolean value
3236 * @param string $trueVal SQL expression to return if true
3237 * @param string $falseVal SQL expression to return if false
3238 * @return string SQL fragment
3240 public function conditional( $cond, $trueVal, $falseVal ) {
3241 if ( is_array( $cond ) ) {
3242 $cond = $this->makeList( $cond, LIST_AND
);
3245 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3249 * Returns a comand for str_replace function in SQL query.
3250 * Uses REPLACE() in MySQL
3252 * @param string $orig Column to modify
3253 * @param string $old Column to seek
3254 * @param string $new Column to replace with
3258 public function strreplace( $orig, $old, $new ) {
3259 return "REPLACE({$orig}, {$old}, {$new})";
3263 * Determines how long the server has been up
3268 public function getServerUptime() {
3273 * Determines if the last failure was due to a deadlock
3278 public function wasDeadlock() {
3283 * Determines if the last failure was due to a lock timeout
3288 public function wasLockTimeout() {
3293 * Determines if the last query error was something that should be dealt
3294 * with by pinging the connection and reissuing the query.
3299 public function wasErrorReissuable() {
3304 * Determines if the last failure was due to the database being read-only.
3309 public function wasReadOnlyError() {
3314 * Perform a deadlock-prone transaction.
3316 * This function invokes a callback function to perform a set of write
3317 * queries. If a deadlock occurs during the processing, the transaction
3318 * will be rolled back and the callback function will be called again.
3321 * $dbw->deadlockLoop( callback, ... );
3323 * Extra arguments are passed through to the specified callback function.
3325 * Returns whatever the callback function returned on its successful,
3326 * iteration, or false on error, for example if the retry limit was
3331 public function deadlockLoop() {
3332 $this->begin( __METHOD__
);
3333 $args = func_get_args();
3334 $function = array_shift( $args );
3335 $oldIgnore = $this->ignoreErrors( true );
3336 $tries = self
::DEADLOCK_TRIES
;
3338 if ( is_array( $function ) ) {
3339 $fname = $function[0];
3345 $retVal = call_user_func_array( $function, $args );
3346 $error = $this->lastError();
3347 $errno = $this->lastErrno();
3348 $sql = $this->lastQuery();
3351 if ( $this->wasDeadlock() ) {
3353 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3355 $this->reportQueryError( $error, $errno, $sql, $fname );
3358 } while ( $this->wasDeadlock() && --$tries > 0 );
3360 $this->ignoreErrors( $oldIgnore );
3362 if ( $tries <= 0 ) {
3363 $this->rollback( __METHOD__
);
3364 $this->reportQueryError( $error, $errno, $sql, $fname );
3368 $this->commit( __METHOD__
);
3375 * Wait for the slave to catch up to a given master position.
3377 * @param DBMasterPos $pos
3378 * @param int $timeout The maximum number of seconds to wait for
3380 * @return int Zero if the slave was past that position already,
3381 * greater than zero if we waited for some period of time, less than
3382 * zero if we timed out.
3384 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3385 # Real waits are implemented in the subclass.
3390 * Get the replication position of this slave
3392 * @return DBMasterPos|bool False if this is not a slave.
3394 public function getSlavePos() {
3400 * Get the position of this master
3402 * @return DBMasterPos|bool False if this is not a master
3404 public function getMasterPos() {
3410 * Run an anonymous function as soon as there is no transaction pending.
3411 * If there is a transaction and it is rolled back, then the callback is cancelled.
3412 * Queries in the function will run in AUTO-COMMIT mode unless there are begin() calls.
3413 * Callbacks must commit any transactions that they begin.
3415 * This is useful for updates to different systems or when separate transactions are needed.
3416 * For example, one might want to enqueue jobs into a system outside the database, but only
3417 * after the database is updated so that the jobs will see the data when they actually run.
3418 * It can also be used for updates that easily cause deadlocks if locks are held too long.
3420 * @param callable $callback
3423 final public function onTransactionIdle( $callback ) {
3424 $this->mTrxIdleCallbacks
[] = array( $callback, wfGetCaller() );
3425 if ( !$this->mTrxLevel
) {
3426 $this->runOnTransactionIdleCallbacks();
3431 * Run an anonymous function before the current transaction commits or now if there is none.
3432 * If there is a transaction and it is rolled back, then the callback is cancelled.
3433 * Callbacks must not start nor commit any transactions.
3435 * This is useful for updates that easily cause deadlocks if locks are held too long
3436 * but where atomicity is strongly desired for these updates and some related updates.
3438 * @param callable $callback
3441 final public function onTransactionPreCommitOrIdle( $callback ) {
3442 if ( $this->mTrxLevel
) {
3443 $this->mTrxPreCommitCallbacks
[] = array( $callback, wfGetCaller() );
3445 $this->onTransactionIdle( $callback ); // this will trigger immediately
3450 * Actually any "on transaction idle" callbacks.
3454 protected function runOnTransactionIdleCallbacks() {
3455 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
3457 $e = $ePrior = null; // last exception
3458 do { // callbacks may add callbacks :)
3459 $callbacks = $this->mTrxIdleCallbacks
;
3460 $this->mTrxIdleCallbacks
= array(); // recursion guard
3461 foreach ( $callbacks as $callback ) {
3463 list( $phpCallback ) = $callback;
3464 $this->clearFlag( DBO_TRX
); // make each query its own transaction
3465 call_user_func( $phpCallback );
3466 $this->setFlag( $autoTrx ? DBO_TRX
: 0 ); // restore automatic begin()
3467 } catch ( Exception
$e ) {
3469 MWExceptionHandler
::logException( $ePrior );
3474 } while ( count( $this->mTrxIdleCallbacks
) );
3476 if ( $e instanceof Exception
) {
3477 throw $e; // re-throw any last exception
3482 * Actually any "on transaction pre-commit" callbacks.
3486 protected function runOnTransactionPreCommitCallbacks() {
3487 $e = $ePrior = null; // last exception
3488 do { // callbacks may add callbacks :)
3489 $callbacks = $this->mTrxPreCommitCallbacks
;
3490 $this->mTrxPreCommitCallbacks
= array(); // recursion guard
3491 foreach ( $callbacks as $callback ) {
3493 list( $phpCallback ) = $callback;
3494 call_user_func( $phpCallback );
3495 } catch ( Exception
$e ) {
3497 MWExceptionHandler
::logException( $ePrior );
3502 } while ( count( $this->mTrxPreCommitCallbacks
) );
3504 if ( $e instanceof Exception
) {
3505 throw $e; // re-throw any last exception
3510 * Begin an atomic section of statements
3512 * If a transaction has been started already, just keep track of the given
3513 * section name to make sure the transaction is not committed pre-maturely.
3514 * This function can be used in layers (with sub-sections), so use a stack
3515 * to keep track of the different atomic sections. If there is no transaction,
3516 * start one implicitly.
3518 * The goal of this function is to create an atomic section of SQL queries
3519 * without having to start a new transaction if it already exists.
3521 * Atomic sections are more strict than transactions. With transactions,
3522 * attempting to begin a new transaction when one is already running results
3523 * in MediaWiki issuing a brief warning and doing an implicit commit. All
3524 * atomic levels *must* be explicitly closed using DatabaseBase::endAtomic(),
3525 * and any database transactions cannot be began or committed until all atomic
3526 * levels are closed. There is no such thing as implicitly opening or closing
3527 * an atomic section.
3530 * @param string $fname
3533 final public function startAtomic( $fname = __METHOD__
) {
3534 if ( !$this->mTrxLevel
) {
3535 $this->begin( $fname );
3536 $this->mTrxAutomatic
= true;
3537 $this->mTrxAutomaticAtomic
= true;
3540 $this->mTrxAtomicLevels
->push( $fname );
3544 * Ends an atomic section of SQL statements
3546 * Ends the next section of atomic SQL statements and commits the transaction
3550 * @see DatabaseBase::startAtomic
3551 * @param string $fname
3554 final public function endAtomic( $fname = __METHOD__
) {
3555 if ( !$this->mTrxLevel
) {
3556 throw new DBUnexpectedError( $this, 'No atomic transaction is open.' );
3558 if ( $this->mTrxAtomicLevels
->isEmpty() ||
3559 $this->mTrxAtomicLevels
->pop() !== $fname
3561 throw new DBUnexpectedError( $this, 'Invalid atomic section ended.' );
3564 if ( $this->mTrxAtomicLevels
->isEmpty() && $this->mTrxAutomaticAtomic
) {
3565 $this->commit( $fname, 'flush' );
3570 * Begin a transaction. If a transaction is already in progress,
3571 * that transaction will be committed before the new transaction is started.
3573 * Note that when the DBO_TRX flag is set (which is usually the case for web
3574 * requests, but not for maintenance scripts), any previous database query
3575 * will have started a transaction automatically.
3577 * Nesting of transactions is not supported. Attempts to nest transactions
3578 * will cause a warning, unless the current transaction was started
3579 * automatically because of the DBO_TRX flag.
3581 * @param string $fname
3584 final public function begin( $fname = __METHOD__
) {
3585 global $wgDebugDBTransactions;
3587 if ( $this->mTrxLevel
) { // implicit commit
3588 if ( !$this->mTrxAtomicLevels
->isEmpty() ) {
3589 // If the current transaction was an automatic atomic one, then we definitely have
3590 // a problem. Same if there is any unclosed atomic level.
3591 throw new DBUnexpectedError( $this,
3592 "Attempted to start explicit transaction when atomic levels are still open."
3594 } elseif ( !$this->mTrxAutomatic
) {
3595 // We want to warn about inadvertently nested begin/commit pairs, but not about
3596 // auto-committing implicit transactions that were started by query() via DBO_TRX
3597 $msg = "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
3598 " performing implicit commit!";
3601 $this->getLogContext( array(
3602 'method' => __METHOD__
,
3607 // if the transaction was automatic and has done write operations,
3608 // log it if $wgDebugDBTransactions is enabled.
3609 if ( $this->mTrxDoneWrites
&& $wgDebugDBTransactions ) {
3610 wfDebug( "$fname: Automatic transaction with writes in progress" .
3611 " (from {$this->mTrxFname}), performing implicit commit!\n"
3616 $this->runOnTransactionPreCommitCallbacks();
3617 $this->doCommit( $fname );
3618 if ( $this->mTrxDoneWrites
) {
3619 Profiler
::instance()->getTransactionProfiler()->transactionWritingOut(
3620 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
3622 $this->runOnTransactionIdleCallbacks();
3625 # Avoid fatals if close() was called
3626 if ( !$this->isOpen() ) {
3627 throw new DBUnexpectedError( $this, "DB connection was already closed." );
3630 $this->doBegin( $fname );
3631 $this->mTrxTimestamp
= microtime( true );
3632 $this->mTrxFname
= $fname;
3633 $this->mTrxDoneWrites
= false;
3634 $this->mTrxAutomatic
= false;
3635 $this->mTrxAutomaticAtomic
= false;
3636 $this->mTrxAtomicLevels
= new SplStack
;
3637 $this->mTrxIdleCallbacks
= array();
3638 $this->mTrxPreCommitCallbacks
= array();
3639 $this->mTrxShortId
= wfRandomString( 12 );
3643 * Issues the BEGIN command to the database server.
3645 * @see DatabaseBase::begin()
3646 * @param string $fname
3648 protected function doBegin( $fname ) {
3649 $this->query( 'BEGIN', $fname );
3650 $this->mTrxLevel
= 1;
3654 * Commits a transaction previously started using begin().
3655 * If no transaction is in progress, a warning is issued.
3657 * Nesting of transactions is not supported.
3659 * @param string $fname
3660 * @param string $flush Flush flag, set to 'flush' to disable warnings about
3661 * explicitly committing implicit transactions, or calling commit when no
3662 * transaction is in progress. This will silently break any ongoing
3663 * explicit transaction. Only set the flush flag if you are sure that it
3664 * is safe to ignore these warnings in your context.
3665 * @throws DBUnexpectedError
3667 final public function commit( $fname = __METHOD__
, $flush = '' ) {
3668 if ( !$this->mTrxAtomicLevels
->isEmpty() ) {
3669 // There are still atomic sections open. This cannot be ignored
3670 throw new DBUnexpectedError(
3672 "Attempted to commit transaction while atomic sections are still open"
3676 if ( $flush === 'flush' ) {
3677 if ( !$this->mTrxLevel
) {
3678 return; // nothing to do
3679 } elseif ( !$this->mTrxAutomatic
) {
3680 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3683 if ( !$this->mTrxLevel
) {
3684 wfWarn( "$fname: No transaction to commit, something got out of sync!" );
3685 return; // nothing to do
3686 } elseif ( $this->mTrxAutomatic
) {
3687 wfWarn( "$fname: Explicit commit of implicit transaction. Something may be out of sync!" );
3691 # Avoid fatals if close() was called
3692 if ( !$this->isOpen() ) {
3693 throw new DBUnexpectedError( $this, "DB connection was already closed." );
3696 $this->runOnTransactionPreCommitCallbacks();
3697 $this->doCommit( $fname );
3698 if ( $this->mTrxDoneWrites
) {
3699 Profiler
::instance()->getTransactionProfiler()->transactionWritingOut(
3700 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
3702 $this->runOnTransactionIdleCallbacks();
3706 * Issues the COMMIT command to the database server.
3708 * @see DatabaseBase::commit()
3709 * @param string $fname
3711 protected function doCommit( $fname ) {
3712 if ( $this->mTrxLevel
) {
3713 $this->query( 'COMMIT', $fname );
3714 $this->mTrxLevel
= 0;
3719 * Rollback a transaction previously started using begin().
3720 * If no transaction is in progress, a warning is issued.
3722 * No-op on non-transactional databases.
3724 * @param string $fname
3725 * @param string $flush Flush flag, set to 'flush' to disable warnings about
3726 * calling rollback when no transaction is in progress. This will silently
3727 * break any ongoing explicit transaction. Only set the flush flag if you
3728 * are sure that it is safe to ignore these warnings in your context.
3729 * @throws DBUnexpectedError
3730 * @since 1.23 Added $flush parameter
3732 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3733 if ( $flush !== 'flush' ) {
3734 if ( !$this->mTrxLevel
) {
3735 wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
3736 return; // nothing to do
3737 } elseif ( $this->mTrxAutomatic
) {
3738 wfWarn( "$fname: Explicit rollback of implicit transaction. Something may be out of sync!" );
3741 if ( !$this->mTrxLevel
) {
3742 return; // nothing to do
3743 } elseif ( !$this->mTrxAutomatic
) {
3744 wfWarn( "$fname: Flushing an explicit transaction, getting out of sync!" );
3748 # Avoid fatals if close() was called
3749 if ( !$this->isOpen() ) {
3750 throw new DBUnexpectedError( $this, "DB connection was already closed." );
3753 $this->doRollback( $fname );
3754 $this->mTrxIdleCallbacks
= array(); // cancel
3755 $this->mTrxPreCommitCallbacks
= array(); // cancel
3756 $this->mTrxAtomicLevels
= new SplStack
;
3757 if ( $this->mTrxDoneWrites
) {
3758 Profiler
::instance()->getTransactionProfiler()->transactionWritingOut(
3759 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
3764 * Issues the ROLLBACK command to the database server.
3766 * @see DatabaseBase::rollback()
3767 * @param string $fname
3769 protected function doRollback( $fname ) {
3770 if ( $this->mTrxLevel
) {
3771 $this->query( 'ROLLBACK', $fname, true );
3772 $this->mTrxLevel
= 0;
3777 * Creates a new table with structure copied from existing table
3778 * Note that unlike most database abstraction functions, this function does not
3779 * automatically append database prefix, because it works at a lower
3780 * abstraction level.
3781 * The table names passed to this function shall not be quoted (this
3782 * function calls addIdentifierQuotes when needed).
3784 * @param string $oldName Name of table whose structure should be copied
3785 * @param string $newName Name of table to be created
3786 * @param bool $temporary Whether the new table should be temporary
3787 * @param string $fname Calling function name
3788 * @throws MWException
3789 * @return bool True if operation was successful
3791 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3794 throw new MWException(
3795 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3799 * List all tables on the database
3801 * @param string $prefix Only show tables with this prefix, e.g. mw_
3802 * @param string $fname Calling function name
3803 * @throws MWException
3805 function listTables( $prefix = null, $fname = __METHOD__
) {
3806 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3810 * Reset the views process cache set by listViews()
3813 final public function clearViewsCache() {
3814 $this->allViews
= null;
3818 * Lists all the VIEWs in the database
3820 * For caching purposes the list of all views should be stored in
3821 * $this->allViews. The process cache can be cleared with clearViewsCache()
3823 * @param string $prefix Only show VIEWs with this prefix, eg. unit_test_
3824 * @param string $fname Name of calling function
3825 * @throws MWException
3828 public function listViews( $prefix = null, $fname = __METHOD__
) {
3829 throw new MWException( 'DatabaseBase::listViews is not implemented in descendant class' );
3833 * Differentiates between a TABLE and a VIEW
3835 * @param string $name Name of the database-structure to test.
3836 * @throws MWException
3839 public function isView( $name ) {
3840 throw new MWException( 'DatabaseBase::isView is not implemented in descendant class' );
3844 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3845 * to the format used for inserting into timestamp fields in this DBMS.
3847 * The result is unquoted, and needs to be passed through addQuotes()
3848 * before it can be included in raw SQL.
3850 * @param string|int $ts
3854 public function timestamp( $ts = 0 ) {
3855 return wfTimestamp( TS_MW
, $ts );
3859 * Convert a timestamp in one of the formats accepted by wfTimestamp()
3860 * to the format used for inserting into timestamp fields in this DBMS. If
3861 * NULL is input, it is passed through, allowing NULL values to be inserted
3862 * into timestamp fields.
3864 * The result is unquoted, and needs to be passed through addQuotes()
3865 * before it can be included in raw SQL.
3867 * @param string|int $ts
3871 public function timestampOrNull( $ts = null ) {
3872 if ( is_null( $ts ) ) {
3875 return $this->timestamp( $ts );
3880 * Take the result from a query, and wrap it in a ResultWrapper if
3881 * necessary. Boolean values are passed through as is, to indicate success
3882 * of write queries or failure.
3884 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3885 * resource, and it was necessary to call this function to convert it to
3886 * a wrapper. Nowadays, raw database objects are never exposed to external
3887 * callers, so this is unnecessary in external code. For compatibility with
3888 * old code, ResultWrapper objects are passed through unaltered.
3890 * @param bool|ResultWrapper|resource $result
3891 * @return bool|ResultWrapper
3893 public function resultObject( $result ) {
3894 if ( empty( $result ) ) {
3896 } elseif ( $result instanceof ResultWrapper
) {
3898 } elseif ( $result === true ) {
3899 // Successful write query
3902 return new ResultWrapper( $this, $result );
3907 * Ping the server and try to reconnect if it there is no connection
3909 * @return bool Success or failure
3911 public function ping() {
3912 # Stub. Not essential to override.
3917 * Get slave lag. Currently supported only by MySQL.
3919 * Note that this function will generate a fatal error on many
3920 * installations. Most callers should use LoadBalancer::safeGetLag()
3923 * @return int Database replication lag in seconds
3925 public function getLag() {
3930 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3934 function maxListLen() {
3939 * Some DBMSs have a special format for inserting into blob fields, they
3940 * don't allow simple quoted strings to be inserted. To insert into such
3941 * a field, pass the data through this function before passing it to
3942 * DatabaseBase::insert().
3947 public function encodeBlob( $b ) {
3952 * Some DBMSs return a special placeholder object representing blob fields
3953 * in result objects. Pass the object through this function to return the
3959 public function decodeBlob( $b ) {
3964 * Override database's default behavior. $options include:
3965 * 'connTimeout' : Set the connection timeout value in seconds.
3966 * May be useful for very long batch queries such as
3967 * full-wiki dumps, where a single query reads out over
3970 * @param array $options
3973 public function setSessionOptions( array $options ) {
3977 * Read and execute SQL commands from a file.
3979 * Returns true on success, error string or exception on failure (depending
3980 * on object's error ignore settings).
3982 * @param string $filename File name to open
3983 * @param bool|callable $lineCallback Optional function called before reading each line
3984 * @param bool|callable $resultCallback Optional function called for each MySQL result
3985 * @param bool|string $fname Calling function name or false if name should be
3986 * generated dynamically using $filename
3987 * @param bool|callable $inputCallback Optional function called for each
3988 * complete line sent
3989 * @throws Exception|MWException
3990 * @return bool|string
3992 public function sourceFile(
3993 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3995 wfSuppressWarnings();
3996 $fp = fopen( $filename, 'r' );
3997 wfRestoreWarnings();
3999 if ( false === $fp ) {
4000 throw new MWException( "Could not open \"{$filename}\".\n" );
4004 $fname = __METHOD__
. "( $filename )";
4008 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4009 } catch ( Exception
$e ) {
4020 * Get the full path of a patch file. Originally based on archive()
4021 * from updaters.inc. Keep in mind this always returns a patch, as
4022 * it fails back to MySQL if no DB-specific patch can be found
4024 * @param string $patch The name of the patch, like patch-something.sql
4025 * @return string Full path to patch file
4027 public function patchPath( $patch ) {
4030 $dbType = $this->getType();
4031 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
4032 return "$IP/maintenance/$dbType/archives/$patch";
4034 return "$IP/maintenance/archives/$patch";
4039 * Set variables to be used in sourceFile/sourceStream, in preference to the
4040 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
4041 * all. If it's set to false, $GLOBALS will be used.
4043 * @param bool|array $vars Mapping variable name to value.
4045 public function setSchemaVars( $vars ) {
4046 $this->mSchemaVars
= $vars;
4050 * Read and execute commands from an open file handle.
4052 * Returns true on success, error string or exception on failure (depending
4053 * on object's error ignore settings).
4055 * @param resource $fp File handle
4056 * @param bool|callable $lineCallback Optional function called before reading each query
4057 * @param bool|callable $resultCallback Optional function called for each MySQL result
4058 * @param string $fname Calling function name
4059 * @param bool|callable $inputCallback Optional function called for each complete query sent
4060 * @return bool|string
4062 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
4063 $fname = __METHOD__
, $inputCallback = false
4067 while ( !feof( $fp ) ) {
4068 if ( $lineCallback ) {
4069 call_user_func( $lineCallback );
4072 $line = trim( fgets( $fp ) );
4074 if ( $line == '' ) {
4078 if ( '-' == $line[0] && '-' == $line[1] ) {
4086 $done = $this->streamStatementEnd( $cmd, $line );
4090 if ( $done ||
feof( $fp ) ) {
4091 $cmd = $this->replaceVars( $cmd );
4093 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
4094 $res = $this->query( $cmd, $fname );
4096 if ( $resultCallback ) {
4097 call_user_func( $resultCallback, $res, $this );
4100 if ( false === $res ) {
4101 $err = $this->lastError();
4103 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4114 * Called by sourceStream() to check if we've reached a statement end
4116 * @param string $sql SQL assembled so far
4117 * @param string $newLine New line about to be added to $sql
4118 * @return bool Whether $newLine contains end of the statement
4120 public function streamStatementEnd( &$sql, &$newLine ) {
4121 if ( $this->delimiter
) {
4123 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4124 if ( $newLine != $prev ) {
4133 * Database independent variable replacement. Replaces a set of variables
4134 * in an SQL statement with their contents as given by $this->getSchemaVars().
4136 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4138 * - '{$var}' should be used for text and is passed through the database's
4140 * - `{$var}` should be used for identifiers (e.g. table and database names).
4141 * It is passed through the database's addIdentifierQuotes method which
4142 * can be overridden if the database uses something other than backticks.
4143 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4144 * database's tableName method.
4145 * - / *i* / passes the name that follows through the database's indexName method.
4146 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4147 * its use should be avoided. In 1.24 and older, string encoding was applied.
4149 * @param string $ins SQL statement to replace variables in
4150 * @return string The new SQL statement with variables replaced
4152 protected function replaceVars( $ins ) {
4154 $vars = $this->getSchemaVars();
4155 return preg_replace_callback(
4157 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4158 \'\{\$ (\w+) }\' | # 3. addQuotes
4159 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4160 /\*\$ (\w+) \*/ # 5. leave unencoded
4162 function ( $m ) use ( $that, $vars ) {
4163 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4164 // check for both nonexistent keys *and* the empty string.
4165 if ( isset( $m[1] ) && $m[1] !== '' ) {
4166 if ( $m[1] === 'i' ) {
4167 return $that->indexName( $m[2] );
4169 return $that->tableName( $m[2] );
4171 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4172 return $that->addQuotes( $vars[$m[3]] );
4173 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4174 return $that->addIdentifierQuotes( $vars[$m[4]] );
4175 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4176 return $vars[$m[5]];
4186 * Get schema variables. If none have been set via setSchemaVars(), then
4187 * use some defaults from the current object.
4191 protected function getSchemaVars() {
4192 if ( $this->mSchemaVars
) {
4193 return $this->mSchemaVars
;
4195 return $this->getDefaultSchemaVars();
4200 * Get schema variables to use if none have been set via setSchemaVars().
4202 * Override this in derived classes to provide variables for tables.sql
4203 * and SQL patch files.
4207 protected function getDefaultSchemaVars() {
4212 * Check to see if a named lock is available. This is non-blocking.
4214 * @param string $lockName Name of lock to poll
4215 * @param string $method Name of method calling us
4219 public function lockIsFree( $lockName, $method ) {
4224 * Acquire a named lock
4226 * Abstracted from Filestore::lock() so child classes can implement for
4229 * @param string $lockName Name of lock to aquire
4230 * @param string $method Name of method calling us
4231 * @param int $timeout
4234 public function lock( $lockName, $method, $timeout = 5 ) {
4241 * @param string $lockName Name of lock to release
4242 * @param string $method Name of method calling us
4244 * @return int Returns 1 if the lock was released, 0 if the lock was not established
4245 * by this thread (in which case the lock is not released), and NULL if the named
4246 * lock did not exist
4248 public function unlock( $lockName, $method ) {
4253 * Lock specific tables
4255 * @param array $read Array of tables to lock for read access
4256 * @param array $write Array of tables to lock for write access
4257 * @param string $method Name of caller
4258 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
4261 public function lockTables( $read, $write, $method, $lowPriority = true ) {
4266 * Unlock specific tables
4268 * @param string $method The caller
4271 public function unlockTables( $method ) {
4277 * @param string $tableName
4278 * @param string $fName
4279 * @return bool|ResultWrapper
4282 public function dropTable( $tableName, $fName = __METHOD__
) {
4283 if ( !$this->tableExists( $tableName, $fName ) ) {
4286 $sql = "DROP TABLE " . $this->tableName( $tableName );
4287 if ( $this->cascadingDeletes() ) {
4291 return $this->query( $sql, $fName );
4295 * Get search engine class. All subclasses of this need to implement this
4296 * if they wish to use searching.
4300 public function getSearchEngine() {
4301 return 'SearchEngineDummy';
4305 * Find out when 'infinity' is. Most DBMSes support this. This is a special
4306 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
4307 * because "i" sorts after all numbers.
4311 public function getInfinity() {
4316 * Encode an expiry time into the DBMS dependent format
4318 * @param string $expiry Timestamp for expiry, or the 'infinity' string
4321 public function encodeExpiry( $expiry ) {
4322 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4323 ?
$this->getInfinity()
4324 : $this->timestamp( $expiry );
4328 * Decode an expiry time into a DBMS independent format
4330 * @param string $expiry DB timestamp field value for expiry
4331 * @param int $format TS_* constant, defaults to TS_MW
4334 public function decodeExpiry( $expiry, $format = TS_MW
) {
4335 return ( $expiry == '' ||
$expiry == $this->getInfinity() )
4337 : wfTimestamp( $format, $expiry );
4341 * Allow or deny "big selects" for this session only. This is done by setting
4342 * the sql_big_selects session variable.
4344 * This is a MySQL-specific feature.
4346 * @param bool|string $value True for allow, false for deny, or "default" to
4347 * restore the initial value
4349 public function setBigSelects( $value = true ) {
4357 public function __toString() {
4358 return (string)$this->mConn
;
4362 * Run a few simple sanity checks
4364 public function __destruct() {
4365 if ( $this->mTrxLevel
&& $this->mTrxDoneWrites
) {
4366 trigger_error( "Uncommitted DB writes (transaction from {$this->mTrxFname})." );
4368 if ( count( $this->mTrxIdleCallbacks
) ||
count( $this->mTrxPreCommitCallbacks
) ) {
4370 foreach ( $this->mTrxIdleCallbacks
as $callbackInfo ) {
4371 $callers[] = $callbackInfo[1];
4373 $callers = implode( ', ', $callers );
4374 trigger_error( "DB transaction callbacks still pending (from $callers)." );