3 * @defgroup Database Database
7 * This file deals with database interface functions
8 * and query specifics/optimisations
11 /** Number of times to re-try an operation in case of deadlock */
12 define( 'DEADLOCK_TRIES', 4 );
13 /** Minimum time to wait before retry, in microseconds */
14 define( 'DEADLOCK_DELAY_MIN', 500000 );
15 /** Maximum time to wait before retry */
16 define( 'DEADLOCK_DELAY_MAX', 1500000 );
19 * Base interface for all DBMS-specific code. At a bare minimum, all of the
20 * following must be implemented to support MediaWiki
25 interface DatabaseType
{
27 * Get the type of the DBMS, as it appears in $wgDBtype.
34 * Open a connection to the database. Usually aborts on failure
36 * @param $server String: database server host
37 * @param $user String: database user name
38 * @param $password String: database user password
39 * @param $dbName String: database name
41 * @throws DBConnectionError
43 function open( $server, $user, $password, $dbName );
46 * Fetch the next row from the given result object, in object form.
47 * Fields can be retrieved with $row->fieldname, with fields acting like
50 * @param $res ResultWrapper|object as returned from DatabaseBase::query(), etc.
52 * @throws DBUnexpectedError Thrown if the database returns an error
54 function fetchObject( $res );
57 * Fetch the next row from the given result object, in associative array
58 * form. Fields are retrieved with $row['fieldname'].
60 * @param $res ResultWrapper result object as returned from DatabaseBase::query(), etc.
62 * @throws DBUnexpectedError Thrown if the database returns an error
64 function fetchRow( $res );
67 * Get the number of rows in a result object
69 * @param $res Mixed: A SQL result
72 function numRows( $res );
75 * Get the number of fields in a result object
76 * @see http://www.php.net/mysql_num_fields
78 * @param $res Mixed: A SQL result
81 function numFields( $res );
84 * Get a field name in a result object
85 * @see http://www.php.net/mysql_field_name
87 * @param $res Mixed: A SQL result
91 function fieldName( $res, $n );
94 * Get the inserted value of an auto-increment row
96 * The value inserted should be fetched from nextSequenceValue()
99 * $id = $dbw->nextSequenceValue('page_page_id_seq');
100 * $dbw->insert('page',array('page_id' => $id));
101 * $id = $dbw->insertId();
108 * Change the position of the cursor in a result object
109 * @see http://www.php.net/mysql_data_seek
111 * @param $res Mixed: A SQL result
112 * @param $row Mixed: Either MySQL row or ResultWrapper
114 function dataSeek( $res, $row );
117 * Get the last error number
118 * @see http://www.php.net/mysql_errno
122 function lastErrno();
125 * Get a description of the last error
126 * @see http://www.php.net/mysql_error
130 function lastError();
133 * mysql_fetch_field() wrapper
134 * Returns false if the field doesn't exist
136 * @param $table string: table name
137 * @param $field string: field name
141 function fieldInfo( $table, $field );
144 * Get information about an index into an object
145 * @param $table string: Table name
146 * @param $index string: Index name
147 * @param $fname string: Calling function name
148 * @return Mixed: Database-specific index description class or false if the index does not exist
150 function indexInfo( $table, $index, $fname = 'Database::indexInfo' );
153 * Get the number of rows affected by the last write query
154 * @see http://www.php.net/mysql_affected_rows
158 function affectedRows();
161 * Wrapper for addslashes()
163 * @param $s string: to be slashed.
164 * @return string: slashed string.
166 function strencode( $s );
169 * Returns a wikitext link to the DB's website, e.g.,
170 * return "[http://www.mysql.com/ MySQL]";
171 * Should at least contain plain text, if for some reason
172 * your database has no website.
174 * @return string: wikitext of a link to the server software's web site
176 static function getSoftwareLink();
179 * A string describing the current software version, like from
180 * mysql_get_server_info().
182 * @return string: Version information from the database server.
184 function getServerVersion();
187 * A string describing the current software version, and possibly
188 * other details in a user-friendly way. Will be listed on Special:Version, etc.
189 * Use getServerVersion() to get machine-friendly information.
191 * @return string: Version information from the database server
193 function getServerInfo();
197 * Database abstraction object
200 abstract class DatabaseBase
implements DatabaseType
{
202 # ------------------------------------------------------------------------------
204 # ------------------------------------------------------------------------------
206 protected $mLastQuery = '';
207 protected $mDoneWrites = false;
208 protected $mPHPError = false;
210 protected $mServer, $mUser, $mPassword, $mDBname;
215 protected $mConn = null;
216 protected $mOpened = false;
218 protected $mTablePrefix;
220 protected $mTrxLevel = 0;
221 protected $mErrorCount = 0;
222 protected $mLBInfo = array();
223 protected $mFakeSlaveLag = null, $mFakeMaster = false;
224 protected $mDefaultBigSelects = null;
225 protected $mSchemaVars = false;
227 protected $preparedArgs;
229 protected $htmlErrors;
231 protected $delimiter = ';';
233 # ------------------------------------------------------------------------------
235 # ------------------------------------------------------------------------------
236 # These optionally set a variable and return the previous state
239 * A string describing the current software version, and possibly
240 * other details in a user-friendly way. Will be listed on Special:Version, etc.
241 * Use getServerVersion() to get machine-friendly information.
243 * @return string: Version information from the database server
245 public function getServerInfo() {
246 return $this->getServerVersion();
250 * Boolean, controls output of large amounts of debug information.
251 * @param $debug bool|null
252 * - true to enable debugging
253 * - false to disable debugging
254 * - omitted or null to do nothing
256 * @return The previous value of the flag
258 function debug( $debug = null ) {
259 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
263 * Turns buffering of SQL result sets on (true) or off (false). Default is
266 * Unbuffered queries are very troublesome in MySQL:
268 * - If another query is executed while the first query is being read
269 * out, the first query is killed. This means you can't call normal
270 * MediaWiki functions while you are reading an unbuffered query result
271 * from a normal wfGetDB() connection.
273 * - Unbuffered queries cause the MySQL server to use large amounts of
274 * memory and to hold broad locks which block other queries.
276 * If you want to limit client-side memory, it's almost always better to
277 * split up queries into batches using a LIMIT clause than to switch off
280 * @param $buffer null|bool
282 * @return The previous value of the flag
284 function bufferResults( $buffer = null ) {
285 if ( is_null( $buffer ) ) {
286 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
288 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
293 * Turns on (false) or off (true) the automatic generation and sending
294 * of a "we're sorry, but there has been a database error" page on
295 * database errors. Default is on (false). When turned off, the
296 * code should use lastErrno() and lastError() to handle the
297 * situation as appropriate.
299 * @param $ignoreErrors bool|null
301 * @return bool The previous value of the flag.
303 function ignoreErrors( $ignoreErrors = null ) {
304 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
308 * Gets or sets the current transaction level.
310 * Historically, transactions were allowed to be "nested". This is no
311 * longer supported, so this function really only returns a boolean.
313 * @param $level An integer (0 or 1), or omitted to leave it unchanged.
314 * @return The previous value
316 function trxLevel( $level = null ) {
317 return wfSetVar( $this->mTrxLevel
, $level );
321 * Get/set the number of errors logged. Only useful when errors are ignored
322 * @param $count The count to set, or omitted to leave it unchanged.
323 * @return The error count
325 function errorCount( $count = null ) {
326 return wfSetVar( $this->mErrorCount
, $count );
330 * Get/set the table prefix.
331 * @param $prefix The table prefix to set, or omitted to leave it unchanged.
332 * @return The previous table prefix.
334 function tablePrefix( $prefix = null ) {
335 return wfSetVar( $this->mTablePrefix
, $prefix );
339 * Get properties passed down from the server info array of the load
342 * @param $name string The entry of the info array to get, or null to get the
345 * @return LoadBalancer|null
347 function getLBInfo( $name = null ) {
348 if ( is_null( $name ) ) {
349 return $this->mLBInfo
;
351 if ( array_key_exists( $name, $this->mLBInfo
) ) {
352 return $this->mLBInfo
[$name];
360 * Set the LB info array, or a member of it. If called with one parameter,
361 * the LB info array is set to that parameter. If it is called with two
362 * parameters, the member with the given name is set to the given value.
367 function setLBInfo( $name, $value = null ) {
368 if ( is_null( $value ) ) {
369 $this->mLBInfo
= $name;
371 $this->mLBInfo
[$name] = $value;
376 * Set lag time in seconds for a fake slave
380 function setFakeSlaveLag( $lag ) {
381 $this->mFakeSlaveLag
= $lag;
385 * Make this connection a fake master
387 * @param $enabled bool
389 function setFakeMaster( $enabled = true ) {
390 $this->mFakeMaster
= $enabled;
394 * Returns true if this database supports (and uses) cascading deletes
398 function cascadingDeletes() {
403 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
407 function cleanupTriggers() {
412 * Returns true if this database is strict about what can be put into an IP field.
413 * Specifically, it uses a NULL value instead of an empty string.
417 function strictIPs() {
422 * Returns true if this database uses timestamps rather than integers
426 function realTimestamps() {
431 * Returns true if this database does an implicit sort when doing GROUP BY
435 function implicitGroupby() {
440 * Returns true if this database does an implicit order by when the column has an index
441 * For example: SELECT page_title FROM page LIMIT 1
445 function implicitOrderby() {
450 * Returns true if this database requires that SELECT DISTINCT queries require that all
451 ORDER BY expressions occur in the SELECT list per the SQL92 standard
455 function standardSelectDistinct() {
460 * Returns true if this database can do a native search on IP columns
461 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
465 function searchableIPs() {
470 * Returns true if this database can use functional indexes
474 function functionalIndexes() {
479 * Return the last query that went through DatabaseBase::query()
482 function lastQuery() {
483 return $this->mLastQuery
;
487 * Returns true if the connection may have been used for write queries.
488 * Should return true if unsure.
492 function doneWrites() {
493 return $this->mDoneWrites
;
497 * Is a connection to the database open?
501 return $this->mOpened
;
505 * Set a flag for this connection
507 * @param $flag Integer: DBO_* constants from Defines.php:
508 * - DBO_DEBUG: output some debug info (same as debug())
509 * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
510 * - DBO_IGNORE: ignore errors (same as ignoreErrors())
511 * - DBO_TRX: automatically start transactions
512 * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
513 * and removes it in command line mode
514 * - DBO_PERSISTENT: use persistant database connection
516 function setFlag( $flag ) {
517 $this->mFlags |
= $flag;
521 * Clear a flag for this connection
523 * @param $flag: same as setFlag()'s $flag param
525 function clearFlag( $flag ) {
526 $this->mFlags
&= ~
$flag;
530 * Returns a boolean whether the flag $flag is set for this connection
532 * @param $flag: same as setFlag()'s $flag param
535 function getFlag( $flag ) {
536 return !!( $this->mFlags
& $flag );
540 * General read-only accessor
542 * @param $name string
546 function getProperty( $name ) {
553 function getWikiID() {
554 if ( $this->mTablePrefix
) {
555 return "{$this->mDBname}-{$this->mTablePrefix}";
557 return $this->mDBname
;
562 * Return a path to the DBMS-specific schema file, otherwise default to tables.sql
566 public function getSchemaPath() {
568 if ( file_exists( "$IP/maintenance/" . $this->getType() . "/tables.sql" ) ) {
569 return "$IP/maintenance/" . $this->getType() . "/tables.sql";
571 return "$IP/maintenance/tables.sql";
575 # ------------------------------------------------------------------------------
577 # ------------------------------------------------------------------------------
581 * @param $server String: database server host
582 * @param $user String: database user name
583 * @param $password String: database user password
584 * @param $dbName String: database name
586 * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
588 function __construct( $server = false, $user = false, $password = false, $dbName = false,
589 $flags = 0, $tablePrefix = 'get from global'
591 global $wgDBprefix, $wgCommandLineMode;
593 $this->mFlags
= $flags;
595 if ( $this->mFlags
& DBO_DEFAULT
) {
596 if ( $wgCommandLineMode ) {
597 $this->mFlags
&= ~DBO_TRX
;
599 $this->mFlags |
= DBO_TRX
;
603 /** Get the default table prefix*/
604 if ( $tablePrefix == 'get from global' ) {
605 $this->mTablePrefix
= $wgDBprefix;
607 $this->mTablePrefix
= $tablePrefix;
611 $this->open( $server, $user, $password, $dbName );
616 * Called by serialize. Throw an exception when DB connection is serialized.
617 * This causes problems on some database engines because the connection is
618 * not restored on unserialize.
620 public function __sleep() {
621 throw new MWException( 'Database serialization may cause problems, since the connection is not restored on wakeup.' );
625 * Same as new DatabaseMysql( ... ), kept for backward compatibility
626 * @deprecated since 1.17
633 * @return DatabaseMysql
635 static function newFromParams( $server, $user, $password, $dbName, $flags = 0 ) {
636 wfDeprecated( __METHOD__
, '1.17' );
637 return new DatabaseMysql( $server, $user, $password, $dbName, $flags );
641 * Same as new factory( ... ), kept for backward compatibility
642 * @deprecated since 1.18
643 * @see Database::factory()
645 public final static function newFromType( $dbType, $p = array() ) {
646 wfDeprecated( __METHOD__
, '1.18' );
647 if ( isset( $p['tableprefix'] ) ) {
648 $p['tablePrefix'] = $p['tableprefix'];
650 return self
::factory( $dbType, $p );
654 * Given a DB type, construct the name of the appropriate child class of
655 * DatabaseBase. This is designed to replace all of the manual stuff like:
656 * $class = 'Database' . ucfirst( strtolower( $type ) );
657 * as well as validate against the canonical list of DB types we have
659 * This factory function is mostly useful for when you need to connect to a
660 * database other than the MediaWiki default (such as for external auth,
661 * an extension, et cetera). Do not use this to connect to the MediaWiki
662 * database. Example uses in core:
663 * @see LoadBalancer::reallyOpenConnection()
664 * @see ExternalUser_MediaWiki::initFromCond()
665 * @see ForeignDBRepo::getMasterDB()
666 * @see WebInstaller_DBConnect::execute()
668 * @param $dbType String A possible DB type
669 * @param $p Array An array of options to pass to the constructor.
670 * Valid options are: host, user, password, dbname, flags, tablePrefix
671 * @return DatabaseBase subclass or null
673 public final static function factory( $dbType, $p = array() ) {
674 $canonicalDBTypes = array(
675 'mysql', 'postgres', 'sqlite', 'oracle', 'mssql', 'ibm_db2'
677 $dbType = strtolower( $dbType );
678 $class = 'Database' . ucfirst( $dbType );
680 if( in_array( $dbType, $canonicalDBTypes ) ) {
682 isset( $p['host'] ) ?
$p['host'] : false,
683 isset( $p['user'] ) ?
$p['user'] : false,
684 isset( $p['password'] ) ?
$p['password'] : false,
685 isset( $p['dbname'] ) ?
$p['dbname'] : false,
686 isset( $p['flags'] ) ?
$p['flags'] : 0,
687 isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global'
689 } elseif ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) {
690 return new $class( $p );
696 protected function installErrorHandler() {
697 $this->mPHPError
= false;
698 $this->htmlErrors
= ini_set( 'html_errors', '0' );
699 set_error_handler( array( $this, 'connectionErrorHandler' ) );
703 * @return bool|string
705 protected function restoreErrorHandler() {
706 restore_error_handler();
707 if ( $this->htmlErrors
!== false ) {
708 ini_set( 'html_errors', $this->htmlErrors
);
710 if ( $this->mPHPError
) {
711 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
712 $error = preg_replace( '!^.*?:(.*)$!', '$1', $error );
723 protected function connectionErrorHandler( $errno, $errstr ) {
724 $this->mPHPError
= $errstr;
728 * Closes a database connection.
729 * if it is open : commits any open transactions
731 * @return Bool operation success. true if already closed.
734 # Stub, should probably be overridden
739 * @param $error String: fallback error message, used if none is given by DB
741 function reportConnectionError( $error = 'Unknown error' ) {
742 $myError = $this->lastError();
748 throw new DBConnectionError( $this, $error );
752 * The DBMS-dependent part of query()
754 * @param $sql String: SQL query.
755 * @return ResultWrapper Result object to feed to fetchObject, fetchRow, ...; or false on failure
757 protected abstract function doQuery( $sql );
760 * Determine whether a query writes to the DB.
761 * Should return true if unsure.
767 function isWriteQuery( $sql ) {
768 return !preg_match( '/^(?:SELECT|BEGIN|COMMIT|SET|SHOW|\(SELECT)\b/i', $sql );
772 * Run an SQL query and return the result. Normally throws a DBQueryError
773 * on failure. If errors are ignored, returns false instead.
775 * In new code, the query wrappers select(), insert(), update(), delete(),
776 * etc. should be used where possible, since they give much better DBMS
777 * independence and automatically quote or validate user input in a variety
778 * of contexts. This function is generally only useful for queries which are
779 * explicitly DBMS-dependent and are unsupported by the query wrappers, such
782 * However, the query wrappers themselves should call this function.
784 * @param $sql String: SQL query
785 * @param $fname String: Name of the calling function, for profiling/SHOW PROCESSLIST
786 * comment (you can use __METHOD__ or add some extra info)
787 * @param $tempIgnore Boolean: Whether to avoid throwing an exception on errors...
788 * maybe best to catch the exception instead?
789 * @return boolean|ResultWrapper. true for a successful write query, ResultWrapper object
790 * for a successful read query, or false on failure if $tempIgnore set
791 * @throws DBQueryError Thrown when the database returns an error of any kind
793 public function query( $sql, $fname = '', $tempIgnore = false ) {
794 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
795 if ( !Profiler
::instance()->isStub() ) {
796 # generalizeSQL will probably cut down the query to reasonable
797 # logging size most of the time. The substr is really just a sanity check.
800 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
801 $totalProf = 'DatabaseBase::query-master';
803 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
804 $totalProf = 'DatabaseBase::query';
807 wfProfileIn( $totalProf );
808 wfProfileIn( $queryProf );
811 $this->mLastQuery
= $sql;
812 if ( !$this->mDoneWrites
&& $this->isWriteQuery( $sql ) ) {
813 # Set a flag indicating that writes have been done
814 wfDebug( __METHOD__
. ": Writes done: $sql\n" );
815 $this->mDoneWrites
= true;
818 # Add a comment for easy SHOW PROCESSLIST interpretation
820 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
821 $userName = $wgUser->getName();
822 if ( mb_strlen( $userName ) > 15 ) {
823 $userName = mb_substr( $userName, 0, 15 ) . '...';
825 $userName = str_replace( '/', '', $userName );
829 $commentedSql = preg_replace( '/\s/', " /* $fname $userName */ ", $sql, 1 );
831 # If DBO_TRX is set, start a transaction
832 if ( ( $this->mFlags
& DBO_TRX
) && !$this->trxLevel() &&
833 $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK' ) {
834 # avoid establishing transactions for SHOW and SET statements too -
835 # that would delay transaction initializations to once connection
836 # is really used by application
837 $sqlstart = substr( $sql, 0, 10 ); // very much worth it, benchmark certified(tm)
838 if ( strpos( $sqlstart, "SHOW " ) !== 0 && strpos( $sqlstart, "SET " ) !== 0 )
842 if ( $this->debug() ) {
846 $sqlx = substr( $commentedSql, 0, 500 );
847 $sqlx = strtr( $sqlx, "\t\n", ' ' );
850 $master = $isMaster ?
'master' : 'slave';
851 wfDebug( "Query {$this->mDBname} ($cnt) ($master): $sqlx\n" );
854 if ( istainted( $sql ) & TC_MYSQL
) {
855 throw new MWException( 'Tainted query found' );
858 $queryId = MWDebug
::query( $sql, $fname, $isMaster );
860 # Do the query and handle errors
861 $ret = $this->doQuery( $commentedSql );
863 MWDebug
::queryTime( $queryId );
865 # Try reconnecting if the connection was lost
866 if ( false === $ret && $this->wasErrorReissuable() ) {
867 # Transaction is gone, like it or not
868 $this->mTrxLevel
= 0;
869 wfDebug( "Connection lost, reconnecting...\n" );
871 if ( $this->ping() ) {
872 wfDebug( "Reconnected\n" );
873 $sqlx = substr( $commentedSql, 0, 500 );
874 $sqlx = strtr( $sqlx, "\t\n", ' ' );
875 global $wgRequestTime;
876 $elapsed = round( microtime( true ) - $wgRequestTime, 3 );
877 if ( $elapsed < 300 ) {
878 # Not a database error to lose a transaction after a minute or two
879 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
881 $ret = $this->doQuery( $commentedSql );
883 wfDebug( "Failed\n" );
887 if ( false === $ret ) {
888 $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
891 if ( !Profiler
::instance()->isStub() ) {
892 wfProfileOut( $queryProf );
893 wfProfileOut( $totalProf );
896 return $this->resultObject( $ret );
900 * Report a query error. Log the error, and if neither the object ignore
901 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
903 * @param $error String
904 * @param $errno Integer
906 * @param $fname String
907 * @param $tempIgnore Boolean
909 function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
910 # Ignore errors during error handling to avoid infinite recursion
911 $ignore = $this->ignoreErrors( true );
912 ++
$this->mErrorCount
;
914 if ( $ignore ||
$tempIgnore ) {
915 wfDebug( "SQL ERROR (ignored): $error\n" );
916 $this->ignoreErrors( $ignore );
918 $sql1line = str_replace( "\n", "\\n", $sql );
919 wfLogDBError( "$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n" );
920 wfDebug( "SQL ERROR: " . $error . "\n" );
921 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
926 * Intended to be compatible with the PEAR::DB wrapper functions.
927 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
929 * ? = scalar value, quoted as necessary
930 * ! = raw SQL bit (a function for instance)
931 * & = filename; reads the file and inserts as a blob
932 * (we don't use this though...)
934 * This function should not be used directly by new code outside of the
935 * database classes. The query wrapper functions (select() etc.) should be
939 * @param $func string
943 function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
944 /* MySQL doesn't support prepared statements (yet), so just
945 pack up the query for reference. We'll manually replace
947 return array( 'query' => $sql, 'func' => $func );
951 * Free a prepared query, generated by prepare().
954 function freePrepared( $prepared ) {
955 /* No-op by default */
959 * Execute a prepared query with the various arguments
960 * @param $prepared String: the prepared sql
961 * @param $args Mixed: Either an array here, or put scalars as varargs
963 * @return ResultWrapper
965 function execute( $prepared, $args = null ) {
966 if ( !is_array( $args ) ) {
968 $args = func_get_args();
969 array_shift( $args );
972 $sql = $this->fillPrepared( $prepared['query'], $args );
974 return $this->query( $sql, $prepared['func'] );
978 * Prepare & execute an SQL statement, quoting and inserting arguments
979 * in the appropriate places.
981 * This function should not be used directly by new code outside of the
982 * database classes. The query wrapper functions (select() etc.) should be
985 * @param $query String
988 * @return ResultWrapper
990 function safeQuery( $query, $args = null ) {
991 $prepared = $this->prepare( $query, 'DatabaseBase::safeQuery' );
993 if ( !is_array( $args ) ) {
995 $args = func_get_args();
996 array_shift( $args );
999 $retval = $this->execute( $prepared, $args );
1000 $this->freePrepared( $prepared );
1006 * For faking prepared SQL statements on DBs that don't support
1008 * @param $preparedQuery String: a 'preparable' SQL statement
1009 * @param $args Array of arguments to fill it with
1010 * @return string executable SQL
1012 function fillPrepared( $preparedQuery, $args ) {
1014 $this->preparedArgs
=& $args;
1016 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1017 array( &$this, 'fillPreparedArg' ), $preparedQuery );
1021 * preg_callback func for fillPrepared()
1022 * The arguments should be in $this->preparedArgs and must not be touched
1023 * while we're doing this.
1025 * @param $matches Array
1028 function fillPreparedArg( $matches ) {
1029 switch( $matches[1] ) {
1030 case '\\?': return '?';
1031 case '\\!': return '!';
1032 case '\\&': return '&';
1035 list( /* $n */ , $arg ) = each( $this->preparedArgs
);
1037 switch( $matches[1] ) {
1038 case '?': return $this->addQuotes( $arg );
1039 case '!': return $arg;
1041 # return $this->addQuotes( file_get_contents( $arg ) );
1042 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
1044 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
1049 * Free a result object returned by query() or select(). It's usually not
1050 * necessary to call this, just use unset() or let the variable holding
1051 * the result object go out of scope.
1053 * @param $res Mixed: A SQL result
1055 function freeResult( $res ) {
1059 * Simple UPDATE wrapper.
1060 * Usually throws a DBQueryError on failure.
1061 * If errors are explicitly ignored, returns success
1063 * This function exists for historical reasons, DatabaseBase::update() has a more standard
1064 * calling convention and feature set
1066 * @param $table string
1070 * @param $fname string
1074 function set( $table, $var, $value, $cond, $fname = 'DatabaseBase::set' ) {
1075 $table = $this->tableName( $table );
1076 $sql = "UPDATE $table SET $var = '" .
1077 $this->strencode( $value ) . "' WHERE ($cond)";
1079 return (bool)$this->query( $sql, $fname );
1083 * A SELECT wrapper which returns a single field from a single result row.
1085 * Usually throws a DBQueryError on failure. If errors are explicitly
1086 * ignored, returns false on failure.
1088 * If no result rows are returned from the query, false is returned.
1090 * @param $table string|array Table name. See DatabaseBase::select() for details.
1091 * @param $var string The field name to select. This must be a valid SQL
1092 * fragment: do not use unvalidated user input.
1093 * @param $cond string|array The condition array. See DatabaseBase::select() for details.
1094 * @param $fname string The function name of the caller.
1095 * @param $options string|array The query options. See DatabaseBase::select() for details.
1097 * @return false|mixed The value from the field, or false on failure.
1099 function selectField( $table, $var, $cond = '', $fname = 'DatabaseBase::selectField',
1100 $options = array() )
1102 if ( !is_array( $options ) ) {
1103 $options = array( $options );
1106 $options['LIMIT'] = 1;
1108 $res = $this->select( $table, $var, $cond, $fname, $options );
1110 if ( $res === false ||
!$this->numRows( $res ) ) {
1114 $row = $this->fetchRow( $res );
1116 if ( $row !== false ) {
1117 return reset( $row );
1124 * Returns an optional USE INDEX clause to go after the table, and a
1125 * string to go at the end of the query.
1127 * @param $options Array: associative array of options to be turned into
1128 * an SQL query, valid keys are listed in the function.
1130 * @see DatabaseBase::select()
1132 function makeSelectOptions( $options ) {
1133 $preLimitTail = $postLimitTail = '';
1136 $noKeyOptions = array();
1138 foreach ( $options as $key => $option ) {
1139 if ( is_numeric( $key ) ) {
1140 $noKeyOptions[$option] = true;
1144 if ( isset( $options['GROUP BY'] ) ) {
1145 $gb = is_array( $options['GROUP BY'] )
1146 ?
implode( ',', $options['GROUP BY'] )
1147 : $options['GROUP BY'];
1148 $preLimitTail .= " GROUP BY {$gb}";
1151 if ( isset( $options['HAVING'] ) ) {
1152 $preLimitTail .= " HAVING {$options['HAVING']}";
1155 if ( isset( $options['ORDER BY'] ) ) {
1156 $ob = is_array( $options['ORDER BY'] )
1157 ?
implode( ',', $options['ORDER BY'] )
1158 : $options['ORDER BY'];
1159 $preLimitTail .= " ORDER BY {$ob}";
1162 // if (isset($options['LIMIT'])) {
1163 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1164 // isset($options['OFFSET']) ? $options['OFFSET']
1168 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1169 $postLimitTail .= ' FOR UPDATE';
1172 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1173 $postLimitTail .= ' LOCK IN SHARE MODE';
1176 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1177 $startOpts .= 'DISTINCT';
1180 # Various MySQL extensions
1181 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1182 $startOpts .= ' /*! STRAIGHT_JOIN */';
1185 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1186 $startOpts .= ' HIGH_PRIORITY';
1189 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1190 $startOpts .= ' SQL_BIG_RESULT';
1193 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1194 $startOpts .= ' SQL_BUFFER_RESULT';
1197 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1198 $startOpts .= ' SQL_SMALL_RESULT';
1201 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1202 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1205 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1206 $startOpts .= ' SQL_CACHE';
1209 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1210 $startOpts .= ' SQL_NO_CACHE';
1213 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1214 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1219 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1223 * Execute a SELECT query constructed using the various parameters provided.
1224 * See below for full details of the parameters.
1226 * @param $table String|Array Table name
1227 * @param $vars String|Array Field names
1228 * @param $conds String|Array Conditions
1229 * @param $fname String Caller function name
1230 * @param $options Array Query options
1231 * @param $join_conds Array Join conditions
1233 * @param $table string|array
1235 * May be either an array of table names, or a single string holding a table
1236 * name. If an array is given, table aliases can be specified, for example:
1238 * array( 'a' => 'user' )
1240 * This includes the user table in the query, with the alias "a" available
1241 * for use in field names (e.g. a.user_name).
1243 * All of the table names given here are automatically run through
1244 * DatabaseBase::tableName(), which causes the table prefix (if any) to be
1245 * added, and various other table name mappings to be performed.
1248 * @param $vars string|array
1250 * May be either a field name or an array of field names. The field names
1251 * here are complete fragments of SQL, for direct inclusion into the SELECT
1252 * query. Expressions and aliases may be specified as in SQL, for example:
1254 * array( 'MAX(rev_id) AS maxrev' )
1256 * If an expression is given, care must be taken to ensure that it is
1260 * @param $conds string|array
1262 * May be either a string containing a single condition, or an array of
1263 * conditions. If an array is given, the conditions constructed from each
1264 * element are combined with AND.
1266 * Array elements may take one of two forms:
1268 * - Elements with a numeric key are interpreted as raw SQL fragments.
1269 * - Elements with a string key are interpreted as equality conditions,
1270 * where the key is the field name.
1271 * - If the value of such an array element is a scalar (such as a
1272 * string), it will be treated as data and thus quoted appropriately.
1273 * If it is null, an IS NULL clause will be added.
1274 * - If the value is an array, an IN(...) clause will be constructed,
1275 * such that the field name may match any of the elements in the
1276 * array. The elements of the array will be quoted.
1278 * Note that expressions are often DBMS-dependent in their syntax.
1279 * DBMS-independent wrappers are provided for constructing several types of
1280 * expression commonly used in condition queries. See:
1281 * - DatabaseBase::buildLike()
1282 * - DatabaseBase::conditional()
1285 * @param $options string|array
1287 * Optional: Array of query options. Boolean options are specified by
1288 * including them in the array as a string value with a numeric key, for
1291 * array( 'FOR UPDATE' )
1293 * The supported options are:
1295 * - OFFSET: Skip this many rows at the start of the result set. OFFSET
1296 * with LIMIT can theoretically be used for paging through a result set,
1297 * but this is discouraged in MediaWiki for performance reasons.
1299 * - LIMIT: Integer: return at most this many rows. The rows are sorted
1300 * and then the first rows are taken until the limit is reached. LIMIT
1301 * is applied to a result set after OFFSET.
1303 * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
1304 * changed until the next COMMIT.
1306 * - DISTINCT: Boolean: return only unique result rows.
1308 * - GROUP BY: May be either an SQL fragment string naming a field or
1309 * expression to group by, or an array of such SQL fragments.
1311 * - HAVING: A string containing a HAVING clause.
1313 * - ORDER BY: May be either an SQL fragment giving a field name or
1314 * expression to order by, or an array of such SQL fragments.
1316 * - USE INDEX: This may be either a string giving the index name to use
1317 * for the query, or an array. If it is an associative array, each key
1318 * gives the table name (or alias), each value gives the index name to
1319 * use for that table. All strings are SQL fragments and so should be
1320 * validated by the caller.
1322 * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
1323 * instead of SELECT.
1325 * And also the following boolean MySQL extensions, see the MySQL manual
1326 * for documentation:
1328 * - LOCK IN SHARE MODE
1332 * - SQL_BUFFER_RESULT
1333 * - SQL_SMALL_RESULT
1334 * - SQL_CALC_FOUND_ROWS
1339 * @param $join_conds string|array
1341 * Optional associative array of table-specific join conditions. In the
1342 * most common case, this is unnecessary, since the join condition can be
1343 * in $conds. However, it is useful for doing a LEFT JOIN.
1345 * The key of the array contains the table name or alias. The value is an
1346 * array with two elements, numbered 0 and 1. The first gives the type of
1347 * join, the second is an SQL fragment giving the join condition for that
1348 * table. For example:
1350 * array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
1352 * @return ResultWrapper. If the query returned no rows, a ResultWrapper
1353 * with no rows in it will be returned. If there was a query error, a
1354 * DBQueryError exception will be thrown, except if the "ignore errors"
1355 * option was set, in which case false will be returned.
1357 function select( $table, $vars, $conds = '', $fname = 'DatabaseBase::select',
1358 $options = array(), $join_conds = array() ) {
1359 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1361 return $this->query( $sql, $fname );
1365 * The equivalent of DatabaseBase::select() except that the constructed SQL
1366 * is returned, instead of being immediately executed.
1368 * @param $table string|array Table name
1369 * @param $vars string|array Field names
1370 * @param $conds string|array Conditions
1371 * @param $fname string Caller function name
1372 * @param $options string|array Query options
1373 * @param $join_conds string|array Join conditions
1375 * @return SQL query string.
1376 * @see DatabaseBase::select()
1378 function selectSQLText( $table, $vars, $conds = '', $fname = 'DatabaseBase::select', $options = array(), $join_conds = array() ) {
1379 if ( is_array( $vars ) ) {
1380 $vars = implode( ',', $vars );
1383 $options = (array)$options;
1385 if ( is_array( $table ) ) {
1386 $useIndex = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1387 ?
$options['USE INDEX']
1389 if ( count( $join_conds ) ||
count( $useIndex ) ) {
1391 $this->tableNamesWithUseIndexOrJOIN( $table, $useIndex, $join_conds );
1393 $from = ' FROM ' . implode( ',', $this->tableNamesWithAlias( $table ) );
1395 } elseif ( $table != '' ) {
1396 if ( $table[0] == ' ' ) {
1397 $from = ' FROM ' . $table;
1399 $from = ' FROM ' . $this->tableName( $table );
1405 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1407 if ( !empty( $conds ) ) {
1408 if ( is_array( $conds ) ) {
1409 $conds = $this->makeList( $conds, LIST_AND
);
1411 $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1413 $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1416 if ( isset( $options['LIMIT'] ) ) {
1417 $sql = $this->limitResult( $sql, $options['LIMIT'],
1418 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1420 $sql = "$sql $postLimitTail";
1422 if ( isset( $options['EXPLAIN'] ) ) {
1423 $sql = 'EXPLAIN ' . $sql;
1430 * Single row SELECT wrapper. Equivalent to DatabaseBase::select(), except
1431 * that a single row object is returned. If the query returns no rows,
1432 * false is returned.
1434 * @param $table string|array Table name
1435 * @param $vars string|array Field names
1436 * @param $conds|array Conditions
1437 * @param $fname string Caller function name
1438 * @param $options string|array Query options
1439 * @param $join_conds array|string Join conditions
1441 * @return ResultWrapper|bool
1443 function selectRow( $table, $vars, $conds, $fname = 'DatabaseBase::selectRow',
1444 $options = array(), $join_conds = array() )
1446 $options['LIMIT'] = 1;
1447 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1449 if ( $res === false ) {
1453 if ( !$this->numRows( $res ) ) {
1457 $obj = $this->fetchObject( $res );
1463 * Estimate rows in dataset.
1465 * MySQL allows you to estimate the number of rows that would be returned
1466 * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
1467 * index cardinality statistics, and is notoriously inaccurate, especially
1468 * when large numbers of rows have recently been added or deleted.
1470 * For DBMSs that don't support fast result size estimation, this function
1471 * will actually perform the SELECT COUNT(*).
1473 * Takes the same arguments as DatabaseBase::select().
1475 * @param $table String: table name
1476 * @param Array|string $vars : unused
1477 * @param Array|string $conds : filters on the table
1478 * @param $fname String: function name for profiling
1479 * @param $options Array: options for select
1480 * @return Integer: row count
1482 public function estimateRowCount( $table, $vars = '*', $conds = '',
1483 $fname = 'DatabaseBase::estimateRowCount', $options = array() )
1486 $res = $this->select ( $table, 'COUNT(*) AS rowcount', $conds, $fname, $options );
1489 $row = $this->fetchRow( $res );
1490 $rows = ( isset( $row['rowcount'] ) ) ?
$row['rowcount'] : 0;
1497 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1498 * It's only slightly flawed. Don't use for anything important.
1500 * @param $sql String A SQL Query
1504 static function generalizeSQL( $sql ) {
1505 # This does the same as the regexp below would do, but in such a way
1506 # as to avoid crashing php on some large strings.
1507 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1509 $sql = str_replace ( "\\\\", '', $sql );
1510 $sql = str_replace ( "\\'", '', $sql );
1511 $sql = str_replace ( "\\\"", '', $sql );
1512 $sql = preg_replace ( "/'.*'/s", "'X'", $sql );
1513 $sql = preg_replace ( '/".*"/s', "'X'", $sql );
1515 # All newlines, tabs, etc replaced by single space
1516 $sql = preg_replace ( '/\s+/', ' ', $sql );
1519 $sql = preg_replace ( '/-?[0-9]+/s', 'N', $sql );
1525 * Determines whether a field exists in a table
1527 * @param $table String: table name
1528 * @param $field String: filed to check on that table
1529 * @param $fname String: calling function name (optional)
1530 * @return Boolean: whether $table has filed $field
1532 function fieldExists( $table, $field, $fname = 'DatabaseBase::fieldExists' ) {
1533 $info = $this->fieldInfo( $table, $field );
1539 * Determines whether an index exists
1540 * Usually throws a DBQueryError on failure
1541 * If errors are explicitly ignored, returns NULL on failure
1545 * @param $fname string
1549 function indexExists( $table, $index, $fname = 'DatabaseBase::indexExists' ) {
1550 $info = $this->indexInfo( $table, $index, $fname );
1551 if ( is_null( $info ) ) {
1554 return $info !== false;
1559 * Query whether a given table exists
1561 * @param $table string
1562 * @param $fname string
1566 function tableExists( $table, $fname = __METHOD__
) {
1567 $table = $this->tableName( $table );
1568 $old = $this->ignoreErrors( true );
1569 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1570 $this->ignoreErrors( $old );
1576 * mysql_field_type() wrapper
1581 function fieldType( $res, $index ) {
1582 if ( $res instanceof ResultWrapper
) {
1583 $res = $res->result
;
1586 return mysql_field_type( $res, $index );
1590 * Determines if a given index is unique
1592 * @param $table string
1593 * @param $index string
1597 function indexUnique( $table, $index ) {
1598 $indexInfo = $this->indexInfo( $table, $index );
1600 if ( !$indexInfo ) {
1604 return !$indexInfo[0]->Non_unique
;
1608 * Helper for DatabaseBase::insert().
1610 * @param $options array
1613 function makeInsertOptions( $options ) {
1614 return implode( ' ', $options );
1618 * INSERT wrapper, inserts an array into a table.
1622 * - A single associative array. The array keys are the field names, and
1623 * the values are the values to insert. The values are treated as data
1624 * and will be quoted appropriately. If NULL is inserted, this will be
1625 * converted to a database NULL.
1626 * - An array with numeric keys, holding a list of associative arrays.
1627 * This causes a multi-row INSERT on DBMSs that support it. The keys in
1628 * each subarray must be identical to each other, and in the same order.
1630 * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
1633 * $options is an array of options, with boolean options encoded as values
1634 * with numeric keys, in the same style as $options in
1635 * DatabaseBase::select(). Supported options are:
1637 * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
1638 * any rows which cause duplicate key errors are not inserted. It's
1639 * possible to determine how many rows were successfully inserted using
1640 * DatabaseBase::affectedRows().
1642 * @param $table String Table name. This will be passed through
1643 * DatabaseBase::tableName().
1644 * @param $a Array of rows to insert
1645 * @param $fname String Calling function name (use __METHOD__) for logs/profiling
1646 * @param $options Array of options
1650 function insert( $table, $a, $fname = 'DatabaseBase::insert', $options = array() ) {
1651 # No rows to insert, easy just return now
1652 if ( !count( $a ) ) {
1656 $table = $this->tableName( $table );
1658 if ( !is_array( $options ) ) {
1659 $options = array( $options );
1662 $options = $this->makeInsertOptions( $options );
1664 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1666 $keys = array_keys( $a[0] );
1669 $keys = array_keys( $a );
1672 $sql = 'INSERT ' . $options .
1673 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1677 foreach ( $a as $row ) {
1683 $sql .= '(' . $this->makeList( $row ) . ')';
1686 $sql .= '(' . $this->makeList( $a ) . ')';
1689 return (bool)$this->query( $sql, $fname );
1693 * Make UPDATE options for the DatabaseBase::update function
1695 * @param $options Array: The options passed to DatabaseBase::update
1698 function makeUpdateOptions( $options ) {
1699 if ( !is_array( $options ) ) {
1700 $options = array( $options );
1705 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1706 $opts[] = $this->lowPriorityOption();
1709 if ( in_array( 'IGNORE', $options ) ) {
1713 return implode( ' ', $opts );
1717 * UPDATE wrapper. Takes a condition array and a SET array.
1719 * @param $table String name of the table to UPDATE. This will be passed through
1720 * DatabaseBase::tableName().
1722 * @param $values Array: An array of values to SET. For each array element,
1723 * the key gives the field name, and the value gives the data
1724 * to set that field to. The data will be quoted by
1725 * DatabaseBase::addQuotes().
1727 * @param $conds Array: An array of conditions (WHERE). See
1728 * DatabaseBase::select() for the details of the format of
1729 * condition arrays. Use '*' to update all rows.
1731 * @param $fname String: The function name of the caller (from __METHOD__),
1732 * for logging and profiling.
1734 * @param $options Array: An array of UPDATE options, can be:
1735 * - IGNORE: Ignore unique key conflicts
1736 * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
1739 function update( $table, $values, $conds, $fname = 'DatabaseBase::update', $options = array() ) {
1740 $table = $this->tableName( $table );
1741 $opts = $this->makeUpdateOptions( $options );
1742 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1744 if ( $conds !== array() && $conds !== '*' ) {
1745 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1748 return $this->query( $sql, $fname );
1752 * Makes an encoded list of strings from an array
1753 * @param $a Array containing the data
1754 * @param $mode int Constant
1755 * - LIST_COMMA: comma separated, no field names
1756 * - LIST_AND: ANDed WHERE clause (without the WHERE). See
1757 * the documentation for $conds in DatabaseBase::select().
1758 * - LIST_OR: ORed WHERE clause (without the WHERE)
1759 * - LIST_SET: comma separated with field names, like a SET clause
1760 * - LIST_NAMES: comma separated field names
1764 function makeList( $a, $mode = LIST_COMMA
) {
1765 if ( !is_array( $a ) ) {
1766 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1772 foreach ( $a as $field => $value ) {
1774 if ( $mode == LIST_AND
) {
1776 } elseif ( $mode == LIST_OR
) {
1785 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1786 $list .= "($value)";
1787 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1789 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1790 if ( count( $value ) == 0 ) {
1791 throw new MWException( __METHOD__
. ': empty input' );
1792 } elseif ( count( $value ) == 1 ) {
1793 // Special-case single values, as IN isn't terribly efficient
1794 // Don't necessarily assume the single key is 0; we don't
1795 // enforce linear numeric ordering on other arrays here.
1796 $value = array_values( $value );
1797 $list .= $field . " = " . $this->addQuotes( $value[0] );
1799 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1801 } elseif ( $value === null ) {
1802 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1803 $list .= "$field IS ";
1804 } elseif ( $mode == LIST_SET
) {
1805 $list .= "$field = ";
1809 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1810 $list .= "$field = ";
1812 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1820 * Build a partial where clause from a 2-d array such as used for LinkBatch.
1821 * The keys on each level may be either integers or strings.
1823 * @param $data Array: organized as 2-d
1824 * array(baseKeyVal => array(subKeyVal => <ignored>, ...), ...)
1825 * @param $baseKey String: field name to match the base-level keys to (eg 'pl_namespace')
1826 * @param $subKey String: field name to match the sub-level keys to (eg 'pl_title')
1827 * @return Mixed: string SQL fragment, or false if no items in array.
1829 function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1832 foreach ( $data as $base => $sub ) {
1833 if ( count( $sub ) ) {
1834 $conds[] = $this->makeList(
1835 array( $baseKey => $base, $subKey => array_keys( $sub ) ),
1841 return $this->makeList( $conds, LIST_OR
);
1843 // Nothing to search for...
1849 * Bitwise operations
1856 function bitNot( $field ) {
1862 * @param $fieldRight
1865 function bitAnd( $fieldLeft, $fieldRight ) {
1866 return "($fieldLeft & $fieldRight)";
1871 * @param $fieldRight
1874 function bitOr( $fieldLeft, $fieldRight ) {
1875 return "($fieldLeft | $fieldRight)";
1879 * Change the current database
1881 * @todo Explain what exactly will fail if this is not overridden.
1885 * @return bool Success or failure
1887 function selectDB( $db ) {
1888 # Stub. Shouldn't cause serious problems if it's not overridden, but
1889 # if your database engine supports a concept similar to MySQL's
1890 # databases you may as well.
1891 $this->mDBname
= $db;
1896 * Get the current DB name
1898 function getDBname() {
1899 return $this->mDBname
;
1903 * Get the server hostname or IP address
1905 function getServer() {
1906 return $this->mServer
;
1910 * Format a table name ready for use in constructing an SQL query
1912 * This does two important things: it quotes the table names to clean them up,
1913 * and it adds a table prefix if only given a table name with no quotes.
1915 * All functions of this object which require a table name call this function
1916 * themselves. Pass the canonical name to such functions. This is only needed
1917 * when calling query() directly.
1919 * @param $name String: database table name
1920 * @param $format String One of:
1921 * quoted - Automatically pass the table name through addIdentifierQuotes()
1922 * so that it can be used in a query.
1923 * raw - Do not add identifier quotes to the table name
1924 * @return String: full database name
1926 function tableName( $name, $format = 'quoted' ) {
1927 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1928 # Skip the entire process when we have a string quoted on both ends.
1929 # Note that we check the end so that we will still quote any use of
1930 # use of `database`.table. But won't break things if someone wants
1931 # to query a database table with a dot in the name.
1932 if ( $this->isQuotedIdentifier( $name ) ) {
1936 # Lets test for any bits of text that should never show up in a table
1937 # name. Basically anything like JOIN or ON which are actually part of
1938 # SQL queries, but may end up inside of the table value to combine
1939 # sql. Such as how the API is doing.
1940 # Note that we use a whitespace test rather than a \b test to avoid
1941 # any remote case where a word like on may be inside of a table name
1942 # surrounded by symbols which may be considered word breaks.
1943 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1947 # Split database and table into proper variables.
1948 # We reverse the explode so that database.table and table both output
1949 # the correct table.
1950 $dbDetails = array_reverse( explode( '.', $name, 2 ) );
1951 if ( isset( $dbDetails[1] ) ) {
1952 list( $table, $database ) = $dbDetails;
1954 list( $table ) = $dbDetails;
1956 $prefix = $this->mTablePrefix
; # Default prefix
1958 # A database name has been specified in input. We don't want any
1960 if ( isset( $database ) ) {
1964 # Note that we use the long format because php will complain in in_array if
1965 # the input is not an array, and will complain in is_array if it is not set.
1966 if ( !isset( $database ) # Don't use shared database if pre selected.
1967 && isset( $wgSharedDB ) # We have a shared database
1968 && !$this->isQuotedIdentifier( $table ) # Paranoia check to prevent shared tables listing '`table`'
1969 && isset( $wgSharedTables )
1970 && is_array( $wgSharedTables )
1971 && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1972 $database = $wgSharedDB;
1973 $prefix = isset( $wgSharedPrefix ) ?
$wgSharedPrefix : $prefix;
1976 # Quote the $database and $table and apply the prefix if not quoted.
1977 if ( isset( $database ) ) {
1978 $database = ( $format == 'quoted' ||
$this->isQuotedIdentifier( $database ) ?
$database : $this->addIdentifierQuotes( $database ) );
1981 $table = "{$prefix}{$table}";
1982 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $table ) ) {
1983 $table = $this->addIdentifierQuotes( "{$table}" );
1986 # Merge our database and table into our final table name.
1987 $tableName = ( isset( $database ) ?
"{$database}.{$table}" : "{$table}" );
1993 * Fetch a number of table names into an array
1994 * This is handy when you need to construct SQL for joins
1997 * extract($dbr->tableNames('user','watchlist'));
1998 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1999 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2003 public function tableNames() {
2004 $inArray = func_get_args();
2007 foreach ( $inArray as $name ) {
2008 $retVal[$name] = $this->tableName( $name );
2015 * Fetch a number of table names into an zero-indexed numerical array
2016 * This is handy when you need to construct SQL for joins
2019 * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
2020 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
2021 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
2025 public function tableNamesN() {
2026 $inArray = func_get_args();
2029 foreach ( $inArray as $name ) {
2030 $retVal[] = $this->tableName( $name );
2037 * Get an aliased table name
2038 * e.g. tableName AS newTableName
2040 * @param $name string Table name, see tableName()
2041 * @param $alias string|bool Alias (optional)
2042 * @return string SQL name for aliased table. Will not alias a table to its own name
2044 public function tableNameWithAlias( $name, $alias = false ) {
2045 if ( !$alias ||
$alias == $name ) {
2046 return $this->tableName( $name );
2048 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2053 * Gets an array of aliased table names
2055 * @param $tables array( [alias] => table )
2056 * @return array of strings, see tableNameWithAlias()
2058 public function tableNamesWithAlias( $tables ) {
2060 foreach ( $tables as $alias => $table ) {
2061 if ( is_numeric( $alias ) ) {
2064 $retval[] = $this->tableNameWithAlias( $table, $alias );
2070 * Get the aliased table name clause for a FROM clause
2071 * which might have a JOIN and/or USE INDEX clause
2073 * @param $tables array ( [alias] => table )
2074 * @param $use_index array Same as for select()
2075 * @param $join_conds array Same as for select()
2078 protected function tableNamesWithUseIndexOrJOIN(
2079 $tables, $use_index = array(), $join_conds = array()
2083 $use_index = (array)$use_index;
2084 $join_conds = (array)$join_conds;
2086 foreach ( $tables as $alias => $table ) {
2087 if ( !is_string( $alias ) ) {
2088 // No alias? Set it equal to the table name
2091 // Is there a JOIN clause for this table?
2092 if ( isset( $join_conds[$alias] ) ) {
2093 list( $joinType, $conds ) = $join_conds[$alias];
2094 $tableClause = $joinType;
2095 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2096 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2097 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2099 $tableClause .= ' ' . $use;
2102 $on = $this->makeList( (array)$conds, LIST_AND
);
2104 $tableClause .= ' ON (' . $on . ')';
2107 $retJOIN[] = $tableClause;
2108 // Is there an INDEX clause for this table?
2109 } elseif ( isset( $use_index[$alias] ) ) {
2110 $tableClause = $this->tableNameWithAlias( $table, $alias );
2111 $tableClause .= ' ' . $this->useIndexClause(
2112 implode( ',', (array)$use_index[$alias] ) );
2114 $ret[] = $tableClause;
2116 $tableClause = $this->tableNameWithAlias( $table, $alias );
2118 $ret[] = $tableClause;
2122 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2123 $straightJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2124 $otherJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2126 // Compile our final table clause
2127 return implode( ' ', array( $straightJoins, $otherJoins ) );
2131 * Get the name of an index in a given table
2137 function indexName( $index ) {
2138 // Backwards-compatibility hack
2140 'ar_usertext_timestamp' => 'usertext_timestamp',
2141 'un_user_id' => 'user_id',
2142 'un_user_ip' => 'user_ip',
2145 if ( isset( $renamed[$index] ) ) {
2146 return $renamed[$index];
2153 * If it's a string, adds quotes and backslashes
2154 * Otherwise returns as-is
2160 function addQuotes( $s ) {
2161 if ( $s === null ) {
2164 # This will also quote numeric values. This should be harmless,
2165 # and protects against weird problems that occur when they really
2166 # _are_ strings such as article titles and string->number->string
2167 # conversion is not 1:1.
2168 return "'" . $this->strencode( $s ) . "'";
2173 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2174 * MySQL uses `backticks` while basically everything else uses double quotes.
2175 * Since MySQL is the odd one out here the double quotes are our generic
2176 * and we implement backticks in DatabaseMysql.
2182 public function addIdentifierQuotes( $s ) {
2183 return '"' . str_replace( '"', '""', $s ) . '"';
2187 * Returns if the given identifier looks quoted or not according to
2188 * the database convention for quoting identifiers .
2190 * @param $name string
2194 public function isQuotedIdentifier( $name ) {
2195 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2199 * Backwards compatibility, identifier quoting originated in DatabasePostgres
2200 * which used quote_ident which does not follow our naming conventions
2201 * was renamed to addIdentifierQuotes.
2202 * @deprecated since 1.18 use addIdentifierQuotes
2208 function quote_ident( $s ) {
2209 wfDeprecated( __METHOD__
, '1.18' );
2210 return $this->addIdentifierQuotes( $s );
2214 * Escape string for safe LIKE usage.
2215 * WARNING: you should almost never use this function directly,
2216 * instead use buildLike() that escapes everything automatically
2217 * @deprecated since 1.17, warnings in 1.17, removed in ???
2223 public function escapeLike( $s ) {
2224 wfDeprecated( __METHOD__
, '1.17' );
2225 return $this->escapeLikeInternal( $s );
2232 protected function escapeLikeInternal( $s ) {
2233 $s = str_replace( '\\', '\\\\', $s );
2234 $s = $this->strencode( $s );
2235 $s = str_replace( array( '%', '_' ), array( '\%', '\_' ), $s );
2241 * LIKE statement wrapper, receives a variable-length argument list with parts of pattern to match
2242 * containing either string literals that will be escaped or tokens returned by anyChar() or anyString().
2243 * Alternatively, the function could be provided with an array of aforementioned parameters.
2245 * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches
2246 * for subpages of 'My page title'.
2247 * Alternatively: $pattern = array( 'My_page_title/', $dbr->anyString() ); $query .= $dbr->buildLike( $pattern );
2250 * @return String: fully built LIKE statement
2252 function buildLike() {
2253 $params = func_get_args();
2255 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2256 $params = $params[0];
2261 foreach ( $params as $value ) {
2262 if ( $value instanceof LikeMatch
) {
2263 $s .= $value->toString();
2265 $s .= $this->escapeLikeInternal( $value );
2269 return " LIKE '" . $s . "' ";
2273 * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
2277 function anyChar() {
2278 return new LikeMatch( '_' );
2282 * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
2286 function anyString() {
2287 return new LikeMatch( '%' );
2291 * Returns an appropriately quoted sequence value for inserting a new row.
2292 * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
2293 * subclass will return an integer, and save the value for insertId()
2295 * Any implementation of this function should *not* involve reusing
2296 * sequence numbers created for rolled-back transactions.
2297 * See http://bugs.mysql.com/bug.php?id=30767 for details.
2298 * @param $seqName string
2301 function nextSequenceValue( $seqName ) {
2306 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2307 * is only needed because a) MySQL must be as efficient as possible due to
2308 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2309 * which index to pick. Anyway, other databases might have different
2310 * indexes on a given table. So don't bother overriding this unless you're
2315 function useIndexClause( $index ) {
2320 * REPLACE query wrapper.
2322 * REPLACE is a very handy MySQL extension, which functions like an INSERT
2323 * except that when there is a duplicate key error, the old row is deleted
2324 * and the new row is inserted in its place.
2326 * We simulate this with standard SQL with a DELETE followed by INSERT. To
2327 * perform the delete, we need to know what the unique indexes are so that
2328 * we know how to find the conflicting rows.
2330 * It may be more efficient to leave off unique indexes which are unlikely
2331 * to collide. However if you do this, you run the risk of encountering
2332 * errors which wouldn't have occurred in MySQL.
2334 * @param $table String: The table to replace the row(s) in.
2335 * @param $rows array Can be either a single row to insert, or multiple rows,
2336 * in the same format as for DatabaseBase::insert()
2337 * @param $uniqueIndexes array is an array of indexes. Each element may be either
2338 * a field name or an array of field names
2339 * @param $fname String: Calling function name (use __METHOD__) for logs/profiling
2341 function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseBase::replace' ) {
2342 $quotedTable = $this->tableName( $table );
2344 if ( count( $rows ) == 0 ) {
2349 if ( !is_array( reset( $rows ) ) ) {
2350 $rows = array( $rows );
2353 foreach( $rows as $row ) {
2354 # Delete rows which collide
2355 if ( $uniqueIndexes ) {
2356 $sql = "DELETE FROM $quotedTable WHERE ";
2358 foreach ( $uniqueIndexes as $index ) {
2365 if ( is_array( $index ) ) {
2367 foreach ( $index as $col ) {
2373 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2376 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2380 $this->query( $sql, $fname );
2383 # Now insert the row
2384 $this->insert( $table, $row );
2389 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2392 * @param $table string Table name
2393 * @param $rows array Rows to insert
2394 * @param $fname string Caller function name
2396 * @return ResultWrapper
2398 protected function nativeReplace( $table, $rows, $fname ) {
2399 $table = $this->tableName( $table );
2402 if ( !is_array( reset( $rows ) ) ) {
2403 $rows = array( $rows );
2406 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2409 foreach ( $rows as $row ) {
2416 $sql .= '(' . $this->makeList( $row ) . ')';
2419 return $this->query( $sql, $fname );
2423 * DELETE where the condition is a join.
2425 * MySQL overrides this to use a multi-table DELETE syntax, in other databases
2426 * we use sub-selects
2428 * For safety, an empty $conds will not delete everything. If you want to
2429 * delete all rows where the join condition matches, set $conds='*'.
2431 * DO NOT put the join condition in $conds.
2433 * @param $delTable String: The table to delete from.
2434 * @param $joinTable String: The other table.
2435 * @param $delVar String: The variable to join on, in the first table.
2436 * @param $joinVar String: The variable to join on, in the second table.
2437 * @param $conds Array: Condition array of field names mapped to variables,
2438 * ANDed together in the WHERE clause
2439 * @param $fname String: Calling function name (use __METHOD__) for
2442 function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2443 $fname = 'DatabaseBase::deleteJoin' )
2446 throw new DBUnexpectedError( $this,
2447 'DatabaseBase::deleteJoin() called with empty $conds' );
2450 $delTable = $this->tableName( $delTable );
2451 $joinTable = $this->tableName( $joinTable );
2452 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2453 if ( $conds != '*' ) {
2454 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2458 $this->query( $sql, $fname );
2462 * Returns the size of a text field, or -1 for "unlimited"
2464 * @param $table string
2465 * @param $field string
2469 function textFieldSize( $table, $field ) {
2470 $table = $this->tableName( $table );
2471 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2472 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2473 $row = $this->fetchObject( $res );
2477 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2487 * A string to insert into queries to show that they're low-priority, like
2488 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2489 * string and nothing bad should happen.
2491 * @return string Returns the text of the low priority option if it is
2492 * supported, or a blank string otherwise
2494 function lowPriorityOption() {
2499 * DELETE query wrapper.
2501 * @param $table Array Table name
2502 * @param $conds String|Array of conditions. See $conds in DatabaseBase::select() for
2503 * the format. Use $conds == "*" to delete all rows
2504 * @param $fname String name of the calling function
2508 function delete( $table, $conds, $fname = 'DatabaseBase::delete' ) {
2510 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2513 $table = $this->tableName( $table );
2514 $sql = "DELETE FROM $table";
2516 if ( $conds != '*' ) {
2517 $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND
);
2520 return $this->query( $sql, $fname );
2524 * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
2525 * into another table.
2527 * @param $destTable string The table name to insert into
2528 * @param $srcTable string|array May be either a table name, or an array of table names
2529 * to include in a join.
2531 * @param $varMap array must be an associative array of the form
2532 * array( 'dest1' => 'source1', ...). Source items may be literals
2533 * rather than field names, but strings should be quoted with
2534 * DatabaseBase::addQuotes()
2536 * @param $conds array Condition array. See $conds in DatabaseBase::select() for
2537 * the details of the format of condition arrays. May be "*" to copy the
2540 * @param $fname string The function name of the caller, from __METHOD__
2542 * @param $insertOptions array Options for the INSERT part of the query, see
2543 * DatabaseBase::insert() for details.
2544 * @param $selectOptions array Options for the SELECT part of the query, see
2545 * DatabaseBase::select() for details.
2547 * @return ResultWrapper
2549 function insertSelect( $destTable, $srcTable, $varMap, $conds,
2550 $fname = 'DatabaseBase::insertSelect',
2551 $insertOptions = array(), $selectOptions = array() )
2553 $destTable = $this->tableName( $destTable );
2555 if ( is_array( $insertOptions ) ) {
2556 $insertOptions = implode( ' ', $insertOptions );
2559 if ( !is_array( $selectOptions ) ) {
2560 $selectOptions = array( $selectOptions );
2563 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
2565 if ( is_array( $srcTable ) ) {
2566 $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
2568 $srcTable = $this->tableName( $srcTable );
2571 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2572 " SELECT $startOpts " . implode( ',', $varMap ) .
2573 " FROM $srcTable $useIndex ";
2575 if ( $conds != '*' ) {
2576 if ( is_array( $conds ) ) {
2577 $conds = $this->makeList( $conds, LIST_AND
);
2579 $sql .= " WHERE $conds";
2582 $sql .= " $tailOpts";
2584 return $this->query( $sql, $fname );
2588 * Construct a LIMIT query with optional offset. This is used for query
2589 * pages. The SQL should be adjusted so that only the first $limit rows
2590 * are returned. If $offset is provided as well, then the first $offset
2591 * rows should be discarded, and the next $limit rows should be returned.
2592 * If the result of the query is not ordered, then the rows to be returned
2593 * are theoretically arbitrary.
2595 * $sql is expected to be a SELECT, if that makes a difference. For
2596 * UPDATE, limitResultForUpdate should be used.
2598 * The version provided by default works in MySQL and SQLite. It will very
2599 * likely need to be overridden for most other DBMSes.
2601 * @param $sql String SQL query we will append the limit too
2602 * @param $limit Integer the SQL limit
2603 * @param $offset Integer|false the SQL offset (default false)
2607 function limitResult( $sql, $limit, $offset = false ) {
2608 if ( !is_numeric( $limit ) ) {
2609 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2612 return "$sql LIMIT "
2613 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2622 function limitResultForUpdate( $sql, $num ) {
2623 return $this->limitResult( $sql, $num, 0 );
2627 * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
2628 * within the UNION construct.
2631 function unionSupportsOrderAndLimit() {
2632 return true; // True for almost every DB supported
2636 * Construct a UNION query
2637 * This is used for providing overload point for other DB abstractions
2638 * not compatible with the MySQL syntax.
2639 * @param $sqls Array: SQL statements to combine
2640 * @param $all Boolean: use UNION ALL
2641 * @return String: SQL fragment
2643 function unionQueries( $sqls, $all ) {
2644 $glue = $all ?
') UNION ALL (' : ') UNION (';
2645 return '(' . implode( $glue, $sqls ) . ')';
2649 * Returns an SQL expression for a simple conditional. This doesn't need
2650 * to be overridden unless CASE isn't supported in your DBMS.
2652 * @param $cond String: SQL expression which will result in a boolean value
2653 * @param $trueVal String: SQL expression to return if true
2654 * @param $falseVal String: SQL expression to return if false
2655 * @return String: SQL fragment
2657 function conditional( $cond, $trueVal, $falseVal ) {
2658 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2662 * Returns a comand for str_replace function in SQL query.
2663 * Uses REPLACE() in MySQL
2665 * @param $orig String: column to modify
2666 * @param $old String: column to seek
2667 * @param $new String: column to replace with
2671 function strreplace( $orig, $old, $new ) {
2672 return "REPLACE({$orig}, {$old}, {$new})";
2676 * Determines how long the server has been up
2681 function getServerUptime() {
2686 * Determines if the last failure was due to a deadlock
2691 function wasDeadlock() {
2696 * Determines if the last failure was due to a lock timeout
2701 function wasLockTimeout() {
2706 * Determines if the last query error was something that should be dealt
2707 * with by pinging the connection and reissuing the query.
2712 function wasErrorReissuable() {
2717 * Determines if the last failure was due to the database being read-only.
2722 function wasReadOnlyError() {
2727 * Perform a deadlock-prone transaction.
2729 * This function invokes a callback function to perform a set of write
2730 * queries. If a deadlock occurs during the processing, the transaction
2731 * will be rolled back and the callback function will be called again.
2734 * $dbw->deadlockLoop( callback, ... );
2736 * Extra arguments are passed through to the specified callback function.
2738 * Returns whatever the callback function returned on its successful,
2739 * iteration, or false on error, for example if the retry limit was
2744 function deadlockLoop() {
2747 $args = func_get_args();
2748 $function = array_shift( $args );
2749 $oldIgnore = $this->ignoreErrors( true );
2750 $tries = DEADLOCK_TRIES
;
2752 if ( is_array( $function ) ) {
2753 $fname = $function[0];
2759 $retVal = call_user_func_array( $function, $args );
2760 $error = $this->lastError();
2761 $errno = $this->lastErrno();
2762 $sql = $this->lastQuery();
2765 if ( $this->wasDeadlock() ) {
2767 usleep( mt_rand( DEADLOCK_DELAY_MIN
, DEADLOCK_DELAY_MAX
) );
2769 $this->reportQueryError( $error, $errno, $sql, $fname );
2772 } while ( $this->wasDeadlock() && --$tries > 0 );
2774 $this->ignoreErrors( $oldIgnore );
2776 if ( $tries <= 0 ) {
2777 $this->rollback( __METHOD__
);
2778 $this->reportQueryError( $error, $errno, $sql, $fname );
2781 $this->commit( __METHOD__
);
2787 * Wait for the slave to catch up to a given master position.
2789 * @param $pos DBMasterPos object
2790 * @param $timeout Integer: the maximum number of seconds to wait for
2793 * @return An integer: zero if the slave was past that position already,
2794 * greater than zero if we waited for some period of time, less than
2795 * zero if we timed out.
2797 function masterPosWait( DBMasterPos
$pos, $timeout ) {
2798 wfProfileIn( __METHOD__
);
2800 if ( !is_null( $this->mFakeSlaveLag
) ) {
2801 $wait = intval( ( $pos->pos
- microtime( true ) +
$this->mFakeSlaveLag
) * 1e6
);
2803 if ( $wait > $timeout * 1e6
) {
2804 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
2805 wfProfileOut( __METHOD__
);
2807 } elseif ( $wait > 0 ) {
2808 wfDebug( "Fake slave waiting $wait us\n" );
2810 wfProfileOut( __METHOD__
);
2813 wfDebug( "Fake slave up to date ($wait us)\n" );
2814 wfProfileOut( __METHOD__
);
2819 wfProfileOut( __METHOD__
);
2821 # Real waits are implemented in the subclass.
2826 * Get the replication position of this slave
2828 * @return DBMasterPos, or false if this is not a slave.
2830 function getSlavePos() {
2831 if ( !is_null( $this->mFakeSlaveLag
) ) {
2832 $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag
);
2833 wfDebug( __METHOD__
. ": fake slave pos = $pos\n" );
2842 * Get the position of this master
2844 * @return DBMasterPos, or false if this is not a master
2846 function getMasterPos() {
2847 if ( $this->mFakeMaster
) {
2848 return new MySQLMasterPos( 'fake', microtime( true ) );
2855 * Begin a transaction, committing any previously open transaction
2857 * @param $fname string
2859 function begin( $fname = 'DatabaseBase::begin' ) {
2860 $this->query( 'BEGIN', $fname );
2861 $this->mTrxLevel
= 1;
2867 * @param $fname string
2869 function commit( $fname = 'DatabaseBase::commit' ) {
2870 if ( $this->mTrxLevel
) {
2871 $this->query( 'COMMIT', $fname );
2872 $this->mTrxLevel
= 0;
2877 * Rollback a transaction.
2878 * No-op on non-transactional databases.
2880 * @param $fname string
2882 function rollback( $fname = 'DatabaseBase::rollback' ) {
2883 if ( $this->mTrxLevel
) {
2884 $this->query( 'ROLLBACK', $fname, true );
2885 $this->mTrxLevel
= 0;
2890 * Creates a new table with structure copied from existing table
2891 * Note that unlike most database abstraction functions, this function does not
2892 * automatically append database prefix, because it works at a lower
2893 * abstraction level.
2894 * The table names passed to this function shall not be quoted (this
2895 * function calls addIdentifierQuotes when needed).
2897 * @param $oldName String: name of table whose structure should be copied
2898 * @param $newName String: name of table to be created
2899 * @param $temporary Boolean: whether the new table should be temporary
2900 * @param $fname String: calling function name
2901 * @return Boolean: true if operation was successful
2903 function duplicateTableStructure( $oldName, $newName, $temporary = false,
2904 $fname = 'DatabaseBase::duplicateTableStructure' )
2906 throw new MWException(
2907 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
2911 * List all tables on the database
2913 * @param $prefix Only show tables with this prefix, e.g. mw_
2914 * @param $fname String: calling function name
2916 function listTables( $prefix = null, $fname = 'DatabaseBase::listTables' ) {
2917 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
2921 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2922 * to the format used for inserting into timestamp fields in this DBMS.
2924 * The result is unquoted, and needs to be passed through addQuotes()
2925 * before it can be included in raw SQL.
2927 * @param $ts string|int
2931 function timestamp( $ts = 0 ) {
2932 return wfTimestamp( TS_MW
, $ts );
2936 * Convert a timestamp in one of the formats accepted by wfTimestamp()
2937 * to the format used for inserting into timestamp fields in this DBMS. If
2938 * NULL is input, it is passed through, allowing NULL values to be inserted
2939 * into timestamp fields.
2941 * The result is unquoted, and needs to be passed through addQuotes()
2942 * before it can be included in raw SQL.
2944 * @param $ts string|int
2948 function timestampOrNull( $ts = null ) {
2949 if ( is_null( $ts ) ) {
2952 return $this->timestamp( $ts );
2957 * Take the result from a query, and wrap it in a ResultWrapper if
2958 * necessary. Boolean values are passed through as is, to indicate success
2959 * of write queries or failure.
2961 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
2962 * resource, and it was necessary to call this function to convert it to
2963 * a wrapper. Nowadays, raw database objects are never exposed to external
2964 * callers, so this is unnecessary in external code. For compatibility with
2965 * old code, ResultWrapper objects are passed through unaltered.
2967 * @param $result bool|ResultWrapper
2969 * @return bool|ResultWrapper
2971 function resultObject( $result ) {
2972 if ( empty( $result ) ) {
2974 } elseif ( $result instanceof ResultWrapper
) {
2976 } elseif ( $result === true ) {
2977 // Successful write query
2980 return new ResultWrapper( $this, $result );
2985 * Return aggregated value alias
2988 * @param $valuename string
2992 function aggregateValue ( $valuedata, $valuename = 'value' ) {
2997 * Ping the server and try to reconnect if it there is no connection
2999 * @return bool Success or failure
3002 # Stub. Not essential to override.
3007 * Get slave lag. Currently supported only by MySQL.
3009 * Note that this function will generate a fatal error on many
3010 * installations. Most callers should use LoadBalancer::safeGetLag()
3013 * @return Database replication lag in seconds
3016 return intval( $this->mFakeSlaveLag
);
3020 * Return the maximum number of items allowed in a list, or 0 for unlimited.
3024 function maxListLen() {
3029 * Some DBMSs have a special format for inserting into blob fields, they
3030 * don't allow simple quoted strings to be inserted. To insert into such
3031 * a field, pass the data through this function before passing it to
3032 * DatabaseBase::insert().
3036 function encodeBlob( $b ) {
3041 * Some DBMSs return a special placeholder object representing blob fields
3042 * in result objects. Pass the object through this function to return the
3047 function decodeBlob( $b ) {
3052 * Override database's default connection timeout
3054 * @param $timeout Integer in seconds
3055 * @deprecated since 1.19; use setSessionOptions()
3057 public function setTimeout( $timeout ) {
3058 wfDeprecated( __METHOD__
, '1.19' );
3059 $this->setSessionOptions( array( 'connTimeout' => $timeout ) );
3063 * Override database's default behavior. $options include:
3064 * 'connTimeout' : Set the connection timeout value in seconds.
3065 * May be useful for very long batch queries such as
3066 * full-wiki dumps, where a single query reads out over
3069 * @param $options Array
3071 public function setSessionOptions( array $options ) {}
3074 * Read and execute SQL commands from a file.
3076 * Returns true on success, error string or exception on failure (depending
3077 * on object's error ignore settings).
3079 * @param $filename String: File name to open
3080 * @param $lineCallback Callback: Optional function called before reading each line
3081 * @param $resultCallback Callback: Optional function called for each MySQL result
3082 * @param $fname String: Calling function name or false if name should be
3083 * generated dynamically using $filename
3084 * @return bool|string
3086 function sourceFile( $filename, $lineCallback = false, $resultCallback = false, $fname = false ) {
3087 wfSuppressWarnings();
3088 $fp = fopen( $filename, 'r' );
3089 wfRestoreWarnings();
3091 if ( false === $fp ) {
3092 throw new MWException( "Could not open \"{$filename}\".\n" );
3096 $fname = __METHOD__
. "( $filename )";
3100 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname );
3102 catch ( MWException
$e ) {
3113 * Get the full path of a patch file. Originally based on archive()
3114 * from updaters.inc. Keep in mind this always returns a patch, as
3115 * it fails back to MySQL if no DB-specific patch can be found
3117 * @param $patch String The name of the patch, like patch-something.sql
3118 * @return String Full path to patch file
3120 public function patchPath( $patch ) {
3123 $dbType = $this->getType();
3124 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3125 return "$IP/maintenance/$dbType/archives/$patch";
3127 return "$IP/maintenance/archives/$patch";
3132 * Set variables to be used in sourceFile/sourceStream, in preference to the
3133 * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
3134 * all. If it's set to false, $GLOBALS will be used.
3136 * @param $vars False, or array mapping variable name to value.
3138 function setSchemaVars( $vars ) {
3139 $this->mSchemaVars
= $vars;
3143 * Read and execute commands from an open file handle.
3145 * Returns true on success, error string or exception on failure (depending
3146 * on object's error ignore settings).
3148 * @param $fp Resource: File handle
3149 * @param $lineCallback Callback: Optional function called before reading each line
3150 * @param $resultCallback Callback: Optional function called for each MySQL result
3151 * @param $fname String: Calling function name
3152 * @return bool|string
3154 function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3155 $fname = 'DatabaseBase::sourceStream' )
3160 while ( !feof( $fp ) ) {
3161 if ( $lineCallback ) {
3162 call_user_func( $lineCallback );
3165 $line = trim( fgets( $fp ) );
3167 if ( $line == '' ) {
3171 if ( '-' == $line[0] && '-' == $line[1] ) {
3179 $done = $this->streamStatementEnd( $cmd, $line );
3183 if ( $done ||
feof( $fp ) ) {
3184 $cmd = $this->replaceVars( $cmd );
3185 $res = $this->query( $cmd, $fname );
3187 if ( $resultCallback ) {
3188 call_user_func( $resultCallback, $res, $this );
3191 if ( false === $res ) {
3192 $err = $this->lastError();
3193 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3205 * Called by sourceStream() to check if we've reached a statement end
3207 * @param $sql String: SQL assembled so far
3208 * @param $newLine String: New line about to be added to $sql
3209 * @returns Bool: Whether $newLine contains end of the statement
3211 protected function streamStatementEnd( &$sql, &$newLine ) {
3212 if ( $this->delimiter
) {
3214 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3215 if ( $newLine != $prev ) {
3223 * Database independent variable replacement. Replaces a set of variables
3224 * in an SQL statement with their contents as given by $this->getSchemaVars().
3226 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3228 * - '{$var}' should be used for text and is passed through the database's
3230 * - `{$var}` should be used for identifiers (eg: table and database names),
3231 * it is passed through the database's addIdentifierQuotes method which
3232 * can be overridden if the database uses something other than backticks.
3233 * - / *$var* / is just encoded, besides traditional table prefix and
3234 * table options its use should be avoided.
3236 * @param $ins String: SQL statement to replace variables in
3237 * @return String The new SQL statement with variables replaced
3239 protected function replaceSchemaVars( $ins ) {
3240 $vars = $this->getSchemaVars();
3241 foreach ( $vars as $var => $value ) {
3243 $ins = str_replace( '\'{$' . $var . '}\'', $this->addQuotes( $value ), $ins );
3245 $ins = str_replace( '`{$' . $var . '}`', $this->addIdentifierQuotes( $value ), $ins );
3247 $ins = str_replace( '/*$' . $var . '*/', $this->strencode( $value ) , $ins );
3253 * Replace variables in sourced SQL
3255 * @param $ins string
3259 protected function replaceVars( $ins ) {
3260 $ins = $this->replaceSchemaVars( $ins );
3263 $ins = preg_replace_callback( '!/\*(?:\$wgDBprefix|_)\*/([a-zA-Z_0-9]*)!',
3264 array( $this, 'tableNameCallback' ), $ins );
3267 $ins = preg_replace_callback( '!/\*i\*/([a-zA-Z_0-9]*)!',
3268 array( $this, 'indexNameCallback' ), $ins );
3274 * Get schema variables. If none have been set via setSchemaVars(), then
3275 * use some defaults from the current object.
3279 protected function getSchemaVars() {
3280 if ( $this->mSchemaVars
) {
3281 return $this->mSchemaVars
;
3283 return $this->getDefaultSchemaVars();
3288 * Get schema variables to use if none have been set via setSchemaVars().
3290 * Override this in derived classes to provide variables for tables.sql
3291 * and SQL patch files.
3295 protected function getDefaultSchemaVars() {
3300 * Table name callback
3302 * @param $matches array
3306 protected function tableNameCallback( $matches ) {
3307 return $this->tableName( $matches[1] );
3311 * Index name callback
3313 * @param $matches array
3317 protected function indexNameCallback( $matches ) {
3318 return $this->indexName( $matches[1] );
3322 * Build a concatenation list to feed into a SQL query
3323 * @param $stringList Array: list of raw SQL expressions; caller is responsible for any quoting
3326 function buildConcat( $stringList ) {
3327 return 'CONCAT(' . implode( ',', $stringList ) . ')';
3331 * Acquire a named lock
3333 * Abstracted from Filestore::lock() so child classes can implement for
3336 * @param $lockName String: name of lock to aquire
3337 * @param $method String: name of method calling us
3338 * @param $timeout Integer: timeout
3341 public function lock( $lockName, $method, $timeout = 5 ) {
3348 * @param $lockName String: Name of lock to release
3349 * @param $method String: Name of method calling us
3351 * @return Returns 1 if the lock was released, 0 if the lock was not established
3352 * by this thread (in which case the lock is not released), and NULL if the named
3353 * lock did not exist
3355 public function unlock( $lockName, $method ) {
3360 * Lock specific tables
3362 * @param $read Array of tables to lock for read access
3363 * @param $write Array of tables to lock for write access
3364 * @param $method String name of caller
3365 * @param $lowPriority bool Whether to indicate writes to be LOW PRIORITY
3369 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3374 * Unlock specific tables
3376 * @param $method String the caller
3380 public function unlockTables( $method ) {
3386 * @param $tableName string
3387 * @param $fName string
3388 * @return bool|ResultWrapper
3391 public function dropTable( $tableName, $fName = 'DatabaseBase::dropTable' ) {
3392 if( !$this->tableExists( $tableName, $fName ) ) {
3395 $sql = "DROP TABLE " . $this->tableName( $tableName );
3396 if( $this->cascadingDeletes() ) {
3399 return $this->query( $sql, $fName );
3403 * Get search engine class. All subclasses of this need to implement this
3404 * if they wish to use searching.
3408 public function getSearchEngine() {
3409 return 'SearchEngineDummy';
3413 * Find out when 'infinity' is. Most DBMSes support this. This is a special
3414 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
3415 * because "i" sorts after all numbers.
3419 public function getInfinity() {
3424 * Encode an expiry time
3426 * @param $expiry String: timestamp for expiry, or the 'infinity' string
3429 public function encodeExpiry( $expiry ) {
3430 if ( $expiry == '' ||
$expiry == $this->getInfinity() ) {
3431 return $this->getInfinity();
3433 return $this->timestamp( $expiry );
3438 * Allow or deny "big selects" for this session only. This is done by setting
3439 * the sql_big_selects session variable.
3441 * This is a MySQL-specific feature.
3443 * @param $value Mixed: true for allow, false for deny, or "default" to
3444 * restore the initial value
3446 public function setBigSelects( $value = true ) {