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Wikimedia\Rdbms\IDatabase Interface Reference

Basic database interface for live and lazy-loaded relation database handles. More...

Inheritance diagram for Wikimedia\Rdbms\IDatabase:

Public Member Functions

 __toString ()
 Get a debugging string that mentions the database type, the ID of this instance, and the ID of any underlying connection resource or driver object if one is present. More...
 
 addIdentifierQuotes ( $s)
 Escape a SQL identifier (e.g. More...
 
 addQuotes ( $s)
 Escape and quote a raw value string for use in a SQL query. More...
 
 affectedRows ()
 Get the number of rows affected by the last write query. More...
 
 aggregateValue ( $valuedata, $valuename='value')
 Return aggregated value alias. More...
 
 anyChar ()
 Returns a token for buildLike() that denotes a '_' to be used in a LIKE query. More...
 
 anyString ()
 Returns a token for buildLike() that denotes a '' to be used in a LIKE query. More...
 
 assertNoOpenTransactions ()
 Assert that all explicit transactions or atomic sections have been closed. More...
 
 begin ( $fname=__METHOD__, $mode=self::TRANSACTION_EXPLICIT)
 Begin a transaction. More...
 
 bitAnd ( $fieldLeft, $fieldRight)
 
 bitNot ( $field)
 
 bitOr ( $fieldLeft, $fieldRight)
 
 buildConcat ( $stringList)
 Build a concatenation list to feed into a SQL query. More...
 
 buildGroupConcatField ( $delim, $table, $field, $conds='', $join_conds=[])
 Build a GROUP_CONCAT or equivalent statement for a query. More...
 
 buildIntegerCast ( $field)
 
 buildLike ( $param,... $params)
 LIKE statement wrapper. More...
 
 buildSelectSubquery ( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Equivalent to IDatabase::selectSQLText() except wraps the result in Subqyery. More...
 
 buildStringCast ( $field)
 
 buildSubString ( $input, $startPosition, $length=null)
 Build a SUBSTRING function. More...
 
 cancelAtomic ( $fname=__METHOD__, AtomicSectionIdentifier $sectionId=null)
 Cancel an atomic section of SQL statements. More...
 
 clearFlag ( $flag, $remember=self::REMEMBER_NOTHING)
 Clear a flag for this connection. More...
 
 close ( $fname=__METHOD__, $owner=null)
 Close the database connection. More...
 
 commit ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)
 Commits a transaction previously started using begin() More...
 
 conditional ( $cond, $trueVal, $falseVal)
 Returns an SQL expression for a simple conditional. More...
 
 databasesAreIndependent ()
 Returns true if DBs are assumed to be on potentially different servers. More...
 
 dataSeek ( $res, $row)
 Change the position of the cursor in a result object. More...
 
 dbSchema ( $schema=null)
 Get/set the db schema. More...
 
 decodeBlob ( $b)
 Some DBMSs return a special placeholder object representing blob fields in result objects. More...
 
 decodeExpiry ( $expiry, $format=TS_MW)
 Decode an expiry time into a DBMS independent format. More...
 
 delete ( $table, $conds, $fname=__METHOD__)
 DELETE query wrapper. More...
 
 deleteJoin ( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname=__METHOD__)
 DELETE where the condition is a join. More...
 
 doAtomicSection ( $fname, callable $callback, $cancelable=self::ATOMIC_NOT_CANCELABLE)
 Perform an atomic section of reversable SQL statements from a callback. More...
 
 encodeBlob ( $b)
 Some DBMSs have a special format for inserting into blob fields, they don't allow simple quoted strings to be inserted. More...
 
 encodeExpiry ( $expiry)
 Encode an expiry time into the DBMS dependent format. More...
 
 endAtomic ( $fname=__METHOD__)
 Ends an atomic section of SQL statements. More...
 
 estimateRowCount ( $tables, $var=' *', $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Estimate the number of rows in dataset. More...
 
 explicitTrxActive ()
 
 fetchObject ( $res)
 Fetch the next row from the given result object, in object form. More...
 
 fetchRow ( $res)
 Fetch the next row from the given result object, in associative array form. More...
 
 fieldExists ( $table, $field, $fname=__METHOD__)
 Determines whether a field exists in a table. More...
 
 fieldName ( $res, $n)
 Get a field name in a result object. More...
 
 flushSnapshot ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)
 Commit any transaction but error out if writes or callbacks are pending. More...
 
 freeResult ( $res)
 Free a result object returned by query() or select() More...
 
 getDBname ()
 Get the current DB name. More...
 
 getDomainID ()
 Return the currently selected domain ID. More...
 
 getFlag ( $flag)
 Returns a boolean whether the flag $flag is set for this connection. More...
 
 getInfinity ()
 Find out when 'infinity' is. More...
 
 getLag ()
 Get the amount of replication lag for this database server. More...
 
 getLBInfo ( $name=null)
 Get properties passed down from the server info array of the load balancer. More...
 
 getMasterPos ()
 Get the position of this master. More...
 
 getReplicaPos ()
 Get the replication position of this replica DB. More...
 
 getScopedLockAndFlush ( $lockKey, $fname, $timeout)
 Acquire a named lock, flush any transaction, and return an RAII style unlocker object. More...
 
 getServer ()
 Get the server hostname or IP address. More...
 
 getServerInfo ()
 Get a human-readable string describing the current software version. More...
 
 getServerUptime ()
 Determines how long the server has been up. More...
 
 getServerVersion ()
 A string describing the current software version, like from mysql_get_server_info() More...
 
 getSessionLagStatus ()
 Get the replica DB lag when the current transaction started or a general lag estimate if not transaction is active. More...
 
 getSoftwareLink ()
 Returns a wikitext style link to the DB's website (e.g. More...
 
 getTopologyRole ()
 Get the replication topology role of this server. More...
 
 getTopologyRootMaster ()
 Get the host (or address) of the root master server for the replication topology. More...
 
 getType ()
 Get the type of the DBMS (e.g. More...
 
 implicitOrderby ()
 Returns true if this database does an implicit order by when the column has an index For example: SELECT page_title FROM page LIMIT 1. More...
 
 indexExists ( $table, $index, $fname=__METHOD__)
 Determines whether an index exists. More...
 
 insert ( $table, $rows, $fname=__METHOD__, $options=[])
 INSERT wrapper, inserts an array into a table. More...
 
 insertId ()
 Get the inserted value of an auto-increment row. More...
 
 insertSelect ( $destTable, $srcTable, $varMap, $conds, $fname=__METHOD__, $insertOptions=[], $selectOptions=[], $selectJoinConds=[])
 INSERT SELECT wrapper. More...
 
 isOpen ()
 
 isReadOnly ()
 
 lastDoneWrites ()
 Get the last time the connection may have been used for a write query. More...
 
 lastErrno ()
 Get the last error number. More...
 
 lastError ()
 Get a description of the last error. More...
 
 lastQuery ()
 Get the last query that sent on account of IDatabase::query() More...
 
 limitResult ( $sql, $limit, $offset=false)
 Construct a LIMIT query with optional offset. More...
 
 lock ( $lockName, $method, $timeout=5)
 Acquire a named lock. More...
 
 lockForUpdate ( $table, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Lock all rows meeting the given conditions/options FOR UPDATE. More...
 
 lockIsFree ( $lockName, $method)
 Check to see if a named lock is not locked by any thread (non-blocking) More...
 
 makeList (array $a, $mode=self::LIST_COMMA)
 Makes an encoded list of strings from an array. More...
 
 makeWhereFrom2d ( $data, $baseKey, $subKey)
 Build a partial where clause from a 2-d array such as used for LinkBatch. More...
 
 masterPosWait (DBMasterPos $pos, $timeout)
 Wait for the replica DB to catch up to a given master position. More...
 
 maxListLen ()
 Return the maximum number of items allowed in a list, or 0 for unlimited. More...
 
 namedLocksEnqueue ()
 Check to see if a named lock used by lock() use blocking queues. More...
 
 nextSequenceValue ( $seqName)
 Deprecated method, calls should be removed. More...
 
 numFields ( $res)
 Get the number of fields in a result object. More...
 
 numRows ( $res)
 Get the number of rows in a query result. More...
 
 onAtomicSectionCancel (callable $callback, $fname=__METHOD__)
 Run a callback when the atomic section is cancelled. More...
 
 onTransactionCommitOrIdle (callable $callback, $fname=__METHOD__)
 Run a callback as soon as there is no transaction pending. More...
 
 onTransactionIdle (callable $callback, $fname=__METHOD__)
 Alias for onTransactionCommitOrIdle() for backwards-compatibility. More...
 
 onTransactionPreCommitOrIdle (callable $callback, $fname=__METHOD__)
 Run a callback before the current transaction commits or now if there is none. More...
 
 onTransactionResolution (callable $callback, $fname=__METHOD__)
 Run a callback as soon as the current transaction commits or rolls back. More...
 
 pendingWriteCallers ()
 Get the list of method names that did write queries for this transaction. More...
 
 pendingWriteQueryDuration ( $type=self::ESTIMATE_TOTAL)
 Get the time spend running write queries for this transaction. More...
 
 pendingWriteRowsAffected ()
 Get the number of affected rows from pending write queries. More...
 
 ping (&$rtt=null)
 Ping the server and try to reconnect if it there is no connection. More...
 
 preCommitCallbacksPending ()
 
 query ( $sql, $fname=__METHOD__, $flags=0)
 Run an SQL query and return the result. More...
 
 replace ( $table, $uniqueIndexes, $rows, $fname=__METHOD__)
 REPLACE query wrapper. More...
 
 restoreFlags ( $state=self::RESTORE_PRIOR)
 Restore the flags to their prior state before the last setFlag/clearFlag call. More...
 
 rollback ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)
 Rollback a transaction previously started using begin() More...
 
 select ( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Execute a SELECT query constructed using the various parameters provided. More...
 
 selectDB ( $db)
 Change the current database. More...
 
 selectDomain ( $domain)
 Set the current domain (database, schema, and table prefix) More...
 
 selectField ( $table, $var, $cond='', $fname=__METHOD__, $options=[], $join_conds=[])
 A SELECT wrapper which returns a single field from a single result row. More...
 
 selectFieldValues ( $table, $var, $cond='', $fname=__METHOD__, $options=[], $join_conds=[])
 A SELECT wrapper which returns a list of single field values from result rows. More...
 
 selectRow ( $table, $vars, $conds, $fname=__METHOD__, $options=[], $join_conds=[])
 Wrapper to IDatabase::select() that only fetches one row (via LIMIT) More...
 
 selectRowCount ( $tables, $var=' *', $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Get the number of rows in dataset. More...
 
 selectSQLText ( $table, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Take the same arguments as IDatabase::select() and return the SQL it would use. More...
 
 serverIsReadOnly ()
 
 setBigSelects ( $value=true)
 Allow or deny "big selects" for this session only. More...
 
 setFlag ( $flag, $remember=self::REMEMBER_NOTHING)
 Set a flag for this connection. More...
 
 setIndexAliases (array $aliases)
 Convert certain index names to alternative names before querying the DB. More...
 
 setLBInfo ( $nameOrArray, $value=null)
 Set the entire array or a particular key of the managing load balancer info array. More...
 
 setSchemaVars ( $vars)
 Set schema variables to be used when streaming commands from SQL files or stdin. More...
 
 setSessionOptions (array $options)
 Override database's default behavior. More...
 
 setTableAliases (array $aliases)
 Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name. More...
 
 setTransactionListener ( $name, callable $callback=null)
 Run a callback after each time any transaction commits or rolls back. More...
 
 startAtomic ( $fname=__METHOD__, $cancelable=self::ATOMIC_NOT_CANCELABLE)
 Begin an atomic section of SQL statements. More...
 
 strreplace ( $orig, $old, $new)
 Returns a SQL expression for simple string replacement (e.g. More...
 
 tableExists ( $table, $fname=__METHOD__)
 Query whether a given table exists. More...
 
 tablePrefix ( $prefix=null)
 Get/set the table prefix. More...
 
 timestamp ( $ts=0)
 Convert a timestamp in one of the formats accepted by ConvertibleTimestamp to the format used for inserting into timestamp fields in this DBMS. More...
 
 timestampOrNull ( $ts=null)
 Convert a timestamp in one of the formats accepted by ConvertibleTimestamp to the format used for inserting into timestamp fields in this DBMS. More...
 
 trxLevel ()
 Gets the current transaction level. More...
 
 trxTimestamp ()
 Get the UNIX timestamp of the time that the transaction was established. More...
 
 unionConditionPermutations ( $table, $vars, array $permute_conds, $extra_conds='', $fname=__METHOD__, $options=[], $join_conds=[])
 Construct a UNION query for permutations of conditions. More...
 
 unionQueries ( $sqls, $all)
 Construct a UNION query. More...
 
 unionSupportsOrderAndLimit ()
 Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION. More...
 
 unlock ( $lockName, $method)
 Release a lock. More...
 
 update ( $table, $values, $conds, $fname=__METHOD__, $options=[])
 UPDATE wrapper. More...
 
 upsert ( $table, array $rows, $uniqueIndexes, array $set, $fname=__METHOD__)
 INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table. More...
 
 wasConnectionLoss ()
 Determines if the last query error was due to a dropped connection. More...
 
 wasDeadlock ()
 Determines if the last failure was due to a deadlock. More...
 
 wasErrorReissuable ()
 Determines if the last query error was due to something outside of the query itself. More...
 
 wasLockTimeout ()
 Determines if the last failure was due to a lock timeout. More...
 
 wasReadOnlyError ()
 Determines if the last failure was due to the database being read-only. More...
 
 writesOrCallbacksPending ()
 Whether there is a transaction open with either possible write queries or unresolved pre-commit/commit/resolution callbacks pending. More...
 
 writesPending ()
 

Detailed Description

Basic database interface for live and lazy-loaded relation database handles.

Note
IDatabase and DBConnRef should be updated to reflect any changes

Definition at line 38 of file IDatabase.php.

Member Function Documentation

◆ __toString()

Wikimedia\Rdbms\IDatabase::__toString ( )

Get a debugging string that mentions the database type, the ID of this instance, and the ID of any underlying connection resource or driver object if one is present.

Returns
string "<db type> object #<X>" or "<db type> object #<X> (resource/handle id #<Y>)"
Since
1.34

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ addIdentifierQuotes()

Wikimedia\Rdbms\IDatabase::addIdentifierQuotes (   $s)

Escape a SQL identifier (e.g.

table, column, database) for use in a SQL query

Depending on the database this will either be backticks or "double quotes"

Parameters
string$s
Returns
string
Since
1.33

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by SqlBagOStuff\initSqliteDatabase().

◆ addQuotes()

◆ affectedRows()

Wikimedia\Rdbms\IDatabase::affectedRows ( )

Get the number of rows affected by the last write query.

Similar to https://www.php.net/mysql_affected_rows but includes rows matched but not changed (ie. an UPDATE which sets all fields to the same value they already have). To get the old mysql_affected_rows behavior, include non-equality of the fields in WHERE.

Returns
int

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by MigrateActors\addActorsForRows(), User\addToDatabase(), User\createNew(), UserGroupMembership\delete(), SqlBagOStuff\deleteServerObjectsExpiringBefore(), UserGroupMembership\insert(), MigrateComments\loadCommentIDs(), DeduplicateArchiveRevId\processArRevIds(), DeleteLocalPasswords\processUsers(), PopulateArchiveRevId\reassignArRevIds(), and User\saveSettings().

◆ aggregateValue()

Wikimedia\Rdbms\IDatabase::aggregateValue (   $valuedata,
  $valuename = 'value' 
)

Return aggregated value alias.

Parameters
array$valuedata
string$valuename
Returns
array|string
Deprecated:
Since 1.33

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ anyChar()

Wikimedia\Rdbms\IDatabase::anyChar ( )

Returns a token for buildLike() that denotes a '_' to be used in a LIKE query.

Returns
LikeMatch

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ anyString()

Wikimedia\Rdbms\IDatabase::anyString ( )

◆ assertNoOpenTransactions()

Wikimedia\Rdbms\IDatabase::assertNoOpenTransactions ( )

Assert that all explicit transactions or atomic sections have been closed.

Exceptions
DBTransactionError
Since
1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\approveMasterChanges().

◆ begin()

Wikimedia\Rdbms\IDatabase::begin (   $fname = __METHOD__,
  $mode = self::TRANSACTION_EXPLICIT 
)

Begin a transaction.

Only call this from code with outer transcation scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported.

Note that when the DBO_TRX flag is set (which is usually the case for web requests, but not for maintenance scripts), any previous database query will have started a transaction automatically.

Nesting of transactions is not supported. Attempts to nest transactions will cause a warning, unless the current transaction was started automatically because of the DBO_TRX flag.

Parameters
string$fnameCalling function name
string$modeA situationally valid IDatabase::TRANSACTION_* constant [optional]
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Maintenance\beginTransaction(), and PopulateArchiveRevId\makeDummyRevisionRow().

◆ bitAnd()

Wikimedia\Rdbms\IDatabase::bitAnd (   $fieldLeft,
  $fieldRight 
)

◆ bitNot()

Wikimedia\Rdbms\IDatabase::bitNot (   $field)
Parameters
string | int$field
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ bitOr()

Wikimedia\Rdbms\IDatabase::bitOr (   $fieldLeft,
  $fieldRight 
)
Parameters
string | int$fieldLeft
string | int$fieldRight
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by RevisionDeleteUser\buildSetBitDeletedField().

◆ buildConcat()

Wikimedia\Rdbms\IDatabase::buildConcat (   $stringList)

Build a concatenation list to feed into a SQL query.

Parameters
string[]$stringListRaw SQL expression list; caller is responsible for escaping
Returns
string

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

Referenced by DeleteLocalPasswords\processUsers().

◆ buildGroupConcatField()

Wikimedia\Rdbms\IDatabase::buildGroupConcatField (   $delim,
  $table,
  $field,
  $conds = '',
  $join_conds = [] 
)

Build a GROUP_CONCAT or equivalent statement for a query.

This is useful for combining a field for several rows into a single string. NULL values will not appear in the output, duplicated values will appear, and the resulting delimiter-separated values have no defined sort order. Code using the results may need to use the PHP unique() or sort() methods.

Parameters
string$delimGlue to bind the results together
string | array$tableTable name
string$fieldField name
string | array$condsConditions
string | array$join_condsJoin conditions
Returns
string SQL text
Since
1.23

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ buildIntegerCast()

Wikimedia\Rdbms\IDatabase::buildIntegerCast (   $field)
Parameters
string$fieldField or column to cast
Returns
string
Since
1.31

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ buildLike()

Wikimedia\Rdbms\IDatabase::buildLike (   $param,
  $params 
)

LIKE statement wrapper.

This takes a variable-length argument list with parts of pattern to match containing either string literals that will be escaped or tokens returned by anyChar() or anyString(). Alternatively, the function could be provided with an array of aforementioned parameters.

Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns a LIKE clause that searches for subpages of 'My page title'. Alternatively: $pattern = [ 'My_page_title/', $dbr->anyString() ]; $query .= $dbr->buildLike( $pattern );

Since
1.16
Parameters
array[] | string | LikeMatch$param
string|LikeMatch...$params
Returns
string Fully built LIKE statement

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by RefreshImageMetadata\getConditions(), UppercaseTitlesForUnicodeTransition\getLikeBatches(), and DeleteLocalPasswords\processUsers().

◆ buildSelectSubquery()

Wikimedia\Rdbms\IDatabase::buildSelectSubquery (   $table,
  $vars,
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Equivalent to IDatabase::selectSQLText() except wraps the result in Subqyery.

See also
IDatabase::selectSQLText()
Parameters
string | array$tableTable name
string | array$varsField names
string | array$condsConditions
string$fnameCaller function name
string | array$optionsQuery options
string | array$join_condsJoin conditions
Returns
Subquery
Since
1.31

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ buildStringCast()

Wikimedia\Rdbms\IDatabase::buildStringCast (   $field)

◆ buildSubString()

Wikimedia\Rdbms\IDatabase::buildSubString (   $input,
  $startPosition,
  $length = null 
)

Build a SUBSTRING function.

Behavior for non-ASCII values is undefined.

Parameters
string$inputField name
int$startPositionPositive integer
int | null$lengthNon-negative integer length or null for no limit
Exceptions
InvalidArgumentException
Returns
string SQL text
Since
1.31

Referenced by DeleteLocalPasswords\processUsers().

◆ cancelAtomic()

Wikimedia\Rdbms\IDatabase::cancelAtomic (   $fname = __METHOD__,
AtomicSectionIdentifier  $sectionId = null 
)

Cancel an atomic section of SQL statements.

This will roll back only the statements executed since the start of the most recent atomic section, and close that section. If a transaction was open before the corresponding startAtomic() call, any statements before that call are not rolled back and the transaction remains open. If the corresponding startAtomic() implicitly started a transaction, that transaction is rolled back.

Note
callers must use additional measures for situations involving two or more (peer) transactions (e.g. updating two database servers at once). The transaction and savepoint logic of startAtomic() are bound to specific IDatabase instances.

Note that a call to IDatabase::rollback() will also roll back any open atomic sections.

Note
As a micro-optimization to save a few DB calls, this method may only be called when startAtomic() was called with the ATOMIC_CANCELABLE flag.
Since
1.31
See also
IDatabase::startAtomic
Parameters
string$fname
AtomicSectionIdentifier | null$sectionIdSection ID from startAtomic(); passing this enables cancellation of unclosed nested sections [optional]
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ clearFlag()

Wikimedia\Rdbms\IDatabase::clearFlag (   $flag,
  $remember = self::REMEMBER_NOTHING 
)

Clear a flag for this connection.

Parameters
int$flagOne of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string$rememberIDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\enforceConnectionFlags(), and JobQueueDB\getScopedNoTrxFlag().

◆ close()

Wikimedia\Rdbms\IDatabase::close (   $fname = __METHOD__,
  $owner = null 
)

Close the database connection.

This should only be called after any transactions have been resolved, aside from read-only automatic transactions (assuming no callbacks are registered). If a transaction is still open anyway, it will be rolled back.

Parameters
string$fnameCaller name
int | null$ownerID of the calling instance (e.g. the LBFactory ID)
Returns
bool Success
Exceptions
DBError

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeAll(), and Wikimedia\Rdbms\LoadBalancer\closeConnection().

◆ commit()

Wikimedia\Rdbms\IDatabase::commit (   $fname = __METHOD__,
  $flush = self::FLUSHING_ONE 
)

Commits a transaction previously started using begin()

If no transaction is in progress, a warning is issued.

Only call this from code with outer transcation scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported.

Parameters
string$fname
string$flushFlush flag, set to situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly committing implicit transactions, or calling commit when no transaction is in progress. This will trigger an exception if there is an ongoing explicit transaction. Only set the flush flag if you are sure that these warnings are not applicable, and no explicit transactions are open.
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\commitMasterChanges(), and Maintenance\commitTransaction().

◆ conditional()

Wikimedia\Rdbms\IDatabase::conditional (   $cond,
  $trueVal,
  $falseVal 
)

Returns an SQL expression for a simple conditional.

This doesn't need to be overridden unless CASE isn't supported in the RDBMS.

Parameters
string | array$condSQL expression which will result in a boolean value
string$trueValSQL expression to return if true
string$falseValSQL expression to return if false
Returns
string SQL fragment

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ databasesAreIndependent()

Wikimedia\Rdbms\IDatabase::databasesAreIndependent ( )

Returns true if DBs are assumed to be on potentially different servers.

In systems like mysql/mariadb, different databases can easily be referenced on a single connection merely by name, even in a single query via JOIN. On the other hand, Postgres treats databases as logically separate, with different database users, requiring special mechanisms like postgres_fdw to "mount" foreign DBs. This is true even among DBs on the same server. Changing the selected database via selectDomain() requires a new connection.

Returns
bool
Since
1.29

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\DatabasePostgres.

◆ dataSeek()

Wikimedia\Rdbms\IDatabase::dataSeek (   $res,
  $row 
)

Change the position of the cursor in a result object.

See also
https://www.php.net/mysql_data_seek
Parameters
mixed$resA SQL result
int$row

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ dbSchema()

Wikimedia\Rdbms\IDatabase::dbSchema (   $schema = null)

Get/set the db schema.

Parameters
string | null$schemaThe database schema to set, or omitted to leave it unchanged
Returns
string The previous db schema

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\isMasterConnectionReadOnly().

◆ decodeBlob()

Wikimedia\Rdbms\IDatabase::decodeBlob (   $b)

Some DBMSs return a special placeholder object representing blob fields in result objects.

Pass the object through this function to return the original string.

Parameters
string | Blob$b
Returns
string
Exceptions
DBError

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ decodeExpiry()

Wikimedia\Rdbms\IDatabase::decodeExpiry (   $expiry,
  $format = TS_MW 
)

Decode an expiry time into a DBMS independent format.

Parameters
string$expiryDB timestamp field value for expiry
int$formatTS_* constant, defaults to TS_MW
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ delete()

Wikimedia\Rdbms\IDatabase::delete (   $table,
  $conds,
  $fname = __METHOD__ 
)

DELETE query wrapper.

Parameters
string$tableTable name
string | array$condsArray of conditions. See $conds in IDatabase::select() for the format. Use $conds == "*" to delete all rows
string$fnameName of the calling function
Returns
bool Return true if no exception was thrown (deprecated since 1.33)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by PopulateArchiveRevId\checkMysqlAutoIncrementBug(), UserGroupMembership\delete(), SqlBagOStuff\deleteServerObjectsExpiringBefore(), DBFileJournal\doPurgeOldLogs(), LCStoreDB\finishWrite(), User\newSystemUser(), DeduplicateArchiveRevId\processArRevIds(), UserGroupMembership\purgeExpired(), MediaWiki\Block\DatabaseBlock\purgeExpired(), Title\purgeExpiredRestrictions(), PopulateArchiveRevId\reassignArRevIds(), and QueryPage\recache().

◆ deleteJoin()

Wikimedia\Rdbms\IDatabase::deleteJoin (   $delTable,
  $joinTable,
  $delVar,
  $joinVar,
  $conds,
  $fname = __METHOD__ 
)

DELETE where the condition is a join.

MySQL overrides this to use a multi-table DELETE syntax, in other databases we use sub-selects

For safety, an empty $conds will not delete everything. If you want to delete all rows where the join condition matches, set $conds='*'.

DO NOT put the join condition in $conds.

Parameters
string$delTableThe table to delete from.
string$joinTableThe other table.
string$delVarThe variable to join on, in the first table.
string$joinVarThe variable to join on, in the second table.
array | string$condsCondition array of field names mapped to variables, ANDed together in the WHERE clause
string$fnameCalling function name (use METHOD) for logs/profiling
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ doAtomicSection()

Wikimedia\Rdbms\IDatabase::doAtomicSection (   $fname,
callable  $callback,
  $cancelable = self::ATOMIC_NOT_CANCELABLE 
)

Perform an atomic section of reversable SQL statements from a callback.

The $callback takes the following arguments:

  • This database object
  • The value of $fname

This will execute the callback inside a pair of startAtomic()/endAtomic() calls. If any exception occurs during execution of the callback, it will be handled as follows:

  • If $cancelable is ATOMIC_CANCELABLE, cancelAtomic() will be called to back out any (and only) statements executed during the atomic section. If that succeeds, then the exception will be re-thrown; if it fails, then a different exception will be thrown and any further query attempts will fail until rollback() is called.
  • If $cancelable is ATOMIC_NOT_CANCELABLE, cancelAtomic() will be called to mark the end of the section and the error will be re-thrown. Any further query attempts will fail until rollback() is called.

This method is convenient for letting calls to the caller of this method be wrapped in a try/catch blocks for exception types that imply that the caller failed but was able to properly discard the changes it made in the transaction. This method can be an alternative to explicit calls to startAtomic()/endAtomic()/cancelAtomic().

Example usage, "RecordStore::save" method:

$dbw->doAtomicSection( __METHOD__, function ( $dbw ) use ( $record ) {
// Create new record metadata row
$dbw->insert( 'records', $record->toArray(), __METHOD__ );
// Figure out where to store the data based on the new row's ID
$path = $this->recordDirectory . '/' . $dbw->insertId();
// Write the record data to the storage system;
// blob store throughs StoreFailureException on failure
$this->blobStore->create( $path, $record->getJSON() );
// Try to cleanup files orphaned by transaction rollback
$dbw->onTransactionResolution(
function ( $type ) use ( $path ) {
if ( $type === IDatabase::TRIGGER_ROLLBACK ) {
$this->blobStore->delete( $path );
}
},
__METHOD__
);
}, $dbw::ATOMIC_CANCELABLE );

Example usage, caller of the "RecordStore::save" method:

$dbw->startAtomic( __METHOD__ );
// ...various SQL writes happen...
try {
$recordStore->save( $record );
} catch ( StoreFailureException $e ) {
// ...various SQL writes happen...
}
// ...various SQL writes happen...
$dbw->endAtomic( __METHOD__ );
See also
Database::startAtomic
Database::endAtomic
Database::cancelAtomic
Parameters
string$fnameCaller name (usually METHOD)
callable$callbackCallback that issues DB updates
string$cancelablePass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.
Returns
mixed $res Result of the callback (since 1.28)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
ExceptionIf an error occurs in the callback
Since
1.27; prior to 1.31 this did a rollback() instead of cancelAtomic(), and assumed no callers up the stack would ever try to catch the exception.

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by PopulateArchiveRevId\checkMysqlAutoIncrementBug(), PopulateArchiveRevId\reassignArRevIds(), and MediaWiki\Storage\NameTableStore\retryStore().

◆ encodeBlob()

Wikimedia\Rdbms\IDatabase::encodeBlob (   $b)

Some DBMSs have a special format for inserting into blob fields, they don't allow simple quoted strings to be inserted.

To insert into such a field, pass the data through this function before passing it to IDatabase::insert().

Parameters
string$b
Returns
string|Blob
Exceptions
DBError

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

Referenced by LCStoreDB\set().

◆ encodeExpiry()

Wikimedia\Rdbms\IDatabase::encodeExpiry (   $expiry)

Encode an expiry time into the DBMS dependent format.

Parameters
string$expiryTimestamp for expiry, or the 'infinity' string
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by MediaWiki\Block\DatabaseBlock\getDatabaseArray().

◆ endAtomic()

Wikimedia\Rdbms\IDatabase::endAtomic (   $fname = __METHOD__)

Ends an atomic section of SQL statements.

Ends the next section of atomic SQL statements and commits the transaction if necessary.

Since
1.23
See also
IDatabase::startAtomic
Parameters
string$fname
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by JobQueueDB\doBatchPushInternal(), LCStoreDB\finishWrite(), SqlBagOStuff\initSqliteDatabase(), UserGroupMembership\insert(), and UserGroupMembership\purgeExpired().

◆ estimateRowCount()

Wikimedia\Rdbms\IDatabase::estimateRowCount (   $tables,
  $var = ' *',
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Estimate the number of rows in dataset.

MySQL allows you to estimate the number of rows that would be returned by a SELECT query, using EXPLAIN SELECT. The estimate is provided using index cardinality statistics, and is notoriously inaccurate, especially when large numbers of rows have recently been added or deleted.

For DBMSs that don't support fast result size estimation, this function will actually perform the SELECT COUNT(*).

Takes the same arguments as IDatabase::select().

Parameters
array | string$tablesTable names
string$varColumn for which NULL values are not counted [default "*"]
array | string$condsFilters on the table
string$fnameFunction name for profiling
array$optionsOptions for select
array | string$join_condsJoin conditions
Returns
int Row count
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\DBConnRef, Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DatabasePostgres.

◆ explicitTrxActive()

Wikimedia\Rdbms\IDatabase::explicitTrxActive ( )
Returns
bool Whether an explicit transaction or atomic sections are still open
Since
1.28

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by DeferredUpdates\areDatabaseTransactionsActive().

◆ fetchObject()

Wikimedia\Rdbms\IDatabase::fetchObject (   $res)

Fetch the next row from the given result object, in object form.

Fields can be retrieved with $row->fieldname, with fields acting like member variables. If no more rows are available, false is returned.

Parameters
IResultWrapper | stdClass$resObject as returned from IDatabase::query(), etc.
Returns
stdClass|bool

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\Database\selectRow(), and Wikimedia\Rdbms\Database\textFieldSize().

◆ fetchRow()

Wikimedia\Rdbms\IDatabase::fetchRow (   $res)

Fetch the next row from the given result object, in associative array form.

Fields are retrieved with $row['fieldname']. If no more rows are available, false is returned.

Parameters
IResultWrapper$resResult object as returned from IDatabase::query(), etc.
Returns
array|bool

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\Database\estimateRowCount(), Wikimedia\Rdbms\Database\selectField(), and Wikimedia\Rdbms\Database\selectRowCount().

◆ fieldExists()

Wikimedia\Rdbms\IDatabase::fieldExists (   $table,
  $field,
  $fname = __METHOD__ 
)

Determines whether a field exists in a table.

Parameters
string$tableTable name
string$fieldFiled to check on that table
string$fnameCalling function name (optional)
Returns
bool Whether $table has filed $field
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ fieldName()

Wikimedia\Rdbms\IDatabase::fieldName (   $res,
  $n 
)

Get a field name in a result object.

See also
https://www.php.net/mysql_field_name
Parameters
mixed$resA SQL result
int$n
Returns
string

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ flushSnapshot()

Wikimedia\Rdbms\IDatabase::flushSnapshot (   $fname = __METHOD__,
  $flush = self::FLUSHING_ONE 
)

Commit any transaction but error out if writes or callbacks are pending.

This is intended for clearing out REPEATABLE-READ snapshots so that callers can see a new point-in-time of the database. This is useful when one of many transaction rounds finished and significant time will pass in the script's lifetime. It is also useful to call on a replica DB after waiting on replication to catch up to the master.

Parameters
string$fnameCalling function name
string$flushFlush flag, set to situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly committing implicit transactions, or calling commit when no transaction is in progress. This will trigger an exception if there is an ongoing explicit transaction. Only set the flush flag if you are sure that these warnings are not applicable, and no explicit transactions are open.
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.28
1.34 Added $flush parameter

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\flushMasterSnapshots(), and Wikimedia\Rdbms\LoadBalancer\flushReplicaSnapshots().

◆ freeResult()

Wikimedia\Rdbms\IDatabase::freeResult (   $res)

Free a result object returned by query() or select()

It's usually not necessary to call this, just use unset() or let the variable holding the result object go out of scope.

Parameters
mixed$resA SQL result

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DBConnRef, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DatabaseMysqlBase.

◆ getDBname()

Wikimedia\Rdbms\IDatabase::getDBname ( )

Get the current DB name.

Returns
string|null

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\isMasterConnectionReadOnly().

◆ getDomainID()

Wikimedia\Rdbms\IDatabase::getDomainID ( )

◆ getFlag()

Wikimedia\Rdbms\IDatabase::getFlag (   $flag)

Returns a boolean whether the flag $flag is set for this connection.

Parameters
int$flagOne of the class IDatabase::DBO_* constants
Returns
bool

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by JobQueueDB\getScopedNoTrxFlag().

◆ getInfinity()

Wikimedia\Rdbms\IDatabase::getInfinity ( )

Find out when 'infinity' is.

Most DBMSes support this. This is a special keyword for timestamps in PostgreSQL, and works with CHAR(14) as well because "i" sorts after all numbers.

Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ getLag()

Wikimedia\Rdbms\IDatabase::getLag ( )

Get the amount of replication lag for this database server.

Callers should avoid using this method while a transaction is active

Returns
int|bool Database replication lag in seconds or false on error
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\safeGetLag().

◆ getLBInfo()

Wikimedia\Rdbms\IDatabase::getLBInfo (   $name = null)

Get properties passed down from the server info array of the load balancer.

Parameters
string | null$nameThe entry of the info array to get, or null to get the whole array
Returns
array|mixed|null

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\closeConnection(), Wikimedia\Rdbms\LoadBalancer\reuseConnection(), Wikimedia\Rdbms\LoadBalancer\setLocalDomainPrefix(), and Wikimedia\Rdbms\LoadBalancer\waitForMasterPos().

◆ getMasterPos()

Wikimedia\Rdbms\IDatabase::getMasterPos ( )

Get the position of this master.

Returns
DBMasterPos|bool False if this is not a master
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ getReplicaPos()

Wikimedia\Rdbms\IDatabase::getReplicaPos ( )

Get the replication position of this replica DB.

Returns
DBMasterPos|bool False if this is not a replica DB
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ getScopedLockAndFlush()

Wikimedia\Rdbms\IDatabase::getScopedLockAndFlush (   $lockKey,
  $fname,
  $timeout 
)

Acquire a named lock, flush any transaction, and return an RAII style unlocker object.

Only call this from outer transcation scope and when only one DB will be affected. See https://www.mediawiki.org/wiki/Database_transactions for details.

This is suitiable for transactions that need to be serialized using cooperative locks, where each transaction can see each others' changes. Any transaction is flushed to clear out stale REPEATABLE-READ snapshot data. Once the returned object falls out of PHP scope, the lock will be released unless a transaction is active. If one is active, then the lock will be released when it either commits or rolls back.

If the lock acquisition failed, then no transaction flush happens, and null is returned.

Parameters
string$lockKeyName of lock to release
string$fnameName of the calling method
int$timeoutAcquisition timeout in seconds
Returns
ScopedCallback|null
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.27

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by LinksUpdate\acquirePageLock(), and UserGroupMembership\purgeExpired().

◆ getServer()

Wikimedia\Rdbms\IDatabase::getServer ( )

◆ getServerInfo()

Wikimedia\Rdbms\IDatabase::getServerInfo ( )

Get a human-readable string describing the current software version.

Use getServerVersion() to get machine-friendly information.

Returns
string Version information from the database server

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ getServerUptime()

Wikimedia\Rdbms\IDatabase::getServerUptime ( )

Determines how long the server has been up.

Returns
int
Exceptions
DBError

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ getServerVersion()

Wikimedia\Rdbms\IDatabase::getServerVersion ( )

A string describing the current software version, like from mysql_get_server_info()

Returns
string Version information from the database server.

Implemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\Database\getServerInfo().

◆ getSessionLagStatus()

Wikimedia\Rdbms\IDatabase::getSessionLagStatus ( )

Get the replica DB lag when the current transaction started or a general lag estimate if not transaction is active.

This is useful when transactions might use snapshot isolation (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data is this lag plus transaction duration. If they don't, it is still safe to be pessimistic. In AUTOCOMMIT mode, this still gives an indication of the staleness of subsequent reads.

Returns
array ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.27

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\Database\getCacheSetOptions().

◆ getSoftwareLink()

Wikimedia\Rdbms\IDatabase::getSoftwareLink ( )

Returns a wikitext style link to the DB's website (e.g.

"[https://www.mysql.com/ MySQL]")

Should at least contain plain text, if for some reason your database has no website.

Returns
string Wikitext of a link to the server software's web site

Implemented in Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ getTopologyRole()

Wikimedia\Rdbms\IDatabase::getTopologyRole ( )

Get the replication topology role of this server.

Returns
string One of the class ROLE_* constants
Since
1.34

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ getTopologyRootMaster()

Wikimedia\Rdbms\IDatabase::getTopologyRootMaster ( )

Get the host (or address) of the root master server for the replication topology.

Returns
string|null Master server name or null if not known
Since
1.34

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ getType()

◆ implicitOrderby()

Wikimedia\Rdbms\IDatabase::implicitOrderby ( )

Returns true if this database does an implicit order by when the column has an index For example: SELECT page_title FROM page LIMIT 1.

Returns
bool

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\DatabasePostgres.

◆ indexExists()

Wikimedia\Rdbms\IDatabase::indexExists (   $table,
  $index,
  $fname = __METHOD__ 
)

Determines whether an index exists.

Parameters
string$table
string$index
string$fname
Returns
bool|null
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ insert()

Wikimedia\Rdbms\IDatabase::insert (   $table,
  $rows,
  $fname = __METHOD__,
  $options = [] 
)

INSERT wrapper, inserts an array into a table.

$a may be either:

  • A single associative array. The array keys are the field names, and the values are the values to insert. The values are treated as data and will be quoted appropriately. If NULL is inserted, this will be converted to a database NULL.
  • An array with numeric keys, holding a list of associative arrays. This causes a multi-row INSERT on DBMSs that support it. The keys in each subarray must be identical to each other, and in the same order.

$options is an array of options, with boolean options encoded as values with numeric keys, in the same style as $options in IDatabase::select(). Supported options are:

  • IGNORE: Boolean: if present, duplicate key errors are ignored, and any rows which cause duplicate key errors are not inserted. It's possible to determine how many rows were successfully inserted using IDatabase::affectedRows().
Parameters
string$tableTable name. This will be passed through Database::tableName().
array$rowsArray of rows to insert
string$fnameCalling function name (use METHOD) for logs/profiling
array$optionsArray of options
Returns
bool Return true if no exception was thrown (deprecated since 1.33)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\DatabasePostgres.

Referenced by MigrateActors\addActorsForRows(), User\addToDatabase(), PopulateArchiveRevId\checkMysqlAutoIncrementBug(), CommentStore\createComment(), User\createNew(), UserGroupMembership\delete(), JobQueueDB\doBatchPushInternal(), DBFileJournal\doLogChangeBatch(), LCStoreDB\finishWrite(), UserGroupMembership\insert(), CommentStore\insertInternal(), MigrateComments\loadCommentIDs(), UserGroupMembership\purgeExpired(), PopulateArchiveRevId\reassignArRevIds(), QueryPage\recache(), MediaWiki\Storage\NameTableStore\retryStore(), and User\updateActorId().

◆ insertId()

Wikimedia\Rdbms\IDatabase::insertId ( )

Get the inserted value of an auto-increment row.

This should only be called after an insert that used an auto-incremented value. If no such insert was previously done in the current database session, the return value is undefined.

Returns
int

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\DatabaseMysqli.

Referenced by User\addToDatabase(), PopulateArchiveRevId\checkMysqlAutoIncrementBug(), CommentStore\createComment(), User\createNew(), and User\updateActorId().

◆ insertSelect()

Wikimedia\Rdbms\IDatabase::insertSelect (   $destTable,
  $srcTable,
  $varMap,
  $conds,
  $fname = __METHOD__,
  $insertOptions = [],
  $selectOptions = [],
  $selectJoinConds = [] 
)

INSERT SELECT wrapper.

Warning
If the insert will use an auto-increment or sequence to determine the value of a column, this may break replication on databases using statement-based replication if the SELECT is not deterministically ordered.
Parameters
string$destTableThe table name to insert into
string | array$srcTableMay be either a table name, or an array of table names to include in a join.
array$varMapMust be an associative array of the form [ 'dest1' => 'source1', ... ]. Source items may be literals rather than field names, but strings should be quoted with IDatabase::addQuotes()
array$condsCondition array. See $conds in IDatabase::select() for the details of the format of condition arrays. May be "*" to copy the whole table.
string$fnameThe function name of the caller, from METHOD
array$insertOptionsOptions for the INSERT part of the query, see IDatabase::insert() for details. Also, one additional option is available: pass 'NO_AUTO_COLUMNS' to hint that the query does not use an auto-increment or sequence to determine any column values.
array$selectOptionsOptions for the SELECT part of the query, see IDatabase::select() for details.
array$selectJoinCondsJoin conditions for the SELECT part of the query, see IDatabase::select() for details.
Returns
bool Return true if no exception was thrown (deprecated since 1.33)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ isOpen()

Wikimedia\Rdbms\IDatabase::isOpen ( )
Returns
bool Whether a connection to the database open

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ isReadOnly()

Wikimedia\Rdbms\IDatabase::isReadOnly ( )
Returns
bool Whether this DB is read-only
Since
1.27

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by LCStoreDB\startWrite().

◆ lastDoneWrites()

Wikimedia\Rdbms\IDatabase::lastDoneWrites ( )

Get the last time the connection may have been used for a write query.

Returns
int|float UNIX timestamp or false
Since
1.24

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\lastMasterChangeTimestamp().

◆ lastErrno()

◆ lastError()

◆ lastQuery()

Wikimedia\Rdbms\IDatabase::lastQuery ( )

Get the last query that sent on account of IDatabase::query()

Returns
string SQL text or empty string if there was no such query

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ limitResult()

Wikimedia\Rdbms\IDatabase::limitResult (   $sql,
  $limit,
  $offset = false 
)

Construct a LIMIT query with optional offset.

The SQL should be adjusted so that only the first $limit rows are returned. If $offset is provided as well, then the first $offset rows should be discarded, and the next $limit rows should be returned. If the result of the query is not ordered, then the rows to be returned are theoretically arbitrary.

$sql is expected to be a SELECT, if that makes a difference.

Parameters
string$sqlSQL query we will append the limit too
int$limitThe SQL limit
int | bool$offsetThe SQL offset (default false)
Returns
string
Since
1.34

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ lock()

Wikimedia\Rdbms\IDatabase::lock (   $lockName,
  $method,
  $timeout = 5 
)

Acquire a named lock.

Named locks are not related to transactions

Parameters
string$lockNameName of lock to aquire
string$methodName of the calling method
int$timeoutAcquisition timeout in seconds (0 means non-blocking)
Returns
bool Success
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ lockForUpdate()

Wikimedia\Rdbms\IDatabase::lockForUpdate (   $table,
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Lock all rows meeting the given conditions/options FOR UPDATE.

Parameters
array | string$tableTable names
array | string$condsFilters on the table
string$fnameFunction name for profiling
array$optionsOptions for select ("FOR UPDATE" is added automatically)
array$join_condsJoin conditions
Returns
int Number of matching rows found (and locked)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by LocalFileMoveBatch\verifyDBUpdates().

◆ lockIsFree()

Wikimedia\Rdbms\IDatabase::lockIsFree (   $lockName,
  $method 
)

Check to see if a named lock is not locked by any thread (non-blocking)

Parameters
string$lockNameName of lock to poll
string$methodName of method calling us
Returns
bool
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.20

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ makeList()

Wikimedia\Rdbms\IDatabase::makeList ( array  $a,
  $mode = self::LIST_COMMA 
)

Makes an encoded list of strings from an array.

These can be used to make conjunctions or disjunctions on SQL condition strings derived from an array (see IDatabase::select() $conds documentation).

Example usage:

$sql = $db->makeList( [
'rev_page' => $id,
$db->makeList( [ 'rev_minor' => 1, 'rev_len' < 500 ], $db::LIST_OR ] )

This would set $sql to "rev_page = '$id' AND (rev_minor = '1' OR rev_len < '500')"

Parameters
array$aContaining the data
int$modeIDatabase class constant:
  • IDatabase::LIST_COMMA: Comma separated, no field names
  • IDatabase::LIST_AND: ANDed WHERE clause (without the WHERE).
  • IDatabase::LIST_OR: ORed WHERE clause (without the WHERE)
  • IDatabase::LIST_SET: Comma separated with field names, like a SET clause
  • IDatabase::LIST_NAMES: Comma separated field names
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by WatchedItemQueryService\getExtraDeletedPageLogEntryRelatedCond(), WatchedItemQueryService\getFromUntilTargetConds(), UppercaseTitlesForUnicodeTransition\getLikeBatches(), WatchedItemQueryService\getStartFromConds(), WANCacheReapUpdate\getTitleChangeEvents(), WatchedItemStore\getVisitingWatchersCondition(), WatchedItemQueryService\getWatchedItemsWithRCInfoQueryConds(), ActorMigration\getWhere(), MigrateComments\loadCommentIDs(), and UserGroupMembership\purgeExpired().

◆ makeWhereFrom2d()

Wikimedia\Rdbms\IDatabase::makeWhereFrom2d (   $data,
  $baseKey,
  $subKey 
)

Build a partial where clause from a 2-d array such as used for LinkBatch.

The keys on each level may be either integers or strings, however it's assumed that $baseKey is probably an integer-typed column (i.e. integer keys are unquoted in the SQL) and $subKey is string-typed (i.e. integer keys are quoted as strings in the SQL).

Todo:
Does this actually belong in the library? It seems overly MW-specific.
Parameters
array$dataOrganized as 2-d [ baseKeyVal => [ subKeyVal => [ignored], ... ], ... ]
string$baseKeyField name to match the base-level keys to (eg 'pl_namespace')
string$subKeyField name to match the sub-level keys to (eg 'pl_title')
Returns
string|bool SQL fragment, or false if no items in array

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ masterPosWait()

Wikimedia\Rdbms\IDatabase::masterPosWait ( DBMasterPos  $pos,
  $timeout 
)

Wait for the replica DB to catch up to a given master position.

Note that this does not start any new transactions. If any existing transaction is flushed, and this is called, then queries will reflect the point the DB was synced up to (on success) without interference from REPEATABLE-READ snapshots.

Parameters
DBMasterPos$pos
int$timeoutThe maximum number of seconds to wait for synchronisation
Returns
int|null Zero if the replica DB was past that position already, greater than zero if we waited for some period of time, less than zero if it timed out, and null on error
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\waitForMasterPos().

◆ maxListLen()

Wikimedia\Rdbms\IDatabase::maxListLen ( )

Return the maximum number of items allowed in a list, or 0 for unlimited.

Returns
int

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ namedLocksEnqueue()

Wikimedia\Rdbms\IDatabase::namedLocksEnqueue ( )

Check to see if a named lock used by lock() use blocking queues.

Returns
bool
Since
1.26

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ nextSequenceValue()

Wikimedia\Rdbms\IDatabase::nextSequenceValue (   $seqName)

Deprecated method, calls should be removed.

This was formerly used for PostgreSQL to handle self::insertId() auto-incrementing fields. It is no longer necessary since DatabasePostgres::insertId() has been reimplemented using lastval()

Implementations should return null if inserting NULL into an auto-incrementing field works, otherwise it should return an instance of NextSequenceValue and filter it on calls to relevant methods.

Deprecated:
since 1.30, no longer needed
Parameters
string$seqName
Returns
null|NextSequenceValue

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ numFields()

Wikimedia\Rdbms\IDatabase::numFields (   $res)

Get the number of fields in a result object.

See also
https://www.php.net/mysql_num_fields
Parameters
mixed$resA SQL result
Returns
int

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ numRows()

Wikimedia\Rdbms\IDatabase::numRows (   $res)

Get the number of rows in a query result.

Returns zero if the query did not return any rows or was a write query.

Parameters
mixed$resA SQL result
Returns
int

Implemented in Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\Database\executeQueryAttempt(), and Wikimedia\Rdbms\Database\selectRow().

◆ onAtomicSectionCancel()

Wikimedia\Rdbms\IDatabase::onAtomicSectionCancel ( callable  $callback,
  $fname = __METHOD__ 
)

Run a callback when the atomic section is cancelled.

The callback is run just after the current atomic section, any outer atomic section, or the whole transaction is rolled back.

An error is thrown if no atomic section is pending. The atomic section need not have been created with the ATOMIC_CANCELABLE flag.

Queries in the function may be running in the context of an outer transaction or may be running in AUTOCOMMIT mode. The callback should use atomic sections if necessary.

Note
do not assume that other IDatabase instances will be AUTOCOMMIT mode

The callback takes the following arguments:

  • IDatabase::TRIGGER_CANCEL or IDatabase::TRIGGER_ROLLBACK
  • This IDatabase instance
Parameters
callable$callback
string$fnameCaller name
Since
1.34

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by MediaWiki\Storage\NameTableStore\retryStore().

◆ onTransactionCommitOrIdle()

Wikimedia\Rdbms\IDatabase::onTransactionCommitOrIdle ( callable  $callback,
  $fname = __METHOD__ 
)

Run a callback as soon as there is no transaction pending.

If there is a transaction and it is rolled back, then the callback is cancelled.

When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.

Queries in the function will run in AUTOCOMMIT mode unless there are begin() calls. Callbacks must commit any transactions that they begin.

This is useful for updates to different systems or when separate transactions are needed. For example, one might want to enqueue jobs into a system outside the database, but only after the database is updated so that the jobs will see the data when they actually run. It can also be used for updates that easily suffer from lock timeouts and deadlocks, but where atomicity is not essential.

Avoid using IDatabase instances aside from this one in the callback, unless such instances never have IDatabase::DBO_TRX set. This keeps callbacks from interfering with one another.

Updates will execute in the order they were enqueued.

Note
do not assume that other IDatabase instances will be AUTOCOMMIT mode

The callback takes the following arguments:

  • How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)
  • This IDatabase instance (since 1.32)
Parameters
callable$callback
string$fnameCaller name
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
ExceptionIf the callback runs immediately and an error occurs in it
Since
1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ onTransactionIdle()

Wikimedia\Rdbms\IDatabase::onTransactionIdle ( callable  $callback,
  $fname = __METHOD__ 
)

Alias for onTransactionCommitOrIdle() for backwards-compatibility.

Parameters
callable$callback
string$fname
Since
1.20
Deprecated:
Since 1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ onTransactionPreCommitOrIdle()

Wikimedia\Rdbms\IDatabase::onTransactionPreCommitOrIdle ( callable  $callback,
  $fname = __METHOD__ 
)

Run a callback before the current transaction commits or now if there is none.

If there is a transaction and it is rolled back, then the callback is cancelled.

When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just before all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.

Callbacks must not start nor commit any transactions. If no transaction is active, then a transaction will wrap the callback.

This is useful for updates that easily suffer from lock timeouts and deadlocks, but where atomicity is strongly desired for these updates and some related updates.

Updates will execute in the order they were enqueued.

The callback takes the one argument:

Parameters
callable$callback
string$fnameCaller name
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
ExceptionIf the callback runs immediately and an error occurs in it
Since
1.22

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ onTransactionResolution()

Wikimedia\Rdbms\IDatabase::onTransactionResolution ( callable  $callback,
  $fname = __METHOD__ 
)

Run a callback as soon as the current transaction commits or rolls back.

An error is thrown if no transaction is pending. Queries in the function will run in AUTOCOMMIT mode unless there are begin() calls. Callbacks must commit any transactions that they begin.

This is useful for combining cooperative locks and DB transactions.

Note this is called when the whole transaction is resolved. To take action immediately when an atomic section is cancelled, use onAtomicSectionCancel().

Note
do not assume that other IDatabase instances will be AUTOCOMMIT mode

The callback takes the following arguments:

  • How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)
  • This IDatabase instance (since 1.32)
Parameters
callable$callback
string$fnameCaller name
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
ExceptionIf the callback runs immediately and an error occurs in it
Since
1.28

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by AutoCommitUpdate\__construct(), and AtomicSectionUpdate\__construct().

◆ pendingWriteCallers()

Wikimedia\Rdbms\IDatabase::pendingWriteCallers ( )

Get the list of method names that did write queries for this transaction.

Returns
array
Since
1.27

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\pendingMasterChangeCallers().

◆ pendingWriteQueryDuration()

Wikimedia\Rdbms\IDatabase::pendingWriteQueryDuration (   $type = self::ESTIMATE_TOTAL)

Get the time spend running write queries for this transaction.

High values could be due to scanning, updates, locking, and such.

Parameters
string$typeIDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL]
Returns
float|bool Returns false if not transaction is active
Since
1.26

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\approveMasterChanges().

◆ pendingWriteRowsAffected()

Wikimedia\Rdbms\IDatabase::pendingWriteRowsAffected ( )

Get the number of affected rows from pending write queries.

Returns
int
Since
1.30

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ ping()

Wikimedia\Rdbms\IDatabase::ping ( $rtt = null)

Ping the server and try to reconnect if it there is no connection.

Parameters
float | null&$rttValue to store the estimated RTT [optional]
Returns
bool Success or failure

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\approveMasterChanges(), and Wikimedia\Rdbms\LoadBalancer\pingAll().

◆ preCommitCallbacksPending()

Wikimedia\Rdbms\IDatabase::preCommitCallbacksPending ( )
Returns
bool Whether there is a transaction open with pre-commit callbacks pending
Since
1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ query()

Wikimedia\Rdbms\IDatabase::query (   $sql,
  $fname = __METHOD__,
  $flags = 0 
)

Run an SQL query and return the result.

If a connection loss is detected, then an attempt to reconnect will be made. For queries that involve no larger transactions or locks, they will be re-issued for convenience, provided the connection was re-established.

In new code, the query wrappers select(), insert(), update(), delete(), etc. should be used where possible, since they give much better DBMS independence and automatically quote or validate user input in a variety of contexts. This function is generally only useful for queries which are explicitly DBMS-dependent and are unsupported by the query wrappers, such as CREATE TABLE.

However, the query wrappers themselves should call this function.

Parameters
string$sqlSQL query
string$fnameName of the calling function, for profiling/SHOW PROCESSLIST comment (you can use METHOD or add some extra info)
int$flagsBitfield of IDatabase::QUERY_* constants. Note that suppression of errors is best handled by try/catch rather than using one of these flags.
Returns
bool|IResultWrapper True for a successful write query, IResultWrapper object for a successful read query, or false on failure if QUERY_SILENCE_ERRORS is set.
Exceptions
DBQueryErrorIf the query is issued, fails, and QUERY_SILENCE_ERRORS is not set.
DBExpectedErrorIf the query is not, and cannot, be issued yet (non-DBQueryError)
DBErrorIf the query is inherently not allowed (non-DBExpectedError)

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by MySqlLockManager\initConnection(), SqlBagOStuff\initSqliteDatabase(), and MwSql\sqlDoQuery().

◆ replace()

Wikimedia\Rdbms\IDatabase::replace (   $table,
  $uniqueIndexes,
  $rows,
  $fname = __METHOD__ 
)

REPLACE query wrapper.

REPLACE is a very handy MySQL extension, which functions like an INSERT except that when there is a duplicate key error, the old row is deleted and the new row is inserted in its place.

We simulate this with standard SQL with a DELETE followed by INSERT. To perform the delete, we need to know what the unique indexes are so that we know how to find the conflicting rows.

It may be more efficient to leave off unique indexes which are unlikely to collide. However if you do this, you run the risk of encountering errors which wouldn't have occurred in MySQL.

Parameters
string$tableThe table to replace the row(s) in.
array[] | string[] | string$uniqueIndexesAll unique indexes. One of the following: a) the one unique field in the table (when no composite unique key exist) b) a list of all unique fields in the table (when no composite unique key exist) c) a list of all unique indexes in the table (each as a list of the indexed fields)
array$rowsCan be either a single row to insert, or multiple rows, in the same format as for IDatabase::insert()
string$fnameCalling function name (use METHOD) for logs/profiling
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\DatabaseMysqlBase.

◆ restoreFlags()

Wikimedia\Rdbms\IDatabase::restoreFlags (   $state = self::RESTORE_PRIOR)

Restore the flags to their prior state before the last setFlag/clearFlag call.

Parameters
string$stateIDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]
Since
1.28

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ rollback()

Wikimedia\Rdbms\IDatabase::rollback (   $fname = __METHOD__,
  $flush = self::FLUSHING_ONE 
)

Rollback a transaction previously started using begin()

Only call this from code with outer transcation scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported. If a serious unexpected error occurs, throwing an Exception is preferrable, using a pre-installed error handler to trigger rollback (in any case, failure to issue COMMIT will cause rollback server-side).

Query, connection, and onTransaction* callback errors will be suppressed and logged.

Parameters
string$fnameCalling function name
string$flushFlush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about calling rollback when no transaction is in progress. This will silently break any ongoing explicit transaction. Only set the flush flag if you are sure that it is safe to ignore these warnings in your context.
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.23 Added $flush parameter

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by SqlBagOStuff\initSqliteDatabase(), PopulateArchiveRevId\makeDummyRevisionRow(), Wikimedia\Rdbms\LoadBalancer\rollbackMasterChanges(), and Maintenance\rollbackTransaction().

◆ select()

Wikimedia\Rdbms\IDatabase::select (   $table,
  $vars,
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Execute a SELECT query constructed using the various parameters provided.

Parameters
string | array$tableTable name(s)

May be either an array of table names, or a single string holding a table name. If an array is given, table aliases can be specified, for example:

[ 'a' => 'user' ]

This includes the user table in the query, with the alias "a" available for use in field names (e.g. a.user_name).

A derived table, defined by the result of selectSQLText(), requires an alias key and a Subquery instance value which wraps the SQL query, for example:

[ 'c' => new Subquery( 'SELECT ...' ) ]

Joins using parentheses for grouping (since MediaWiki 1.31) may be constructed using nested arrays. For example,

[ 'tableA', 'nestedB' => [ 'tableB', 'b2' => 'tableB2' ] ]

along with $join_conds like

[ 'b2' => [ 'JOIN', 'b_id = b2_id' ], 'nestedB' => [ 'LEFT JOIN', 'b_a = a_id' ] ]

will produce SQL something like

FROM tableA LEFT JOIN (tableB JOIN tableB2 AS b2 ON (b_id = b2_id)) ON (b_a = a_id)

All of the table names given here are automatically run through Database::tableName(), which causes the table prefix (if any) to be added, and various other table name mappings to be performed.

Do not use untrusted user input as a table name. Alias names should not have characters outside of the Basic multilingual plane.

Parameters
string | array$varsField name(s)

May be either a field name or an array of field names. The field names can be complete fragments of SQL, for direct inclusion into the SELECT query. If an array is given, field aliases can be specified, for example:

[ 'maxrev' => 'MAX(rev_id)' ]

This includes an expression with the alias "maxrev" in the query.

If an expression is given, care must be taken to ensure that it is DBMS-independent.

Untrusted user input must not be passed to this parameter.

Parameters
string | array$condsMay be either a string containing a single condition, or an array of conditions. If an array is given, the conditions constructed from each element are combined with AND.

Array elements may take one of two forms:

  • Elements with a numeric key are interpreted as raw SQL fragments.
  • Elements with a string key are interpreted as equality conditions, where the key is the field name.
    • If the value of such an array element is a scalar (such as a string), it will be treated as data and thus quoted appropriately. If it is null, an IS NULL clause will be added.
    • If the value is an array, an IN (...) clause will be constructed from its non-null elements, and an IS NULL clause will be added if null is present, such that the field may match any of the elements in the array. The non-null elements will be quoted.

Note that expressions are often DBMS-dependent in their syntax. DBMS-independent wrappers are provided for constructing several types of expression commonly used in condition queries. See:

Untrusted user input is safe in the values of string keys, however untrusted input must not be used in the array key names or in the values of numeric keys. Escaping of untrusted input used in values of numeric keys should be done via IDatabase::addQuotes()

Use an empty array, string, or '*' to update all rows.

Parameters
string$fnameCaller function name
string | array$optionsQuery options

Optional: Array of query options. Boolean options are specified by including them in the array as a string value with a numeric key, for example:

[ 'FOR UPDATE' ]

The supported options are:

  • OFFSET: Skip this many rows at the start of the result set. OFFSET with LIMIT can theoretically be used for paging through a result set, but this is discouraged for performance reasons.
  • LIMIT: Integer: return at most this many rows. The rows are sorted and then the first rows are taken until the limit is reached. LIMIT is applied to a result set after OFFSET.
  • LOCK IN SHARE MODE: Boolean: lock the returned rows so that they can't be changed until the next COMMIT. Cannot be used with aggregate functions (COUNT, MAX, etc., but also DISTINCT).
  • FOR UPDATE: Boolean: lock the returned rows so that they can't be changed nor read with LOCK IN SHARE MODE until the next COMMIT. Cannot be used with aggregate functions (COUNT, MAX, etc., but also DISTINCT).
  • DISTINCT: Boolean: return only unique result rows.
  • GROUP BY: May be either an SQL fragment string naming a field or expression to group by, or an array of such SQL fragments.
  • HAVING: May be either an string containing a HAVING clause or an array of conditions building the HAVING clause. If an array is given, the conditions constructed from each element are combined with AND.
  • ORDER BY: May be either an SQL fragment giving a field name or expression to order by, or an array of such SQL fragments.
  • USE INDEX: This may be either a string giving the index name to use for the query, or an array. If it is an associative array, each key gives the table name (or alias), each value gives the index name to use for that table. All strings are SQL fragments and so should be validated by the caller.
  • EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run, instead of SELECT.

And also the following boolean MySQL extensions, see the MySQL manual for documentation:

  • STRAIGHT_JOIN
  • SQL_BIG_RESULT
  • SQL_BUFFER_RESULT
  • SQL_SMALL_RESULT
  • SQL_CALC_FOUND_ROWS
Parameters
string | array$join_condsJoin conditions

Optional associative array of table-specific join conditions. In the most common case, this is unnecessary, since the join condition can be in $conds. However, it is useful for doing a LEFT JOIN.

The key of the array contains the table name or alias. The value is an array with two elements, numbered 0 and 1. The first gives the type of join, the second is the same as the $conds parameter. Thus it can be an SQL fragment, or an array where the string keys are equality and the numeric keys are SQL fragments all AND'd together. For example:

[ 'page' => [ 'LEFT JOIN', 'page_latest=rev_id' ] ]

Returns
IResultWrapper Resulting rows
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by MigrateActors\addActorsForRows(), SqlBagOStuff\deleteServerObjectsExpiringBefore(), JobQueueDB\doBatchPushInternal(), DBFileJournal\doGetChangeEntries(), RefreshImageMetadata\execute(), ResourceLoaderWikiModule\fetchTitleInfo(), WANCacheReapUpdate\getTitleChangeEvents(), MigrateComments\loadCommentIDs(), MediaWiki\Storage\NameTableStore\loadTable(), PopulateContentModel\populatePage(), PopulateContentModel\populateRevisionOrArchive(), DeduplicateArchiveRevId\processArRevIds(), UppercaseTitlesForUnicodeTransition\processTable(), and UserGroupMembership\purgeExpired().

◆ selectDB()

Wikimedia\Rdbms\IDatabase::selectDB (   $db)

Change the current database.

This should only be called by a load balancer or if the handle is not attached to one

Parameters
string$db
Returns
bool True unless an exception was thrown
Exceptions
DBConnectionErrorIf databasesAreIndependent() is true and connection change fails
DBErrorOn query error or if database changes are disallowed
Deprecated:
Since 1.32 Use selectDomain() instead

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ selectDomain()

Wikimedia\Rdbms\IDatabase::selectDomain (   $domain)

Set the current domain (database, schema, and table prefix)

This will throw an error for some database types if the database is unspecified

This should only be called by a load balancer or if the handle is not attached to one

Parameters
string | DatabaseDomain$domain
Exceptions
DBConnectionErrorIf databasesAreIndependent() is true and connection change fails
DBErrorOn query error, if domain changes are disallowed, or the domain is invalid
Since
1.32

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ selectField()

Wikimedia\Rdbms\IDatabase::selectField (   $table,
  $var,
  $cond = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

A SELECT wrapper which returns a single field from a single result row.

If no result rows are returned from the query, false is returned.

Parameters
string | array$tableTable name. See IDatabase::select() for details.
string$varThe field name to select. This must be a valid SQL fragment: do not use unvalidated user input.
string | array$condThe condition array. See IDatabase::select() for details.
string$fnameThe function name of the caller.
string | array$optionsThe query options. See IDatabase::select() for details.
string | array$join_condsThe query join conditions. See IDatabase::select() for details.
Returns
mixed The value from the field
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by User\addToDatabase(), PopulateArchiveRevId\checkMysqlAutoIncrementBug(), CommentStore\createComment(), DBFileJournal\doGetCurrentPosition(), DBFileJournal\doGetPositionAtTime(), UserGroupMembership\insert(), UppercaseTitlesForUnicodeTransition\isUserPage(), and PopulateArchiveRevId\makeDummyRevisionRow().

◆ selectFieldValues()

Wikimedia\Rdbms\IDatabase::selectFieldValues (   $table,
  $var,
  $cond = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

A SELECT wrapper which returns a list of single field values from result rows.

If no result rows are returned from the query, false is returned.

Parameters
string | array$tableTable name. See IDatabase::select() for details.
string$varThe field name to select. This must be a valid SQL fragment: do not use unvalidated user input.
string | array$condThe condition array. See IDatabase::select() for details.
string$fnameThe function name of the caller.
string | array$optionsThe query options. See IDatabase::select() for details.
string | array$join_condsThe query join conditions. See IDatabase::select() for details.
Returns
array The values from the field in the order they were returned from the DB
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.25

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by ChangeTags\getTags(), PurgeJobUtils\invalidatePages(), UppercaseTitlesForUnicodeTransition\processUsers(), MediaWiki\Block\DatabaseBlock\purgeExpired(), Title\purgeExpiredRestrictions(), and PopulateArchiveRevId\reassignArRevIds().

◆ selectRow()

Wikimedia\Rdbms\IDatabase::selectRow (   $table,
  $vars,
  $conds,
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Wrapper to IDatabase::select() that only fetches one row (via LIMIT)

If the query returns no rows, false is returned.

This method is convenient for fetching a row based on a unique key condition.

Parameters
string | array$tableTable name
string | array$varsField names
string | array$condsConditions
string$fnameCaller function name
string | array$optionsQuery options
array | string$join_condsJoin conditions
Returns
stdClass|bool
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by SiteStats\doLoadFromDB(), LinkCache\fetchPageRow(), CommentStore\getCommentInternal(), PopulateArchiveRevId\makeDummyRevisionRow(), DatabaseLogEntry\newFromId(), and User\newSystemUser().

◆ selectRowCount()

Wikimedia\Rdbms\IDatabase::selectRowCount (   $tables,
  $var = ' *',
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Get the number of rows in dataset.

This is useful when trying to do COUNT(*) but with a LIMIT for performance.

Takes the same arguments as IDatabase::select().

Since
1.27 Added $join_conds parameter
Parameters
array | string$tablesTable names
string$varColumn for which NULL values are not counted [default "*"]
array | string$condsFilters on the table
string$fnameFunction name for profiling
array$optionsOptions for select
array$join_condsJoin conditions (since 1.27)
Returns
int Row count
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\DBConnRef, and Wikimedia\Rdbms\Database.

Referenced by PopulateArchiveRevId\isNewInstall().

◆ selectSQLText()

Wikimedia\Rdbms\IDatabase::selectSQLText (   $table,
  $vars,
  $conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Take the same arguments as IDatabase::select() and return the SQL it would use.

This can be useful for making UNION queries, where the SQL text of each query is needed. In general, however, callers outside of Database classes should just use select().

See also
IDatabase::select()
Parameters
string | array$tableTable name
string | array$varsField names
string | array$condsConditions
string$fnameCaller function name
string | array$optionsQuery options
string | array$join_condsJoin conditions
Returns
string SQL query string

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ serverIsReadOnly()

Wikimedia\Rdbms\IDatabase::serverIsReadOnly ( )

◆ setBigSelects()

Wikimedia\Rdbms\IDatabase::setBigSelects (   $value = true)

Allow or deny "big selects" for this session only.

This is done by setting the sql_big_selects session variable.

This is a MySQL-specific feature.

Parameters
bool | string$valueTrue for allow, false for deny, or "default" to restore the initial value

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

◆ setFlag()

Wikimedia\Rdbms\IDatabase::setFlag (   $flag,
  $remember = self::REMEMBER_NOTHING 
)

Set a flag for this connection.

Parameters
int$flagOne of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string$rememberIDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by DatabaseUpdater\__construct(), and JobQueueDB\getScopedNoTrxFlag().

◆ setIndexAliases()

Wikimedia\Rdbms\IDatabase::setIndexAliases ( array  $aliases)

Convert certain index names to alternative names before querying the DB.

Note that this applies to indexes regardless of the table they belong to.

This can be employed when an index was renamed X => Y in code, but the new Y-named indexes were not yet built on all DBs. After all the Y-named ones are added by the DBA, the aliases can be removed, and then the old X-named indexes dropped.

Parameters
string[]$aliases
Since
1.31

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ setLBInfo()

Wikimedia\Rdbms\IDatabase::setLBInfo (   $nameOrArray,
  $value = null 
)

Set the entire array or a particular key of the managing load balancer info array.

Keys matching the IDatabase::LB_* constants are also used internally by subclasses

Parameters
array | string$nameOrArrayThe new array or the name of a key to set
array | null$valueIf $nameOrArray is a string, the new key value (null to unset)

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\reuseConnection().

◆ setSchemaVars()

Wikimedia\Rdbms\IDatabase::setSchemaVars (   $vars)

Set schema variables to be used when streaming commands from SQL files or stdin.

Variables appear as SQL comments and are substituted by their corresponding values

Parameters
array | null$varsMap of (variable => value) or null to use the defaults

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ setSessionOptions()

Wikimedia\Rdbms\IDatabase::setSessionOptions ( array  $options)

Override database's default behavior.

$options include: 'connTimeout' : Set the connection timeout value in seconds. May be useful for very long batch queries such as full-wiki dumps, where a single query reads out over hours or days.

Parameters
array$options
Returns
void
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by BackupDumper\backupDb().

◆ setTableAliases()

Wikimedia\Rdbms\IDatabase::setTableAliases ( array  $aliases)

Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

For example, "user" can be converted to "myschema.mydbname.user" for convenience. Appearances like user, somedb.user, somedb.someschema.user will used literally.

Calling this twice will completely clear any old table aliases. Also, note that callers are responsible for making sure the schemas and databases actually exist.

Parameters
array[]$aliasesMap of (table => (dbname, schema, prefix) map)
Since
1.28

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ setTransactionListener()

Wikimedia\Rdbms\IDatabase::setTransactionListener (   $name,
callable  $callback = null 
)

Run a callback after each time any transaction commits or rolls back.

The callback takes two arguments:

  • IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK
  • This IDatabase object Callbacks must commit any transactions that they begin.

Registering a callback here will not affect writesOrCallbacks() pending.

Since callbacks from this or onTransactionCommitOrIdle() can start and end transactions, a single call to IDatabase::commit might trigger multiple runs of the listener callbacks.

Parameters
string$nameCallback name
callable | null$callbackUse null to unset a listener
Since
1.28

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\setTransactionListener().

◆ startAtomic()

Wikimedia\Rdbms\IDatabase::startAtomic (   $fname = __METHOD__,
  $cancelable = self::ATOMIC_NOT_CANCELABLE 
)

Begin an atomic section of SQL statements.

Start an implicit transaction if no transaction is already active, set a savepoint (if $cancelable is ATOMIC_CANCELABLE), and track the given section name to enforce that the transaction is not committed prematurely. The end of the section must be signified exactly once, either by endAtomic() or cancelAtomic(). Sections can have have layers of inner sections (sub-sections), but all sections must be ended in order of innermost to outermost. Transactions cannot be started or committed until all atomic sections are closed.

ATOMIC_CANCELABLE is useful when the caller needs to handle specific failure cases by discarding the section's writes. This should not be used for failures when:

  • upsert() could easily be used instead
  • insert() with IGNORE could easily be used instead
  • select() with FOR UPDATE could be checked before issuing writes instead
  • The failure is from code that runs after the first write but doesn't need to
  • The failures are from contention solvable via onTransactionPreCommitOrIdle()
  • The failures are deadlocks; the RDBMs usually discard the whole transaction
Note
callers must use additional measures for situations involving two or more (peer) transactions (e.g. updating two database servers at once). The transaction and savepoint logic of this method only applies to this specific IDatabase instance.

Example usage:

// Start a transaction if there isn't one already
$dbw->startAtomic( __METHOD__ );
// Serialize these thread table updates
$dbw->select( 'thread', '1', [ 'td_id' => $tid ], __METHOD__, 'FOR UPDATE' );
// Add a new comment for the thread
$dbw->insert( 'comment', $row, __METHOD__ );
$cid = $db->insertId();
// Update thread reference to last comment
$dbw->update( 'thread', [ 'td_latest' => $cid ], [ 'td_id' => $tid ], __METHOD__ );
// Demark the end of this conceptual unit of updates
$dbw->endAtomic( __METHOD__ );

Example usage (atomic changes that might have to be discarded):

// Start a transaction if there isn't one already
$sectionId = $dbw->startAtomic( __METHOD__, $dbw::ATOMIC_CANCELABLE );
// Create new record metadata row
$dbw->insert( 'records', $row, __METHOD__ );
// Figure out where to store the data based on the new row's ID
$path = $recordDirectory . '/' . $dbw->insertId();
// Write the record data to the storage system
$status = $fileBackend->create( [ 'dst' => $path, 'content' => $data ] );
if ( $status->isOK() ) {
// Try to cleanup files orphaned by transaction rollback
$dbw->onTransactionResolution(
function ( $type ) use ( $fileBackend, $path ) {
if ( $type === IDatabase::TRIGGER_ROLLBACK ) {
$fileBackend->delete( [ 'src' => $path ] );
}
},
__METHOD__
);
// Demark the end of this conceptual unit of updates
$dbw->endAtomic( __METHOD__ );
} else {
// Discard these writes from the transaction (preserving prior writes)
$dbw->cancelAtomic( __METHOD__, $sectionId );
}
Since
1.23
Parameters
string$fname
string$cancelablePass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.
Returns
AtomicSectionIdentifier section ID token
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by JobQueueDB\doBatchPushInternal(), LCStoreDB\finishWrite(), MySqlLockManager\initConnection(), SqlBagOStuff\initSqliteDatabase(), UserGroupMembership\insert(), and UserGroupMembership\purgeExpired().

◆ strreplace()

Wikimedia\Rdbms\IDatabase::strreplace (   $orig,
  $old,
  $new 
)

Returns a SQL expression for simple string replacement (e.g.

REPLACE() in mysql)

Parameters
string$origColumn to modify
string$oldColumn to seek
string$newColumn to replace with
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ tableExists()

Wikimedia\Rdbms\IDatabase::tableExists (   $table,
  $fname = __METHOD__ 
)

Query whether a given table exists.

Parameters
string$table
string$fname
Returns
bool
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by SqlBagOStuff\initSqliteDatabase().

◆ tablePrefix()

Wikimedia\Rdbms\IDatabase::tablePrefix (   $prefix = null)

Get/set the table prefix.

Parameters
string | null$prefixThe table prefix to set, or omitted to leave it unchanged
Returns
string The previous table prefix

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by SqlBagOStuff\initSqliteDatabase(), and Wikimedia\Rdbms\LoadBalancer\setLocalDomainPrefix().

◆ timestamp()

◆ timestampOrNull()

Wikimedia\Rdbms\IDatabase::timestampOrNull (   $ts = null)

Convert a timestamp in one of the formats accepted by ConvertibleTimestamp to the format used for inserting into timestamp fields in this DBMS.

If NULL is input, it is passed through, allowing NULL values to be inserted into timestamp fields.

The result is unquoted, and needs to be passed through addQuotes() before it can be included in raw SQL.

Parameters
string | int | null$ts
Returns
string

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by User\addToDatabase(), and User\saveSettings().

◆ trxLevel()

Wikimedia\Rdbms\IDatabase::trxLevel ( )

Gets the current transaction level.

Historically, transactions were allowed to be "nested". This is no longer supported, so this function really only returns a boolean.

Returns
int The previous value

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\enforceConnectionFlags().

◆ trxTimestamp()

Wikimedia\Rdbms\IDatabase::trxTimestamp ( )

Get the UNIX timestamp of the time that the transaction was established.

This can be used to reason about the staleness of SELECT data in REPEATABLE-READ transaction isolation level. Callers can assume that if a view-snapshot isolation is used, then the data read by SQL queries is at least up to date to that point (possibly more up-to-date since the first SELECT defines the snapshot).

Returns
float|null Returns null if there is not active transaction
Since
1.25

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ unionConditionPermutations()

Wikimedia\Rdbms\IDatabase::unionConditionPermutations (   $table,
  $vars,
array  $permute_conds,
  $extra_conds = '',
  $fname = __METHOD__,
  $options = [],
  $join_conds = [] 
)

Construct a UNION query for permutations of conditions.

Databases sometimes have trouble with queries that have multiple values for multiple condition parameters combined with limits and ordering. This method constructs queries for the Cartesian product of the conditions and unions them all together.

See also
IDatabase::select()
Parameters
string | array$tableTable name
string | array$varsField names
array$permute_condsConditions for the Cartesian product. Keys are field names, values are arrays of the possible values for that field.
string | array$extra_condsAdditional conditions to include in the query.
string$fnameCaller function name
string | array$optionsQuery options. In addition to the options recognized by IDatabase::select(), the following may be used:
  • NOTALL: Set to use UNION instead of UNION ALL.
  • INNER ORDER BY: If specified and supported, subqueries will use this instead of ORDER BY.
string | array$join_condsJoin conditions
Returns
string SQL query string.
Since
1.30

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ unionQueries()

Wikimedia\Rdbms\IDatabase::unionQueries (   $sqls,
  $all 
)

Construct a UNION query.

This is used for providing overload point for other DB abstractions not compatible with the MySQL syntax.

Parameters
array$sqlsSQL statements to combine
bool$allEither IDatabase::UNION_ALL or IDatabase::UNION_DISTINCT
Returns
string SQL fragment

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ unionSupportsOrderAndLimit()

Wikimedia\Rdbms\IDatabase::unionSupportsOrderAndLimit ( )

Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION.

Returns
bool

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ unlock()

Wikimedia\Rdbms\IDatabase::unlock (   $lockName,
  $method 
)

Release a lock.

Named locks are not related to transactions

Parameters
string$lockNameName of lock to release
string$methodName of the calling method
Returns
bool Success
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ update()

Wikimedia\Rdbms\IDatabase::update (   $table,
  $values,
  $conds,
  $fname = __METHOD__,
  $options = [] 
)

UPDATE wrapper.

Takes a condition array and a SET array.

Parameters
string$tableName of the table to UPDATE. This will be passed through Database::tableName().
array$valuesAn array of values to SET. For each array element, the key gives the field name, and the value gives the data to set that field to. The data will be quoted by IDatabase::addQuotes(). Values with integer keys form unquoted SET statements, which can be used for things like "field = field + 1" or similar computed values.
array | string$condsAn array of conditions (WHERE). See IDatabase::select() for the details of the format of condition arrays. Use '*' to update all rows.
string$fnameThe function name of the caller (from METHOD), for logging and profiling.
array$optionsAn array of UPDATE options, can be:
  • IGNORE: Ignore unique key conflicts
Returns
bool Return true if no exception was thrown (deprecated since 1.33)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by SiteStatsUpdate\cacheUpdate(), LocalFileMoveBatch\doDBUpdates(), SiteStatsUpdate\doUpdate(), UppercaseTitlesForUnicodeTransition\doUpdate(), UserGroupMembership\insert(), Title\invalidateCache(), PurgeJobUtils\invalidatePages(), User\newSystemUser(), DeleteLocalPasswords\processUsers(), PopulateArchiveRevId\reassignArRevIds(), User\saveSettings(), PopulateContentModel\updatePageRows(), and PopulateContentModel\updateRevisionOrArchiveRows().

◆ upsert()

Wikimedia\Rdbms\IDatabase::upsert (   $table,
array  $rows,
  $uniqueIndexes,
array  $set,
  $fname = __METHOD__ 
)

INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table.

This updates any conflicting rows (according to the unique indexes) using the provided SET clause and inserts any remaining (non-conflicted) rows.

$rows may be either:

  • A single associative array. The array keys are the field names, and the values are the values to insert. The values are treated as data and will be quoted appropriately. If NULL is inserted, this will be converted to a database NULL.
  • An array with numeric keys, holding a list of associative arrays. This causes a multi-row INSERT on DBMSs that support it. The keys in each subarray must be identical to each other, and in the same order.

It may be more efficient to leave off unique indexes which are unlikely to collide. However if you do this, you run the risk of encountering errors which wouldn't have occurred in MySQL.

Parameters
string$tableTable name. This will be passed through Database::tableName().
array | array[]$rowsA single row or list of rows to insert
array[] | string[] | string$uniqueIndexesAll unique indexes. One of the following: a) the one unique field in the table (when no composite unique key exist) b) a list of all unique fields in the table (when no composite unique key exist) c) a list of all unique indexes in the table (each as a list of the indexed fields)
array$setAn array of values to SET. For each array element, the key gives the field name, and the value gives the data to set that field to. The data will be quoted by IDatabase::addQuotes(). Values with integer keys form unquoted SET statements, which can be used for things like "field = field + 1" or similar computed values.
string$fnameCalling function name (use METHOD) for logs/profiling
Returns
bool Return true if no exception was thrown (deprecated since 1.33)
Exceptions
DBErrorIf an error occurs, see IDatabase::query()
Since
1.22

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, and Wikimedia\Rdbms\DBConnRef.

Referenced by ActorMigration\getInsertValuesWithTempTable().

◆ wasConnectionLoss()

Wikimedia\Rdbms\IDatabase::wasConnectionLoss ( )

Determines if the last query error was due to a dropped connection.

Note that during a connection loss, the prior transaction will have been lost

Returns
bool
Since
1.31

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ wasDeadlock()

Wikimedia\Rdbms\IDatabase::wasDeadlock ( )

Determines if the last failure was due to a deadlock.

Note that during a deadlock, the prior transaction will have been lost

Returns
bool

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

◆ wasErrorReissuable()

Wikimedia\Rdbms\IDatabase::wasErrorReissuable ( )

Determines if the last query error was due to something outside of the query itself.

Note that the transaction may have been lost, discarding prior writes and results

Returns
bool

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

◆ wasLockTimeout()

Wikimedia\Rdbms\IDatabase::wasLockTimeout ( )

Determines if the last failure was due to a lock timeout.

Note that during a lock wait timeout, the prior transaction will have been lost

Returns
bool

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabasePostgres, and Wikimedia\Rdbms\DBConnRef.

◆ wasReadOnlyError()

Wikimedia\Rdbms\IDatabase::wasReadOnlyError ( )

Determines if the last failure was due to the database being read-only.

Returns
bool

Implemented in Wikimedia\Rdbms\Database, Wikimedia\Rdbms\DatabaseMysqlBase, Wikimedia\Rdbms\DatabaseSqlite, and Wikimedia\Rdbms\DBConnRef.

Referenced by LCStoreDB\finishWrite().

◆ writesOrCallbacksPending()

Wikimedia\Rdbms\IDatabase::writesOrCallbacksPending ( )

Whether there is a transaction open with either possible write queries or unresolved pre-commit/commit/resolution callbacks pending.

This does not count recurring callbacks, e.g. from setTransactionListener().

Returns
bool

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.

Referenced by Wikimedia\Rdbms\LoadBalancer\approveMasterChanges(), DeferredUpdates\areDatabaseTransactionsActive(), and Wikimedia\Rdbms\LoadBalancer\hasMasterChanges().

◆ writesPending()

Wikimedia\Rdbms\IDatabase::writesPending ( )
Returns
bool Whether there is a transaction open with possible write queries
Since
1.27

Implemented in Wikimedia\Rdbms\Database, and Wikimedia\Rdbms\DBConnRef.


The documentation for this interface was generated from the following file:
LIST_AND
const LIST_AND
Definition: Defines.php:39
LIST_OR
const LIST_OR
Definition: Defines.php:42
$path
$path
Definition: NoLocalSettings.php:25
$type
$type
Definition: testCompression.php:50