Wikimedia\Rdbms\IMaintainableDatabase Interface Reference

Advanced database interface for IDatabase handles that include maintenance methods. More...

Inheritance diagram for Wikimedia\Rdbms\IMaintainableDatabase:

Collaboration diagram for Wikimedia\Rdbms\IMaintainableDatabase:

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

Detailed Description

Advanced database interface for IDatabase handles that include maintenance methods.

This is useful for type-hints used by installer, upgrader, and background scripts that will make use of lower-level and longer-running queries, including schema changes.

Since

1.28

Definition at line 38 of file IMaintainableDatabase.php.

Member Function Documentation

deadlockLoop()

Wikimedia\Rdbms\IMaintainableDatabase::deadlockLoop

(

)

Perform a deadlock-prone transaction.

This function invokes a callback function to perform a set of write queries. If a deadlock occurs during the processing, the transaction will be rolled back and the callback function will be called again.

Avoid using this method outside of Job or Maintenance classes.

Usage: $dbw->deadlockLoop( callback, ... );

Extra arguments are passed through to the specified callback function. This method requires that no transactions are already active to avoid causing premature commits or exceptions.

Returns whatever the callback function returned on its successful, iteration, or false on error, for example if the retry limit was reached.

Returns

mixed

Exceptions

DBUnexpectedError
Exception

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

dropTable()

Wikimedia\Rdbms\IMaintainableDatabase::dropTable	(		$tableName,
			$fName = __METHOD__
	)

Delete a table.

Parameters

string	$tableName
string	$fName

Returns

bool|IResultWrapper

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

duplicateTableStructure()

Wikimedia\Rdbms\IMaintainableDatabase::duplicateTableStructure	(		$oldName,
			$newName,
			$temporary = false,
			$fname = __METHOD__
	)

Creates a new table with structure copied from existing table.

Note that unlike most database abstraction functions, this function does not automatically append database prefix, because it works at a lower abstraction level. The table names passed to this function shall not be quoted (this function calls addIdentifierQuotes() when needed).

Parameters

string	$oldName	Name of table whose structure should be copied
string	$newName	Name of table to be created
bool	$temporary	Whether the new table should be temporary
string	$fname	Calling function name

Returns

bool True if operation was successful

Exceptions

RuntimeException

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

fieldInfo()

Wikimedia\Rdbms\IMaintainableDatabase::fieldInfo	(		$table,
			$field
	)

mysql_fetch_field() wrapper Returns false if the field doesn't exist

Parameters

string	$table	Table name
string	$field	Field name

Returns

false|Field

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

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

indexUnique()

Wikimedia\Rdbms\IMaintainableDatabase::indexUnique	(		$table,
			$index
	)

Determines if a given index is unique.

Parameters

string	$table
string	$index

Returns

bool

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

listTables()

Wikimedia\Rdbms\IMaintainableDatabase::listTables	(		$prefix = null,
			$fname = __METHOD__
	)

List all tables on the database.

Parameters

string | null	$prefix	Only show tables with this prefix, e.g. mw_
string	$fname	Calling function name

Exceptions

DBError

Returns

array

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

listViews()

Wikimedia\Rdbms\IMaintainableDatabase::listViews	(		$prefix = null,
			$fname = __METHOD__
	)

Lists all the VIEWs in the database.

Parameters

string | null	$prefix	Only show VIEWs with this prefix, eg. unit_test_
string	$fname	Name of calling function

Exceptions

RuntimeException

Returns

array

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

lockTables()

Wikimedia\Rdbms\IMaintainableDatabase::lockTables	(	array	$read,
		array	$write,
			$method
	)

Lock specific tables.

Any pending transaction should be resolved before calling this method, since: a) Doing so resets any REPEATABLE-READ snapshot of the data to a fresh one. b) Previous row and table locks from the transaction or session may be released by LOCK TABLES, which may be unsafe for the changes in such a transaction. c) The main use case of lockTables() is to avoid deadlocks and timeouts by locking entire tables in order to do long-running, batched, and lag-aware, updates. Batching and replication lag checks do not work when all the updates happen in a transaction.

Always get all relevant table locks up-front in one call, since LOCK TABLES might release any prior table locks on some RDBMes (e.g MySQL).

For compatibility, callers should check tableLocksHaveTransactionScope() before using this method. If locks are scoped specifically to transactions then caller must either:

• a) Start a new transaction and acquire table locks for the scope of that transaction, doing all row updates within that transaction. It will not be possible to update rows in batches; this might result in high replication lag.
• b) Forgo table locks entirely and avoid calling this method. Careful use of hints like LOCK IN SHARE MODE and FOR UPDATE and the use of query batching may be preferrable to using table locks with a potentially large transaction. Use of MySQL and Postges style REPEATABLE-READ (Snapshot Isolation with or without First-Committer-Rule) can also be considered for certain tasks that require a consistent view of entire tables.

If session scoped locks are not supported, then calling lockTables() will trigger startAtomic(), with unlockTables() triggering endAtomic(). This will automatically start a transaction if one is not already present and cause the locks to be released when the transaction finishes (normally during the unlockTables() call).

In any case, avoid using begin()/commit() in code that runs while such table locks are acquired, as that breaks in case when a transaction is needed. The startAtomic() and endAtomic() methods are safe, however, since they will join any existing transaction.

Parameters

array	$read	Array of tables to lock for read access
array	$write	Array of tables to lock for write access
string	$method	Name of caller

Returns

bool

Since

1.29

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

sourceFile()

Wikimedia\Rdbms\IMaintainableDatabase::sourceFile	(		$filename,
		callable	$lineCallback = null,
		callable	$resultCallback = null,
			$fname = false,
		callable	$inputCallback = null
	)

Read and execute SQL commands from a file.

Returns true on success, error string or exception on failure (depending on object's error ignore settings).

Parameters

string	$filename	File name to open
callable | null	$lineCallback	Optional function called before reading each line
callable | null	$resultCallback	Optional function called for each MySQL result
bool | string	$fname	Calling function name or false if name should be generated dynamically using $filename
callable | null	$inputCallback	Optional function called for each complete line sent

Returns

bool|string

Exceptions

Exception

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

sourceStream()

Wikimedia\Rdbms\IMaintainableDatabase::sourceStream	(		$fp,
		callable	$lineCallback = null,
		callable	$resultCallback = null,
			$fname = __METHOD__,
		callable	$inputCallback = null
	)

Read and execute commands from an open file handle.

Returns true on success, error string or exception on failure (depending on object's error ignore settings).

Parameters

resource	$fp	File handle
callable | null	$lineCallback	Optional function called before reading each query
callable | null	$resultCallback	Optional function called for each MySQL result
string	$fname	Calling function name
callable | null	$inputCallback	Optional function called for each complete query sent

Returns

bool|string

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

streamStatementEnd()

Wikimedia\Rdbms\IMaintainableDatabase::streamStatementEnd	(	&	$sql,
		&	$newLine
	)

Called by sourceStream() to check if we've reached a statement end.

Parameters

string	&$sql	SQL assembled so far
string	&$newLine	New line about to be added to $sql

Returns

bool Whether $newLine contains end of the statement

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

tableLocksHaveTransactionScope()

Wikimedia\Rdbms\IMaintainableDatabase::tableLocksHaveTransactionScope

(

)

Checks if table locks acquired by lockTables() are transaction-bound in their scope.

Transaction-bound table locks will be released when the current transaction terminates. Table locks that are not bound to a transaction are not effected by BEGIN/COMMIT/ROLLBACK and will last until either lockTables()/unlockTables() is called or the TCP connection to the database is closed.

Returns

bool

Since

1.29

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

tableName()

Wikimedia\Rdbms\IMaintainableDatabase::tableName	(		$name,
			$format = 'quoted'
	)

Format a table name ready for use in constructing an SQL query.

This does two important things: it quotes the table names to clean them up, and it adds a table prefix if only given a table name with no quotes.

All functions of this object which require a table name call this function themselves. Pass the canonical name to such functions. This is only needed when calling query() directly.

Note

This function does not sanitize user input. It is not safe to use this function to escape user input.

Parameters

string	$name	Database table name
string	$format	One of: quoted - Automatically pass the table name through addIdentifierQuotes() so that it can be used in a query. raw - Do not add identifier quotes to the table name

Returns

string Full database name

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

Referenced by SqlBagOStuff\initSqliteDatabase().

tableNames()

Wikimedia\Rdbms\IMaintainableDatabase::tableNames

(

)

Fetch a number of table names into an array This is handy when you need to construct SQL for joins.

Example: list( $user, $watchlist ) = $dbr->tableNames( 'user', 'watchlist' ) ); $sql = "SELECT wl_namespace, wl_title FROM $watchlist, $user WHERE wl_user=user_id AND wl_user=$nameWithQuotes";

Returns

array

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

tableNamesN()

Wikimedia\Rdbms\IMaintainableDatabase::tableNamesN

(

)

Fetch a number of table names into an zero-indexed numerical array This is handy when you need to construct SQL for joins.

Example: list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' ); $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user WHERE wl_user=user_id AND wl_user=$nameWithQuotes";

Returns

array

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

textFieldSize()

Wikimedia\Rdbms\IMaintainableDatabase::textFieldSize	(		$table,
			$field
	)

Returns the size of a text field, or -1 for "unlimited".

Parameters

string	$table
string	$field

Returns

int

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

unlockTables()

Wikimedia\Rdbms\IMaintainableDatabase::unlockTables

(

$method

)

Unlock all tables locked via lockTables()

If table locks are scoped to transactions, then locks might not be released until the transaction ends, which could happen after this method is called.

Parameters

string

$method

The caller

Returns

bool

Since

1.29

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

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The documentation for this interface was generated from the following file:

• includes/libs/rdbms/database/IMaintainableDatabase.php