Wikimedia\Rdbms\DBConnRef Class Reference

Helper class used for automatically re-using IDatabase connections and lazily establishing the actual network connection to a database host. More...

Inherits Stringable, Wikimedia\Rdbms\IMaintainableDatabase, and Wikimedia\Rdbms\IDatabaseForOwner.

Collaboration diagram for Wikimedia\Rdbms\DBConnRef:

Public Member Functions
	__call ( $name, array $arguments)
	__construct (ILoadBalancer $lb, $params, $role, &$modcount=0)
	__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.table, column, database) for use in a SQL queryDepending on the database this will either be backticks or "double quotes" Parameters string $s Returns string Since 1.33
	addQuotes ( $s)
	Escape and quote a raw value string for use in a SQL query. Parameters ?scalar | RawSQLValue | Blob $s Returns string
	affectedRows ()
	Get the number of rows affected by the last query method call.This method should only be called when all the following hold true: (a) A method call was made to insert(), upsert(), replace(), update(), delete(), insertSelect(), query() with a non-SELECT statement, or queryMulti() with a non-SELECT terminal statement (b) The method call succeeded (c) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType() In all other cases, the return value is unspecified.UPDATE queries consider rows affected even when all their new column values match the previous values. Such rows can be excluded from the count by changing the WHERE clause to filter them out.If the last query method call was to query() or queryMulti(), then the results are based on the (last) statement provided to that call and are driver-specific. Returns int
	andExpr (array $conds)
	See Expression::__construct() Since 1.43 Parameters non-empty-array<string,?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob>>|non-empty-array<int,IExpression> $conds Returns AndExpressionGroup
	anyChar ()
	Returns a token for buildLike() that denotes a '_' to be used in a LIKE query. Returns LikeMatch
	anyString ()
	Returns a token for buildLike() that denotes a '' to be used in a LIKE query. Returns LikeMatch
	begin ( $fname=__METHOD__, $mode=IDatabase::TRANSACTION_EXPLICIT)
	Begin a transaction.Only call this from code with outer transaction 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 $fname Calling function name string $mode A situationally valid IDatabase::TRANSACTION_* constant [optional] Exceptions DBError If an error occurs, { See also query}
	bitAnd ( $fieldLeft, $fieldRight)
	Parameters string | int $fieldLeft string | int $fieldRight Returns string
	bitNot ( $field)
	Parameters string | int $field Returns string
	bitOr ( $fieldLeft, $fieldRight)
	Parameters string | int $fieldLeft string | int $fieldRight Returns string
	buildComparison (string $op, array $conds)
	Build a condition comparing multiple values, for use with indexes that cover multiple fields, common when e.g.paging through results or doing batch operations.For example, you might be displaying a list of people ordered alphabetically by their last and first name, split across multiple pages. The first page of the results ended at Jane Doe. When building the query for the next page, you would use: $queryBuilder->where( $db->buildComparison( '>', [ 'last' => 'Doe', 'first' => 'Jane' ] ) ); This will return people whose last name follows Doe, or whose last name is Doe and first name follows Jane.Note that the order of keys in the associative array $conds is significant, and must match the order of fields used by the index.When comparing a single value, prefer using the expression builder: $db->expr( 'key', '<=', $val ) // equivalent to: $db->buildComparison( '<=', [ 'key' => $val ] ) 'key <= ' . $db->addQuotes( $val ) Parameters string $op Comparison operator, one of '>', '>=', '<', '<=' non-empty-array<string,mixed> $conds Map of field names to their values to use in the comparison Returns string SQL code
	buildConcat ( $stringList)
	Build a concatenation list to feed into a SQL query. Parameters string[] $stringList Raw SQL expression list; caller is responsible for escaping Returns string
	buildExcludedValue ( $column)
	Build a reference to a column value from the conflicting proposed upsert() row.The reference comes in the form of an alias, function, or parenthesized SQL expression. It can be used in upsert() SET expressions to handle the merging of column values between each conflicting pair of existing and proposed rows. Such proposed rows are said to have been "excluded" from insertion in favor of updating the existing row.This is useful for multi-row upserts() since the proposed values cannot just be included as literals in the SET expressions. See also IDatabase::upsert() Parameters string $column Column name Returns string SQL expression returning a scalar Since 1.39
	buildGreatest ( $fields, $values)
	Build a GREATEST function statement comparing columns/values.Integer and float values in $values will not be quotedIf $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases. Parameters string | string[] $fields Name(s) of column(s) with values to compare string | int | float | string[] | int[] | float[] $values Values to compare Returns mixed Since 1.35 in IDatabase, moved to ISQLPlatform in 1.39
	buildGroupConcat ( $field, $delim)
	Build a GROUP_CONCAT expression. Parameters string $field Field name string $delim Delimiter Returns string
	buildGroupConcatField ( $delim, $tables, $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 $delim Glue to bind the results together string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string $field Field name string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Conditions string | array $join_conds Join conditions Returns string SQL text Since 1.23
	buildIntegerCast ( $field)
	Parameters string $field Field or column to cast Returns string Since 1.31 in IDatabase, moved to ISQLPlatform in 1.39
	buildLeast ( $fields, $values)
	Build a LEAST function statement comparing columns/values.Integer and float values in $values will not be quotedIf $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases. Parameters string | string[] $fields Name(s) of column(s) with values to compare string | int | float | string[] | int[] | float[] $values Values to compare Returns mixed Since 1.35 in IDatabase, moved to ISQLPlatform in 1.39
	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 the 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 in IDatabase, moved to ISQLPlatform in 1.39 Parameters string|LikeMatch|non-empty-array<string|LikeMatch> $param string|LikeMatch ...$params Returns string Fully built LIKE statement
	buildSelectSubquery ( $tables, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
	Equivalent to IDatabase::selectSQLText() except wraps the result in Subquery. See also IDatabase::selectSQLText() Parameters string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string | array $vars Field names string | array $conds Conditions string $fname Caller function name string | array $options Query options string | array $join_conds Join conditions Returns Subquery Since 1.31
	buildStringCast ( $field)
	Parameters string $field Field or column to cast Returns string Since 1.28 in IDatabase, moved to ISQLPlatform in 1.39
	buildSubstring ( $input, $startPosition, $length=null)
	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 an optimization to save rountrips, 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 $sectionId Section ID from startAtomic(); passing this enables cancellation of unclosed nested sections [optional] Exceptions DBError If an error occurs, { See also query}
	clearFlag ( $flag, $remember=self::REMEMBER_NOTHING)
	Clear a flag for this connection. Parameters int $flag One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX) string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
	close ( $fname=__METHOD__)
	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. Access: internal Only for use by LoadBalancer Parameters string $fname Caller name Returns bool Success Exceptions DBError
	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 transaction scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported. Parameters string $fname string $flush Flush 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 DBError If an error occurs, { See also query}
	conditional ( $cond, $caseTrueExpression, $caseFalseExpression)
	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|IExpression|array<string,?scalar|non-empty-array<int,?scalar>>|array<int,string|IExpression> $cond SQL condition expression (yields a boolean) string | int $caseTrueExpression SQL expression to return when the condition is true string | int $caseFalseExpression SQL expression to return when the condition is false Returns string SQL fragment
	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
	dbSchema ( $schema=null)
	Get/set the db schema. Parameters string | null $schema The database schema to set, or omitted to leave it unchanged Returns string The previous db schema
	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
	decodeExpiry ( $expiry, $format=TS_MW)
	Decode an expiry time into a DBMS independent format. Parameters string $expiry DB timestamp field value for expiry int $format TS_* constant, defaults to TS_MW Returns string
	delete ( $table, $conds, $fname=__METHOD__)
	Delete all rows in a table that match a condition.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Access: internal callers outside of rdbms library should use DeleteQueryBuilder instead. Parameters string $table The unqualified name of a table string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Array of conditions. See $conds in IDatabase::select() In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'delete' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to delete all rows. string $fname Name of the calling function Returns bool Return true if no exception was thrown (deprecated since 1.33) Exceptions DBError If an error occurs, { See also query}
	deleteJoin ( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname=__METHOD__)
	Delete all rows in a table that match a condition which includes a join.For safety, an empty $conds will not delete everything. If you want to delete all rows where the join condition matches, set $conds=IDatabase::ALL_ROWS.DO NOT put the join condition in $conds.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Parameters string $delTable The unqualified name of the table to delete rows from. string $joinTable The unqualified name of the reference table to join on. string $delVar The variable to join on, in the first table. string $joinVar The variable to join on, in the second table. string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause string $fname Calling function name (use METHOD) for logs/profiling Exceptions DBError If an error occurs, { See also query}
	doAtomicSection ( $fname, callable $callback, $cancelable=self::ATOMIC_NOT_CANCELABLE)
	Perform an atomic section of reversible 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 throws 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 $fname Caller name (usually METHOD) callable $callback Callback that issues write queries string $cancelable Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section. Returns mixed Result of the callback (since 1.28) Exceptions DBError If an error occurs, { See also query} Exceptions Exception If 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.
	dropTable ( $table, $fname=__METHOD__)
	Delete a table. Parameters string $table The unqualified name of a table string $fname Returns bool Whether the table already existed Exceptions DBError If an error occurs
	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
	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
	encodeExpiry ( $expiry)
	Encode an expiry time into the DBMS dependent format. Parameters string $expiry Timestamp for expiry, or the 'infinity' string Returns string
	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 DBError If an error occurs, { See also query}
	ensureConnection ()
	Connect to the database if we are not already connected.
	estimateRowCount ( $tables, $vars=' *', $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().New callers should use newSelectQueryBuilder with SelectQueryBuilder::estimateRowCount instead, which is more readable and less error-prone. Access: internal Parameters string | string[] $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string $var Column for which NULL values are not counted [default "*"] string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Filters on the table string $fname Function name for profiling array $options Options for select array | string $join_conds Join conditions Returns int Row count Exceptions DBError If an error occurs, { See also query}
	explicitTrxActive ()
	Check whether there is a transaction open at the specific request of a caller.Explicit transactions are spawned by begin(), startAtomic(), and doAtomicSection(). Note that explicit transactions should not be confused with explicit transaction rounds. Returns bool Since 1.28
	expr (string $field, string $op, $value)
	See Expression::__construct() Since 1.42 Parameters string $field string $op One of '>', '<', '!=', '=', '>=', '<=', IExpression::LIKE, IExpression::NOT_LIKE ?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob> $value Returns Expression
	factorConds ( $condsArray)
	Given an array of condition arrays representing an OR list of AND lists, for example:(A=1 AND B=2) OR (A=1 AND B=3)produce an SQL expression in which the conditions are factored:(A=1 AND (B=2 OR B=3))We also use IN() to simplify further:(A=1 AND (B IN (2,3))More compactly, in boolean algebra notation, a sum of products, e.g. AB + AC is factored to produce A(B+C). Factoring proceeds recursively to reduce expressions with any number of variables, for example AEP + AEQ + AFP + AFQ = A(E(P+Q) + F(P+Q))The algorithm is simple and will not necessarily find the shortest possible expression. For the best results, fields should be given in a consistent order, and the fields with values likely to be shared should be leftmost in the associative arrays. Parameters array $condsArray An array of associative arrays. The associative array keys represent field names, and the values represent the field values to compare against. Returns string SQL expression fragment
	fieldExists ( $table, $field, $fname=__METHOD__)
	Determines whether a field exists in a table. Parameters string $table The unqualified name of a table string $field Field to check on that table string $fname Calling function name Returns bool Whether $table has field $field Exceptions DBError If an error occurs, { See also query}
	fieldInfo ( $table, $field)
	Get information about a field Returns false if the field doesn't exist. Parameters string $table The unqualified name of a table string $field Field name Returns false|Field
	flushSession ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)
	Release important session-level state (named lock, table locks) as post-rollback cleanup.This should only be called by a load balancer or if the handle is not attached to one. Also, there must be no chance that a future caller will still be expecting some of the lost session state.Connection and query errors will be suppressed and logged Parameters string $fname Calling function name string $flush Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. 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 DBError If an error occurs, { See also query} Since 1.38
	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 server after waiting on replication to catch up to the primary server. Parameters string $fname Calling function name string $flush Flush 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 DBError If an error occurs, { See also query} Since 1.28 1.34 Added $flush parameter
	getDBname ()
	Get the current database name; null if there isn't one. Returns string|null
	getDomainID ()
	Return the currently selected domain ID.Null components (database/schema) might change once a connection is established Returns string
	getFlag ( $flag)
	Returns a boolean whether the flag $flag is set for this connection. Parameters int $flag One of the class IDatabase::DBO_* constants Returns bool
	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
	getLag ()
	Get the seconds of replication lag on this database server.Callers should avoid using this method while a transaction is active Returns float|int|false Database replication lag in seconds or false on error Exceptions DBError If an error occurs, { See also query}
	getLBInfo ( $name=null)
	Get properties passed down from the server info array of the load balancer. Access: internal should not be called outside of rdbms library. Parameters string | null $name The entry of the info array to get, or null to get the whole array Returns array|mixed|null
	getPrimaryKeyColumns ( $table, $fname=__METHOD__)
	Get the primary key columns of a table. Access: internal to be used by updater only Parameters string $table The unqualified name of a table string $fname Calling function name Returns string[] Exceptions DBError If an error occurs, { See also query}
	getPrimaryPos ()
	Get the replication position of this primary DB server. Returns DBPrimaryPos|false Position; false if this is not a primary DB Exceptions DBError If an error occurs, { See also query} Since 1.37
	getProperty ( $name)
	getReferenceRole ()
	getScopedLockAndFlush ( $lockKey, $fname, $timeout)
	Acquire a named lock, flush any transaction, and return an RAII style unlocker object.Only call this from outer transaction scope and when only one DB server will be affected. See https://www.mediawiki.org/wiki/Database_transactions for details.This is suitable 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 $lockKey Name of lock to release string $fname Name of the calling method int $timeout Acquisition timeout in seconds Returns ScopedCallback|null Exceptions DBError If an error occurs, { See also query} Since 1.27
	getServer ()
	Get the hostname or IP address of the server. Returns string|null
	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
	getServerName ()
	Get the readable name for the server. Returns string Readable server name, falling back to the hostname or IP address Since 1.36
	getServerVersion ()
	A string describing the current software version. Returns string Version information from the database server.
	getSessionLagStatus ()
	Get a cached estimate of the seconds of replication lag on this database server, using the estimate obtained at the start of the current transaction if one 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 DBError If an error occurs, { See also query} Since 1.27
	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
	getTableAliases ()
	Return current table aliases. Access: internal only to be used inside rdbms library
	getType ()
	Get the RDBMS type of the server (e.g."mysql", "sqlite") Returns string
	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
	indexExists ( $table, $index, $fname=__METHOD__)
	Determines whether an index exists. Parameters string $table The unqualified name of a table string $index string $fname Returns bool Exceptions DBError If an error occurs, { See also query}
	indexUnique ( $table, $index, $fname=__METHOD__)
	Determines if a given index is unique. Parameters string $table The unqualified name of a table string $index string $fname Calling function name Returns bool|null Returns null if the index does not exist Exceptions DBError If an error occurs, { See also query}
	insert ( $table, $rows, $fname=__METHOD__, $options=[])
	Insert row(s) into a table, in the provided order.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Access: internal callers outside of rdbms library should use InsertQueryBuilder instead. Parameters string $table The unqualified name of a table array | array[] $rows Row(s) to insert, as either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other. string $fname Calling function name (use METHOD) for logs/profiling string | array $options Combination map/list where each string-keyed entry maps a non-boolean option to the option parameters and each integer-keyed value is the name of a boolean option. Supported options are: IGNORE: Boolean: skip insertion of rows that would cause unique key conflicts. IDatabase::affectedRows() can be used to determine how many rows were inserted. Returns bool Return true if no exception was thrown (deprecated since 1.33) Exceptions DBError If an error occurs, { See also query}
	insertId ()
	Get the sequence-based ID assigned by the last query method call.This method should only be called when all the following hold true: (a) A method call was made to insert(), upsert(), replace(), or insertSelect() (b) The method call attempts to insert exactly one row (c) The method call omits the value of exactly one auto-increment column (d) The method call succeeded (e) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType() In all other cases, the return value is unspecified.When the query method is either insert() with "IGNORE", upsert(), or insertSelect(), callers should first check affectedRows() before calling this method, making sure that the query method actually created a row. Otherwise, an ID from a previous insert might be incorrectly assumed to belong to last insert. Returns int
	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. This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Parameters string $destTable Unqualified name of destination table string | array $srcTable Unqualified name of source table(s) (use an array for a join) array $varMap Must 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() string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Condition array. See $conds in IDatabase::select() for the details of the format of condition arrays. May be "*" to copy the whole table. string $fname The function name of the caller, from METHOD array $insertOptions Options 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 $selectOptions Options for the SELECT part of the query, see IDatabase::select() for details. array $selectJoinConds Join 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 DBError If an error occurs, { See also query}
	isOpen ()
	Returns bool Whether a connection to the database open
	isReadOnly ()
	Check if this DB server is marked as read-only according to load balancer info. Note LoadBalancer checks serverIsReadOnly() when setting the load balancer info array Returns bool Since 1.27
	lastDoneWrites ()
	Get the last time that the connection was used to commit a write. Access: internal Should only be called from the rdbms library. Returns float|null UNIX timestamp; null if no writes were committed Since 1.24
	lastErrno ()
	Get the RDBMS-specific error code from the last attempted query statement. Returns int|string Error code (integer or hexadecimal depending on RDBMS type)
	lastError ()
	Get the RDBMS-specific error description from the last attempted query statement. Returns string
	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 $sql SQL query we will append the limit too int $limit The SQL limit int | false $offset The SQL offset (default false) Returns string Since 1.34 in IDatabase, moved to ISQLPlatform in 1.39
	listTables ( $prefix=null, $fname=__METHOD__)
	List all tables on the database.Since MW 1.42, this will no longer include MySQL views. Parameters string | null $prefix Only show tables with this prefix, e.g. mw_ string $fname Calling function name Exceptions DBError Returns array
	lock ( $lockName, $method, $timeout=5, $flags=0)
	Acquire a named lock.Named locks are not related to transactions Parameters string $lockName Name of lock to acquire string $method Name of the calling method int $timeout Acquisition timeout in seconds (0 means non-blocking) int $flags Bit field of IDatabase::LOCK_* constants Returns bool|float|null Success (bool); acquisition time (float/null) if LOCK_TIMESTAMP Exceptions DBError If an error occurs, { See also query}
	lockForUpdate ( $table, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
	Lock all rows meeting the given conditions/options FOR UPDATE. Parameters string | string[] $table The unqualified name of table(s) (use an array for a join) string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Condition in the format of IDatabase::select() conditions string $fname Function name for profiling array $options Options for select ("FOR UPDATE" is added automatically) array $join_conds Join conditions Returns int Number of matching rows found (and locked) Exceptions DBError If an error occurs, { See also query} Since 1.32 Deprecated since 1.43; Use SelectQueryBuilder::acquireRowLocks
	lockIsFree ( $lockName, $method)
	Check to see if a named lock is not locked by any thread (non-blocking) Parameters string $lockName Name of lock to poll string $method Name of method calling us Returns bool Exceptions DBError If an error occurs, { See also query} Since 1.20
	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 also IDatabase::select} $conds documentation). Example usage: $sql = $db->makeList( [ 'rev_page' => $id, $db->makeList( [ 'rev_minor' => 1, 'rev_len < 500' ], $db::LIST_OR ) ], $db::LIST_AND ); This would set $sql to "rev_page = '$id' AND (rev_minor = 1 OR rev_len < 500)" Parameters array $a Containing the data int $mode IDatabase 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 DBError If an error occurs, { See also IDatabase::query} Returns string
	makeWhereFrom2d ( $data, $baseKey, $subKey)
	Build a "OR" condition with pairs from a two-dimensional array.The associative array should have integer keys relating to the $baseKey field. The nested array should have string keys for the $subKey field. The inner values are ignored, and are typically boolean true.Example usage: $data = [ 2 => [ 'Foo' => true, 'Bar' => true, ], 3 => [ 'Quux' => true, ], ]; // (page_namespace = 2 AND page_title IN ('Foo','Bar')) // OR (page_namespace = 3 AND page_title = 'Quux') Todo This is effectively specific to MediaWiki's LinkBatch. Consider deprecating or generalising slightly. Parameters array $data Nested array, must be non-empty string $baseKey Field name to match the base-level keys to (eg 'pl_namespace') string $subKey Field name to match the sub-level keys to (eg 'pl_title') Returns string SQL fragment
	newDeleteQueryBuilder ()
	Get an DeleteQueryBuilder bound to this connection.
	newInsertQueryBuilder ()
	Get an InsertQueryBuilder bound to this connection.
	newReplaceQueryBuilder ()
	Get an ReplaceQueryBuilder bound to this connection.
	newSelectQueryBuilder ()
	Create an empty SelectQueryBuilder which can be used to run queries against this connection.
	newUnionQueryBuilder ()
	Create an empty UnionQueryBuilder which can be used to run queries against this connection.
	newUpdateQueryBuilder ()
	Get an UpdateQueryBuilder bound to this connection.
	onTransactionCommitOrIdle (callable $callback, $fname=__METHOD__)
	Run a callback when 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 after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().Use this method only for the following purposes: (a) RDBMS updates, prone to lock timeouts/deadlocks, that do not require atomicity with respect to the updates in the current transaction (if any) (b) Purges to lightweight cache services due to RDBMS updates (c) Updates to secondary DBs/stores that must only commit once the updates in the current transaction (if any) are committed (e.g. insert user account row to DB1, then, initialize corresponding LDAP account) The callback takes the following arguments: How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE) Callbacks will execute in the order they were enqueued. Parameters callable $callback string $fname Caller name Exceptions DBError If an error occurs, { See also query} Exceptions Exception If the callback runs immediately and an error occurs in it Since 1.32
	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 after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.If there is no current transaction, one will be created to wrap the callback. Callbacks cannot use begin()/commit() to manage transactions. The use of other IDatabase handles from the callback should be avoided.Use this method only for the following purposes: a) RDBMS updates, prone to lock timeouts/deadlocks, that require atomicity with respect to the updates in the current transaction (if any) b) Purges to lightweight cache services due to RDBMS updates Callbacks will execute in the order they were enqueued. Parameters callable $callback string $fname Caller name Exceptions DBError If an error occurs, { See also query} Exceptions Exception If the callback runs immediately and an error occurs in it Since 1.22
	onTransactionResolution (callable $callback, $fname=__METHOD__)
	Run a callback when the current transaction commits or rolls back.An error is thrown if no transaction is pending.When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT/ROLLBACK.This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().Use this method only for the following purposes: (a) Release of cooperative locks on resources (b) Cancellation of in-process deferred tasks The callback takes the following arguments: How the current atomic section (if any) or overall transaction (otherwise) ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK) Callbacks will execute in the order they were enqueued. Parameters callable $callback string $fname Caller name Exceptions DBError If an error occurs, { See also query} Exceptions Exception If the callback runs immediately and an error occurs in it Since 1.28
	orExpr (array $conds)
	See Expression::__construct() Since 1.43 Parameters non-empty-array<string,?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob>>|non-empty-array<int,IExpression> $conds Returns OrExpressionGroup
	pendingWriteCallers ()
	Get the list of method names that did write queries for this transaction. Returns array Since 1.27
	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 $type IDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL] Returns float|false Returns false if not transaction is active Since 1.26
	ping (&$rtt=null)
	primaryPosWait (DBPrimaryPos $pos, $timeout)
	Wait for the replica server to catch up to a given primary server position.Note that this does not start any new transactions.Callers might want to flush any existing transaction before invoking this method. Upon success, this assures that replica server queries will reflect all changes up to the given position, without interference from prior REPEATABLE-READ snapshots. Parameters DBPrimaryPos $pos int $timeout The maximum number of seconds to wait for synchronisation Returns int|null Zero if the replica DB server 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 DBError If an error occurs, { See also query} Since 1.37
	query ( $sql, $fname=__METHOD__, $flags=0)
	Run an SQL query statement 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.Callers should avoid the use of statements like BEGIN, COMMIT, and ROLLBACK. Methods like startAtomic(), endAtomic(), and cancelAtomic() can be used instead. Parameters string | Query $sql Single-statement SQL query string $fname Caller name; used for profiling/SHOW PROCESSLIST comments int $flags Bit field of ISQLPlatform::QUERY_* constants 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 DBQueryError If the query is issued, fails, and QUERY_SILENCE_ERRORS is not set DBExpectedError If the query is not, and cannot, be issued yet (non-DBQueryError) DBError If the query is inherently not allowed (non-DBExpectedError)
	replace ( $table, $uniqueKeys, $rows, $fname=__METHOD__)
	Insert row(s) into a table, in the provided order, while deleting conflicting rows.Conflicts are determined by the provided unique indexes. Note that it is possible for the provided rows to conflict even among themselves; it is preferable for the caller to de-duplicate such input beforehand.Note some important implications of the deletion semantics: If the table has an AUTOINCREMENT column and $rows omit that column, then any conflicting existing rows will be replaced with newer having higher values for that column, even if nothing else changed. There might be worse contention than upsert() due to the use of gap-locking. This does not apply to RDBMS types that use predicate locking nor those that just lock the whole table or databases anyway. This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Access: internal callers outside of rdbms library should use ReplaceQueryBuilder instead. Parameters string $table The unqualified name of a table string | string[] | string[][] $uniqueKeys Column name or non-empty list of column name lists that define all applicable unique keys on the table. There must only be one such key. Each unique key on the table is "applicable" unless either: It involves an AUTOINCREMENT column for which no values are assigned in $rows It involves a UUID column for which newly generated UUIDs are assigned in $rows array | array[] $rows Row(s) to insert, in the form of either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. Columns belonging to a key in $uniqueKeys must be defined here and non-null. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other. string $fname Calling function name (use METHOD) for logs/profiling Exceptions DBError If an error occurs, { See also query}
	restoreFlags ( $state=self::RESTORE_PRIOR)
	Restore the flags to their prior state before the last setFlag/clearFlag call. Parameters string $state IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR] Since 1.28
	rollback ( $fname=__METHOD__, $flush=self::FLUSHING_ONE)
	Rollback a transaction previously started using begin()Only call this from code with outer transaction 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 preferable, 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 $fname Calling function name string $flush Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. 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 DBError If an error occurs, { See also query} Since 1.23 Added $flush parameter
	select ( $tables, $vars, $conds='', $fname=__METHOD__, $options=[], $join_conds=[])
	Execute a SELECT query constructed using the various parameters provided.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchResultSet instead, which is more readable and less error-prone. Parameters string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". Each table reference assigns a table name to a specified collection of rows for the context of the query (e.g. field expressions, WHERE clause, GROUP BY clause, HAVING clause, etc...). Use of multiple table references implies a JOIN.If a string is given, it must hold the name of the table having the specified collection of rows. If an array is given, each entry must be one of the following: A string holding the name of the existing table which has the collection of rows. If keyed by a string, the key will be the assigned table name. A Subquery instance which specifies the collection of rows derived from a subquery. If keyed by a string, the key will be the assigned table name. Otherwise, the SQL text of the subquery will be the assigned table name. An array specifying the collection of rows derived from a parenthesized JOIN. It must be keyed by a string, which will be used as the assigned table name. String keys allow table aliases to 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 likeFROM 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 $vars Field 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|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds May 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: IDatabase::buildLike() IDatabase::conditional() 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 IDatabase::ALL_ROWS to select all rows.You can put simple join conditions here, but this is strongly discouraged. Instead of // $conds... 'rev_actor = actor_id', use (see below for $join_conds): // $join_conds... 'actor' => [ 'JOIN', 'rev_actor = actor_id' ], Parameters string $fname Caller function name string | array $options Query 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 a 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. IGNORE INDEX: This may be either be a string giving an index name to ignore 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 ignore 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. MAX_EXECUTION_TIME: (only in MySQL/MariaDB) maximum allowed time to run the query in milliseconds (if database supports it). 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_conds Join conditions Optional associative array of table-specific join conditions. Simple conditions can also be specified in the regular $conds, but this is strongly discouraged in favor of the more explicit syntax here.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' ] ] Access: internal Returns IResultWrapper Resulting rows Exceptions DBError If an error occurs, { See also query}
	selectDomain ( $domain)
	Set the current domain (database, schema, and table prefix)This will throw an error for some database types if the database is unspecifiedThis should only be called by a load balancer or if the handle is not attached to one Parameters string | DatabaseDomain $domain Exceptions DBConnectionError If databasesAreIndependent() is true and connection change fails DBError On query error, if domain changes are disallowed, or the domain is invalid Since 1.32
	selectField ( $tables, $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.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchField instead, which is more readable and less error-prone. Access: internal callers outside of rdbms library should use SelectQueryBuilder instead. Parameters string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string | array $var The field name to select. This must be a valid SQL fragment: do not use unvalidated user input. Can be an array, but must contain exactly 1 element then. { See also select} for details. Parameters string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $cond The condition array. { See also select} for details. Parameters string $fname The function name of the caller. string | array $options The query options. { See also select} for details. Parameters string | array $join_conds The query join conditions. { See also select} for details. Returns mixed|false The value from the field, or false if nothing was found Exceptions DBError If an error occurs, { See also query}
	selectFieldValues ( $tables, $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, an empty array is returned.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchFieldValues instead, which is more readable and less error-prone. Access: internal callers outside of rdbms library should use SelectQueryBuilder instead. Parameters string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string $var The field name to select. This must be a valid SQL fragment: do not use unvalidated user input. string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $cond The condition array. { See also select} for details. Parameters string $fname The function name of the caller. string | array $options The query options. { See also select} for details. Parameters string | array $join_conds The query join conditions. { See also select} for details. Returns array The values from the field in the order they were returned from the DB Exceptions DBError If an error occurs, { See also query} Since 1.25
	selectRow ( $tables, $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.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRow instead, which is more readable and less error-prone. Access: internal Parameters string | array $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string | array $vars Field names string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Conditions string $fname Caller function name string | array $options Query options array | string $join_conds Join conditions Returns stdClass|false Exceptions DBError If an error occurs, { See also query}
	selectRowCount ( $tables, $vars=' *', $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().New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRowCount instead, which is more readable and less error-prone. Since 1.27 Added $join_conds parameter Access: internal Parameters string | string[] $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". { See also select} for details. Parameters string $var Column for which NULL values are not counted [default "*"] string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Filters on the table string $fname Function name for profiling array $options Options for select array $join_conds Join conditions (since 1.27) Returns int Row count Exceptions DBError If an error occurs, { See also query}
	selectSQLText ( $tables, $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 $tables Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". string | array $vars Field names string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Conditions string $fname Caller function name string | array $options Query options string | array $join_conds Join conditions Returns string SQL query string
	serverIsReadOnly ()
	Returns bool Whether this DB server is running in server-side read-only mode Exceptions DBError If an error occurs, { See also query} Since 1.28
	setFlag ( $flag, $remember=self::REMEMBER_NOTHING)
	Set a flag for this connection. Parameters int $flag One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX) string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
	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 Access: internal should not be called outside of rdbms library. Parameters array | string $nameOrArray The new array or the name of a key to set array | mixed | null $value If $nameOrArray is a string, the new key value (null to unset)
	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 $vars Map of (variable => value) or null to use the defaults
	setSessionOptions (array $options)
	Override database's default behavior.Not all options are supported on all database backends; unsupported options are silently ignored.$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. Only supported on MySQL and MariaDB. 'groupConcatMaxLen': Maximum length of a GROUP_CONCAT() result. Only supported on MySQL and MariaDB. Parameters array $options Returns void Exceptions DBError If an error occurs, { See also query}
	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[] $aliases Map of (unqualified name of table => (dbname, schema, prefix) map) Since 1.28 in IDatabase, moved to ISQLPlatform in 1.39
	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 $name Callback name callable | null $callback Use null to unset a listener Since 1.28 Deprecated Since 1.44
	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 string | false $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
	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
	startAtomic ( $fname=__METHOD__, $cancelable=IDatabase::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 $cancelable Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section. Returns AtomicSectionIdentifier section ID token Exceptions DBError If an error occurs, { See also query}
	streamStatementEnd (&$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
	strreplace ( $orig, $old, $new)
	Returns a SQL expression for simple string replacement (e.g.REPLACE() in mysql) Parameters string $orig Column to modify string $old Column to seek string $new Column to replace with Returns string
	tableExists ( $table, $fname=__METHOD__)
	Query whether a given table exists. Parameters string $table The unqualified name of a table string $fname Returns bool Exceptions DBError If an error occurs, { See also query}
	tableName ( $name, $format='quoted')
	tableNames (... $tables)
	tableNamesN (... $tables)
	Fetch a number of table names into a zero-indexed numerical array.Much like tableName(), this is only needed when calling query() directly. You should prefer calling other methods, or using SelectQueryBuilder.Theoretical example (which really does not require raw SQL): [ $user, $watchlist ] = $dbr->tableNamesN( 'user', 'watchlist' ); $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user WHERE wl_user=user_id AND wl_user=$nameWithQuotes"; Parameters string ...$tables Returns array Deprecated Since 1.43; if you must format table names, write several calls to tableName.
	tablePrefix ( $prefix=null)
	Get/set the table prefix. Parameters string | null $prefix The table prefix to set, or omitted to leave it unchanged Returns string The previous 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.The result is unquoted, and needs to be passed through addQuotes() before it can be included in raw SQL. Parameters string | int $ts Returns string
	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|null
	truncateTable ( $table, $fname=__METHOD__)
	Delete all data in a table and reset any sequences owned by that table. Parameters string $table The unqualified name of a table string $fname Exceptions DBError If an error occurs Since 1.42
	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
	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
	unionQueries ( $sqls, $all, $options=[])
	Construct a UNION query.This is used for providing overload point for other DB abstractions not compatible with the MySQL syntax. Access: internal callers outside of rdbms library should use UnionQueryBuilder instead. Parameters array $sqls SQL statements to combine bool $all Either IDatabase::UNION_ALL or IDatabase::UNION_DISTINCT array $options Query options Returns string SQL fragment
	unionSupportsOrderAndLimit ()
	Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION. Returns bool
	unlock ( $lockName, $method)
	Release a lock.Named locks are not related to transactions Parameters string $lockName Name of lock to release string $method Name of the calling method Returns bool Success Exceptions DBError If an error occurs, { See also query}
	update ( $table, $set, $conds, $fname=__METHOD__, $options=[])
	Update all rows in a table that match a given condition.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Access: internal callers outside of rdbms library should use UpdateQueryBuilder instead. Parameters string $table The unqualified name of a table array<string,?scalar|RawSQLValue>|array<int,string> $set Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL expression in the format of a column assignment within UPDATE...SET. The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment format is useful for updates like "column = column + X". All assignments have no defined execution order, so they should not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments. string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression> $conds Condition in the format of IDatabase::select() conditions. In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'update' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to update all rows. string $fname Calling function name (use METHOD) for logs/profiling string | array $options Combination map/list where each string-keyed entry maps a non-boolean option to the option parameters and each integer-keyed value is the name of a boolean option. Supported options are: IGNORE: Boolean: skip update of rows that would cause unique key conflicts. IDatabase::affectedRows() includes all matching rows, that includes also rows not updated due to key conflict. Returns bool Return true if no exception was thrown (deprecated since 1.33) Exceptions DBError If an error occurs, { See also query}
	upsert ( $table, array $rows, $uniqueKeys, array $set, $fname=__METHOD__)
	Upsert row(s) into a table, in the provided order, while updating conflicting rows.Conflicts are determined by the provided unique indexes. Note that it is possible for the provided rows to conflict even among themselves; it is preferable for the caller to de-duplicate such input beforehand.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation. Access: internal callers outside of rdbms library should use InsertQueryBuilder instead. Parameters string $table The unqualified name of a table array | array[] $rows Row(s) to insert, in the form of either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. Columns belonging to a key in $uniqueKeys must be defined here and non-null. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other. string | string[] | string[][] $uniqueKeys Column name or non-empty list of column name lists that define all applicable unique keys on the table. There must only be one such key. Each unique key on the table is "applicable" unless either: It involves an AUTOINCREMENT column for which no values are assigned in $rows It involves a UUID column for which newly generated UUIDs are assigned in $rows array<string,?scalar|RawSQLValue>|array<int,string> $set Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL assignment expression of the form "<unquoted alphanumeric column> = <SQL expression>". The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment entries are useful for updates like "column = column + X". All of the assignments have no defined execution order, so callers should make sure that they not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments, even if they are just "secondary" unique keys. For multi-row upserts, use buildExcludedValue() to reference the value of a column from the corresponding row in $rows that conflicts with the current row. string $fname Calling function name (use METHOD) for logs/profiling Exceptions DBError If an error occurs, { See also query} Since 1.22
	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
	writesPending ()
	Returns bool Whether there is a transaction open with possible write queries Since 1.27
Public Member Functions inherited from Wikimedia\Rdbms\IReadableDatabase
	ping ()
	Ping the server and try to reconnect if it there is no connection.
Public Member Functions inherited from Wikimedia\Rdbms\Platform\ISQLPlatform
	buildSubString ( $input, $startPosition, $length=null)
	Build a SUBSTRING function.
	tableName (string $name, $format='quoted')
	Format a table name ready for use in constructing an SQL query.

Protected Member Functions
	assertRoleAllowsWrites ()
	Error out if the role is not DB_PRIMARY.
	getDomainChangeException ()
	normalizeServerIndex ( $i)

Additional Inherited Members
Public Attributes inherited from Wikimedia\Rdbms\IDatabase
const	ATOMIC_CANCELABLE = 'cancelable'
	Atomic section is cancelable.
const	ATOMIC_NOT_CANCELABLE = ''
	Atomic section is not cancelable.
const	ESTIMATE_DB_APPLY = 'apply'
	Estimate time to apply (scanning, applying)
const	ESTIMATE_TOTAL = 'total'
	Estimate total time (RTT, scanning, waiting on locks, applying)
const	FLUSHING_ALL_PEERS = 'flush'
	Commit/rollback is from the owning connection manager for the IDatabase handle.
const	FLUSHING_INTERNAL = 'flush-internal'
	Commit/rollback is from the IDatabase handle internally.
const	FLUSHING_ONE = ''
	Commit/rollback is from outside the IDatabase handle and connection manager.
const	LB_READ_ONLY_REASON = 'readOnlyReason'
	Field for getLBInfo()/setLBInfo(); configured read-only mode explanation or false.
const	LB_TRX_ROUND_FNAME = 'trxRoundOwner'
	Field for getLBInfo()/setLBInfo(); relevant transaction round owner name or null.
const	LB_TRX_ROUND_ID = self::LB_TRX_ROUND_FNAME
	Alias to LB_TRX_ROUND_FNAME.
const	LB_TRX_ROUND_LEVEL = 'trxRoundLevel'
	Field for getLBInfo()/setLBInfo(); relevant transaction round level (1 or 0)
const	LOCK_TIMESTAMP = 1
	Flag to return the lock acquisition timestamp (null if not acquired)
const	ROLE_STATIC_CLONE = 'static-clone'
	Replica server within a static dataset.
const	ROLE_STREAMING_MASTER = 'streaming-master'
	Primary server than can stream writes to replica servers.
const	ROLE_STREAMING_REPLICA = 'streaming-replica'
	Replica server that receives writes from a primary server.
const	ROLE_UNKNOWN = 'unknown'
	Server with unknown topology role.
const	TRANSACTION_EXPLICIT = ''
	Transaction is requested by regular caller outside of the DB layer.
const	TRANSACTION_INTERNAL = 'implicit'
	Transaction is requested internally via DBO_TRX/startAtomic()
const	TRIGGER_CANCEL = 4
	Callback triggered by atomic section cancel (ROLLBACK TO SAVEPOINT)
const	TRIGGER_COMMIT = 2
	Callback triggered by COMMIT.
const	TRIGGER_IDLE = 1
	Callback triggered immediately due to no active transaction.
const	TRIGGER_ROLLBACK = 3
	Callback triggered by ROLLBACK.
Public Attributes inherited from Wikimedia\Rdbms\IReadableDatabase
const	UNION_ALL = true
	Parameter to unionQueries() for UNION ALL.
const	UNION_DISTINCT = false
	Parameter to unionQueries() for UNION DISTINCT.
Public Attributes inherited from Wikimedia\Rdbms\Platform\ISQLPlatform
const	ALL_ROWS = '*'
	Unconditional update/delete of whole table.
const	CALLER_SUBQUERY = 'subquery'
	Special value for ->caller() / $fname parameter used when providing a caller is not expected, because we're formatting a subquery that won't be executed directly.
const	CALLER_UNKNOWN = 'unknown'
	Special value for ->caller() / $fname parameter used when a caller is not provided.
const	LIST_AND = 1
	Combine list with AND clauses.
const	LIST_COMMA = 0
	Combine list with comma delimiters.
const	LIST_NAMES = 3
	Treat as field name and do not apply value escaping.
const	LIST_OR = 4
	Combine list with OR clauses.
const	LIST_SET = 2
	Convert map into a SET clause.
const	QUERY_CHANGE_LOCKS = 512
	Query is a command for advisory locks.
const	QUERY_CHANGE_NONE = 32
	Query is a read-only Data Query Language query.
const	QUERY_CHANGE_ROWS = 128
	Query is a Data Manipulation Language command (INSERT, DELETE, LOCK, ...)
const	QUERY_CHANGE_SCHEMA = 256
	Query is a Data Definition Language command.
const	QUERY_CHANGE_TRX = 64
	Query is a Transaction Control Language command (BEGIN, USE, SET, ...)
const	QUERY_IGNORE_DBO_TRX = 8
	Ignore the current presence of any DBO_TRX flag.
const	QUERY_NO_RETRY = 16
	Do not try to retry the query if the connection was lost.
const	QUERY_NORMAL = 0
	Idiom for "no special flags".
const	QUERY_PSEUDO_PERMANENT = 2
	Track a TEMPORARY table CREATE as if it was for a permanent table (for testing)
const	QUERY_REPLICA_ROLE = 4
	Enforce that a query does not make effective writes.
const	QUERY_SILENCE_ERRORS = 1
	Ignore query errors and return false when they happen.
Public Attributes inherited from Wikimedia\Rdbms\Database\IDatabaseFlags
const	DBO_COMPRESS = 512
	Enable compression in connection protocol.
const	DBO_DDLMODE = 128
	Schema file mode; was used by Oracle.
const	DBO_DEBUG = 1
	Enable debug logging of all SQL queries.
const	DBO_DEFAULT = 16
	Join load balancer transaction rounds (which control DBO_TRX) in non-CLI mode.
const	DBO_GAUGE = 1024
	Optimize connection for guaging server state (e.g.
const	DBO_IGNORE = 4
	Unused since 1.31.
const	DBO_NOBUFFER = 2
	Unused since 1.34.
const	DBO_PERSISTENT = 32
	Use DB persistent connections if possible.
const	DBO_SSL = 256
	Enable SSL/TLS in connection protocol.
const	DBO_SYSDBA = 64
	DBA session mode; was used by Oracle.
const	DBO_TRX = 8
	Automatically start a transaction before running a query if none is active.
const	REMEMBER_NOTHING = ''
	Do not remember the prior flags.
const	REMEMBER_PRIOR = 'remember'
	Remember the prior flags.
const	RESTORE_INITIAL = 'initial'
	Restore to the initial flag state.
const	RESTORE_PRIOR = 'prior'
	Restore to the prior flag state.

Detailed Description

Helper class used for automatically re-using IDatabase connections and lazily establishing the actual network connection to a database host.

It does this by deferring to ILoadBalancer::getConnectionInternal, which in turn ensures we share and re-use a single connection for a given database wherever possible.

This class previously used an RAII-style pattern where connections would be claimed from a pool, and then added back to the pool for re-use only after the calling code's variable for this object went out of scope (a __destruct got called when the calling function returns or throws). This is no longer needed today as LoadBalancer now permits re-use internally even for overlapping callers, where two pieces of code may both obtain their own DBConnRef object and where both are used alternatingly, and yet still share the same connection.

Example:

function getRowData() {
    $conn = $this->lb->getConnection( DB_REPLICA );
    $row = $conn->select( ... );
    return $row ? (array)$row : false;
}

Since

1.22

Definition at line 37 of file DBConnRef.php.

Constructor & Destructor Documentation

__construct()

Wikimedia\Rdbms\DBConnRef::__construct	(	ILoadBalancer	$lb,
			$params,
			$role,
		&	$modcount = 0 )

Access: internal

May not be used outside Rdbms LoadBalancer

Parameters

ILoadBalancer	$lb	Connection manager for $conn
array	$params	[server index, query groups, domain, flags]
int	$role	The type of connection asked for; one of DB_PRIMARY/DB_REPLICA
null | int	&$modcount	Reference to a modification counter. This is for LoadBalancer::reconfigure to indicate that a new connection should be acquired.

Definition at line 75 of file DBConnRef.php.

References Wikimedia\Rdbms\DatabaseDomain\newFromId().

Member Function Documentation

__call()

Wikimedia\Rdbms\DBConnRef::__call	(		$name,
		array	$arguments )

Definition at line 124 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\ensureConnection().

Referenced by Wikimedia\Rdbms\DBConnRef\affectedRows(), Wikimedia\Rdbms\DBConnRef\clearFlag(), Wikimedia\Rdbms\DBConnRef\dbSchema(), Wikimedia\Rdbms\DBConnRef\explicitTrxActive(), Wikimedia\Rdbms\DBConnRef\getDomainID(), Wikimedia\Rdbms\DBConnRef\getFlag(), Wikimedia\Rdbms\DBConnRef\getLBInfo(), Wikimedia\Rdbms\DBConnRef\getProperty(), Wikimedia\Rdbms\DBConnRef\getServerInfo(), Wikimedia\Rdbms\DBConnRef\getServerVersion(), Wikimedia\Rdbms\DBConnRef\getSoftwareLink(), Wikimedia\Rdbms\DBConnRef\getType(), Wikimedia\Rdbms\DBConnRef\implicitOrderby(), Wikimedia\Rdbms\DBConnRef\insertId(), Wikimedia\Rdbms\DBConnRef\isOpen(), Wikimedia\Rdbms\DBConnRef\lastDoneWrites(), Wikimedia\Rdbms\DBConnRef\lastErrno(), Wikimedia\Rdbms\DBConnRef\lastError(), Wikimedia\Rdbms\DBConnRef\pendingWriteCallers(), Wikimedia\Rdbms\DBConnRef\pendingWriteQueryDuration(), Wikimedia\Rdbms\DBConnRef\query(), Wikimedia\Rdbms\DBConnRef\restoreFlags(), Wikimedia\Rdbms\DBConnRef\setFlag(), Wikimedia\Rdbms\DBConnRef\tablePrefix(), Wikimedia\Rdbms\DBConnRef\trxLevel(), Wikimedia\Rdbms\DBConnRef\trxTimestamp(), Wikimedia\Rdbms\DBConnRef\writesOrCallbacksPending(), and Wikimedia\Rdbms\DBConnRef\writesPending().

__toString()

Wikimedia\Rdbms\DBConnRef::__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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 981 of file DBConnRef.php.

addIdentifierQuotes()

Wikimedia\Rdbms\DBConnRef::addIdentifierQuotes

(

$s

)

Escape a SQL identifier (e.g.table, column, database) for use in a SQL queryDepending on the database this will either be backticks or "double quotes"

Parameters

string

$s

Returns

string

Since

1.33

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 620 of file DBConnRef.php.

addQuotes()

Wikimedia\Rdbms\DBConnRef::addQuotes

(

$s

)

Escape and quote a raw value string for use in a SQL query.

Parameters

?scalar | RawSQLValue | Blob

$s

Returns

string

Implements Wikimedia\Rdbms\Database\DbQuoter.

Definition at line 597 of file DBConnRef.php.

affectedRows()

Wikimedia\Rdbms\DBConnRef::affectedRows

(

)

Get the number of rows affected by the last query method call.This method should only be called when all the following hold true:

• (a) A method call was made to insert(), upsert(), replace(), update(), delete(), insertSelect(), query() with a non-SELECT statement, or queryMulti() with a non-SELECT terminal statement
• (b) The method call succeeded
• (c) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType()

In all other cases, the return value is unspecified.UPDATE queries consider rows affected even when all their new column values match the previous values. Such rows can be excluded from the count by changing the WHERE clause to filter them out.If the last query method call was to query() or queryMulti(), then the results are based on the (last) statement provided to that call and are driver-specific.

Returns

int

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 306 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

andExpr()

Wikimedia\Rdbms\DBConnRef::andExpr

(

array

$conds

)

See Expression::__construct()

Since

1.43

Parameters

non-empty-array<string,?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob>>|non-empty-array<int,IExpression>

$conds

Returns

AndExpressionGroup

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 608 of file DBConnRef.php.

anyChar()

Wikimedia\Rdbms\DBConnRef::anyChar

(

)

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

Returns

LikeMatch

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 630 of file DBConnRef.php.

anyString()

Wikimedia\Rdbms\DBConnRef::anyString

(

)

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

Returns

LikeMatch

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 635 of file DBConnRef.php.

assertRoleAllowsWrites()

Wikimedia\Rdbms\DBConnRef::assertRoleAllowsWrites ( )

protected

Error out if the role is not DB_PRIMARY.

Note that the underlying connection may or may not itself be read-only. It could even be to a writable primary (both server-side and to the application). This error is meant for the case when a DB_REPLICA handle was requested but a a write was attempted on that handle regardless.

In configurations where the primary DB has some generic read load or is the only server, DB_PRIMARY/DB_REPLICA will sometimes (or always) use the same connection to the primary DB. This does not effect the role of DBConnRef instances.

Exceptions

DBReadOnlyRoleError

Definition at line 1002 of file DBConnRef.php.

begin()

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

Begin a transaction.Only call this from code with outer transaction 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	$fname	Calling function name
string	$mode	A situationally valid IDatabase::TRANSACTION_* constant [optional]

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 768 of file DBConnRef.php.

bitAnd()

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

Parameters

string | int	$fieldLeft
string | int	$fieldRight

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 491 of file DBConnRef.php.

bitNot()

Wikimedia\Rdbms\DBConnRef::bitNot

(

$field

)

Parameters

string | int

$field

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 486 of file DBConnRef.php.

bitOr()

Wikimedia\Rdbms\DBConnRef::bitOr	(		$fieldLeft,
			$fieldRight )

Parameters

string | int	$fieldLeft
string | int	$fieldRight

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 496 of file DBConnRef.php.

buildComparison()

Wikimedia\Rdbms\DBConnRef::buildComparison	(	string	$op,
		array	$conds )

Build a condition comparing multiple values, for use with indexes that cover multiple fields, common when e.g.paging through results or doing batch operations.For example, you might be displaying a list of people ordered alphabetically by their last and first name, split across multiple pages. The first page of the results ended at Jane Doe. When building the query for the next page, you would use:

$queryBuilder->where( $db->buildComparison( '>', [ 'last' => 'Doe', 'first' => 'Jane' ] ) );

This will return people whose last name follows Doe, or whose last name is Doe and first name follows Jane.Note that the order of keys in the associative array $conds is significant, and must match the order of fields used by the index.When comparing a single value, prefer using the expression builder:

$db->expr( 'key', '<=', $val )

// equivalent to:
$db->buildComparison( '<=', [ 'key' => $val ] )
'key <= ' . $db->addQuotes( $val )

Parameters

string	$op	Comparison operator, one of '>', '>=', '<', '<='
	non-empty-array<string,mixed>	$conds Map of field names to their values to use in the comparison

Returns

string SQL code

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 466 of file DBConnRef.php.

buildConcat()

Wikimedia\Rdbms\DBConnRef::buildConcat

(

$stringList

)

Build a concatenation list to feed into a SQL query.

Parameters

string[]

$stringList

Raw SQL expression list; caller is responsible for escaping

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 501 of file DBConnRef.php.

buildExcludedValue()

Wikimedia\Rdbms\DBConnRef::buildExcludedValue

(

$column

)

Build a reference to a column value from the conflicting proposed upsert() row.The reference comes in the form of an alias, function, or parenthesized SQL expression. It can be used in upsert() SET expressions to handle the merging of column values between each conflicting pair of existing and proposed rows. Such proposed rows are said to have been "excluded" from insertion in favor of updating the existing row.This is useful for multi-row upserts() since the proposed values cannot just be included as literals in the SET expressions.

See also

IDatabase::upsert()

Parameters

string

$column

Column name

Returns

string SQL expression returning a scalar

Since

1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 543 of file DBConnRef.php.

buildGreatest()

Wikimedia\Rdbms\DBConnRef::buildGreatest	(		$fields,
			$values )

Build a GREATEST function statement comparing columns/values.Integer and float values in $values will not be quotedIf $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases.

Parameters

string | string[]	$fields	Name(s) of column(s) with values to compare
string | int | float | string[] | int[] | float[]	$values	Values to compare

Returns

mixed

Since

1.35 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 518 of file DBConnRef.php.

buildGroupConcat()

Wikimedia\Rdbms\DBConnRef::buildGroupConcat	(		$field,
			$delim )

Build a GROUP_CONCAT expression.

Parameters

string	$field	Field name
string	$delim	Delimiter

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 506 of file DBConnRef.php.

buildGroupConcatField()

Wikimedia\Rdbms\DBConnRef::buildGroupConcatField	(		$delim,
			$tables,
			$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	$delim	Glue to bind the results together
string | array	$tables	Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string	$field	Field name
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Conditions
string | array	$join_conds	Join conditions

Returns

string SQL text

Since

1.23

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 511 of file DBConnRef.php.

buildIntegerCast()

Wikimedia\Rdbms\DBConnRef::buildIntegerCast

(

$field

)

Parameters

string

$field

Field or column to cast

Returns

string

Since

1.31 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 538 of file DBConnRef.php.

buildLeast()

Wikimedia\Rdbms\DBConnRef::buildLeast	(		$fields,
			$values )

Build a LEAST function statement comparing columns/values.Integer and float values in $values will not be quotedIf $fields is an array, then each value with a string key is treated as an expression (which must be manually quoted); such string keys do not appear in the SQL and are only descriptive aliases.

Parameters

string | string[]	$fields	Name(s) of column(s) with values to compare
string | int | float | string[] | int[] | float[]	$values	Values to compare

Returns

mixed

Since

1.35 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 523 of file DBConnRef.php.

buildLike()

Wikimedia\Rdbms\DBConnRef::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 the 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 in IDatabase, moved to ISQLPlatform in 1.39

Parameters

string|LikeMatch|non-empty-array<string|LikeMatch>	$param
string|LikeMatch	...$params

Returns

string Fully built LIKE statement

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 625 of file DBConnRef.php.

buildSelectSubquery()

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

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

See also

IDatabase::selectSQLText()

Parameters

string | array

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string | array	$vars	Field names
string | array	$conds	Conditions
string	$fname	Caller function name
string | array	$options	Query options
string | array	$join_conds	Join conditions

Returns

Subquery

Since

1.31

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 548 of file DBConnRef.php.

buildStringCast()

Wikimedia\Rdbms\DBConnRef::buildStringCast

(

$field

)

Parameters

string

$field

Field or column to cast

Returns

string

Since

1.28 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 533 of file DBConnRef.php.

buildSubstring()

Wikimedia\Rdbms\DBConnRef::buildSubstring	(		$input,
			$startPosition,
			$length = null )

Definition at line 528 of file DBConnRef.php.

cancelAtomic()

Wikimedia\Rdbms\DBConnRef::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 an optimization to save rountrips, 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	$sectionId	Section ID from startAtomic(); passing this enables cancellation of unclosed nested sections [optional]

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 754 of file DBConnRef.php.

clearFlag()

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

Clear a flag for this connection.

Parameters

int	$flag	One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string	$remember	IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implements Wikimedia\Rdbms\Database\IDatabaseFlags.

Definition at line 247 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

close()

Wikimedia\Rdbms\DBConnRef::close

(

$fname = __METHOD__

)

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.

Access: internal

Only for use by LoadBalancer

Parameters

string

$fname

Caller name

Returns

bool Success

Exceptions

DBError

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 321 of file DBConnRef.php.

commit()

Wikimedia\Rdbms\DBConnRef::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 transaction scope. See https://www.mediawiki.org/wiki/Database_transactions for details. Nesting of transactions is not supported.

Parameters

string	$fname
string	$flush	Flush 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

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 773 of file DBConnRef.php.

conditional()

Wikimedia\Rdbms\DBConnRef::conditional	(		$cond,
			$caseTrueExpression,
			$caseFalseExpression )

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|IExpression|array<string,?scalar|non-empty-array<int,?scalar>>|array<int,string|IExpression>	$cond SQL condition expression (yields a boolean)
string | int	$caseTrueExpression	SQL expression to return when the condition is true
string | int	$caseFalseExpression	SQL expression to return when the condition is false

Returns

string SQL fragment

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 692 of file DBConnRef.php.

databasesAreIndependent()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 556 of file DBConnRef.php.

dbSchema()

Wikimedia\Rdbms\DBConnRef::dbSchema

(

$schema = null

)

Get/set the db schema.

Parameters

string | null

$schema

The database schema to set, or omitted to leave it unchanged

Returns

string The previous db schema

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 177 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call(), and Wikimedia\Rdbms\DBConnRef\getDomainChangeException().

decodeBlob()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 825 of file DBConnRef.php.

decodeExpiry()

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

Decode an expiry time into a DBMS independent format.

Parameters

string	$expiry	DB timestamp field value for expiry
int	$format	TS_* constant, defaults to TS_MW

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 878 of file DBConnRef.php.

delete()

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

Delete all rows in a table that match a condition.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal

callers outside of rdbms library should use DeleteQueryBuilder instead.

Parameters

string	$table	The unqualified name of a table
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Array of conditions. See $conds in IDatabase::select() In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'delete' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to delete all rows.
string	$fname	Name of the calling function

Returns

bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 665 of file DBConnRef.php.

deleteJoin()

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

Delete all rows in a table that match a condition which includes a join.For safety, an empty $conds will not delete everything. If you want to delete all rows where the join condition matches, set $conds=IDatabase::ALL_ROWS.DO NOT put the join condition in $conds.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Parameters

string	$delTable	The unqualified name of the table to delete rows from.
string	$joinTable	The unqualified name of the reference table to join on.
string	$delVar	The variable to join on, in the first table.
string	$joinVar	The variable to join on, in the second table.
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 656 of file DBConnRef.php.

doAtomicSection()

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

Perform an atomic section of reversible 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 throws 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	$fname	Caller name (usually METHOD)
callable	$callback	Callback that issues write queries
string	$cancelable	Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.

Returns

mixed Result of the callback (since 1.28)

Exceptions

DBError

If an error occurs, {

See also

query}

Exceptions

Exception

If 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.

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 760 of file DBConnRef.php.

dropTable()

Wikimedia\Rdbms\DBConnRef::dropTable	(		$table,
			$fname = __METHOD__ )

Delete a table.

Parameters

string	$table	The unqualified name of a table
string	$fname

Returns

bool Whether the table already existed

Exceptions

DBError

If an error occurs

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 939 of file DBConnRef.php.

duplicateTableStructure()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 958 of file DBConnRef.php.

encodeBlob()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 820 of file DBConnRef.php.

encodeExpiry()

Wikimedia\Rdbms\DBConnRef::encodeExpiry

(

$expiry

)

Encode an expiry time into the DBMS dependent format.

Parameters

string

$expiry

Timestamp for expiry, or the 'infinity' string

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 873 of file DBConnRef.php.

endAtomic()

Wikimedia\Rdbms\DBConnRef::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

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 748 of file DBConnRef.php.

ensureConnection()

Wikimedia\Rdbms\DBConnRef::ensureConnection

(

)

Connect to the database if we are not already connected.

Definition at line 94 of file DBConnRef.php.

Referenced by Wikimedia\Rdbms\DBConnRef\__call().

estimateRowCount()

Wikimedia\Rdbms\DBConnRef::estimateRowCount	(		$tables,
			$vars = '*',
			$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().New callers should use newSelectQueryBuilder with SelectQueryBuilder::estimateRowCount instead, which is more readable and less error-prone.

Access: internal

Parameters

string | string[]

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string	$var	Column for which NULL values are not counted [default "*"]
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select
array | string	$join_conds	Join conditions

Returns

int Row count

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 409 of file DBConnRef.php.

explicitTrxActive()

Wikimedia\Rdbms\DBConnRef::explicitTrxActive

(

)

Check whether there is a transaction open at the specific request of a caller.Explicit transactions are spawned by begin(), startAtomic(), and doAtomicSection(). Note that explicit transactions should not be confused with explicit transaction rounds.

Returns

bool

Since

1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 154 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

expr()

Wikimedia\Rdbms\DBConnRef::expr	(	string	$field,
		string	$op,
			$value )

See Expression::__construct()

Since

1.42

Parameters

string	$field
string	$op	One of '>', '<', '!=', '=', '>=', '<=', IExpression::LIKE, IExpression::NOT_LIKE
	?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob>	$value

Returns

Expression

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 602 of file DBConnRef.php.

factorConds()

Wikimedia\Rdbms\DBConnRef::factorConds

(

$condsArray

)

Given an array of condition arrays representing an OR list of AND lists, for example:(A=1 AND B=2) OR (A=1 AND B=3)produce an SQL expression in which the conditions are factored:(A=1 AND (B=2 OR B=3))We also use IN() to simplify further:(A=1 AND (B IN (2,3))More compactly, in boolean algebra notation, a sum of products, e.g. AB + AC is factored to produce A(B+C). Factoring proceeds recursively to reduce expressions with any number of variables, for example AEP + AEQ + AFP + AFQ = A(E(P+Q) + F(P+Q))The algorithm is simple and will not necessarily find the shortest possible expression. For the best results, fields should be given in a consistent order, and the fields with values likely to be shared should be leftmost in the associative arrays.

Parameters

array

$condsArray

An array of associative arrays. The associative array keys represent field names, and the values represent the field values to compare against.

Returns

string SQL expression fragment

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 481 of file DBConnRef.php.

fieldExists()

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

Determines whether a field exists in a table.

Parameters

string	$table	The unqualified name of a table
string	$field	Field to check on that table
string	$fname	Calling function name

Returns

bool Whether $table has field $field

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 432 of file DBConnRef.php.

fieldInfo()

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

Get information about a field Returns false if the field doesn't exist.

Parameters

string	$table	The unqualified name of a table
string	$field	Field name

Returns

false|Field

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 977 of file DBConnRef.php.

flushSession()

Wikimedia\Rdbms\DBConnRef::flushSession	(		$fname = __METHOD__,
			$flush = self::FLUSHING_ONE )

Release important session-level state (named lock, table locks) as post-rollback cleanup.This should only be called by a load balancer or if the handle is not attached to one. Also, there must be no chance that a future caller will still be expecting some of the lost session state.Connection and query errors will be suppressed and logged

Parameters

string	$fname	Calling function name
string	$flush	Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. 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

DBError

If an error occurs, {

See also

query}

Since

1.38

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 783 of file DBConnRef.php.

flushSnapshot()

Wikimedia\Rdbms\DBConnRef::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 server after waiting on replication to catch up to the primary server.

Parameters

string	$fname	Calling function name
string	$flush	Flush 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

DBError

If an error occurs, {

See also

query}

Since

1.28

1.34 Added $flush parameter

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 788 of file DBConnRef.php.

getDBname()

Wikimedia\Rdbms\DBConnRef::getDBname

(

)

Get the current database name; null if there isn't one.

Returns

string|null

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 568 of file DBConnRef.php.

getDomainChangeException()

Wikimedia\Rdbms\DBConnRef::getDomainChangeException ( )

protected

Returns

DBUnexpectedError

Definition at line 1012 of file DBConnRef.php.

Referenced by Wikimedia\Rdbms\DBConnRef\dbSchema(), Wikimedia\Rdbms\DBConnRef\setLBInfo(), and Wikimedia\Rdbms\DBConnRef\tablePrefix().

getDomainID()

Wikimedia\Rdbms\DBConnRef::getDomainID

(

)

Return the currently selected domain ID.Null components (database/schema) might change once a connection is established

Returns

string

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 267 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getFlag()

Wikimedia\Rdbms\DBConnRef::getFlag

(

$flag

)

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

Parameters

int

$flag

One of the class IDatabase::DBO_* constants

Returns

bool

Implements Wikimedia\Rdbms\Database\IDatabaseFlags.

Definition at line 257 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getInfinity()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 868 of file DBConnRef.php.

getLag()

Wikimedia\Rdbms\DBConnRef::getLag

(

)

Get the seconds of replication lag on this database server.Callers should avoid using this method while a transaction is active

Returns

float|int|false Database replication lag in seconds or false on error

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 810 of file DBConnRef.php.

getLBInfo()

Wikimedia\Rdbms\DBConnRef::getLBInfo

(

$name = null

)

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

Access: internal

should not be called outside of rdbms library.

Parameters

string | null

$name

The entry of the info array to get, or null to get the whole array

Returns

array|mixed|null

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 195 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getPrimaryKeyColumns()

Wikimedia\Rdbms\DBConnRef::getPrimaryKeyColumns	(		$table,
			$fname = __METHOD__ )

Get the primary key columns of a table.

Access: internal

to be used by updater only

Parameters

string	$table	The unqualified name of a table
string	$fname	Calling function name

Returns

string[]

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 442 of file DBConnRef.php.

getPrimaryPos()

Wikimedia\Rdbms\DBConnRef::getPrimaryPos

(

)

Get the replication position of this primary DB server.

Returns

DBPrimaryPos|false Position; false if this is not a primary DB

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.37

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 707 of file DBConnRef.php.

getProperty()

Wikimedia\Rdbms\DBConnRef::getProperty

(

$name

)

Definition at line 262 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getReferenceRole()

Wikimedia\Rdbms\DBConnRef::getReferenceRole

(

)

Returns

int DB_PRIMARY when this requires the primary DB, otherwise DB_REPLICA

Since

1.33

Definition at line 134 of file DBConnRef.php.

getScopedLockAndFlush()

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

Acquire a named lock, flush any transaction, and return an RAII style unlocker object.Only call this from outer transaction scope and when only one DB server will be affected. See https://www.mediawiki.org/wiki/Database_transactions for details.This is suitable 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	$lockKey	Name of lock to release
string	$fname	Name of the calling method
int	$timeout	Acquisition timeout in seconds

Returns

ScopedCallback|null

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 861 of file DBConnRef.php.

getServer()

Wikimedia\Rdbms\DBConnRef::getServer

(

)

Get the hostname or IP address of the server.

Returns

string|null

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 578 of file DBConnRef.php.

getServerInfo()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 139 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getServerName()

Wikimedia\Rdbms\DBConnRef::getServerName

(

)

Get the readable name for the server.

Returns

string Readable server name, falling back to the hostname or IP address

Since

1.36

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 583 of file DBConnRef.php.

getServerVersion()

Wikimedia\Rdbms\DBConnRef::getServerVersion

(

)

A string describing the current software version.

Returns

string Version information from the database server.

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 316 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getSessionLagStatus()

Wikimedia\Rdbms\DBConnRef::getSessionLagStatus

(

)

Get a cached estimate of the seconds of replication lag on this database server, using the estimate obtained at the start of the current transaction if one 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

DBError

If an error occurs, {

See also

query}

Since

1.27

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 815 of file DBConnRef.php.

getSoftwareLink()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 311 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

getTableAliases()

Wikimedia\Rdbms\DBConnRef::getTableAliases

(

)

Return current table aliases.

Access: internal

only to be used inside rdbms library

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 893 of file DBConnRef.php.

getType()

Wikimedia\Rdbms\DBConnRef::getType

(

)

Get the RDBMS type of the server (e.g."mysql", "sqlite")

Returns

string

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 277 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call(), and Wikimedia\Rdbms\DBConnRef\normalizeServerIndex().

implicitOrderby()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 207 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

indexExists()

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

Determines whether an index exists.

Parameters

string	$table	The unqualified name of a table
string	$index
string	$fname

Returns

bool

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 437 of file DBConnRef.php.

indexUnique()

Wikimedia\Rdbms\DBConnRef::indexUnique	(		$table,
			$index,
			$fname = __METHOD__ )

Determines if a given index is unique.

Parameters

string	$table	The unqualified name of a table
string	$index
string	$fname	Calling function name

Returns

bool|null Returns null if the index does not exist

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 967 of file DBConnRef.php.

insert()

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

Insert row(s) into a table, in the provided order.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal

callers outside of rdbms library should use InsertQueryBuilder instead.

Parameters

string	$table	The unqualified name of a table
array | array[]	$rows	Row(s) to insert, as either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other.
string	$fname	Calling function name (use METHOD) for logs/profiling
string | array	$options	Combination map/list where each string-keyed entry maps a non-boolean option to the option parameters and each integer-keyed value is the name of a boolean option. Supported options are: IGNORE: Boolean: skip insertion of rows that would cause unique key conflicts. IDatabase::affectedRows() can be used to determine how many rows were inserted.

Returns

bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 452 of file DBConnRef.php.

insertId()

Wikimedia\Rdbms\DBConnRef::insertId

(

)

Get the sequence-based ID assigned by the last query method call.This method should only be called when all the following hold true:

• (a) A method call was made to insert(), upsert(), replace(), or insertSelect()
• (b) The method call attempts to insert exactly one row
• (c) The method call omits the value of exactly one auto-increment column
• (d) The method call succeeded
• (e) No subsequent method calls were made, with the exception of affectedRows(), lastErrno(), lastError(), and getType()

In all other cases, the return value is unspecified.When the query method is either insert() with "IGNORE", upsert(), or insertSelect(), callers should first check affectedRows() before calling this method, making sure that the query method actually created a row. Otherwise, an ID from a previous insert might be incorrectly assumed to belong to last insert.

Returns

int

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 291 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

insertSelect()

Wikimedia\Rdbms\DBConnRef::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.

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Parameters

string	$destTable	Unqualified name of destination table
string | array	$srcTable	Unqualified name of source table(s) (use an array for a join)
array	$varMap	Must 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()
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Condition array. See $conds in IDatabase::select() for the details of the format of condition arrays. May be "*" to copy the whole table.
string	$fname	The function name of the caller, from METHOD
array	$insertOptions	Options 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	$selectOptions	Options for the SELECT part of the query, see IDatabase::select() for details.
array	$selectJoinConds	Join 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

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 672 of file DBConnRef.php.

isOpen()

Wikimedia\Rdbms\DBConnRef::isOpen

(

)

Returns

bool Whether a connection to the database open

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 237 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

isReadOnly()

Wikimedia\Rdbms\DBConnRef::isReadOnly

(

)

Check if this DB server is marked as read-only according to load balancer info.

Note

LoadBalancer checks serverIsReadOnly() when setting the load balancer info array

Returns

bool

Since

1.27

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 883 of file DBConnRef.php.

lastDoneWrites()

Wikimedia\Rdbms\DBConnRef::lastDoneWrites

(

)

Get the last time that the connection was used to commit a write.

Access: internal

Should only be called from the rdbms library.

Returns

float|null UNIX timestamp; null if no writes were committed

Since

1.24

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 212 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

lastErrno()

Wikimedia\Rdbms\DBConnRef::lastErrno

(

)

Get the RDBMS-specific error code from the last attempted query statement.

Returns

int|string Error code (integer or hexadecimal depending on RDBMS type)

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 296 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

lastError()

Wikimedia\Rdbms\DBConnRef::lastError

(

)

Get the RDBMS-specific error description from the last attempted query statement.

Returns

string

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 301 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

limitResult()

Wikimedia\Rdbms\DBConnRef::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	$sql	SQL query we will append the limit too
int	$limit	The SQL limit
int | false	$offset	The SQL offset (default false)

Returns

string

Since

1.34 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 396 of file DBConnRef.php.

listTables()

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

List all tables on the database.Since MW 1.42, this will no longer include MySQL views.

Parameters

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

Exceptions

DBError

Returns

array

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 972 of file DBConnRef.php.

lock()

Wikimedia\Rdbms\DBConnRef::lock	(		$lockName,
			$method,
			$timeout = 5,
			$flags = 0 )

Acquire a named lock.Named locks are not related to transactions

Parameters

string	$lockName	Name of lock to acquire
string	$method	Name of the calling method
int	$timeout	Acquisition timeout in seconds (0 means non-blocking)
int	$flags	Bit field of IDatabase::LOCK_* constants

Returns

bool|float|null Success (bool); acquisition time (float/null) if LOCK_TIMESTAMP

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 847 of file DBConnRef.php.

lockForUpdate()

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

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

Parameters

string | string[]	$table	The unqualified name of table(s) (use an array for a join)
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Condition in the format of IDatabase::select() conditions
string	$fname	Function name for profiling
array	$options	Options for select ("FOR UPDATE" is added automatically)
array	$join_conds	Join conditions

Returns

int Number of matching rows found (and locked)

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.32

Deprecated

since 1.43; Use SelectQueryBuilder::acquireRowLocks

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 423 of file DBConnRef.php.

lockIsFree()

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

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

Parameters

string	$lockName	Name of lock to poll
string	$method	Name of method calling us

Returns

bool

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.20

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 840 of file DBConnRef.php.

makeList()

Wikimedia\Rdbms\DBConnRef::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 also

IDatabase::select} $conds documentation).

Example usage:

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

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

Parameters

array	$a	Containing the data
int	$mode	IDatabase 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

DBError

If an error occurs, {

See also

IDatabase::query}

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 471 of file DBConnRef.php.

makeWhereFrom2d()

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

Build a "OR" condition with pairs from a two-dimensional array.The associative array should have integer keys relating to the $baseKey field. The nested array should have string keys for the $subKey field. The inner values are ignored, and are typically boolean true.Example usage:

$data = [
    2 => [
        'Foo' => true,
        'Bar' => true,
    ],
    3 => [
        'Quux' => true,
    ],
];
// (page_namespace = 2 AND page_title IN ('Foo','Bar'))
// OR (page_namespace = 3 AND page_title = 'Quux')

Todo

This is effectively specific to MediaWiki's LinkBatch. Consider deprecating or generalising slightly.

Parameters

array	$data	Nested array, must be non-empty
string	$baseKey	Field name to match the base-level keys to (eg 'pl_namespace')
string	$subKey	Field name to match the sub-level keys to (eg 'pl_title')

Returns

string SQL fragment

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 476 of file DBConnRef.php.

newDeleteQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newDeleteQueryBuilder

(

)

Get an DeleteQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Returns

DeleteQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 350 of file DBConnRef.php.

newInsertQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newInsertQueryBuilder

(

)

Get an InsertQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Returns

InsertQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 355 of file DBConnRef.php.

newReplaceQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newReplaceQueryBuilder

(

)

Get an ReplaceQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Returns

ReplaceQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 360 of file DBConnRef.php.

newSelectQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newSelectQueryBuilder

(

)

Create an empty SelectQueryBuilder which can be used to run queries against this connection.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Returns

SelectQueryBuilder

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 335 of file DBConnRef.php.

newUnionQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newUnionQueryBuilder

(

)

Create an empty UnionQueryBuilder which can be used to run queries against this connection.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Since

1.41

Returns

UnionQueryBuilder

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 340 of file DBConnRef.php.

newUpdateQueryBuilder()

Wikimedia\Rdbms\DBConnRef::newUpdateQueryBuilder

(

)

Get an UpdateQueryBuilder bound to this connection.

This is overridden by DBConnRef.

Note

A new query builder must be created per query. Query builders should not be reused since this uses a fluent interface and the state of the builder changes during the query which may cause unexpected results.

Returns

UpdateQueryBuilder

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 345 of file DBConnRef.php.

normalizeServerIndex()

Wikimedia\Rdbms\DBConnRef::normalizeServerIndex ( $i )

protected

Parameters

int

$i

Specific or virtual (DB_PRIMARY/DB_REPLICA) server index

Returns

int|mixed

Definition at line 1025 of file DBConnRef.php.

Referenced by Wikimedia\Rdbms\DBConnRef\getType().

onTransactionCommitOrIdle()

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

Run a callback when 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 after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().Use this method only for the following purposes:

• (a) RDBMS updates, prone to lock timeouts/deadlocks, that do not require atomicity with respect to the updates in the current transaction (if any)
• (b) Purges to lightweight cache services due to RDBMS updates
• (c) Updates to secondary DBs/stores that must only commit once the updates in the current transaction (if any) are committed (e.g. insert user account row to DB1, then, initialize corresponding LDAP account)

The callback takes the following arguments:

• How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)

Callbacks will execute in the order they were enqueued.

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError

If an error occurs, {

See also

query}

Exceptions

Exception

If the callback runs immediately and an error occurs in it

Since

1.32

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 723 of file DBConnRef.php.

onTransactionPreCommitOrIdle()

Wikimedia\Rdbms\DBConnRef::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 after all peer transactions COMMIT. If the transaction round is rolled back, then the callback is cancelled.If there is no current transaction, one will be created to wrap the callback. Callbacks cannot use begin()/commit() to manage transactions. The use of other IDatabase handles from the callback should be avoided.Use this method only for the following purposes:

• a) RDBMS updates, prone to lock timeouts/deadlocks, that require atomicity with respect to the updates in the current transaction (if any)
• b) Purges to lightweight cache services due to RDBMS updates

Callbacks will execute in the order they were enqueued.

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError

If an error occurs, {

See also

query}

Exceptions

Exception

If the callback runs immediately and an error occurs in it

Since

1.22

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 729 of file DBConnRef.php.

onTransactionResolution()

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

Run a callback when the current transaction commits or rolls back.An error is thrown if no transaction is pending.When transaction round mode (DBO_TRX) is set, the callback will run at the end of the round, just after all peer transactions COMMIT/ROLLBACK.This IDatabase instance will start off in auto-commit mode when the callback starts. The use of other IDatabase handles from the callback should be avoided unless they are known to be in auto-commit mode. Callbacks that create transactions via begin() or startAtomic() must have matching calls to commit()/endAtomic().Use this method only for the following purposes:

• (a) Release of cooperative locks on resources
• (b) Cancellation of in-process deferred tasks

The callback takes the following arguments:

• How the current atomic section (if any) or overall transaction (otherwise) ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)

Callbacks will execute in the order they were enqueued.

Parameters

callable	$callback
string	$fname	Caller name

Exceptions

DBError

If an error occurs, {

See also

query}

Exceptions

Exception

If the callback runs immediately and an error occurs in it

Since

1.28

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 717 of file DBConnRef.php.

orExpr()

Wikimedia\Rdbms\DBConnRef::orExpr

(

array

$conds

)

See Expression::__construct()

Since

1.43

Parameters

non-empty-array<string,?scalar|RawSQLValue|Blob|LikeValue|non-empty-list<scalar|Blob>>|non-empty-array<int,IExpression>

$conds

Returns

OrExpressionGroup

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 614 of file DBConnRef.php.

pendingWriteCallers()

Wikimedia\Rdbms\DBConnRef::pendingWriteCallers

(

)

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

Returns

array

Since

1.27

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 232 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

pendingWriteQueryDuration()

Wikimedia\Rdbms\DBConnRef::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

$type

IDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL]

Returns

float|false Returns false if not transaction is active

Since

1.26

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 227 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

ping()

Wikimedia\Rdbms\DBConnRef::ping

(

&

$rtt = null

)

Definition at line 803 of file DBConnRef.php.

primaryPosWait()

Wikimedia\Rdbms\DBConnRef::primaryPosWait	(	DBPrimaryPos	$pos,
			$timeout )

Wait for the replica server to catch up to a given primary server position.Note that this does not start any new transactions.Callers might want to flush any existing transaction before invoking this method. Upon success, this assures that replica server queries will reflect all changes up to the given position, without interference from prior REPEATABLE-READ snapshots.

Parameters

DBPrimaryPos	$pos
int	$timeout	The maximum number of seconds to wait for synchronisation

Returns

int|null Zero if the replica DB server 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

DBError

If an error occurs, {

See also

query}

Since

1.37

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 702 of file DBConnRef.php.

query()

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

Run an SQL query statement 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.Callers should avoid the use of statements like BEGIN, COMMIT, and ROLLBACK. Methods like startAtomic(), endAtomic(), and cancelAtomic() can be used instead.

Parameters

string | Query	$sql	Single-statement SQL query
string	$fname	Caller name; used for profiling/SHOW PROCESSLIST comments
int	$flags	Bit field of ISQLPlatform::QUERY_* constants

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

DBQueryError	If the query is issued, fails, and QUERY_SILENCE_ERRORS is not set
DBExpectedError	If the query is not, and cannot, be issued yet (non-DBQueryError)
DBError	If the query is inherently not allowed (non-DBExpectedError)

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 327 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call(), Wikimedia\Rdbms\ILoadBalancer\DB_PRIMARY, and Wikimedia\Rdbms\Platform\ISQLPlatform\QUERY_REPLICA_ROLE.

replace()

Wikimedia\Rdbms\DBConnRef::replace	(		$table,
			$uniqueKeys,
			$rows,
			$fname = __METHOD__ )

Insert row(s) into a table, in the provided order, while deleting conflicting rows.Conflicts are determined by the provided unique indexes. Note that it is possible for the provided rows to conflict even among themselves; it is preferable for the caller to de-duplicate such input beforehand.Note some important implications of the deletion semantics:

• If the table has an AUTOINCREMENT column and $rows omit that column, then any conflicting existing rows will be replaced with newer having higher values for that column, even if nothing else changed.
• There might be worse contention than upsert() due to the use of gap-locking. This does not apply to RDBMS types that use predicate locking nor those that just lock the whole table or databases anyway.

This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal

callers outside of rdbms library should use ReplaceQueryBuilder instead.

Parameters

string	$table	The unqualified name of a table
string | string[] | string[][]	$uniqueKeys	Column name or non-empty list of column name lists that define all applicable unique keys on the table. There must only be one such key. Each unique key on the table is "applicable" unless either: It involves an AUTOINCREMENT column for which no values are assigned in $rows It involves a UUID column for which newly generated UUIDs are assigned in $rows
array | array[]	$rows	Row(s) to insert, in the form of either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. Columns belonging to a key in $uniqueKeys must be defined here and non-null. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other.
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 640 of file DBConnRef.php.

restoreFlags()

Wikimedia\Rdbms\DBConnRef::restoreFlags

(

$state = self::RESTORE_PRIOR

)

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

Parameters

string

$state

IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]

Since

1.28

Implements Wikimedia\Rdbms\Database\IDatabaseFlags.

Definition at line 252 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

rollback()

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

Rollback a transaction previously started using begin()Only call this from code with outer transaction 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 preferable, 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	$fname	Calling function name
string	$flush	Flush flag, set to a situationally valid IDatabase::FLUSHING_* constant to disable warnings about explicitly rolling back implicit transactions. 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

DBError

If an error occurs, {

See also

query}

Since

1.23 Added $flush parameter

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 778 of file DBConnRef.php.

select()

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

Execute a SELECT query constructed using the various parameters provided.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchResultSet instead, which is more readable and less error-prone.

Parameters

string | array

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>".

Each table reference assigns a table name to a specified collection of rows for the context of the query (e.g. field expressions, WHERE clause, GROUP BY clause, HAVING clause, etc...). Use of multiple table references implies a JOIN.If a string is given, it must hold the name of the table having the specified collection of rows. If an array is given, each entry must be one of the following:

• A string holding the name of the existing table which has the collection of rows. If keyed by a string, the key will be the assigned table name.
• A Subquery instance which specifies the collection of rows derived from a subquery. If keyed by a string, the key will be the assigned table name. Otherwise, the SQL text of the subquery will be the assigned table name.
• An array specifying the collection of rows derived from a parenthesized JOIN. It must be keyed by a string, which will be used as the assigned table name.

String keys allow table aliases to 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 likeFROM 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

$vars

Field 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|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>

$conds

May 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:

• IDatabase::buildLike()
• IDatabase::conditional()

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 IDatabase::ALL_ROWS to select all rows.You can put simple join conditions here, but this is strongly discouraged. Instead of

// $conds...
'rev_actor = actor_id',

use (see below for $join_conds):

// $join_conds...
'actor' => [ 'JOIN', 'rev_actor = actor_id' ],

Parameters

string	$fname	Caller function name
string | array	$options	Query 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 a 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.
• IGNORE INDEX: This may be either be a string giving an index name to ignore 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 ignore 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.
• MAX_EXECUTION_TIME: (only in MySQL/MariaDB) maximum allowed time to run the query in milliseconds (if database supports it).

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_conds

Join conditions

Optional associative array of table-specific join conditions. Simple conditions can also be specified in the regular $conds, but this is strongly discouraged in favor of the more explicit syntax here.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' ] ]

Access: internal

Returns

IResultWrapper Resulting rows

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 380 of file DBConnRef.php.

selectDomain()

Wikimedia\Rdbms\DBConnRef::selectDomain

(

$domain

)

Set the current domain (database, schema, and table prefix)This will throw an error for some database types if the database is unspecifiedThis should only be called by a load balancer or if the handle is not attached to one

Parameters

string | DatabaseDomain

$domain

Exceptions

DBConnectionError	If databasesAreIndependent() is true and connection change fails
DBError	On query error, if domain changes are disallowed, or the domain is invalid

Since

1.32

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 561 of file DBConnRef.php.

selectField()

Wikimedia\Rdbms\DBConnRef::selectField	(		$tables,
			$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.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchField instead, which is more readable and less error-prone.

Access: internal

callers outside of rdbms library should use SelectQueryBuilder instead.

Parameters

string | array

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string | array

$var

The field name to select. This must be a valid SQL fragment: do not use unvalidated user input. Can be an array, but must contain exactly 1 element then. {

See also

select} for details.

Parameters

string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>

$cond The condition array. {

See also

select} for details.

Parameters

string	$fname	The function name of the caller.
string | array	$options	The query options. {

See also

select} for details.

Parameters

string | array

$join_conds

The query join conditions. {

See also

select} for details.

Returns

mixed|false The value from the field, or false if nothing was found

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 366 of file DBConnRef.php.

selectFieldValues()

Wikimedia\Rdbms\DBConnRef::selectFieldValues	(		$tables,
			$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, an empty array is returned.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchFieldValues instead, which is more readable and less error-prone.

Access: internal

callers outside of rdbms library should use SelectQueryBuilder instead.

Parameters

string | array

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string	$var	The field name to select. This must be a valid SQL fragment: do not use unvalidated user input.
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$cond The condition array. {

See also

select} for details.

Parameters

string	$fname	The function name of the caller.
string | array	$options	The query options. {

See also

select} for details.

Parameters

string | array

$join_conds

The query join conditions. {

See also

select} for details.

Returns

array The values from the field in the order they were returned from the DB

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.25

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 373 of file DBConnRef.php.

selectRow()

Wikimedia\Rdbms\DBConnRef::selectRow	(		$tables,
			$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.New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRow instead, which is more readable and less error-prone.

Access: internal

Parameters

string | array

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string | array	$vars	Field names
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Conditions
string	$fname	Caller function name
string | array	$options	Query options
array | string	$join_conds	Join conditions

Returns

stdClass|false

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 401 of file DBConnRef.php.

selectRowCount()

Wikimedia\Rdbms\DBConnRef::selectRowCount	(		$tables,
			$vars = '*',
			$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().New callers should use newSelectQueryBuilder with SelectQueryBuilder::fetchRowCount instead, which is more readable and less error-prone.

Since

1.27 Added $join_conds parameter

Access: internal

Parameters

string | string[]

$tables

Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>". {

See also

select} for details.

Parameters

string	$var	Column for which NULL values are not counted [default "*"]
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Filters on the table
string	$fname	Function name for profiling
array	$options	Options for select
array	$join_conds	Join conditions (since 1.27)

Returns

int Row count

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 416 of file DBConnRef.php.

selectSQLText()

Wikimedia\Rdbms\DBConnRef::selectSQLText	(		$tables,
			$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	$tables	Table reference(s), using the unqualified name of tables or of the form "information_schema.<identifier>".
string | array	$vars	Field names
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Conditions
string	$fname	Caller function name
string | array	$options	Query options
string | array	$join_conds	Join conditions

Returns

string SQL query string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 388 of file DBConnRef.php.

serverIsReadOnly()

Wikimedia\Rdbms\DBConnRef::serverIsReadOnly

(

)

Returns

bool Whether this DB server is running in server-side read-only mode

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.28

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 712 of file DBConnRef.php.

setFlag()

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

Set a flag for this connection.

Parameters

int	$flag	One of (IDatabase::DBO_DEBUG, IDatabase::DBO_TRX)
string	$remember	IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]

Implements Wikimedia\Rdbms\Database\IDatabaseFlags.

Definition at line 242 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

setLBInfo()

Wikimedia\Rdbms\DBConnRef::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

Access: internal

should not be called outside of rdbms library.

Parameters

array | string	$nameOrArray	The new array or the name of a key to set
array | mixed | null	$value	If $nameOrArray is a string, the new key value (null to unset)

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 200 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\getDomainChangeException().

setSchemaVars()

Wikimedia\Rdbms\DBConnRef::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

$vars

Map of (variable => value) or null to use the defaults

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 835 of file DBConnRef.php.

setSessionOptions()

Wikimedia\Rdbms\DBConnRef::setSessionOptions

(

array

$options

)

Override database's default behavior.Not all options are supported on all database backends; unsupported options are silently ignored.$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. Only supported on MySQL and MariaDB.
• 'groupConcatMaxLen': Maximum length of a GROUP_CONCAT() result. Only supported on MySQL and MariaDB.

Parameters

array

$options

Returns

void

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 830 of file DBConnRef.php.

setTableAliases()

Wikimedia\Rdbms\DBConnRef::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[]

$aliases

Map of (unqualified name of table => (dbname, schema, prefix) map)

Since

1.28 in IDatabase, moved to ISQLPlatform in 1.39

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 888 of file DBConnRef.php.

setTransactionListener()

Wikimedia\Rdbms\DBConnRef::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	$name	Callback name
callable | null	$callback	Use null to unset a listener

Since

1.28

Deprecated

Since 1.44

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 735 of file DBConnRef.php.

sourceFile()

Wikimedia\Rdbms\DBConnRef::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
string | false	$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

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 913 of file DBConnRef.php.

sourceStream()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 926 of file DBConnRef.php.

startAtomic()

Wikimedia\Rdbms\DBConnRef::startAtomic	(		$fname = __METHOD__,
			$cancelable = IDatabase::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	$cancelable	Pass self::ATOMIC_CANCELABLE to use a savepoint and enable self::cancelAtomic() for this section.

Returns

AtomicSectionIdentifier section ID token

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 740 of file DBConnRef.php.

streamStatementEnd()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 953 of file DBConnRef.php.

strreplace()

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

Returns a SQL expression for simple string replacement (e.g.REPLACE() in mysql)

Parameters

string	$orig	Column to modify
string	$old	Column to seek
string	$new	Column to replace with

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 697 of file DBConnRef.php.

tableExists()

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

Query whether a given table exists.

Parameters

string	$table	The unqualified name of a table
string	$fname

Returns

bool

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 447 of file DBConnRef.php.

tableName()

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

Definition at line 898 of file DBConnRef.php.

tableNames()

Wikimedia\Rdbms\DBConnRef::tableNames

(

$tables

)

Definition at line 903 of file DBConnRef.php.

tableNamesN()

Wikimedia\Rdbms\DBConnRef::tableNamesN

(

$tables

)

Fetch a number of table names into a zero-indexed numerical array.Much like tableName(), this is only needed when calling query() directly. You should prefer calling other methods, or using SelectQueryBuilder.Theoretical example (which really does not require raw SQL):

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

Parameters

string

...$tables

Returns

array

Deprecated

Since 1.43; if you must format table names, write several calls to tableName.

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 908 of file DBConnRef.php.

tablePrefix()

Wikimedia\Rdbms\DBConnRef::tablePrefix

(

$prefix = null

)

Get/set the table prefix.

Parameters

string | null

$prefix

The table prefix to set, or omitted to leave it unchanged

Returns

string The previous table prefix

Implements Wikimedia\Rdbms\IReadableDatabase.

Definition at line 159 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call(), and Wikimedia\Rdbms\DBConnRef\getDomainChangeException().

timestamp()

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

Parameters

string | int

$ts

Returns

string

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 793 of file DBConnRef.php.

timestampOrNull()

Wikimedia\Rdbms\DBConnRef::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|null

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 798 of file DBConnRef.php.

truncateTable()

Wikimedia\Rdbms\DBConnRef::truncateTable	(		$table,
			$fname = __METHOD__ )

Delete all data in a table and reset any sequences owned by that table.

Parameters

string	$table	The unqualified name of a table
string	$fname

Exceptions

DBError

If an error occurs

Since

1.42

Implements Wikimedia\Rdbms\IMaintainableDatabase.

Definition at line 946 of file DBConnRef.php.

trxLevel()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 144 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

trxTimestamp()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 149 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

unionQueries()

Wikimedia\Rdbms\DBConnRef::unionQueries	(		$sqls,
			$all,
			$options = [] )

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

Access: internal

callers outside of rdbms library should use UnionQueryBuilder instead.

Parameters

array	$sqls	SQL statements to combine
bool	$all	Either IDatabase::UNION_ALL or IDatabase::UNION_DISTINCT
array	$options	Query options

Returns

string SQL fragment

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 687 of file DBConnRef.php.

unionSupportsOrderAndLimit()

Wikimedia\Rdbms\DBConnRef::unionSupportsOrderAndLimit

(

)

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

Returns

bool

Implements Wikimedia\Rdbms\Platform\ISQLPlatform.

Definition at line 682 of file DBConnRef.php.

unlock()

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

Release a lock.Named locks are not related to transactions

Parameters

string	$lockName	Name of lock to release
string	$method	Name of the calling method

Returns

bool Success

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 854 of file DBConnRef.php.

update()

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

Update all rows in a table that match a given condition.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal

callers outside of rdbms library should use UpdateQueryBuilder instead.

Parameters

string	$table	The unqualified name of a table
	array<string,?scalar|RawSQLValue>|array<int,string>	$set Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL expression in the format of a column assignment within UPDATE...SET. The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment format is useful for updates like "column = column + X". All assignments have no defined execution order, so they should not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments.
	string|IExpression|array<string,?scalar|non-empty-array<int,?scalar>|RawSQLValue>|array<int,string|IExpression>	$conds Condition in the format of IDatabase::select() conditions. In order to prevent possible performance or replication issues or damaging a data accidentally, an empty condition for 'update' queries isn't allowed. IDatabase::ALL_ROWS should be passed explicitly in order to update all rows.
string	$fname	Calling function name (use METHOD) for logs/profiling
string | array	$options	Combination map/list where each string-keyed entry maps a non-boolean option to the option parameters and each integer-keyed value is the name of a boolean option. Supported options are: IGNORE: Boolean: skip update of rows that would cause unique key conflicts. IDatabase::affectedRows() includes all matching rows, that includes also rows not updated due to key conflict.

Returns

bool Return true if no exception was thrown (deprecated since 1.33)

Exceptions

DBError

If an error occurs, {

See also

query}

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 459 of file DBConnRef.php.

upsert()

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

Upsert row(s) into a table, in the provided order, while updating conflicting rows.Conflicts are determined by the provided unique indexes. Note that it is possible for the provided rows to conflict even among themselves; it is preferable for the caller to de-duplicate such input beforehand.This operation will be seen by affectedRows()/insertId() as one query statement, regardless of how many statements are actually sent by the class implementation.

Access: internal

callers outside of rdbms library should use InsertQueryBuilder instead.

Parameters

string	$table	The unqualified name of a table
array | array[]	$rows	Row(s) to insert, in the form of either: A string-keyed map of (column name => value) defining a new row. Values are treated as literals and quoted appropriately; null is interpreted as NULL. Columns belonging to a key in $uniqueKeys must be defined here and non-null. An integer-keyed list of such string-keyed maps, defining a list of new rows. The keys in each map must be identical to each other and in the same order. The rows must not collide with each other.
string | string[] | string[][]	$uniqueKeys	Column name or non-empty list of column name lists that define all applicable unique keys on the table. There must only be one such key. Each unique key on the table is "applicable" unless either: It involves an AUTOINCREMENT column for which no values are assigned in $rows It involves a UUID column for which newly generated UUIDs are assigned in $rows
	array<string,?scalar|RawSQLValue>|array<int,string>	$set Combination map/list where each string-keyed entry maps a column to a literal assigned value and each integer-keyed value is a SQL assignment expression of the form "<unquoted alphanumeric column> = <SQL expression>". The (column => value) entries are convenient due to automatic value quoting and conversion of null to NULL. The SQL assignment entries are useful for updates like "column = column + X". All of the assignments have no defined execution order, so callers should make sure that they not depend on each other. Do not modify AUTOINCREMENT or UUID columns in assignments, even if they are just "secondary" unique keys. For multi-row upserts, use buildExcludedValue() to reference the value of a column from the corresponding row in $rows that conflicts with the current row.
string	$fname	Calling function name (use METHOD) for logs/profiling

Exceptions

DBError

If an error occurs, {

See also

query}

Since

1.22

Implements Wikimedia\Rdbms\IDatabase.

Definition at line 647 of file DBConnRef.php.

writesOrCallbacksPending()

Wikimedia\Rdbms\DBConnRef::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

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 222 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

writesPending()

Wikimedia\Rdbms\DBConnRef::writesPending

(

)

Returns

bool Whether there is a transaction open with possible write queries

Since

1.27

Implements Wikimedia\Rdbms\IDatabaseForOwner.

Definition at line 217 of file DBConnRef.php.

References Wikimedia\Rdbms\DBConnRef\__call().

---

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

• includes/libs/Rdbms/Database/DBConnRef.php