MediaWiki  1.28.1
IMaintainableDatabase Interface Reference

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

Inheritance diagram for IMaintainableDatabase:
Collaboration diagram for IMaintainableDatabase:

Public Member Functions

 deadlockLoop ()
 Perform a deadlock-prone transaction. More...
 
 dropTable ($tableName, $fName=__METHOD__)
 Delete a table. More...
 
 listViews ($prefix=null, $fname=__METHOD__)
 Lists all the VIEWs in the database. More...
 
 sourceFile ($filename, callable $lineCallback=null, callable $resultCallback=null, $fname=false, callable $inputCallback=null)
 Read and execute SQL commands from a file. More...
 
 sourceStream ($fp, callable $lineCallback=null, callable $resultCallback=null, $fname=__METHOD__, callable $inputCallback=null)
 Read and execute commands from an open file handle. More...
 
 streamStatementEnd (&$sql, &$newLine)
 Called by sourceStream() to check if we've reached a statement end. More...
 
 tableName ($name, $format= 'quoted')
 Format a table name ready for use in constructing an SQL query. More...
 
 tableNames ()
 Fetch a number of table names into an array This is handy when you need to construct SQL for joins. More...
 
 tableNamesN ()
 Fetch a number of table names into an zero-indexed numerical array This is handy when you need to construct SQL for joins. More...
 
 textFieldSize ($table, $field)
 Returns the size of a text field, or -1 for "unlimited". More...
 
- Public Member Functions inherited from IDatabase
 addQuotes ($s)
 Adds quotes and backslashes. More...
 
 affectedRows ()
 Get the number of rows affected by the last write query. More...
 
 aggregateValue ($valuedata, $valuename= 'value')
 Return aggregated value alias. More...
 
 anyChar ()
 Returns a token for buildLike() that denotes a '_' to be used in a LIKE query. More...
 
 anyString ()
 Returns a token for buildLike() that denotes a '' to be used in a LIKE query. More...
 
 begin ($fname=__METHOD__, $mode=self::TRANSACTION_EXPLICIT)
 Begin a transaction. More...
 
 bitAnd ($fieldLeft, $fieldRight)
 
 bitNot ($field)
 
 bitOr ($fieldLeft, $fieldRight)
 
 bufferResults ($buffer=null)
 Turns buffering of SQL result sets on (true) or off (false). More...
 
 buildConcat ($stringList)
 Build a concatenation list to feed into a SQL query. More...
 
 buildGroupConcatField ($delim, $table, $field, $conds= '', $join_conds=[])
 Build a GROUP_CONCAT or equivalent statement for a query. More...
 
 buildLike ()
 LIKE statement wrapper, receives 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(). More...
 
 buildStringCast ($field)
 
 clearFlag ($flag, $remember=self::REMEMBER_NOTHING)
 Clear a flag for this connection. More...
 
 close ()
 Closes a database connection. More...
 
 commit ($fname=__METHOD__, $flush= '')
 Commits a transaction previously started using begin(). More...
 
 conditional ($cond, $trueVal, $falseVal)
 Returns an SQL expression for a simple conditional. More...
 
 dataSeek ($res, $row)
 Change the position of the cursor in a result object. More...
 
 dbSchema ($schema=null)
 Get/set the db schema. More...
 
 decodeBlob ($b)
 Some DBMSs return a special placeholder object representing blob fields in result objects. More...
 
 decodeExpiry ($expiry, $format=TS_MW)
 Decode an expiry time into a DBMS independent format. More...
 
 delete ($table, $conds, $fname=__METHOD__)
 DELETE query wrapper. More...
 
 deleteJoin ($delTable, $joinTable, $delVar, $joinVar, $conds, $fname=__METHOD__)
 DELETE where the condition is a join. More...
 
 doAtomicSection ($fname, callable $callback)
 Run a callback to do an atomic set of updates for this database. More...
 
 doneWrites ()
 Returns true if the connection may have been used for write queries. More...
 
 encodeBlob ($b)
 Some DBMSs have a special format for inserting into blob fields, they don't allow simple quoted strings to be inserted. More...
 
 encodeExpiry ($expiry)
 Encode an expiry time into the DBMS dependent format. More...
 
 endAtomic ($fname=__METHOD__)
 Ends an atomic section of SQL statements. More...
 
 estimateRowCount ($table, $vars= '*', $conds= '', $fname=__METHOD__, $options=[])
 Estimate the number of rows in dataset. More...
 
 explicitTrxActive ()
 
 fetchObject ($res)
 Fetch the next row from the given result object, in object form. More...
 
 fetchRow ($res)
 Fetch the next row from the given result object, in associative array form. More...
 
 fieldExists ($table, $field, $fname=__METHOD__)
 Determines whether a field exists in a table. More...
 
 fieldInfo ($table, $field)
 mysql_fetch_field() wrapper Returns false if the field doesn't exist More...
 
 fieldName ($res, $n)
 Get a field name in a result object. More...
 
 flushSnapshot ($fname=__METHOD__)
 Commit any transaction but error out if writes or callbacks are pending. More...
 
 freeResult ($res)
 Free a result object returned by query() or select(). More...
 
 getDBname ()
 Get the current DB name. More...
 
 getDomainID ()
 
 getFlag ($flag)
 Returns a boolean whether the flag $flag is set for this connection. More...
 
 getInfinity ()
 Find out when 'infinity' is. More...
 
 getLag ()
 Get replica DB lag. More...
 
 getLBInfo ($name=null)
 Get properties passed down from the server info array of the load balancer. More...
 
 getMasterPos ()
 Get the position of this master. More...
 
 getReplicaPos ()
 Get the replication position of this replica DB. More...
 
 getScopedLockAndFlush ($lockKey, $fname, $timeout)
 Acquire a named lock, flush any transaction, and return an RAII style unlocker object. More...
 
 getSearchEngine ()
 
 getServer ()
 Get the server hostname or IP address. More...
 
 getServerInfo ()
 A string describing the current software version, and possibly other details in a user-friendly way. More...
 
 getServerUptime ()
 Determines how long the server has been up. More...
 
 getServerVersion ()
 A string describing the current software version, like from mysql_get_server_info(). More...
 
 getSessionLagStatus ()
 Get the replica DB lag when the current transaction started or a general lag estimate if not transaction is active. More...
 
 getSoftwareLink ()
 Returns a wikitext link to the DB's website, e.g., return "[http://www.mysql.com/ MySQL]"; Should at least contain plain text, if for some reason your database has no website. More...
 
 getType ()
 Get the type of the DBMS, as it appears in $wgDBtype. More...
 
 getWikiID ()
 Alias for getDomainID() More...
 
 implicitGroupby ()
 Returns true if this database does an implicit sort when doing GROUP BY. More...
 
 implicitOrderby ()
 Returns true if this database does an implicit order by when the column has an index For example: SELECT page_title FROM page LIMIT 1. More...
 
 indexExists ($table, $index, $fname=__METHOD__)
 Determines whether an index exists Usually throws a DBQueryError on failure If errors are explicitly ignored, returns NULL on failure. More...
 
 indexUnique ($table, $index)
 Determines if a given index is unique. More...
 
 insert ($table, $a, $fname=__METHOD__, $options=[])
 INSERT wrapper, inserts an array into a table. More...
 
 insertId ()
 Get the inserted value of an auto-increment row. More...
 
 insertSelect ($destTable, $srcTable, $varMap, $conds, $fname=__METHOD__, $insertOptions=[], $selectOptions=[])
 INSERT SELECT wrapper. More...
 
 isOpen ()
 Is a connection to the database open? More...
 
 isReadOnly ()
 
 lastDoneWrites ()
 Returns the last time the connection may have been used for write queries. More...
 
 lastErrno ()
 Get the last error number. More...
 
 lastError ()
 Get a description of the last error. More...
 
 lastQuery ()
 Return the last query that went through IDatabase::query() More...
 
 listTables ($prefix=null, $fname=__METHOD__)
 List all tables on the database. More...
 
 lock ($lockName, $method, $timeout=5)
 Acquire a named lock. More...
 
 lockIsFree ($lockName, $method)
 Check to see if a named lock is available (non-blocking) More...
 
 makeList ($a, $mode=self::LIST_COMMA)
 Makes an encoded list of strings from an array. More...
 
 makeWhereFrom2d ($data, $baseKey, $subKey)
 Build a partial where clause from a 2-d array such as used for LinkBatch. More...
 
 masterPosWait (DBMasterPos $pos, $timeout)
 Wait for the replica DB to catch up to a given master position. More...
 
 maxListLen ()
 Return the maximum number of items allowed in a list, or 0 for unlimited. More...
 
 namedLocksEnqueue ()
 Check to see if a named lock used by lock() use blocking queues. More...
 
 nextSequenceValue ($seqName)
 Returns an appropriately quoted sequence value for inserting a new row. More...
 
 numFields ($res)
 Get the number of fields in a result object. More...
 
 numRows ($res)
 Get the number of rows in a result object. More...
 
 onTransactionIdle (callable $callback, $fname=__METHOD__)
 Run a callback as soon as there is no transaction pending. More...
 
 onTransactionPreCommitOrIdle (callable $callback, $fname=__METHOD__)
 Run a callback before the current transaction commits or now if there is none. More...
 
 onTransactionResolution (callable $callback, $fname=__METHOD__)
 Run a callback as soon as the current transaction commits or rolls back. More...
 
 open ($server, $user, $password, $dbName)
 Open a connection to the database. More...
 
 pendingWriteCallers ()
 Get the list of method names that did write queries for this transaction. More...
 
 pendingWriteQueryDuration ($type=self::ESTIMATE_TOTAL)
 Get the time spend running write queries for this transaction. More...
 
 ping (&$rtt=null)
 Ping the server and try to reconnect if it there is no connection. More...
 
 query ($sql, $fname=__METHOD__, $tempIgnore=false)
 Run an SQL query and return the result. More...
 
 replace ($table, $uniqueIndexes, $rows, $fname=__METHOD__)
 REPLACE query wrapper. More...
 
 reportConnectionError ($error= 'Unknown error')
 
 reportQueryError ($error, $errno, $sql, $fname, $tempIgnore=false)
 Report a query error. More...
 
 restoreFlags ($state=self::RESTORE_PRIOR)
 Restore the flags to their prior state before the last setFlag/clearFlag call. More...
 
 rollback ($fname=__METHOD__, $flush= '')
 Rollback a transaction previously started using begin(). More...
 
 select ($table, $vars, $conds= '', $fname=__METHOD__, $options=[], $join_conds=[])
 Execute a SELECT query constructed using the various parameters provided. More...
 
 selectDB ($db)
 Change the current database. More...
 
 selectField ($table, $var, $cond= '', $fname=__METHOD__, $options=[])
 A SELECT wrapper which returns a single field from a single result row. More...
 
 selectFieldValues ($table, $var, $cond= '', $fname=__METHOD__, $options=[])
 A SELECT wrapper which returns a list of single field values from result rows. More...
 
 selectRow ($table, $vars, $conds, $fname=__METHOD__, $options=[], $join_conds=[])
 Single row SELECT wrapper. More...
 
 selectRowCount ($tables, $vars= '*', $conds= '', $fname=__METHOD__, $options=[], $join_conds=[])
 Get the number of rows in dataset. More...
 
 selectSQLText ($table, $vars, $conds= '', $fname=__METHOD__, $options=[], $join_conds=[])
 The equivalent of IDatabase::select() except that the constructed SQL is returned, instead of being immediately executed. More...
 
 serverIsReadOnly ()
 
 setBigSelects ($value=true)
 Allow or deny "big selects" for this session only. More...
 
 setFlag ($flag, $remember=self::REMEMBER_NOTHING)
 Set a flag for this connection. More...
 
 setLazyMasterHandle (IDatabase $conn)
 Set a lazy-connecting DB handle to the master DB (for replication status purposes) More...
 
 setLBInfo ($name, $value=null)
 Set the LB info array, or a member of it. More...
 
 setSchemaVars ($vars)
 Set variables to be used in sourceFile/sourceStream, in preference to the ones in $GLOBALS. More...
 
 setSessionOptions (array $options)
 Override database's default behavior. More...
 
 setTableAliases (array $aliases)
 Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name. More...
 
 setTransactionListener ($name, callable $callback=null)
 Run a callback each time any transaction commits or rolls back. More...
 
 startAtomic ($fname=__METHOD__)
 Begin an atomic section of statements. More...
 
 strreplace ($orig, $old, $new)
 Returns a comand for str_replace function in SQL query. More...
 
 tableExists ($table, $fname=__METHOD__)
 Query whether a given table exists. More...
 
 tablePrefix ($prefix=null)
 Get/set the table prefix. More...
 
 timestamp ($ts=0)
 Convert a timestamp in one of the formats accepted by wfTimestamp() to the format used for inserting into timestamp fields in this DBMS. More...
 
 timestampOrNull ($ts=null)
 Convert a timestamp in one of the formats accepted by wfTimestamp() to the format used for inserting into timestamp fields in this DBMS. More...
 
 trxLevel ()
 Gets the current transaction level. More...
 
 trxTimestamp ()
 Get the UNIX timestamp of the time that the transaction was established. More...
 
 unionQueries ($sqls, $all)
 Construct a UNION query This is used for providing overload point for other DB abstractions not compatible with the MySQL syntax. More...
 
 unionSupportsOrderAndLimit ()
 Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries within the UNION construct. More...
 
 unlock ($lockName, $method)
 Release a lock. More...
 
 update ($table, $values, $conds, $fname=__METHOD__, $options=[])
 UPDATE wrapper. More...
 
 upsert ($table, array $rows, array $uniqueIndexes, array $set, $fname=__METHOD__)
 INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table. More...
 
 wasDeadlock ()
 Determines if the last failure was due to a deadlock. More...
 
 wasErrorReissuable ()
 Determines if the last query error was due to a dropped connection and should be dealt with by pinging the connection and reissuing the query. More...
 
 wasLockTimeout ()
 Determines if the last failure was due to a lock timeout. More...
 
 wasReadOnlyError ()
 Determines if the last failure was due to the database being read-only. More...
 
 writesOrCallbacksPending ()
 Returns true if there is a transaction open with possible write queries or transaction pre-commit/idle callbacks waiting on it to finish. More...
 
 writesPending ()
 

Detailed Description

Advanced database interface for IDatabase handles that include maintenance methods.

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

Since
1.28

Definition at line 35 of file IMaintainableDatabase.php.

Member Function Documentation

IMaintainableDatabase::deadlockLoop ( )

Perform a deadlock-prone transaction.

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

Avoid using this method outside of Job or Maintenance classes.

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

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

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

Returns
mixed
Exceptions
DBUnexpectedError
Exception

Implemented in Database, and DatabaseSqlite.

IMaintainableDatabase::dropTable (   $tableName,
  $fName = __METHOD__ 
)

Delete a table.

Parameters
string$tableName
string$fName
Returns
bool|ResultWrapper

Implemented in Database, DatabaseMysqlBase, and DatabaseSqlite.

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

Lists all the VIEWs in the database.

Parameters
string$prefixOnly show VIEWs with this prefix, eg. unit_test_
string$fnameName of calling function
Exceptions
RuntimeException
Returns
array

Implemented in Database, and DatabaseMysqlBase.

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

Read and execute SQL commands from a file.

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

Parameters
string$filenameFile name to open
callable | null$lineCallbackOptional function called before reading each line
callable | null$resultCallbackOptional function called for each MySQL result
bool | string$fnameCalling function name or false if name should be generated dynamically using $filename
callable | null$inputCallbackOptional function called for each complete line sent
Returns
bool|string
Exceptions
Exception

Implemented in Database.

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

Read and execute commands from an open file handle.

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

Parameters
resource$fpFile handle
callable | null$lineCallbackOptional function called before reading each query
callable | null$resultCallbackOptional function called for each MySQL result
string$fnameCalling function name
callable | null$inputCallbackOptional function called for each complete query sent
Returns
bool|string

Implemented in Database.

IMaintainableDatabase::streamStatementEnd ( $sql,
$newLine 
)

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

Parameters
string&$sqlSQL assembled so far
string&$newLineNew line about to be added to $sql
Returns
bool Whether $newLine contains end of the statement

Implemented in Database, DatabasePostgres, and DatabaseMysqlBase.

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

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

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

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

Note
This function does not sanitize user input. It is not safe to use this function to escape user input.
Parameters
string$nameDatabase table name
string$formatOne of: quoted - Automatically pass the table name through addIdentifierQuotes() so that it can be used in a query. raw - Do not add identifier quotes to the table name
Returns
string Full database name

Implemented in Database, DatabasePostgres, and DatabaseSqlite.

IMaintainableDatabase::tableNames ( )

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

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

Returns
array

Implemented in Database.

IMaintainableDatabase::tableNamesN ( )

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

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

Returns
array

Implemented in Database.

IMaintainableDatabase::textFieldSize (   $table,
  $field 
)

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

Parameters
string$table
string$field
Returns
int

Implemented in Database, DatabasePostgres, and DatabaseSqlite.


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