QSqlDriver

Synopsis

Functions

• def isIdentifierEscaped (identifier, type)
• def isOpenError ()
• def lastError ()
• def numericalPrecisionPolicy ()
• def setNumericalPrecisionPolicy (precisionPolicy)
• def stripDelimiters (identifier, type)
• def subscribeToNotification (name)
• def subscribedToNotifications ()
• def unsubscribeFromNotification (name)

Virtual functions

• def beginTransaction ()
• def close ()
• def commitTransaction ()
• def createResult ()
• def escapeIdentifier (identifier, type)
• def formatValue (field[, trimStrings=false])
• def hasFeature (f)
• def isOpen ()
• def open (db[, user=”“[, password=”“[, host=”“[, port=-1[, connOpts=”“]]]]])
• def primaryIndex (tableName)
• def record (tableName)
• def rollbackTransaction ()
• def setLastError (e)
• def setOpen (o)
• def setOpenError (e)
• def sqlStatement (type, tableName, rec, preparedStatement)
• def tables (tableType)

Slots

• def isIdentifierEscapedImplementation (identifier, type)
• def stripDelimitersImplementation (identifier, type)
• def subscribeToNotificationImplementation (name)
• def subscribedToNotificationsImplementation ()
• def unsubscribeFromNotificationImplementation (name)

Signals

• def notification (name)

Detailed Description

The PySide.QtSql.QSqlDriver class is an abstract base class for accessing specific SQL databases.

This class should not be used directly. Use PySide.QtSql.QSqlDatabase instead.

If you want to create your own SQL drivers, you can subclass this class and reimplement its pure virtual functions and those virtual functions that you need. See How to Write Your Own Database Driver for more information.

See also

PySide.QtSql.QSqlDatabase PySide.QtSql.QSqlResult

class PySide.QtSql.QSqlDriver([parent=None])

Parameters:parent – PySide.QtCore.QObject

Constructs a new driver with the given parent .

PySide.QtSql.QSqlDriver.StatementType

This enum contains a list of SQL statement (or clause) types the driver can create.

Constant	Description
QSqlDriver.WhereStatement	An SQL WHERE statement (e.g., WHERE f = 5).
QSqlDriver.SelectStatement	An SQL SELECT statement (e.g., SELECT f FROM t).
QSqlDriver.UpdateStatement	An SQL UPDATE statement (e.g., UPDATE TABLE t set f = 1).
QSqlDriver.InsertStatement	An SQL INSERT statement (e.g., INSERT INTO t (f) values (1)).
QSqlDriver.DeleteStatement	An SQL DELETE statement (e.g., DELETE FROM t).

See also

PySide.QtSql.QSqlDriver.sqlStatement()

PySide.QtSql.QSqlDriver.IdentifierType

This enum contains a list of SQL identifier types.

Constant	Description
QSqlDriver.FieldName	A SQL field name
QSqlDriver.TableName	A SQL table name

PySide.QtSql.QSqlDriver.DriverFeature

This enum contains a list of features a driver might support. Use PySide.QtSql.QSqlDriver.hasFeature() to query whether a feature is supported or not.

Constant	Description
QSqlDriver.Transactions	Whether the driver supports SQL transactions.
QSqlDriver.QuerySize	Whether the database is capable of reporting the size of a query. Note that some databases do not support returning the size (i.e. number of rows returned) of a query, in which case QSqlQuery.size() will return -1.
QSqlDriver.BLOB	Whether the driver supports Binary Large Object fields.
QSqlDriver.Unicode	Whether the driver supports Unicode strings if the database server does.
QSqlDriver.PreparedQueries	Whether the driver supports prepared query execution.
QSqlDriver.NamedPlaceholders	Whether the driver supports the use of named placeholders.
QSqlDriver.PositionalPlaceholders	Whether the driver supports the use of positional placeholders.
QSqlDriver.LastInsertId	Whether the driver supports returning the Id of the last touched row.
QSqlDriver.BatchOperations	Whether the driver supports batched operations, see QSqlQuery.execBatch()
QSqlDriver.SimpleLocking	Whether the driver disallows a write lock on a table while other queries have a read lock on it.
QSqlDriver.LowPrecisionNumbers	Whether the driver allows fetching numerical values with low precision.
QSqlDriver.EventNotifications	Whether the driver supports database event notifications.
QSqlDriver.FinishQuery	Whether the driver can do any low-level resource cleanup when QSqlQuery.finish() is called.
QSqlDriver.MultipleResultSets	Whether the driver can access multiple result sets returned from batched statements or stored procedures.

More information about supported features can be found in the Qt SQL driver documentation.

See also

PySide.QtSql.QSqlDriver.hasFeature()

PySide.QtSql.QSqlDriver.beginTransaction()

Return type:PySide.QtCore.bool

This function is called to begin a transaction. If successful, return true, otherwise return false. The default implementation does nothing and returns false.

See also

PySide.QtSql.QSqlDriver.commitTransaction() PySide.QtSql.QSqlDriver.rollbackTransaction()

PySide.QtSql.QSqlDriver.close()

Derived classes must reimplement this pure virtual function in order to close the database connection. Return true on success, false on failure.

See also

PySide.QtSql.QSqlDriver.open() PySide.QtSql.QSqlDriver.setOpen()

PySide.QtSql.QSqlDriver.commitTransaction()

Return type:PySide.QtCore.bool

This function is called to commit a transaction. If successful, return true, otherwise return false. The default implementation does nothing and returns false.

See also

PySide.QtSql.QSqlDriver.beginTransaction() PySide.QtSql.QSqlDriver.rollbackTransaction()

PySide.QtSql.QSqlDriver.createResult()

Return type:PySide.QtSql.QSqlResult

Creates an empty SQL result on the database. Derived classes must reimplement this function and return a PySide.QtSql.QSqlResult object appropriate for their database to the caller.

PySide.QtSql.QSqlDriver.escapeIdentifier(identifier, type)

Parameters:

• identifier – unicode
• type – PySide.QtSql.QSqlDriver.IdentifierType

Return type:

unicode

Returns the identifier escaped according to the database rules. identifier can either be a table name or field name, dependent on type .

The default implementation does nothing.

See also

PySide.QtSql.QSqlDriver.isIdentifierEscaped()

PySide.QtSql.QSqlDriver.formatValue(field[, trimStrings=false])

Parameters:

• field – PySide.QtSql.QSqlField
• trimStrings – PySide.QtCore.bool

Return type:

unicode

Returns a string representation of the field value for the database. This is used, for example, when constructing INSERT and UPDATE statements.

The default implementation returns the value formatted as a string according to the following rules:

• If field is character data, the value is returned enclosed in single quotation marks, which is appropriate for many SQL databases. Any embedded single-quote characters are escaped (replaced with two single-quote characters). If trimStrings is true (the default is false), all trailing whitespace is trimmed from the field.
• If field is date/time data, the value is formatted in ISO format and enclosed in single quotation marks. If the date/time data is invalid, “NULL” is returned.
• If field is bytearray data, and the driver can edit binary fields, the value is formatted as a hexadecimal string.
• For any other field type, toString() is called on its value and the result of this is returned.

See also

QVariant.toString()

PySide.QtSql.QSqlDriver.hasFeature(f)

Parameters:f – PySide.QtSql.QSqlDriver.DriverFeature Return type:PySide.QtCore.bool

Returns true if the driver supports feature feature ; otherwise returns false.

Note that some databases need to be PySide.QtSql.QSqlDriver.open() before this can be determined.

See also

QSqlDriver.DriverFeature

PySide.QtSql.QSqlDriver.isIdentifierEscaped(identifier, type)

Parameters:

• identifier – unicode
• type – PySide.QtSql.QSqlDriver.IdentifierType

Return type:

PySide.QtCore.bool

Returns whether identifier is escaped according to the database rules. identifier can either be a table name or field name, dependent on type .

Warning

Because of binary compatibility constraints, this function is not virtual. If you want to provide your own implementation in your PySide.QtSql.QSqlDriver subclass, reimplement the PySide.QtSql.QSqlDriver.isIdentifierEscapedImplementation() slot in your subclass instead. The isIdentifierEscapedFunction() will dynamically detect the slot and call it.

See also

PySide.QtSql.QSqlDriver.stripDelimiters() PySide.QtSql.QSqlDriver.escapeIdentifier()

PySide.QtSql.QSqlDriver.isIdentifierEscapedImplementation(identifier, type)

Parameters:

• identifier – unicode
• type – PySide.QtSql.QSqlDriver.IdentifierType

Return type:

PySide.QtCore.bool

This slot returns whether identifier is escaped according to the database rules. identifier can either be a table name or field name, dependent on type .

Because of binary compatibility constraints, PySide.QtSql.QSqlDriver.isIdentifierEscaped() function (introduced in Qt 4.5) is not virtual. Instead, PySide.QtSql.QSqlDriver.isIdentifierEscaped() will dynamically detect and call this slot. The default implementation assumes the escape/delimiter character is a double quote. Reimplement this slot in your own PySide.QtSql.QSqlDriver if your database engine uses a different delimiter character.

See also

PySide.QtSql.QSqlDriver.isIdentifierEscaped()

PySide.QtSql.QSqlDriver.isOpen()

Return type:PySide.QtCore.bool

Returns true if the database connection is open; otherwise returns false.

PySide.QtSql.QSqlDriver.isOpenError()

Return type:PySide.QtCore.bool

Returns true if the there was an error opening the database connection; otherwise returns false.

PySide.QtSql.QSqlDriver.lastError()

Return type:PySide.QtSql.QSqlError

Returns a PySide.QtSql.QSqlError object which contains information about the last error that occurred on the database.

See also

PySide.QtSql.QSqlDriver.setLastError()

PySide.QtSql.QSqlDriver.notification(name)

Parameters:name – unicode

PySide.QtSql.QSqlDriver.numericalPrecisionPolicy()

Return type:PySide.QtSql.QSql.NumericalPrecisionPolicy

Returns the current default precision policy for the database connection.

See also

QSql.NumericalPrecisionPolicy PySide.QtSql.QSqlDriver.setNumericalPrecisionPolicy() QSqlQuery.numericalPrecisionPolicy() QSqlQuery.setNumericalPrecisionPolicy()

PySide.QtSql.QSqlDriver.open(db[, user=""[, password=""[, host=""[, port=-1[, connOpts=""]]]]])

Parameters:

• db – unicode
• user – unicode
• password – unicode
• host – unicode
• port – PySide.QtCore.int
• connOpts – unicode

Return type:

PySide.QtCore.bool

Derived classes must reimplement this pure virtual function to open a database connection on database db , using user name user , password password , host host , port port and connection options options .

The function must return true on success and false on failure.

See also

PySide.QtSql.QSqlDriver.setOpen()

PySide.QtSql.QSqlDriver.primaryIndex(tableName)

Parameters:tableName – unicode Return type:PySide.QtSql.QSqlIndex

Returns the primary index for table tableName . Returns an empty PySide.QtSql.QSqlIndex if the table doesn’t have a primary index. The default implementation returns an empty index.

PySide.QtSql.QSqlDriver.record(tableName)

Parameters:tableName – unicode Return type:PySide.QtSql.QSqlRecord

Returns a PySide.QtSql.QSqlRecord populated with the names of the fields in table tableName . If no such table exists, an empty record is returned. The default implementation returns an empty record.

PySide.QtSql.QSqlDriver.rollbackTransaction()

Return type:PySide.QtCore.bool

This function is called to rollback a transaction. If successful, return true, otherwise return false. The default implementation does nothing and returns false.

See also

PySide.QtSql.QSqlDriver.beginTransaction() PySide.QtSql.QSqlDriver.commitTransaction()

PySide.QtSql.QSqlDriver.setLastError(e)

Parameters:e – PySide.QtSql.QSqlError

This function is used to set the value of the last error, error , that occurred on the database.

See also

PySide.QtSql.QSqlDriver.lastError()

PySide.QtSql.QSqlDriver.setNumericalPrecisionPolicy(precisionPolicy)

Parameters:precisionPolicy – PySide.QtSql.QSql.NumericalPrecisionPolicy

PySide.QtSql.QSqlDriver.setOpen(o)

Parameters:o – PySide.QtCore.bool

This function sets the open state of the database to open . Derived classes can use this function to report the status of PySide.QtSql.QSqlDriver.open() .

See also

PySide.QtSql.QSqlDriver.open() PySide.QtSql.QSqlDriver.setOpenError()

PySide.QtSql.QSqlDriver.setOpenError(e)

Parameters:e – PySide.QtCore.bool

This function sets the open error state of the database to error . Derived classes can use this function to report the status of PySide.QtSql.QSqlDriver.open() . Note that if error is true the open state of the database is set to closed (i.e., PySide.QtSql.QSqlDriver.isOpen() returns false).

See also

PySide.QtSql.QSqlDriver.isOpenError() PySide.QtSql.QSqlDriver.open() PySide.QtSql.QSqlDriver.setOpen()

PySide.QtSql.QSqlDriver.sqlStatement(type, tableName, rec, preparedStatement)

Parameters:

• type – PySide.QtSql.QSqlDriver.StatementType
• tableName – unicode
• rec – PySide.QtSql.QSqlRecord
• preparedStatement – PySide.QtCore.bool

Return type:

unicode

Returns a SQL statement of type type for the table tableName with the values from rec . If preparedStatement is true, the string will contain placeholders instead of values.

This method can be used to manipulate tables without having to worry about database-dependent SQL dialects. For non-prepared statements, the values will be properly escaped.

PySide.QtSql.QSqlDriver.stripDelimiters(identifier, type)

Parameters:

• identifier – unicode
• type – PySide.QtSql.QSqlDriver.IdentifierType

Return type:

unicode

Returns the identifier with the leading and trailing delimiters removed, identifier can either be a table name or field name, dependent on type . If identifier does not have leading and trailing delimiter characters, identifier is returned without modification.

Warning

Because of binary compatibility constraints, this function is not virtual, If you want to provide your own implementation in your PySide.QtSql.QSqlDriver subclass, reimplement the PySide.QtSql.QSqlDriver.stripDelimitersImplementation() slot in your subclass instead. The PySide.QtSql.QSqlDriver.stripDelimiters() function will dynamically detect the slot and call it.

See also

PySide.QtSql.QSqlDriver.isIdentifierEscaped()

PySide.QtSql.QSqlDriver.stripDelimitersImplementation(identifier, type)

Parameters:

• identifier – unicode
• type – PySide.QtSql.QSqlDriver.IdentifierType

Return type:

unicode

This slot returns identifier with the leading and trailing delimiters removed, identifier can either be a tablename or field name, dependent on type . If identifier does not have leading and trailing delimiter characters, identifier is returned without modification.

Because of binary compatibility constraints, the PySide.QtSql.QSqlDriver.stripDelimiters() function (introduced in Qt 4.5) is not virtual. Instead, PySide.QtSql.QSqlDriver.stripDelimiters() will dynamically detect and call this slot. It generally unnecessary to reimplement this slot.

See also

PySide.QtSql.QSqlDriver.stripDelimiters()

PySide.QtSql.QSqlDriver.subscribeToNotification(name)

Parameters:name – unicode Return type:PySide.QtCore.bool

This function is called to subscribe to event notifications from the database. name identifies the event notification.

If successful, return true, otherwise return false.

The database must be open when this function is called. When the database is closed by calling PySide.QtSql.QSqlDriver.close() all subscribed event notifications are automatically unsubscribed. Note that calling PySide.QtSql.QSqlDriver.open() on an already open database may implicitly cause PySide.QtSql.QSqlDriver.close() to be called, which will cause the driver to unsubscribe from all event notifications.

When an event notification identified by name is posted by the database the PySide.QtSql.QSqlDriver.notification() signal is emitted.

Warning

Because of binary compatibility constraints, this function is not virtual. If you want to provide event notification support in your own PySide.QtSql.QSqlDriver subclass, reimplement the PySide.QtSql.QSqlDriver.subscribeToNotificationImplementation() slot in your subclass instead. The PySide.QtSql.QSqlDriver.subscribeToNotification() function will dynamically detect the slot and call it.

See also

PySide.QtSql.QSqlDriver.unsubscribeFromNotification() PySide.QtSql.QSqlDriver.subscribedToNotifications() QSqlDriver.hasFeature()

PySide.QtSql.QSqlDriver.subscribeToNotificationImplementation(name)

Parameters:name – unicode Return type:PySide.QtCore.bool

This slot is called to subscribe to event notifications from the database. name identifies the event notification.

If successful, return true, otherwise return false.

The database must be open when this slot is called. When the database is closed by calling PySide.QtSql.QSqlDriver.close() all subscribed event notifications are automatically unsubscribed. Note that calling PySide.QtSql.QSqlDriver.open() on an already open database may implicitly cause PySide.QtSql.QSqlDriver.close() to be called, which will cause the driver to unsubscribe from all event notifications.

When an event notification identified by name is posted by the database the PySide.QtSql.QSqlDriver.notification() signal is emitted.

Reimplement this slot to provide your own PySide.QtSql.QSqlDriver subclass with event notification support; because of binary compatibility constraints, the PySide.QtSql.QSqlDriver.subscribeToNotification() function (introduced in Qt 4.4) is not virtual. Instead, PySide.QtSql.QSqlDriver.subscribeToNotification() will dynamically detect and call this slot. The default implementation does nothing and returns false.

See also

PySide.QtSql.QSqlDriver.subscribeToNotification()

PySide.QtSql.QSqlDriver.subscribedToNotifications()

Return type:list of strings

Returns a list of the names of the event notifications that are currently subscribed to.

Warning

Because of binary compatibility constraints, this function is not virtual. If you want to provide event notification support in your own PySide.QtSql.QSqlDriver subclass, reimplement the PySide.QtSql.QSqlDriver.subscribedToNotificationsImplementation() slot in your subclass instead. The PySide.QtSql.QSqlDriver.subscribedToNotifications() function will dynamically detect the slot and call it.

See also

PySide.QtSql.QSqlDriver.subscribeToNotification() PySide.QtSql.QSqlDriver.unsubscribeFromNotification()

PySide.QtSql.QSqlDriver.subscribedToNotificationsImplementation()

Return type:list of strings

Returns a list of the names of the event notifications that are currently subscribed to.

Reimplement this slot to provide your own PySide.QtSql.QSqlDriver subclass with event notification support; because of binary compatibility constraints, the PySide.QtSql.QSqlDriver.subscribedToNotifications() function (introduced in Qt 4.4) is not virtual. Instead, PySide.QtSql.QSqlDriver.subscribedToNotifications() will dynamically detect and call this slot. The default implementation simply returns an empty PySide.QtCore.QStringList .

See also

PySide.QtSql.QSqlDriver.subscribedToNotifications()

PySide.QtSql.QSqlDriver.tables(tableType)

Parameters:tableType – PySide.QtSql.QSql.TableType Return type:list of strings

PySide.QtSql.QSqlDriver.unsubscribeFromNotification(name)

Parameters:name – unicode Return type:PySide.QtCore.bool

This function is called to unsubscribe from event notifications from the database. name identifies the event notification.

If successful, return true, otherwise return false.

The database must be open when this function is called. All subscribed event notifications are automatically unsubscribed from when the PySide.QtSql.QSqlDriver.close() function is called.

After calling this function the PySide.QtSql.QSqlDriver.notification() signal will no longer be emitted when an event notification identified by name is posted by the database.

Warning

Because of binary compatibility constraints, this function is not virtual. If you want to provide event notification support in your own PySide.QtSql.QSqlDriver subclass, reimplement the PySide.QtSql.QSqlDriver.unsubscribeFromNotificationImplementation() slot in your subclass instead. The PySide.QtSql.QSqlDriver.unsubscribeFromNotification() function will dynamically detect the slot and call it.

See also

PySide.QtSql.QSqlDriver.subscribeToNotification() PySide.QtSql.QSqlDriver.subscribedToNotifications()

PySide.QtSql.QSqlDriver.unsubscribeFromNotificationImplementation(name)

Parameters:name – unicode Return type:PySide.QtCore.bool

This slot is called to unsubscribe from event notifications from the database. name identifies the event notification.

If successful, return true, otherwise return false.

The database must be open when this slot is called. All subscribed event notifications are automatically unsubscribed from when the PySide.QtSql.QSqlDriver.close() function is called.

After calling this slot the PySide.QtSql.QSqlDriver.notification() signal will no longer be emitted when an event notification identified by name is posted by the database.

Reimplement this slot to provide your own PySide.QtSql.QSqlDriver subclass with event notification support; because of binary compatibility constraints, the PySide.QtSql.QSqlDriver.unsubscribeFromNotification() function (introduced in Qt 4.4) is not virtual. Instead, PySide.QtSql.QSqlDriver.unsubscribeFromNotification() will dynamically detect and call this slot. The default implementation does nothing and returns false.

See also

PySide.QtSql.QSqlDriver.unsubscribeFromNotification()