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

#include <qsqldriver.h>

Inheritance diagram for QSqlDriver:

Collaboration diagram for QSqlDriver:

Public Types
enum	DriverFeature { Transactions , QuerySize , BLOB , Unicode , PreparedQueries , NamedPlaceholders , PositionalPlaceholders , LastInsertId , BatchOperations , SimpleLocking , LowPrecisionNumbers , EventNotifications , FinishQuery , MultipleResultSets , CancelQuery }
	This enum contains a list of features a driver might support. More...

enum	StatementType { WhereStatement , SelectStatement , UpdateStatement , InsertStatement , DeleteStatement }
	This enum contains a list of SQL statement (or clause) types the driver can create. More...

enum	IdentifierType { FieldName , TableName }
	This enum contains a list of SQL identifier types. More...

enum	NotificationSource { UnknownSource , SelfSource , OtherSource }
	This enum contains a list of SQL notification sources. More...

enum	DbmsType { UnknownDbms , MSSqlServer , MySqlServer , PostgreSQL , Oracle , Sybase , SQLite , Interbase , DB2 , MimerSQL }

Public Slots
virtual bool	cancelQuery ()

Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals
void	notification (const QString &name, QSqlDriver::NotificationSource source, const QVariant &payload)

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QSqlDriver (QObject *parent=nullptr)
	Constructs a new driver with the given parent.

	~QSqlDriver ()
	Destroys the object and frees any allocated resources.

virtual bool	isOpen () const
	Returns `true` if the database connection is open; otherwise returns false.

bool	isOpenError () const
	Returns `true` if the there was an error opening the database connection; otherwise returns `false`.

virtual bool	beginTransaction ()
	This function is called to begin a transaction.

virtual bool	commitTransaction ()
	This function is called to commit a transaction.

virtual bool	rollbackTransaction ()
	This function is called to rollback a transaction.

virtual QStringList	tables (QSql::TableType tableType) const
	Returns a list of the names of the tables in the database.

virtual QSqlIndex	primaryIndex (const QString &tableName) const
	Returns the primary index for table tableName.

virtual QSqlRecord	record (const QString &tableName) const
	Returns a QSqlRecord populated with the names of the fields in table tableName.

virtual QString	formatValue (const QSqlField &field, bool trimStrings=false) const
	Returns a string representation of the field value for the database.

virtual QString	escapeIdentifier (const QString &identifier, IdentifierType type) const
	Returns the identifier escaped according to the database rules.

virtual QString	sqlStatement (StatementType type, const QString &tableName, const QSqlRecord &rec, bool preparedStatement) const
	Returns a SQL statement of type type for the table tableName with the values from rec.

QSqlError	lastError () const
	Returns a QSqlError object which contains information about the last error that occurred on the database.

virtual QVariant	handle () const
	Returns the low-level database handle wrapped in a QVariant or an invalid variant if there is no handle.

virtual bool	hasFeature (DriverFeature f) const =0
	Returns `true` if the driver supports feature feature; otherwise returns `false`.

virtual void	close ()=0
	Derived classes must reimplement this pure virtual function in order to close the database connection.

virtual QSqlResult *	createResult () const =0
	Creates an empty SQL result on the database.

virtual bool	open (const QString &db, const QString &user=QString(), const QString &password=QString(), const QString &host=QString(), int port=-1, const QString &connOpts=QString())=0
	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.

virtual bool	subscribeToNotification (const QString &name)
	This function is called to subscribe to event notifications from the database.

virtual bool	unsubscribeFromNotification (const QString &name)
	This function is called to unsubscribe from event notifications from the database.

virtual QStringList	subscribedToNotifications () const
	Returns a list of the names of the event notifications that are currently subscribed to.

virtual bool	isIdentifierEscaped (const QString &identifier, IdentifierType type) const
	Returns whether identifier is escaped according to the database rules.

virtual QString	stripDelimiters (const QString &identifier, IdentifierType type) const
	Returns the identifier with the leading and trailing delimiters removed, identifier can either be a table name or field name, dependent on type.

void	setNumericalPrecisionPolicy (QSql::NumericalPrecisionPolicy precisionPolicy)
	Sets \l numericalPrecisionPolicy to precisionPolicy.

QSql::NumericalPrecisionPolicy	numericalPrecisionPolicy () const
	Returns the \l numericalPrecisionPolicy.

DbmsType	dbmsType () const

virtual int	maximumIdentifierLength (IdentifierType type) const

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

virtual bool	eventFilter (QObject watched, QEvent event)
	Filters events if this object has been installed as an event filter for the watched object.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Protected Member Functions
	QSqlDriver (QSqlDriverPrivate &dd, QObject *parent=nullptr)

virtual void	setOpen (bool o)
	This function sets the open state of the database to open.

virtual void	setOpenError (bool e)
	This function sets the open error state of the database to error.

virtual void	setLastError (const QSqlError &e)
	This function is used to set the value of the last error, error, that occurred on the database.

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Properties
QSql::NumericalPrecisionPolicy	numericalPrecisionPolicy

Properties inherited from QObject
QString	objectName
	the name of this object

Friends
class	QSqlDatabase

class	QSqlResultPrivate

Additional Inherited Members
Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

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

\inmodule QtSql

This class should not be used directly. Use 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 \l{How to Write Your Own Database Driver} for more information.

See also: QSqlDatabase, QSqlResult

Definition at line 25 of file qsqldriver.h.

Member Enumeration Documentation

◆ DbmsType

enum QSqlDriver::DbmsType

This enum contains DBMS types.

\value UnknownDbms \value MSSqlServer \value MySqlServer \value PostgreSQL \value Oracle \value Sybase \value SQLite \value Interbase \value DB2 \value [since 6.6] MimerSQL

Enumerator
UnknownDbms
MSSqlServer
MySqlServer
PostgreSQL
Oracle
Sybase
SQLite
Interbase
DB2
MimerSQL

Definition at line 45 of file qsqldriver.h.

◆ DriverFeature

enum QSqlDriver::DriverFeature

This enum contains a list of features a driver might support.

Use hasFeature() to query whether a feature is supported or not.

\value Transactions Whether the driver supports SQL transactions. \value 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. \value BLOB Whether the driver supports Binary Large Object fields. \value Unicode Whether the driver supports Unicode strings if the database server does. \value PreparedQueries Whether the driver supports prepared query execution. \value NamedPlaceholders Whether the driver supports the use of named placeholders. \value PositionalPlaceholders Whether the driver supports the use of positional placeholders. \value LastInsertId Whether the driver supports returning the Id of the last touched row. \value BatchOperations Whether the driver supports batched operations, see QSqlQuery::execBatch() \value SimpleLocking Whether the driver disallows a write lock on a table while other queries have a read lock on it. \value LowPrecisionNumbers Whether the driver allows fetching numerical values with low precision. \value EventNotifications Whether the driver supports database event notifications. \value FinishQuery Whether the driver can do any low-level resource cleanup when QSqlQuery::finish() is called. \value MultipleResultSets Whether the driver can access multiple result sets returned from batched statements or stored procedures. \value CancelQuery Whether the driver allows cancelling a running query.

More information about supported features can be found in the \l{sql-driver.html}{Qt SQL driver} documentation.

See also: hasFeature()

Enumerator
Transactions
QuerySize
BLOB
Unicode
PreparedQueries
NamedPlaceholders
PositionalPlaceholders
LastInsertId
BatchOperations
SimpleLocking
LowPrecisionNumbers
EventNotifications
FinishQuery
MultipleResultSets
CancelQuery

Definition at line 33 of file qsqldriver.h.

◆ IdentifierType

enum QSqlDriver::IdentifierType

This enum contains a list of SQL identifier types.

\value FieldName A SQL field name \value TableName A SQL table name

Enumerator
FieldName
TableName

Definition at line 41 of file qsqldriver.h.

◆ NotificationSource

enum QSqlDriver::NotificationSource

This enum contains a list of SQL notification sources.

\value UnknownSource The notification source is unknown \value SelfSource The notification source is this connection \value OtherSource The notification source is another connection

Enumerator
UnknownSource
SelfSource
OtherSource

Definition at line 43 of file qsqldriver.h.

◆ StatementType

enum QSqlDriver::StatementType

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

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

See also: sqlStatement()

Enumerator
WhereStatement
SelectStatement
UpdateStatement
InsertStatement
DeleteStatement

Definition at line 38 of file qsqldriver.h.

Constructor & Destructor Documentation

◆ QSqlDriver() [1/2]

QSqlDriver::QSqlDriver ( QObject * parent = nullptr )

explicit

Constructs a new driver with the given parent.

Definition at line 51 of file qsqldriver.cpp.

◆ ~QSqlDriver()

QSqlDriver::~QSqlDriver ( )

Destroys the object and frees any allocated resources.

Definition at line 67 of file qsqldriver.cpp.

◆ QSqlDriver() [2/2]

QSqlDriver::QSqlDriver	(	QSqlDriverPrivate &	dd,
		QObject *	parent = nullptr )

protected

Definition at line 58 of file qsqldriver.cpp.

Member Function Documentation

◆ beginTransaction()

bool QSqlDriver::beginTransaction ( )

virtual

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: commitTransaction(), rollbackTransaction()

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 272 of file qsqldriver.cpp.

Referenced by QSqlDatabase::transaction().

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◆ cancelQuery

bool QSqlDriver::cancelQuery ( )

virtualslot

Since: 5.0

Tries to cancel the running query, if the underlying driver has the capability to cancel queries. Returns true on success, otherwise false.

This function can be called from a different thread.

If you use this function as a slot, you need to use a Qt::DirectConnection from a different thread.

Reimplement this function to support canceling running queries in your own QSqlDriver subclass. It must be implemented in a thread-safe manner.

See also: QSqlDriver::hasFeature()

Definition at line 784 of file qsqldriver.cpp.

◆ close()

bool QSqlDriver::close ( )

pure virtual

Derived classes must reimplement this pure virtual function in order to close the database connection.

Return true on success, false on failure.

See also: open(), setOpen()

Implemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, QSQLiteDriver, XyzDriver, and QSqlNullDriver.

Referenced by QSqlDatabase::close().

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◆ commitTransaction()

bool QSqlDriver::commitTransaction ( )

virtual

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: beginTransaction(), rollbackTransaction()

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 285 of file qsqldriver.cpp.

Referenced by QSqlDatabase::commit().

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◆ createResult()

QSqlResult * QSqlDriver::createResult ( ) const

pure virtual

Creates an empty SQL result on the database.

Derived classes must reimplement this function and return a QSqlResult object appropriate for their database to the caller.

Implemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, QSQLiteDriver, XyzDriver, and QSqlNullDriver.

Referenced by qInit().

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◆ dbmsType()

QSqlDriver::DbmsType QSqlDriver::dbmsType ( ) const

Since: 5.4

Returns the current DBMS type for the database connection.

Definition at line 760 of file qsqldriver.cpp.

References d.

Referenced by QSqlResultPrivate::namedToPositionalBinding(), and QSqlResultPrivate::positionalToNamedBinding().

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◆ escapeIdentifier()

QString QSqlDriver::escapeIdentifier	(	const QString &	identifier,
		IdentifierType	type ) const

virtual

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: isIdentifierEscaped()

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QODBCDriver, QPSQLDriver, QSQLiteDriver, and QOCIDriver.

Definition at line 374 of file qsqldriver.cpp.

Referenced by prepareIdentifier().

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◆ formatValue()

QString QSqlDriver::formatValue	(	const QSqlField &	field,
		bool	trimStrings = false ) const

virtual

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:

\list

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 \l{QByteArray}{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.

\endlist

See also: QVariant::toString()

Reimplemented in QDB2Driver, QIBaseDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, and QPSQLDriver.

Definition at line 559 of file qsqldriver.cpp.

References ba, BLOB, hasFeature(), QMetaType::id(), QSqlField::isNull(), Qt::ISODate, QDate::isValid(), QTime::isValid(), QDateTime::isValid(), QSqlField::metaType, QString::number(), Q_FALLTHROUGH, QByteArray::reserve(), QByteArray::size(), QString::size(), QVariant::toBool(), QVariant::toByteArray(), QVariant::toDate(), QVariant::toDateTime(), QtMiscUtils::toHexLower(), QVariant::toString(), QVariant::toTime(), QVariant::userType(), and QSqlField::value.

Referenced by QSqlResult::exec(), QDB2Driver::formatValue(), QIBaseDriver::formatValue(), QMYSQLDriver::formatValue(), QOCIDriver::formatValue(), QODBCDriver::formatValue(), QPSQLDriver::formatValue(), qCreateParamString(), and sqlStatement().

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◆ handle()

QVariant QSqlDriver::handle ( ) const

virtual

Returns the low-level database handle wrapped in a QVariant or an invalid variant if there is no handle.

Warning: Use this with uttermost care and only if you know what you're doing.; The handle returned here can become a stale pointer if the connection is modified (for example, if you close the connection).; The handle can be NULL if the connection is not open yet.

The handle returned here is database-dependent, you should query the type name of the variant before accessing it.

This example retrieves the handle for a connection to sqlite:

QSqlDatabase db = QSqlDatabase::database();
QVariant v = db.driver()->handle();
if (v.isValid() && (qstrcmp(v.typeName(), "sqlite3*") == 0)) {
    // v.data() returns a pointer to the handle
    sqlite3 *handle = *static_cast<sqlite3 **>(v.data());
    if (handle) {
        // ...
    }
}

This snippet returns the handle for PostgreSQL or MySQL:

if (qstrcmp(v.typeName(), "PGconn*") == 0) {
    PGconn *handle = *static_cast<PGconn **>(v.data());
    if (handle) {
        // ...
    }
}
 
if (qstrcmp(v.typeName(), "MYSQL*") == 0) {
    MYSQL *handle = *static_cast<MYSQL **>(v.data());
    if (handle) {
        // ...
    }
}

See also: QSqlResult::handle()

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 660 of file qsqldriver.cpp.

◆ hasFeature()

bool QSqlDriver::hasFeature ( DriverFeature feature ) const

pure virtual

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

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

See also: DriverFeature

Implemented in QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, QSQLiteDriver, QDB2Driver, XyzDriver, and QSqlNullDriver.

Referenced by QSqlDatabase::commit(), QSqlTableModelPrivate::exec(), formatValue(), QSqlDatabase::rollback(), and QSqlDatabase::transaction().

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◆ isIdentifierEscaped()

bool QSqlDriver::isIdentifierEscaped	(	const QString &	identifier,
		IdentifierType	type ) const

virtual

Returns whether identifier is escaped according to the database rules.

identifier can either be a table name or field name, dependent on type.

Reimplement this function if you want to provide your own implementation in your QSqlDriver subclass,

See also: stripDelimiters(), escapeIdentifier()

Reimplemented in QMYSQLDriver, QODBCDriver, and QSQLiteDriver.

Definition at line 389 of file qsqldriver.cpp.

References QString::endsWith(), Q_UNUSED, QString::size(), and QString::startsWith().

Referenced by QOCIDriver::escapeIdentifier(), QRelation::populateDictionary(), prepareIdentifier(), QDB2Driver::primaryIndex(), QMimerSQLDriver::primaryIndex(), QOCIDriver::primaryIndex(), QDB2Driver::record(), QMimerSQLDriver::record(), QOCIDriver::record(), stripDelimiters(), QSqlTableModelPrivate::strippedFieldName(), QDB2Driver::tables(), and QOCIDriver::tables().

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◆ isOpen()

bool QSqlDriver::isOpen ( ) const

virtual

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

Reimplemented in QPSQLDriver.

Definition at line 120 of file qsqldriver.cpp.

References d.

Referenced by QOCIDriver::~QOCIDriver(), QDB2Driver::beginTransaction(), QIBaseDriver::beginTransaction(), QMYSQLDriver::beginTransaction(), QOCIDriver::beginTransaction(), QODBCDriver::beginTransaction(), QSQLiteDriver::beginTransaction(), QDB2Driver::close(), QIBaseDriver::close(), QMimerSQLDriver::close(), QMYSQLDriver::close(), QOCIDriver::close(), QSQLiteDriver::close(), QDB2Driver::commitTransaction(), QIBaseDriver::commitTransaction(), QMYSQLDriver::commitTransaction(), QOCIDriver::commitTransaction(), QODBCDriver::commitTransaction(), QSQLiteDriver::commitTransaction(), QMYSQLDriver::formatValue(), QSqlDatabase::isOpen(), QDB2Driver::open(), QIBaseDriver::open(), QMimerSQLDriver::open(), QMYSQLDriver::open(), QOCIDriver::open(), QODBCDriver::open(), QSQLiteDriver::open(), QIBaseDriver::primaryIndex(), QDB2Driver::primaryIndex(), QMimerSQLDriver::primaryIndex(), QMYSQLDriver::primaryIndex(), QOCIDriver::primaryIndex(), QODBCDriver::primaryIndex(), QSQLiteDriver::primaryIndex(), QDB2Driver::record(), QIBaseDriver::record(), QMimerSQLDriver::record(), QMYSQLDriver::record(), QOCIDriver::record(), QODBCDriver::record(), QSQLiteDriver::record(), QDB2Driver::rollbackTransaction(), QIBaseDriver::rollbackTransaction(), QMYSQLDriver::rollbackTransaction(), QOCIDriver::rollbackTransaction(), QODBCDriver::rollbackTransaction(), QSQLiteDriver::rollbackTransaction(), QIBaseDriver::subscribeToNotification(), QSQLiteDriver::subscribeToNotification(), QDB2Driver::tables(), QMimerSQLDriver::tables(), QIBaseDriver::tables(), QOCIDriver::tables(), QODBCDriver::tables(), QSQLiteDriver::tables(), QIBaseDriver::unsubscribeFromNotification(), and QSQLiteDriver::unsubscribeFromNotification().

◆ isOpenError()

bool QSqlDriver::isOpenError ( ) const

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

Definition at line 131 of file qsqldriver.cpp.

References d.

Referenced by QIBaseDriver::beginTransaction(), QSQLiteDriver::beginTransaction(), QIBaseDriver::commitTransaction(), QSQLiteDriver::commitTransaction(), QSqlDatabase::isOpenError(), QIBaseDriver::rollbackTransaction(), and QSQLiteDriver::rollbackTransaction().

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◆ lastError()

QSqlError QSqlDriver::lastError ( ) const

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

Definition at line 321 of file qsqldriver.cpp.

References d.

Referenced by QSqlDatabase::lastError(), and QIBaseDriver::open().

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◆ maximumIdentifierLength()

int QSqlDriver::maximumIdentifierLength ( QSqlDriver::IdentifierType type ) const

virtual

Since: 6.0

Returns the maximum length for the identifier type according to the database settings. Returns INT_MAX by default if the is no maximum for the database.

Reimplemented in QIBaseDriver, and QOCIDriver.

Definition at line 796 of file qsqldriver.cpp.

References Q_UNUSED.

◆ notification

QSqlDriver::notification	(	const QString &	name,
		QSqlDriver::NotificationSource	source,
		const QVariant &	payload )

signal

Since: 5.0

This signal is emitted when the database posts an event notification that the driver subscribes to. name identifies the event notification, source indicates the signal source, payload holds the extra data optionally delivered with the notification.

See also: subscribeToNotification()

◆ numericalPrecisionPolicy()

QSql::NumericalPrecisionPolicy QSqlDriver::numericalPrecisionPolicy ( ) const

Returns the \l numericalPrecisionPolicy.

Definition at line 748 of file qsqldriver.cpp.

References d.

◆ open()

bool QSqlDriver::open	(	const QString &	db,
		const QString &	user = QString(),
		const QString &	password = QString(),
		const QString &	host = QString(),
		int	port = -1,
		const QString &	options = QString() )

pure virtual

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: setOpen()

Implemented in XyzDriver, QSqlNullDriver, QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Referenced by QSqlDatabase::open(), QIBaseDriver::open(), QSqlDatabase::open(), and setOpen().

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◆ primaryIndex()

QSqlIndex QSqlDriver::primaryIndex ( const QString & tableName ) const

virtual

Returns the primary index for table tableName.

Returns an empty QSqlIndex if the table doesn't have a primary index. The default implementation returns an empty index.

Reimplemented in QIBaseDriver, QDB2Driver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 349 of file qsqldriver.cpp.

Referenced by QSqlDatabase::primaryIndex().

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◆ record()

QSqlRecord QSqlDriver::record ( const QString & tableName ) const

virtual

Returns a 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.

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 361 of file qsqldriver.cpp.

Referenced by QSqlDatabase::record().

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◆ rollbackTransaction()

bool QSqlDriver::rollbackTransaction ( )

virtual

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: beginTransaction(), commitTransaction()

Reimplemented in QDB2Driver, QIBaseDriver, QMimerSQLDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 298 of file qsqldriver.cpp.

Referenced by QSqlDatabase::rollback().

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◆ setLastError()

void QSqlDriver::setLastError ( const QSqlError & error )

protectedvirtual

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

See also: lastError()

Reimplemented in QSqlNullDriver.

Definition at line 310 of file qsqldriver.cpp.

References d, and error.

Referenced by QOCIDriver::QOCIDriver(), QSqlNullDriver::QSqlNullDriver(), QMimerSQLDriver::beginTransaction(), QMYSQLDriver::beginTransaction(), QOCIDriver::beginTransaction(), QODBCDriver::beginTransaction(), QPSQLDriver::beginTransaction(), QSQLiteDriver::beginTransaction(), QSQLiteDriver::close(), QDB2Driver::commitTransaction(), QMimerSQLDriver::commitTransaction(), QMYSQLDriver::commitTransaction(), QOCIDriver::commitTransaction(), QODBCDriver::commitTransaction(), QPSQLDriver::commitTransaction(), QSQLiteDriver::commitTransaction(), QDB2Driver::open(), QMimerSQLDriver::open(), QMYSQLDriver::open(), QOCIDriver::open(), QODBCDriver::open(), QPSQLDriver::open(), QSQLiteDriver::open(), QDB2Driver::rollbackTransaction(), QMimerSQLDriver::rollbackTransaction(), QMYSQLDriver::rollbackTransaction(), QOCIDriver::rollbackTransaction(), QODBCDriver::rollbackTransaction(), QPSQLDriver::rollbackTransaction(), QSQLiteDriver::rollbackTransaction(), QIBaseDriver::subscribeToNotification(), QPSQLDriver::subscribeToNotification(), QIBaseDriver::unsubscribeFromNotification(), and QPSQLDriver::unsubscribeFromNotification().

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◆ setNumericalPrecisionPolicy()

void QSqlDriver::setNumericalPrecisionPolicy ( QSql::NumericalPrecisionPolicy precisionPolicy )

Sets \l numericalPrecisionPolicy to precisionPolicy.

Definition at line 729 of file qsqldriver.cpp.

References d.

Referenced by QSqlDatabasePrivate::QSqlDatabasePrivate(), QSqlDatabasePrivate::copy(), and QSqlDatabase::setNumericalPrecisionPolicy().

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◆ setOpen()

void QSqlDriver::setOpen ( bool open )

protectedvirtual

This function sets the open state of the database to open.

Derived classes can use this function to report the status of open().

See also: open(), setOpenError()

Reimplemented in QSqlNullDriver.

Definition at line 241 of file qsqldriver.cpp.

References d, and open().

Referenced by QDB2Driver::QDB2Driver(), QIBaseDriver::QIBaseDriver(), QMYSQLDriver::QMYSQLDriver(), QOCIDriver::QOCIDriver(), QODBCDriver::QODBCDriver(), QPSQLDriver::QPSQLDriver(), QSQLiteDriver::QSQLiteDriver(), QDB2Driver::close(), QIBaseDriver::close(), QMimerSQLDriver::close(), QMYSQLDriver::close(), QOCIDriver::close(), QODBCDriver::close(), QPSQLDriver::close(), QSQLiteDriver::close(), QDB2Driver::open(), QIBaseDriver::open(), QMimerSQLDriver::open(), QMYSQLDriver::open(), QOCIDriver::open(), QODBCDriver::open(), QPSQLDriver::open(), and QSQLiteDriver::open().

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◆ setOpenError()

void QSqlDriver::setOpenError ( bool error )

protectedvirtual

This function sets the open error state of the database to error.

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

See also: open(), setOpen()

Reimplemented in QSqlNullDriver.

Definition at line 256 of file qsqldriver.cpp.

References d, and error.

Referenced by QDB2Driver::QDB2Driver(), QIBaseDriver::QIBaseDriver(), QMYSQLDriver::QMYSQLDriver(), QOCIDriver::QOCIDriver(), QODBCDriver::QODBCDriver(), QPSQLDriver::QPSQLDriver(), QSQLiteDriver::QSQLiteDriver(), QDB2Driver::close(), QIBaseDriver::close(), QMimerSQLDriver::close(), QMYSQLDriver::close(), QOCIDriver::close(), QODBCDriver::close(), QPSQLDriver::close(), QSQLiteDriver::close(), QDB2Driver::open(), QIBaseDriver::open(), QMimerSQLDriver::open(), QMYSQLDriver::open(), QOCIDriver::open(), QODBCDriver::open(), QPSQLDriver::open(), and QSQLiteDriver::open().

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◆ sqlStatement()

QString QSqlDriver::sqlStatement	(	StatementType	type,
		const QString &	tableName,
		const QSqlRecord &	rec,
		bool	preparedStatement ) const

virtual

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.

The generated flag in each field of rec determines whether the field is included in the generated statement.

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.

In the WHERE statement, each non-null field of rec specifies a filter condition of equality to the field value, or if prepared, a placeholder. However, prepared or not, a null field specifies the condition IS NULL and never introduces a placeholder. The application must not attempt to bind data for the null field during execution. The field must be set to some non-null value if a placeholder is desired. Furthermore, since non-null fields specify equality conditions and SQL NULL is not equal to anything, even itself, it is generally not useful to bind a null to a placeholder.

Definition at line 444 of file qsqldriver.cpp.

References append(), QString::append(), QString::clear(), QSqlRecord::count(), DeleteStatement, QSqlRecord::field(), FieldName, QSqlRecord::fieldName(), formatValue(), i, InsertStatement, QString::isEmpty(), QSqlRecord::isGenerated(), QSqlRecord::isNull(), prepareIdentifier(), QString::reserve(), SelectStatement, TableName, UpdateStatement, and WhereStatement.

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◆ stripDelimiters()

QString QSqlDriver::stripDelimiters	(	const QString &	identifier,
		IdentifierType	type ) const

virtual

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.

Reimplement this function if you want to provide your own implementation in your QSqlDriver subclass,

See also: isIdentifierEscaped()

Reimplemented in QSQLiteDriver.

Definition at line 409 of file qsqldriver.cpp.

References QString::chop(), isIdentifierEscaped(), QString::mid(), and ret.

Referenced by QRelation::populateDictionary(), QIBaseDriver::primaryIndex(), QDB2Driver::primaryIndex(), QMimerSQLDriver::primaryIndex(), QOCIDriver::primaryIndex(), QPSQLDriver::primaryIndex(), QDB2Driver::record(), QIBaseDriver::record(), QMimerSQLDriver::record(), QOCIDriver::record(), QPSQLDriver::record(), QSqlTableModelPrivate::strippedFieldName(), QDB2Driver::tables(), and QOCIDriver::tables().

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◆ subscribedToNotifications()

QStringList QSqlDriver::subscribedToNotifications ( ) const

virtual

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

Reimplement this function if you want to provide event notification support in your own QSqlDriver subclass,

See also: subscribeToNotification(), unsubscribeFromNotification()

Reimplemented in QIBaseDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 721 of file qsqldriver.cpp.

◆ subscribeToNotification()

bool QSqlDriver::subscribeToNotification ( const QString & name )

virtual

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 close() all subscribed event notifications are automatically unsubscribed. Note that calling open() on an already open database may implicitly cause 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 notification() signal is emitted.

Reimplement this function if you want to provide event notification support in your own QSqlDriver subclass,

See also: unsubscribeFromNotification(), subscribedToNotifications(), QSqlDriver::hasFeature()

Reimplemented in QIBaseDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 684 of file qsqldriver.cpp.

References Q_UNUSED.

◆ tables()

QStringList QSqlDriver::tables ( QSql::TableType tableType ) const

virtual

Returns a list of the names of the tables in the database.

The default implementation returns an empty list.

The tableType argument describes what types of tables should be returned. Due to binary compatibility, the string contains the value of the enum QSql::TableTypes as text. An empty string should be treated as QSql::Tables for backward compatibility.

Reimplemented in QDB2Driver, QMimerSQLDriver, QIBaseDriver, QMYSQLDriver, QOCIDriver, QODBCDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 338 of file qsqldriver.cpp.

Referenced by QSqlDatabase::tables().

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◆ unsubscribeFromNotification()

bool QSqlDriver::unsubscribeFromNotification ( const QString & name )

virtual

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 close() function is called.

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

Reimplement this function if you want to provide event notification support in your own QSqlDriver subclass,

See also: subscribeToNotification(), subscribedToNotifications()

Reimplemented in QIBaseDriver, QPSQLDriver, and QSQLiteDriver.

Definition at line 707 of file qsqldriver.cpp.

References Q_UNUSED.

Friends And Related Symbol Documentation

◆ QSqlDatabase

friend class QSqlDatabase

friend

Definition at line 27 of file qsqldriver.h.

◆ QSqlResultPrivate

friend class QSqlResultPrivate

friend

Definition at line 28 of file qsqldriver.h.

Property Documentation

◆ numericalPrecisionPolicy

QSqlDriver::numericalPrecisionPolicy

readwrite

Since: 6.8

This property holds the precision policy for the database connection.

Note: Setting the precision policy doesn't affect any currently active queries.

See also: QSql::NumericalPrecisionPolicy, QSqlQuery::numericalPrecisionPolicy, QSqlDatabase::numericalPrecisionPolicy

Definition at line 58 of file qsqldriver.h.

Referenced by QSqlDatabase::numericalPrecisionPolicy().

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

qtbase/src/sql/kernel/qsqldriver.h (6dfc988ea0160071d33870c1a58d0e9d34aeac5d)
qtbase/src/sql/kernel/qsqldriver.cpp (781135b0d2b2814dd504fb7578703bbeda022c51)

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Friends

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ DbmsType

◆ DriverFeature

◆ IdentifierType

◆ NotificationSource

◆ StatementType

Constructor & Destructor Documentation

◆ QSqlDriver() [1/2]

◆ ~QSqlDriver()

◆ QSqlDriver() [2/2]

Member Function Documentation

◆ beginTransaction()

◆ cancelQuery

◆ close()

◆ commitTransaction()

◆ createResult()

◆ dbmsType()

◆ escapeIdentifier()

◆ formatValue()

◆ handle()

◆ hasFeature()

◆ isIdentifierEscaped()

◆ isOpen()

◆ isOpenError()

◆ lastError()

◆ maximumIdentifierLength()

◆ notification

◆ numericalPrecisionPolicy()

◆ open()

◆ primaryIndex()

◆ record()

◆ rollbackTransaction()

◆ setLastError()

◆ setNumericalPrecisionPolicy()

◆ setOpen()

◆ setOpenError()

◆ sqlStatement()

◆ stripDelimiters()

◆ subscribedToNotifications()

◆ subscribeToNotification()

◆ tables()

◆ unsubscribeFromNotification()

Friends And Related Symbol Documentation

◆ QSqlDatabase

◆ QSqlResultPrivate

Property Documentation

◆ numericalPrecisionPolicy