#SQLITE TRANSACTION ROLLBACK HOW TO#
#SQLITE TRANSACTION ROLLBACK DRIVERS#
#SQLITE TRANSACTION ROLLBACK DRIVER#
#SQLITE TRANSACTION ROLLBACK CODE#

#SQLITE TRANSACTION ROLLBACK DRIVER#

Returns true if a driver called name is available otherwise returns false. bool QSqlDatabase:: isDriverAvailable(const QString & name) Returns the connection's host name it may be empty. If query is empty, an empty, invalid query is returned and lastError() is not affected. Use lastError() to retrieve error information. QSqlQuery QSqlDatabase:: exec(const QString & query = QString()) constĮxecutes a SQL statement on the database and returns a QSqlQuery object. Returns a list of all the available database drivers. QString QSqlDatabase:: driverName() const Returns the database driver used to access the database connection. QSqlDriver *QSqlDatabase:: driver() const Note: The database name is not the connection name. Returns the connection's database name, which may be empty. QString QSqlDatabase:: databaseName() const See also isOpen() and Threads and the SQL Module. If connectionName does not exist in the list of databases, an invalid connection is returned. If no connectionName is specified the default connection is used. If open is true (the default) and the database connection is not already open it is opened now. The database connection must have been previously added with addDatabase(). Returns the database connection called connectionName. QSqlDatabase QSqlDatabase:: database(const QString & connectionName = QLatin1StringView(defaultConnection), bool open = true) See also connectionNames(), database(), and Threads and the SQL Module. Returns true if the list of database connections contains connectionName otherwise returns false. bool QSqlDatabase:: contains(const QString & connectionName = QLatin1StringView(defaultConnection)) See also contains(), database(), and Threads and the SQL Module. Returns a list containing the names of all connections. QStringList QSqlDatabase:: connectionNames() Note: The connection name is not the database name. For example, you can create a PostgreSQL connection with your own QPSQL driver like this:

#SQLITE TRANSACTION ROLLBACK CODE#

If you do this, it is recommended that you include the driver code in your application.

#SQLITE TRANSACTION ROLLBACK DRIVERS#

It might be your own database driver, or you might just need to instantiate one of the Qt drivers yourself. This overload is useful when you want to create a database connection with a driver you instantiated yourself. QSqlDatabase QSqlDatabase:: addDatabase( QSqlDriver * driver, const QString & connectionName = QLatin1StringView(defaultConnection)) See also database(), removeDatabase(), and Threads and the SQL Module. e.g., call some or all of setDatabaseName(), setUserName(), setPassword(), setHostName(), setPort(), and setConnectOptions(), and, finally, open(). If you call this function more than once without specifying connectionName, the default connection will be the one replaced.īefore using the connection, it must be initialized. Warning: If you add a connection with the same name as an existing connection, the new connection replaces the old one.

#SQLITE TRANSACTION ROLLBACK HOW TO#

The following snippet shows how to create and open a default connection to a PostgreSQL database: Subsequently, the default connection will be assumed if you call any static member function without specifying the connection name. To create the default connection, don't pass the connection name argument when you call addDatabase(). QSqlDatabase also supports the concept of a default connection, which is the unnamed connection.

You can have multiple connections to one database. A connection is known by its own name, not by the name of the database it connects to. See How to Write Your Own Database Driver for more information.Ĭreate a connection (i.e., an instance of QSqlDatabase) by calling one of the static addDatabase() functions, where you specify the driver or type of driver to use (depending on the type of database) and a connection name. Alternatively, you can subclass your own database driver from QSqlDriver. The connection provides access to the database via one of the supported database drivers, which are derived from QSqlDriver. An instance of QSqlDatabase represents the connection. The QSqlDatabase class provides an interface for accessing a database through a connection. Tables(QSql::TableType type = QSql::Tables) const SetNumericalPrecisionPolicy(QSql::NumericalPrecisionPolicy precisionPolicy) SetConnectOptions(const QString & options = QString()) PrimaryIndex(const QString & tablename) const

Open(const QString & user, const QString & password) Exec(const QString & query = QString()) const

Sqlite transaction rollback