QSql Namespace

The QSql namespace contains miscellaneous identifiers used throughout the Qt SQL library. More...

 #include <QtSql>

Types

enum	Location { BeforeFirstRow, AfterLastRow }
enum	NumericalPrecisionPolicy { LowPrecisionInt32, LowPrecisionInt64, LowPrecisionDouble, HighPrecision }
flags	ParamType
enum	ParamTypeFlag { In, Out, InOut, Binary }
enum	TableType { Tables, SystemTables, Views, AllTables }

Detailed Description

The QSql namespace contains miscellaneous identifiers used throughout the Qt SQL library.

See also Qt SQL Module.

Type Documentation

enum QSql::Location

This enum type describes special SQL navigation locations:

Constant	Value	Description
`QSql::BeforeFirstRow`	`-1`	Before the first record.
`QSql::AfterLastRow`	`-2`	After the last record.

See also QSqlQuery::at().

enum QSql::NumericalPrecisionPolicy

This enum type describes at which precision levels numercial values are read from a database.

Some databases support numerical values with a precision that is not storable in a C++ basic data type. The default behavior is to bind these values as a QString. This enum can be used to override this behavior.

Constant	Value	Description
`QSql::LowPrecisionInt32`	`0x01`	Force 32bit integer values. In case of floating point numbers, the fractional part is silently discarded.
`QSql::LowPrecisionInt64`	`0x02`	Force 64bit integer values. In case of floating point numbers, the fractional part is silently discarded.
`QSql::LowPrecisionDouble`	`0x04`	Force `double` values.
`QSql::HighPrecision`	`0`	The default behavior - try to preserve maximum precision.

Note: The actual behaviour if an overflow occurs is driver specific. The Oracle database just returns an error in this case.

enum QSql::ParamTypeFlag
flags QSql::ParamType

This enum is used to specify the type of a bind parameter.

Constant	Value	Description
`QSql::In`	`0x00000001`	The bind parameter is used to put data into the database.
`QSql::Out`	`0x00000002`	The bind parameter is used to receive data from the database.
`QSql::InOut`	`In \| Out`	The bind parameter is used to put data into the database; it will be overwritten with output data on executing a query.
`QSql::Binary`	`0x00000004`	This must be OR'd with one of the other flags if you want to indicate that the data being transferred is raw binary data.

The ParamType type is a typedef for QFlags<ParamTypeFlag>. It stores an OR combination of ParamTypeFlag values.

enum QSql::TableType

This enum type describes types of SQL tables.

Constant	Value	Description
`QSql::Tables`	`0x01`	All the tables visible to the user.
`QSql::SystemTables`	`0x02`	Internal tables used by the database.
`QSql::Views`	`0x04`	All the views visible to the user.
`QSql::AllTables`	`0xff`	All of the above.

The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation.

Documentation sources may be obtained from www.qt-project.org.

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