QSql Namespace

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

Header: #include <QSql>
CMake: find_package(Qt6 REQUIRED COMPONENTS Sql)
target_link_libraries(mytarget PRIVATE Qt6::Sql)
qmake: QT += sql

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

See also Qt SQL.

Type Documentation

enum QSql::Location

This enum type describes special SQL navigation locations:

ConstantValueDescription
QSql::BeforeFirstRow-1Before the first record.
QSql::AfterLastRow-2After the last record.

See also QSqlQuery::at().

enum QSql::NumericalPrecisionPolicy

Numerical values in a database can have precisions greater than their corresponding C++ types. This enum lists the policies for representing such values in the application.

ConstantValueDescription
QSql::LowPrecisionInt320x01Force 32bit integer values. In case of floating point numbers, the fractional part is silently discarded.
QSql::LowPrecisionInt640x02Force 64bit integer values. In case of floating point numbers, the fractional part is silently discarded.
QSql::LowPrecisionDouble0x04Force double values. This is the default policy.
QSql::HighPrecision0Strings will be used to preserve 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.

ConstantValueDescription
QSql::In0x00000001The bind parameter is used to put data into the database.
QSql::Out0x00000002The bind parameter is used to receive data from the database.
QSql::InOutIn | OutThe bind parameter is used to put data into the database; it will be overwritten with output data on executing a query.
QSql::Binary0x00000004This 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.

ConstantValueDescription
QSql::Tables0x01All the tables visible to the user.
QSql::SystemTables0x02Internal tables used by the database.
QSql::Views0x04All the views visible to the user.
QSql::AllTables0xffAll of the above.

© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. 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. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.