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

QSql is part of Database Classes.

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:

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

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. This is the default policy.
`QSql::HighPrecision`	`0`	Strings 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.

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.

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