QSql Namespace
The QSql namespace contains miscellaneous identifiers used throughout the Qt SQL module. More...
| Header: | #include <QSql> |
| 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
The QSql namespace contains miscellaneous identifiers used throughout the Qt SQL module.
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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