QSqlPropertyMap Class

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# QSqlPropertyMap Class Reference
[sql module]

The QSqlPropertyMap class is used to map widgets to SQL fields. More...

`#include <qsqlpropertymap.h>`

List of all member functions.

## Public Members

- QSqlPropertyMap ()
- virtual ~QSqlPropertyMap ()
- QVariant property ( QWidget * widget )
- virtual void setProperty ( QWidget * widget, const QVariant & value )
- void insert ( const QString & classname, const QString & property )
- void remove ( const QString & classname )

## Static Public Members

- QSqlPropertyMap * defaultMap ()
- void installDefaultMap ( QSqlPropertyMap * map )

## Detailed Description

The QSqlPropertyMap class is used to map widgets to SQL fields.

The SQL module uses Qt object properties to insert and extract values from editor widgets.

This class is used to map editors to SQL fields. This works by associating SQL editor class names to the properties used to insert and extract values to/from the editor.

For example, a QLineEdit can be used to edit text strings and other data types in QDataTables or QSqlForms. Several properties are defined in QLineEdit, but only the text property is used to insert and extract text from a QLineEdit. Both QDataTable and QSqlForm use the global QSqlPropertyMap for inserting and extracting values to and from an editor widget. The global property map defines several common widgets and properties that are suitable for many applications. You can add and remove widget properties to suit your specific needs.

If you want to use custom editors with your QDataTable or QSqlForm, you must install your own QSqlPropertyMap for that table or form. Example:

        QSqlPropertyMap *myMap  = new QSqlPropertyMap();
        QSqlForm        *myForm = new QSqlForm( this );
        MyEditor myEditor( this );

        // Set the QSqlForm's record buffer to the update buffer of
        // a pre-existing QSqlCursor called 'cur'.
        myForm->setRecord( cur->primeUpdate() );

        // Install the customized map
        myMap->insert( "MyEditor", "content" );
        myForm->installPropertyMap( myMap ); // myForm now owns myMap
        ...
        // Insert a field into the form that uses a myEditor to edit the
        // field 'somefield'
        myForm->insert( &myEditor, "somefield" );

        // Update myEditor with the value from the mapped database field
        myForm->readFields();
        ...
        // Let the user edit the form
        ...
        // Update the database fields with the values in the form
        myForm->writeFields();
        ...

You can also replace the global QSqlPropertyMap that is used by default. (Bear in mind that QSqlPropertyMap takes ownership of the new default map.)

        QSqlPropertyMap *myMap = new QSqlPropertyMap;

        myMap->insert( "MyEditor", "content" );
        QSqlPropertyMap::installDefaultMap( myMap );
        ...

See also QDataTable, QSqlForm, QSqlEditorFactory, and Database Classes.

## Member Function Documentation

### QSqlPropertyMap::QSqlPropertyMap ()

Constructs a QSqlPropertyMap.

The default property mappings used by Qt widgets are:

Widgets | Property
--- | ---
QCheckBox, QRadioButton | checked
QComboBox, QListBox | currentItem
QDateEdit | date
QDateTimeEdit | dateTime
QTextBrowser | source
QButton, QDial, QLabel, QLineEdit, QMultiLineEdit, QPushButton, QTextEdit, | text
QTimeEdit | time
QLCDNumber, QScrollBar QSlider, QSpinBox | value

### QSqlPropertyMap::~QSqlPropertyMap ()`[virtual]`

Destroys the QSqlPropertyMap.

Note that if the QSqlPropertyMap is installed with installPropertyMap() the object it was installed into, e.g. the QSqlForm, takes ownership and will delete the QSqlPropertyMap when necessary.

### QSqlPropertyMap * QSqlPropertyMap::defaultMap ()`[static]`

Returns the application global QSqlPropertyMap.

### void QSqlPropertyMap::insert ( const QString & classname, const QString & property )

Insert a new classname/property pair, which is used for custom SQL field editors. There must be a `Q_PROPERTY` clause in the classname class declaration for the property.

Example: sql/overview/custom1/main.cpp.

### void QSqlPropertyMap::installDefaultMap ( QSqlPropertyMap * map )`[static]`

Replaces the global default property map with map. All QDataTable and QSqlForm instantiations will use this new map for inserting and extracting values to and from editors. QSqlPropertyMap takes ownership of \a map, and destroys it when it is no longer needed.

### QVariant QSqlPropertyMap::property ( QWidget * widget )

Returns the mapped property of widget as a QVariant.

### void QSqlPropertyMap::remove ( const QString & classname )

Removes classname from the map.

### void QSqlPropertyMap::setProperty ( QWidget * widget, const QVariant & value )`[virtual]`

Sets the property of widget to value.

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