QSqlPropertyMap Class Reference
[sql module]

Detailed Description

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:

QSqlPropertyMap::~QSqlPropertyMap () [virtual]

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]

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

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

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

QVariant QSqlPropertyMap::property ( QWidget * widget )

void QSqlPropertyMap::remove ( const QString & classname )

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

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