how to update database, when a row deleted Or Added in the smartGwt ListGrid

    i want to delete the row from the grid...and changes should reflect
    into my database..Please provide me some idea to do that...

The above code was later updated by me and i already added the data source in which i am initializing the fields. Updated code as follws 
listgrid = new SigmaListGrid();
listgrid.setDataSource(screenDS);
return listgrid;                                                                                                       public 
SigmaListGrid() {
        setShowFilterEditor(true);
        setHeight100();
        setWidth100();
        setShowRecordComponents(true);
        setShowRecordComponentsByCell(true);
        setCanRemoveRecords(true);
        setShowAllRecords(true);
        setCanResizeFields(true);
        setCanEdit(true);
        setAutoSaveEdits(false);
    }                                                                       
}

===

public class ScreenDataSource extends TPDDataSource {

/**
 * @param id
 */
public ScreenDataSource(String id) {
    super(id);
    initializeFields();
}

private void initializeFields() {

    DataSourceField pkField = new DataSourceIntegerField(...
    DataSourceField screenName = new DataSourceTextField(.....);
    screenName.setCanEdit(true);

    setFields(pkField, screenName;
}

@Override
public void clearData() {
    // TODO Auto-generated method stub

}
/**
 * This method will populate the data
 * @param records
 */
public void setData(List<ScreenGridRecord> records) {
    clearData();
    for (ScreenGridRecord screenGridRecord : records) {
        addData(screenGridRecord);
    }
}


@Override
public void setData() {

}   

}

Thanks @kimi ,i am adding a new row in list 
grid by listgrid.startEditingNew(); in newly added row i am inserting new data.Now i 开发者_运维百科want to save the data @ server side .I also used listgrid.saveAllEdits(); but it is not working .            

First of all, your ListGrid does not have a DataSource in the provided code. A ListGrid needs a DataSource to be data bound.

From a user interface point-of-view that code should be functional, given that your ListGrid's datasource implements the needed operations (add, fetch, update, remove). I'm guessing you do not have the DataSource set up properly.