Bug 207564 Column sorting based on data type
Only string sorting happens when a column is selected in preview result page of DataSet Editor irrespective of type of data shown in that column. I'd like to be able to sort the data based on its datatype when a column is selected.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
*/
	private void cleanUnusedResultSetColumn( DataSetHandle dataSetHandle,
			DataSetViewData[] dsItemModel )
	{
		PropertyHandle handle = dataSetHandle.getPropertyHandle( DataSetHandle.RESULT_SET_PROP );
		if ( handle != null && handle.getListValue( ) != null )
		{
			ArrayList list = handle.getListValue( );
			int count = list.size( );
			for ( int n = count - 1; n >= 0; n-- )
			{
				ResultSetColumn rsColumn = (ResultSetColumn) list.get( n );
				String columnName = (String) rsColumn.getColumnName( );
				boolean found = false;
				for ( int m = 0; m < dsItemModel.length; m++ )
				{
					if ( columnName.equals( dsItemModel[m].getName( ) ) )
					{
						found = true;
						break;
					}
				}
				if ( !found )
				{
					try
					{
						
						handle.removeItem( rsColumn );
					}
					catch ( PropertyValueException e )