Bug 122854 There is redundant columns in "available columns" list in "export data" dialog.
Description: There is redundant columns in "available columns" list in "export data" dialog. Steps to reproduce: 1. Preview attached design in web viewer. 2. Select the table and click on "export" button. 3. There is a "detail" column name in "available columns" list which is not data set column.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/ReportQueryBuilder.java
}
		/**
		 * @param group
		 *            a grouping in a list
		 * @param handle
		 *            handle to a grouping element
		 */
		protected void handleListGroup( ListGroupDesign group,
				GroupHandle handle, Object value )
		{
			IGroupDefinition groupDefn = handleGroup( group, handle );
			pushQuery( groupDefn );
			pushExpressions( groupDefn.getBeforeExpressions( ) );
			visitListBand( group.getHeader( ), value );
			popExpressions( );
			pushExpressions( groupDefn.getAfterExpressions( ) );
			visitListBand( group.getFooter( ), value );
			popExpressions( );
			popQuery( );
		}
		/**
		 * processes a table/list group
		 */
		protected IGroupDefinition handleGroup( GroupDesign group,
				GroupHandle handle )
		{
			GroupDefinition groupDefn = new GroupDefinition( group.getName( ) );
			groupDefn.setKeyExpression( handle.getKeyExpr( ) );
			String interval = handle.getInterval( );
			if ( interval != null )