Bug 177504 Engine doesn't provide SubQuery for extended item
Engine doesn't provide SubQuery for extended item, so chart can't use container's binding to execute the query. If possible, engine could provide an option for extended item to choose whether engine could create the query, so extended item won't create SubQuery by itself.
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 handleListingGroup( GroupDesign group,
				GroupHandle handle, Object value )
		{
			assert value instanceof IBaseQueryDefinition;
			IBaseQueryDefinition query = (IBaseQueryDefinition)value;
			
			IGroupDefinition groupDefn = handleGroup( group, handle, query );
			transformExpressions( group, query, groupDefn.getName( ) );
			handleListingBand( group.getHeader( ), query, true, groupDefn );
			handleListingBand( group.getFooter( ), query, true, groupDefn );
		}		
		/**
		 * processes a table/list group
		 */
		protected IGroupDefinition handleGroup( GroupDesign group,
				GroupHandle handle, IBaseQueryDefinition query )
		{
			GroupDefinition groupDefn = new GroupDefinition( group.getName( ) );
			groupDefn.setKeyExpression( handle.getKeyExpr( ) );
			String interval = handle.getInterval( );