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
{
	protected static Logger logger = Logger.getLogger( ReportQueryBuilder.class
			.getName( ) );
	private ExpressionUtil expressionUtil;
	
	private QueryBuilderVisitor queryBuilder;
	
	/**
	 * query and it's IDs
	 */
	protected HashMap queryIDs;
	
	/**
	 * query and result metaData
	 */
	protected HashMap resultMetaData;
	
	/**
	 * a collection of all the queries
	 */
	protected Collection queries;
	/**
	 * entry point to the report
	 */
	protected Report report;
	
	/**
	 * the execution context