Bug 124251 the data cann't been exported.
Description: the data cann't been exported. Steps to reproduce: 1. new a report 2. new a datasource and a data set(DS_A) 3. use an external library 4. drag a table to the report layout from the imported library 5. insert an another table into the layout of the report and bind the data set(DS_A) 6. preview in the 'Web Viewer' and export the data Actual result: The data can been exported. Expect result: The data can been exporteded
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/DataExtractionTask.java
*/
	protected HashMap mapQueryToDispName;
	
	/*
	 * map query to value expressions
	 */
	protected HashMap mapQueryToValueExprs;
	
	/*
	 * map result set name to query
	 */
	protected HashMap mapResultSetNameToQuery;
	
	/**
	 * the logger
	 */
	protected static Logger logger = Logger.getLogger( DteDataEngine.class
			.getName( ) );
	
	public DataExtractionTask( ReportEngine engine, IReportRunnable runnable,
			ReportDocumentReader reader ) throws EngineException
	{
		super( engine, runnable );
		
		
		this.reportDocReader = reader;
		executionContext.setReportDocument( reportDocReader );
		executionContext.setFactoryMode( false );
		executionContext.setPresentationMode( true );
		report = new ReportParser( ).parse( ( (ReportRunnable) runnable )