Bug 123576 Data can't be retrieved when exporting data
Description: Data can't be retrieved when exporting data Steps to reproduce: 1.Preview the attached file in Web Viewer 2.Exported the data in table Expected result: The data is exported as a CSV file Actual result: No data is retrieved
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/api/impl/DataExtractionTask.java
{
			resultMetaList.clear();
		}
		
		if ( queryResultName != null )
		{
			try
			{
				IQueryResults queryResults = dataEngine.getQueryResults( queryResultName );
				
				assert queryResults.getResultIterator() != null;
				
				currentResult = new ExtractionResults( queryResults.getResultIterator() 
						, selectedColumns, getValueExpressions( rptItem.getQuery( ) ) );
				return currentResult;
				
			}
			catch ( BirtException e )
			{
				e.printStackTrace();
			}
		}
		else
		{
			DataSetID parentId = dataSetId.getParentID( );
			assert parentId != null;
			try
			{
				queryResultName = parentId.getDataSetName( );
				DataSetID parId = parentId;