Bug 145478 Unable "Select Value" in the Join data set's filter
Step to reproduce: 1.new a join data set(please use the attached file) 2.right click the dataset and click the Edit 3.go to the Filter pane and set a filer 4.click the list of Value1 Actual result: A warning pop up and cant select Value.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
* @return
	 * @throws BirtException
	 */
	private IQueryResults executeQuery( DataRequestSession session,
			QueryDefinition queryDefn ) throws BirtException
	{
		IQueryResults resultSet = session.executeQuery( queryDefn,
				null,
				null,
				null );
		return resultSet;
	}
	
	/**
	 * 
	 * @param dataSet
	 * @param resultSet
	 * @throws BirtException
	 */
	private void saveResultToDataItems( DataSetHandle dataSet,
			IQueryResults resultSet ) throws BirtException
	{
		
		IResultMetaData metaData = resultSet.getResultMetaData( );
		
		int columnCount = 0;
		if ( metaData != null )
			columnCount = metaData.getColumnCount( );
		DataSetViewData[] columns = new DataSetViewData[columnCount];