Bug 417305 A sample chart has no data
chart/org.eclipse.birt.chart.examples/src/org/eclipse/birt/chart/examples/view/models/WorkingWithBIRTDataEngine.java
DataEngine dataEngine = newDataEngine( );
		dataEngine.defineDataSource( odaDataSource );
		dataEngine.defineDataSet( odaDataSet );
		IPreparedQuery preparedQuery = dataEngine.prepare( query );
		IQueryResults queryResults = preparedQuery.execute( null );
		
		return new GroupedRowExpressionsEvaluator( queryResults.getResultIterator( ),
				true ){
			public Object evaluate( String expression )
			{
				String bindingName = expressionMap.get( expression );
				if ( bindingName != null)
					return super.evaluate( bindingName );
					return super.evaluate( expression );
			}
		};
	}
	/**
	 * Create query definition.
	 * 
	 * @param odaDataSet
	 * @param expressions
	 * @return
	 * @throws ChartException
	 */
	private QueryDefinition createQueryDefinition(
			OdaDataSetDesign odaDataSet, String[] expressions )
			throws ChartException
	{
		QueryDefinition queryDefn = new QueryDefinition( );