Bug 192083 [regression]DataException when preview attached xtab report.[1102]
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/DataRequestSessionImpl.java
}
	/*
	 * @see org.eclipse.birt.report.data.adaptor.impl.IDataRequestSession#shutdown()
	 */
	public void shutdown( )
	{
		dataEngine.shutdown( );
		dataEngine = null;
	}
	/**
	 * get the distinct value of query
	 * @param dataSet
	 * @param inputParamBindings
	 * @param columnBindings
	 * @param boundColumnName
	 * @return
	 * @throws BirtException
	 */
	private IQueryResults getGroupingQueryResults( DataSetHandle dataSet,
			Iterator inputParamBindings, Iterator columnBindings,
			String boundColumnName ) throws BirtException
	{
		assert dataSet != null;
		
		
		
		
		
		
		QueryDefinition query = new QueryDefinition( );