Bug 136553 [regression]Preview error when set invalid group interval.
Description: Preview error when set invalid group interval. Steps to reproduce: 1. Insert a table 2. Add a group on number column, set interval to Year,1 3. Preview 4. Edit group on string column set interval to Prefix,1 5. Preview Expected result: Error msg about invalid group interval. Actual result: Error happened while running the report
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/DteDataEngine.java
protected HashMap queryMap = new HashMap( );
	/**
	 * creates data engine, by first look into the directory specified by
	 * configuration variable odadriver, for oda configuration file. The oda
	 * configuration file is at $odadriver/drivers/driverType/odaconfig.xml.
	 * <p>
	 * 
	 * If the config variable is not set, search configuration file at
	 * ./drivers/driverType/odaconfig.xml.
	 * 
	 * @param context
	 */
	public DteDataEngine( ExecutionContext context )
	{
		this.context = context;
		try
		{
			Scriptable scope = context.getScope( );
			
			
			context.registerBean( "row", new NativeRowObject( scope, rsets ) );
			
			DataEngineContext dteContext = DataEngineContext.newInstance(
					DataEngineContext.DIRECT_PRESENTATION, context
							.getSharedScope( ), null, null );
			dteEngine = DataEngine.newDataEngine( dteContext );
		}
		catch ( Exception ex )
		{
			logger.log( Level.SEVERE, "can't create the DTE data engine", ex );