Bug 141064 Remove group level data binding
This bug covers the engine part of the task to remove group level data binding. After the hange, all binding expressions will be defined on the table level, and each binding expression will have an AggregateOn field to explicitly define the group level for that expression.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/ReportQueryBuilder.java
* 
		 * @param handle
		 *            a filter condition handle
		 * @return the filter
		 */
		private IFilterDefinition createFilter( FilterConditionHandle handle )
		{
			String filterExpr = handle.getExpr( );
			if ( filterExpr == null || filterExpr.length( ) == 0 )
				return null; 
			
			String filterOpr = handle.getOperator( );
			if ( filterOpr == null || filterOpr.length( ) == 0 )
				return new FilterDefinition( new ScriptExpression( filterExpr ) );
			/*
			 * has operator defined, try to convert filter condition to
			 * operator/operand style column filter with 0 to 2 operands
			 */
			String column = filterExpr;
			int dteOpr = ModelDteApiAdapter.toDteFilterOperator( filterOpr );
			String operand1 = handle.getValue1( );
			String operand2 = handle.getValue2( );
			return new FilterDefinition( new ConditionalExpression( column,
					dteOpr, operand1, operand2 ) );
		}
		/**
		 * create a filter array given a filter condition handle iterator
		 * 
		 * @param iter
		 *            the iterator