Bug 122254 Not Like operator is missing in the Filter tab of Data Set window
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
private static boolean isDateOrString( Object result )
		{
			return ( result instanceof Date ) || ( result instanceof String );
		}
		/**
		 * To check whether the expressions are comparable. If so, they will be
		 * formatted to the comparable.For operands, only ExprTextAndValue is
		 * acceptable.
		 * 
		 * @param obj
		 * @param operator
		 * @param op1
		 * @param op2
		 * @return
		 * @throws DataException
		 */
		private static Object[] isComparable( Object obj, int operator,
				ExprTextAndValue op1, ExprTextAndValue op2 )
				throws DataException
		{
			if ( needFormat( obj, operator, op1, op2 ) )
				return formatToComparable( obj, op1, op2 );
			return null;
		}
		/**
		 * 
		 * @param obj
		 * @param operator
		 * @param op1
		 * @param op2