internal static Expression WidowedDate( ParameterExpression parm, CMSDataContext Db, CompareType op, DateTime? date) { Expression<Func<Person, DateTime?>> pred = p => Db.WidowedDate(p.PeopleId); Expression left = Expression.Invoke(pred, parm); var right = Expression.Constant(date, typeof(DateTime?)); return Compare(left, op, right); }