public IHttpActionResult GetStudentClassByEmpId(int?id)
        {
            ObjectParameter CL_TRNNO = new System.Data.Entity.Core.Objects.ObjectParameter("CL_TRNNO", typeof(double));

            if (!ModelState.IsValid)
            {
                return(BadRequest("Invalid data."));
            }

            using (var ctx = new EMSEntities())
            {
                ctx.spFindStudentClass(id, CL_TRNNO);
                var res = CL_TRNNO.Value;

                if (res == null)
                {
                    return(NotFound());
                }

                return(Ok(res));
            }
        }