public ActionResult Create(ExamResultVM examResult)
        {
            if (ModelState.IsValid)
            {
                StudentSubject studentSubject = db.StudentSubjects.FirstOrDefault(s =>
                                                                                  s.StudentId == examResult.StudentId && s.SubjectId == examResult.SubjectId);
                if (studentSubject != null)
                {
                    ExamResult result = new ExamResult()
                    {
                        StudentId = examResult.StudentId,
                        SubjectId = examResult.SubjectId,
                        //Status = "Pass"
                    };
                    db.ExamResults.Add(result);
                    db.SaveChanges();
                    return(RedirectToAction("Index"));
                }
                else
                {
                    ModelState.AddModelError("", "You have to assign subject first!!");
                    ViewBag.StudentId = new SelectList(db.Students, "Id", "Student_Id");
                    ViewBag.SubjectId = db.Subjects.ToList();
                    return(View(examResult));
                }
            }

            //ViewBag.StudentSubjectId = new SelectList(db.StudentSubjects, "Id", "Id", examResult.StudentSubjectId);
            ViewBag.StudentId = new SelectList(db.Students, "Id", "Student_Id");
            ViewBag.SubjectId = db.Subjects.ToList();
            return(View(examResult));
        }
        // GET: ExamResults
        public ActionResult Index()
        {
            var examResults = db.ExamResults.OrderBy(c => c.Student.Student_Id).Include(e => e.Student).Include(e => e.Subject);

            ViewBag.StudentId = new SelectList(db.Students, "Id", "Student_Id");
            ViewBag.SubjectId = db.Subjects.ToList();
            var vm = new ExamResultVM();

            vm.ExamResults = examResults.ToList();
            return(View(vm));
            //ViewBag.Result = result;
            //return View();
        }