What is the difference below codes? Is there an way to optimize?

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C#

.NET

LINQ

MVC

Hi,

What is the difference between below code? Which on is best?

// LINQ Query
                objSubjectList.selectedSubjects = (from ss in db.studentSubject
                                                   join sub in db.subject on ss.subjectId equals sub.id
                                                   where ss.studentId == studentId
                                                   select new
                                                   {
                                                       sub.id,
                                                       sub.subjectName
                                                   }).AsEnumerable()
                                                  .Select(t => new subject
                                                  {
                                                      id = t.id,
                                                      subjectName = t.subjectName
                                                  }).ToList();

// Lambda Expression
                objSubjectList.selectedSubjects = db.studentSubject.Join(db.subject,ss => ss.subjectId, sub => sub.id,
                                                    (ss, sub) => new { ss, sub })
                                                    .Where(m => m.ss.studentId == studentId)
                                                    .Select(c => new
                                                    {
                                                        c.sub.id,
                                                        c.sub.subjectName
                                                    }).AsEnumerable()
                                                    .Select(t => new subject
                                                    {
                                                        id = t.id,
                                                        subjectName = t.subjectName
                                                    }).ToList();

Is there any way to optimize the lamda expression?

Thanks

// code

@{
    ViewBag.Title = "AssignSubjects";
}

<h2>AssignSubjects</h2>

Students:   @Html.DropDownList("Student", (List<SelectListItem>)ViewData["StudentList"])
Subjects:   @Html.DropDownList("Subject", (List<SelectListItem>)ViewData["SubjectList"])


<div>
    <div>
        <h4>UnSelected Subjects</h4>
        <ul id="UnSelectedSubjects">

        </ul>
    </div>

    <div>
        <h4>Selected Subjects</h4>
        <ul id="SelectedSubjects">

        </ul>
    </div>
</div>

<script src="~/Scripts/jquery-1.10.2.js"></script>
<script>
    $(document).ready(function () {


        $('#Student').bind('change', function (event) {
            var stdId = $("#Student :selected").val();
            var id = event.target.id;
            GetSubjectList(stdId);
        });

        $('#UnSelectedSubjects').bind('dblclick', function (event) {
            var stdId = $("#Student :selected").val();
            var subId = event.target.id;
            AddSubject(stdId, subId);
        });

        $('#SelectedSubjects').bind('dblclick', function (event) {
            var stdId = $("#Student :selected").val();
            var subId = event.target.id;
            RemoveSubjectOfStudent(stdId, subId);
        });
    });


    var GetSubjectList = function (stdId) {
        $.ajax({
            cache: false,
            type: "POST",
            async: "false",
            url: "/Home/GetSubjectByStudent/",
            data: { studentId: stdId },
            dataType: "json"
        }).success(function (result) {
            var unSelectedSub = result.unSelectedSubjects;
            var selectedSub = result.selectedSubjects;

            $('#UnSelectedSubjects').html('');
            $('#SelectedSubjects').html('');

            for (var i = 0; i < unSelectedSub.length; i++) {
                var item = unSelectedSub[i];
                $('#UnSelectedSubjects').append('<li id=' + item.id + '>' + item.subjectName + '</li>')
            }

            for (var i = 0; i < selectedSub.length; i++) {
                var item = selectedSub[i];
                $('#SelectedSubjects').append('<li id=' + item.id + '>' + item.subjectName + '</li>')
            }
        });
    };

    var AddSubject = function (stdId, subId) {
        $.ajax({
            cache: false,
            type: "POST",
            async: "false",
            url: "/Home/AssignSubjectToStudent/",
            data: { studentId: stdId, subjectId: subId },
            dataType: "json"
        }).success(function (result) {
            if (result == "OK") {
                GetSubjectList(stdId)
            }
        });
    };

    function RemoveSubjectOfStudent(stdId, subId) {
        $.ajax({
            cache: false,
            type: "POST",
            async: "false",
            url: "/Home/RemoveSubjectOfStudent/",
            data: { studentId: stdId, subjectId: subId },
            dataType:"json"
        }).success(function (result) {
            if (result == "OK") {
                GetSubjectList(stdId)
            }
        });
    }

</script>

//
public class HomeController : Controller
{
schooldbEntities db;
List<student> studentList = new List<student>();
SubjectList objSubjectList = new SubjectList();
[HttpGet]
public ActionResult RegisterStudent()
{
student objStudent = new student();
return View(objStudent);
}

[HttpPost]
public ActionResult RegisterStudent(student objStudent)
{
try
{
if (ModelState.IsValid)
{
using (db = new schooldbEntities())
{
db.student.Add(objStudent);
var res = db.SaveChanges();
}
}
ViewBag.Result = "Success";

}
catch (Exception)
{
ViewBag.Result = "Failed";
}
return View();
}

[HttpGet]
public ActionResult AddSubject()
{
subject sub = new subject();
return View(sub);
}

[HttpPost]
public ActionResult AddSubject(subject objSubject)
{
try
{
if (ModelState.IsValid)
{
using (db = new schooldbEntities())
{
db.subject.Add(objSubject);
db.SaveChanges();
}
}

ViewBag.Result = "Success";
}
catch (Exception)
{
ViewBag.Result = "Failed";
}
return View();
}

[HttpGet]
public ActionResult AssignSubjects()
{
using (db = new schooldbEntities())
{
ViewData["StudentList"] = db.student.Select(c => new { c.id, c.name }).AsEnumerable().Select(t => new SelectListItem { Value = t.id.ToString(), Text = t.name }).ToList();
ViewData["SubjectList"] = db.subject.Select(c => new { c.id, c.subjectName }).AsEnumerable().Select(t => new SelectListItem { Value = t.id.ToString(), Text = t.subjectName }).ToList();
}
return View();
}

[HttpPost]
public ActionResult GetSubjectByStudent(int studentId)
{
using (db = new schooldbEntities())
{
// LINQ Query
//objSubjectList.selectedSubjects = (from ss in db.studentSubject
// join sub in db.subject on ss.subjectId equals sub.id
// where ss.studentId == studentId
// select new
// {
// sub.id,
// sub.subjectName
// }).AsEnumerable()
// .Select(t => new subject
// {
// id = t.id,
// subjectName = t.subjectName
// }).ToList();

// Lambda Expression
objSubjectList.selectedSubjects = db.studentSubject.Join(db.subject,ss => ss.subjectId, sub => sub.id,
(ss, sub) => new { ss, sub })
.Where(m => m.ss.studentId == studentId)
.Select(c => new
{
c.sub.id,
c.sub.subjectName
}).AsEnumerable()
.Select(t => new subject
{
id = t.id,
subjectName = t.subjectName
}).ToList();

var allSubjects = db.subject.ToList();

objSubjectList.unSelectedSubjects = allSubjects.Where(item => !objSubjectList.selectedSubjects.Any(c => c.id == item.id)).ToList();
}
return Json(objSubjectList, JsonRequestBehavior.AllowGet);
}

[HttpPost]
public ActionResult AssignSubjectToStudent(int studentId, int subjectId)
{
string status = string.Empty;
using (db = new schooldbEntities())
{
db.studentSubject.Add(new studentSubject { studentId = studentId, subjectId = subjectId});
db.SaveChanges();
status = "OK";
}

return Json(status, JsonRequestBehavior.AllowGet);
}

[HttpPost]
public ActionResult RemoveSubjectOfStudent(int studentId, int subjectId)
{
string status = string.Empty;
using (db = new schooldbEntities())
{
var obj = db.studentSubject.Where(c => c.studentId == studentId && c.subjectId == subjectId).FirstOrDefault();
db.studentSubject.Remove(obj);
db.SaveChanges();
status = "OK";
}

return Json(status, JsonRequestBehavior.AllowGet);
}
}

class SubjectList
{
public List<subject> unSelectedSubjects { get; set; }
public List<subject> selectedSubjects { get; set; }
}
//
<connectionstrings>
<add name="NewConnection">
connectionString="Data Source=.;
Initial Catalog=schooldb;
Persist Security Info=True;
User ID=sa;
Password=sql" providerName="System.Data.SqlClient" />

//