Perform CRUD in controller with ViewModel in ASP.NET MVC

Question

From my two models Student and InventoryRecord. I created a ViewModel named TestViewModel. I'm confused as to how do I write my controller?

public class TestViewModel
{
    //from Student model
    [Key]
    public string UserID { get; set; }
    public string PhoneNumber{ get; set; }
    public string Address{ get; set; }
    //other properties

    //from Inventory model
    public string FathersName { get; set; }
    public string FathersAddress { get; set; }
    //other properties

}

When I'm using only my main model Student. This is how I write my controller:

// GET: Students/CreateEdit
    public ActionResult InventoryRecord()
    {
        var currentUserId = User.Identity.GetUserId();
        var newid = db.Students.FirstOrDefault(d => d.UserID == currentUserId);

        if (newid == null)
        {
            newid = db.Students.Create();
            newid.UserID = currentUserId;
            db.Students.Add(newid);

        }

        Student student = db.Students.Find(newid.UserID);
        if (student == null)
        {
            return HttpNotFound();
        }

        return View(student);
    }

    // POST: Students/CreateEdit
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult InventoryRecord(Student student)
    {

        var currentUserId = User.Identity.GetUserId();
        var userName = User.Identity.GetUserName();
        var u = db.Students.FirstOrDefault(d => d.UserID == currentUserId);

        if (u == null)
        {
            u = db.Students.Create();
            u.UserID = currentUserId;
            db.Students.Add(u);

        }

        if (ModelState.IsValid)
        {
            u.PhoneNumber = student.PhoneNumber;
            u.Address = student.Address;
            //other properties

            db.SaveChanges();

            TempData["Message"] = "User: " + userName + ", details successfully updated!";
        }

        return View(student);
    }

Now, I'm really confused how to proceed here. How should I write my controller if I'm using my TestViewModel? Someone please point me in the right direction. Thank you.

Answer 1

Well personally I would move the code out of the controller.

However for example you just need to create an instance of your TestViewModel and pass that to your view. You may also need to update your View if you specific the model in the cshtml.

public ActionResult InventoryRecord()
{
    var currentUserId = User.Identity.GetUserId();
    var newid = db.Students.FirstOrDefault(d => d.UserID == currentUserId);

    if (newid == null)
    {
        newid = db.Students.Create();
        newid.UserID = currentUserId;
        db.Students.Add(newid);

    }

    Student student = db.Students.Find(newid.UserID);
    if (student == null)
    {
        return HttpNotFound();
    }

    TestViewModel model = new TestViewModel
    {
        UserID = student.UserId,
        PhoneNumber = student.PhoneNumber,
        //add the rest.
    };

    return View(model);
}