ArgumentNullException when saving to database

Question

I am trying to save changes to a database using EntityFramework, however I get a null excpetion error, but I know the data is not null.

  public partial class Model1
{
    public int ID { get; set; }
    public string Code { get; set; }
    public bool Compulsary { get; set; }
    public string Year { get; set; }
}



  private Entity  db = new Entity();
 [HttpPost]
    public ActionResult Add(string code)
    {

        HttpCookie cookie = Request.Cookies["Login"];
        int ID = int.Parse(cookie["ID"]);
        Model1 model1 = new Model1
        {
            ID = ID,
            Code = code,
            Compulsary = false,
            Year = "P2"
        };

        db.Model1.Add(model1);
        db.SaveChanges();

        return View();
    }

When it gets to db.SaveChanged then I get an error.

Answer 1

It looks like from here, the Code property could be at fault.

int ID = int.Parse(cookie["ID"]);

If the above line were at fault, it would fail on that line. The remaining properties are hard-coded, except for Code. You could be returning a null value from the post into a (possibly) non-nullable field in the database.

A possible cause is post variable naming. Check to make sure they are the same name.