Inserting into association table (ASP.NET MVC)

Question

I am writing my first ASP.NET MVC project, and very inexperienced in this subject so please bear with me.

I have to use an existing database for a new application I need to build. I have set this up as a datasource, and used the ADO.NET Entity Data Model to select the tables I need. I have one table that holds categories associated with a parent record, joined by a unique ID. This table doesn't appear in the designer but comes the Associations folder. How do I insert records into this table? Or am I going about this completely wrong?

Here is the code I have so far for Create:

//
// POST: /Home/Create
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Create([Bind(Exclude = "KeyID")] KeyDate dateToCreate, int topic, int level, int subject, int audience)
{
    dateToCreate.Created = DateTime.Now;
    dateToCreate.CreatedBy = User.Identity.Name;

    if (!ModelState.IsValid)
        return View();

    keyDateRepository.Add(dateToCreate);
    keyDateRepository.Save();

    return RedirectToAction("Index");
}

Here's the code for the repository:

//
// Insert/Delete Methods

public void Add(KeyDate keyDate)
{
   db.KeyDates.AddObject(keyDate);
}

[...]

//
// Persistence

public void Save()
{
    db.SaveChanges();
}

Any help much appreciated.

Answer 1

Well, I figured it out. I didn't realise that all I needed to do was to add the categories to the instance of that object.

dateToCreate.Categories.Add(keyDateRepository.GetCategory(topic));
dateToCreate.Categories.Add(keyDateRepository.GetCategory(level));
dateToCreate.Categories.Add(keyDateRepository.GetCategory(subject));
dateToCreate.Categories.Add(keyDateRepository.GetCategory(audience));