Question

Right now I have three controllers. Random (the parent), Menu & Name (the children).

I have several methods in RandomController that work on the database, but I want Menu & Name to specify different databases. However, if I remove the database context declaration from Random, it throws all sorts of errors.

As a side note, Random will never be accessed on its own, it only exists to provide code for Menu & Name

The entire controller isn’t really necessary, but here are some of the methods I have to give an idea. All of the db. statements break when I move the ComboContext declaration to the children.

public class RandomController : Controller
{

    publicCombosContext db = new CombosContext();
    //
    // GET: /Home/

    public ActionResult Index()
    {
        var rows = db.Combos.OrderBy(a => a.Id).ToArray();
        int arrLength = rows.Length;
        Random ran = new Random();

        Combo newCombo = new Combo
        {
            MainPrefix = rows[ran.Next(0, arrLength)].MainPrefix,
            MainDescriptor = rows[ran.Next(0, arrLength)].MainDescriptor,
            MainDish = rows[ran.Next(0, arrLength)].MainDish,
            Connector = rows[ran.Next(0, arrLength)].Connector,
            SecondaryDescriptor = rows[ran.Next(0, arrLength)].SecondaryDescriptor,
            SecondaryDish = rows[ran.Next(0, arrLength)].SecondaryDish
        };

        return View(newCombo);
    }
    public ActionResult Create()
    {
        return View(new Combo());
    }

    [HttpPost]
    public ActionResult Create(Combo model)
    {
        db.Combos.Add(model);
        db.SaveChanges();
        return RedirectToAction("Create");
    }

    public ActionResult Edit(int id)
    {
        Combo editMe = db.Combos.Find(id);
        return View(editMe);
    }

    [HttpPost]
    public ActionResult Edit(Combo editMe)
    {
        if (ModelState.IsValid)
        {
            db.Entry(editMe).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        else
        {
            return View(editMe);
        }

    }
}

Answer 1

Another way to do it is to add an abstract property to the parent controller where the type is an interface implemented by the contexts you need to use.

public RandomController : Controller
{
    ...
    protected abstract IContext Db { get; }
    ...
}

public MenuController : RandomController
{
    private SomeContext db = new SomeContext();

    ...

    protected override IContext Db { get { return db; } }

    ...
}