1-n relations and EntityKey with EntityFramework

Question

Hi all. When I have an entity that holds a reference to a singular entity I can create an EntityKey and assign that value to the EntityNameReference.Value property. It works perfectly and like a charm.

If I have an entity that holds a reference to multiple entities I cannot succeed in doing the same thing. Suppose an entity called Application that has a property that contains references to Modules (so Application has a List property called Modules).

How can I programmatically attach entity keys to that kind of property?

I tried something like this, without any success:

foreach(int idModule in selectedModules)
{
Module m = new Module();
m.EntityKey = new EntityKey("myModel.ModuleSet", "idModule", idModule);
ctx.Attach(m); //Here I have an exception
app.Modules.Add(m);

Thanks a lot for your help. Marco

Answer 1

Does Module have Application navigation property? It should.

I would write something like:

foreach(int idModule in selectedModules)
{
    Module m = new Module();
    m.EntityKey = new EntityKey("myModel.ModuleSet", "idModule", idModule);
    m.Application = app;
    app.Modules.Add(m);
}
ctx.SaveChanges();