Oracle ODP.Net and EF CodeFirst - SaveChanges Error

Question

Could someone help me with this:

The code:

Role r = new Role { ID = 1, Name = \"Members\" };
ctx.Roles.Attach(r);

//Saving User
User u = new User {
         


        

Answer 1

The idea with the Attach() method is that you have an entity that is known to be in the DB but not being tracked by this context, right? My question to you is do you know for sure that this Role here:

Role r = new Role { ID = 1, Name = "Members" };

is something that exists already? If it doesn't, I don't think what you want to do is use

ctx.Roles.Attach(r);

rather it is that you'd write:

ctx.Roles.Add(r);

and then you could turn around and write

User u = new User {
    Login = login,
    Password = password,
    Status = 1,
};

ctx.Users.Add(u);
u.Roles.Add(r);
ctx.SaveChanges();

The issue your first example has is that this new Role is really new to the DB so attaching it isn't what you'd want to do, rather you'd want to Add it.

And the single call to ctx.SaveChanges() should work just fine here.