Question

I have an MVC3 Project in C#.Net. I have Object1 with a list of Object2…

    //navigation Property(s)
    public virtual ICollection<Object2> Object2s { get; set; }

Object2 has an Object1 property and an Object1_Id property

    public int Object1_Id { get; set; }
    public virtual Object1 Object1 { get; set; }

When I run the Index View for Object2 I get the message “Invalid column name ‘Object1_Id1′”. Weird….it’s looking for an automated column. When I remove the Object1_Id from Object2, it does fine until I go to Save in the Create View. It then throws an error message:

{"Cannot insert the value NULL into column 'Object1_Id', table 'dbo.Object2'; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated."}

I’m sure I’m just missing an easy step. Any ideas?

Answer 1

I figured out my question. When I call the Create post action on my Object2 Controller, I retrieve the parent Object1, create a Guid for my new Object2, add the new Object2 to the Object1.Object2s collection, set Object1 state to modified, then save the db:

            var object1ToUpdate = db.Object1s.Where(
                    aObject1 => aObject1.Id.Equals(myId)
                ).Include(aObject1 => aObject1.Object2s).Single();
            string id = Guid.NewGuid().ToString();
            Object2.Id = Guid.NewGuid();
            object1ToUpdate.Object2s.Add(Object2);
            db.Entry(object1ToUpdate).State = EntityState.Modified;
            db.SaveChanges();