如何将实体添加到现有实体MVC 2 EF

Question

I am creating a MVC 2 website. I'm a beginner. I created a Model to use EF. The relationship is between a user table and a product table (one to many relationship). I am able to create new users and save them on the DB using linq to entities. My question is how do I add a product to an existing user. I was starting with the code below but it does not work. Intellisense doesn't see the queryuser.Product whats wrong with my code or what is the right way to do it. If someone can help me it would be great

 public void Insert(Product obj)
    {
        if (HttpContext.Current.Session["userid"] != null)
        {
            string userid2 = HttpContext.Current.Session["userid"].ToString();

            var queryuser = from p in entities.Users
                            where p.UserID == userid2
                            select p;

            queryuser.Product.Add(obj);
            entities.Users.Add(queryuser);
            entities.SaveChanges();
        }                                                         
    }

I am calling this method from my controller.

Answer 1

queryuser is an IQueryable and you are treating it like a single object.

You might try replacing:

queryuser.Product.Add(obj);
entities.Users.Add(queryuser);

with

user = queryuser.First();
user.Product.Add(obj);
entities.Users.Add(user);