Question

I’m trying to use context as partially as possible because I want my software to be used by multiple users and I already had problems with contexts integration… so what I’m doing is calling the context like that:

entityManager = new EntityManager();

IEnumerable<customers_question_set> customersQuestionSets = 
entityManager.GetTradersCustomersQuestionSets(trader.id).ToArray<customers_question_set>();

entityManager = null;

This way, I believe, not only I’m closing everything with =null but also detaching the objects from the context by .ToArray().

But now I’m trying to add new item to the database and I’ve met a problem. This are my actions:

private void button1_Click(object sender, EventArgs e)
    {
        trader trader = new trader();
        trader.companies.Add(parent.GetCompany());
        trader.login = textBox1.Text;
        trader.password_hash = Hasher.ToSha256Hash(textBox2.Text);

        EntityManager entityManager = new EntityManager();
        entityManager.SaveTrader(trader);
        entityManager = null;

        this.RefreshLists();
    }

public class EntityManager
{

    private mentor11Entities Mentor11Entities = new mentor11Entities();

    private mentor11Entities GetMentor11()
    {
        return this.Mentor11Entities;
    }

    public void SaveTrader(trader trader)
    {
        GetMentor11().traders.AddObject(trader);
        GetMentor11().AcceptAllChanges();
        GetMentor11().SaveChanges();
    }

[...]

}

The error happens at GetMentor11().traders.AddObject(trader) – how to detach it if it’s a new member I didn’t even take from anywhere?

Answer 1

As there are a lot of people having problem with this and in the Internet there is no simple (for beginners as I am) explanation I could find… I will share how I resolve my problem.

1. I’ve made EntityManager static after all.

2. I discovered “StoreWins” refresh type (It’s making sure that the output is always as in the server)

And so it looks like this and working fine:

public static void SaveTrader(trader trader)
    {
        Mentor11Entities.Refresh(System.Data.Objects.RefreshMode.StoreWins, Mentor11Entities.traders);
        GetMentor11().AddTotraders(trader);
        GetMentor11().SaveChanges();
        GetMentor11().AcceptAllChanges();
        Mentor11Entities.Refresh(System.Data.Objects.RefreshMode.StoreWins, Mentor11Entities.traders);
    }