Entity Framework won't persist data in SQL Express (MDF)

Question

I was developing an application using Entity Framework and storing data in a .mdf database. My code can read the data, apparently it can save too, but only apparently. It ge

Answer 1

A few things leap to mind:

• double/treble-check your connection string; are you really talking to the file that you think you are?
• are you using transactions anywhere and not committing them?
• do you have the mdf file set to "Copy Always" (or whatever it is).... i.e. are you constantly overwriting the mdf whenever you hit build/play?

Also - I don't think it'll matter in this case, but to verify data you should use a different entities/data-context:

using (DatabaseEntities e = new DatabaseEntities()) {
    for (int i = 0; i < 50; i++) {
        User u = new User();
        u.Nome = "User" + i.ToString();
        e.AddToUser(u);
    }
    int c = e.SaveChanges(true);
}
using (DatabaseEntities e = new DatabaseEntities()) {
    List us = e.User.Where(x => x.ID < 50).ToList();
    foreach (User u in us)
        Console.WriteLine("ID: " + u.ID + " Hello from " + u.Nome);
}
Console.ReadKey();

Like I said - I doubt it'll matter here, but worth checking...