Question

I have a method like this:

    public FbUser FindUserByGraphOrInsert(dynamic json, bool commit = false)
    {
        string graphId = json.id;

        EntityDataModelContext context = DataContext.GetDataContext();
        FbUser user = context.FbUsers.FirstOrDefault(u => u.FbGraphId == graphId);

        if (user == null)
        {
            user = new FbUser();
            user.FbGraphId = json.id;
            user.FbUsername = StringExtensions.UnicodeDecode(json.name);

            context.FbUsers.AddObject(user);

            if (commit)
                context.SaveChanges();
        }

        return user;
    }

I call this method repeatedly in a loop (say upwards of 80 times), with commit = false

Thing is, I expected this method to let me know if the user is already in the context, but this doesn’t seem to be the case.

The result is that when I finally save changes, I get a list of 80 users, where 27 are distinct.

I expect this method to return those 27, how could I change it to achieve this?
Do I really need to save changes every single time?

Answer 1

Based on Polity’s answer, I implemented the following extension method, which worked.

    public static IEnumerable<T> IncludeUnsaved<T>(this ObjectSet<T> set) where T : class
    {
        var addedObjects = set.Context.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Added);
        var equalObjects = addedObjects.Select(e => e.Entity).OfType<T>();

        return equalObjects.Concat(set);
    }