I'm tring to receive an entity and then update it, but I want to get it with no tracking, so I can attach it back to the context.
I have the EntityFramework.dll referenced (4.1). I generated the database from the model. (not code-first).
Get user:
db.Users.MergeOption = MergeOption.NoTracking;
IQueryable<User> query = db.Users;//.AsNoTracking(); //<-- apparently, this is code-first only.
return query;
Update user:
db.Users.Attach(user); //error here.
ObjectStateEntry entry = db.ObjectStateManager.GetObjectStateEntry(user);
entry.SetModifiedProperty(propertyName);
db.SaveChanges();
return user;
Error:
An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.
I call the method like this:
var user = userRepository.GetUsers().FirstOrDefault(u => u.UserId == userId);
user.Identifiers.Add(someIdent);
userRepository.UpdateUser(user);