public void Save(int seminar_id, List <int> attendees) { var elements = (from a in context.Attendees where a.SeminarID == seminar_id select a); context.RemoveRange(elements); foreach (int person_id in attendees) { var a = new Attendee() { SeminarID = seminar_id, PersonID = person_id }; context.Attendees.Add(a); } context.SaveChanges(); }