public void Update(WatchListGroup group) { if (group.WatchListGroupId == 0) { throw new System.Exception("Group does not exists"); } var watchList = _watchListRepository.GetById(group.WatchListGroupId); if (watchList == null) { throw new System.Exception("Group does not exists"); } _watchListRepository.Attach(watchList); watchList.InjectFrom(group); _watchListRepository.SaveChanges(); }