public void UpdateQuy(int IDQuy, decimal?MoneyPlus) { if (MoneyPlus.HasValue && MoneyPlus != 0) { using (var db = new QLTCEntities()) { var quy = db.Quys.FirstOrDefault(q => q.IDQuy == IDQuy); if (quy != null) { quy.Money += MoneyPlus; db.SaveChanges(); } } } }