internal static CODE_RESULT_RETURN Update(Quyen hv)
 {
     using (var db = DBContext.GetContext())
     {
         var hvc = db.Quyen.FirstOrDefault(h => h.MaQuyen  == hv.MaQuyen);
         if (hvc != null)
         {
             hvc.TenQuyen = hv.TenQuyen;
             db.SaveChanges();
             return CODE_RESULT_RETURN.ThanhCong;
         }
         return CODE_RESULT_RETURN.ThatBai;
     }
 }
 internal static CODE_RESULT_RETURN Add(Quyen sp)
 {
     using (var context = DBContext.GetContext())
     {
         try
         {
             var n1 = context.Quyen.FirstOrDefault(n => n.MaQuyen == sp.MaQuyen);
             if (n1 == null)
             {
                 context.Quyen.Add(sp);
                 context.SaveChanges();
                 return CODE_RESULT_RETURN.ThanhCong;
             }
             return CODE_RESULT_RETURN.MaTrung;
         }
         catch
         {
             return CODE_RESULT_RETURN.ThatBai;
         }
     }
 }