public IEnumerable<DON_VI_DKDT_ByIdResult> DON_VI_DKDT_ById(string id)
 {
     try
     {
         using (var dataContext = new OOAD_EDUManagementDataContext())
         {
             return dataContext.DON_VI_DKDT_ById(id).ToList();
         }
     }
     catch (Exception e)
     {
         return null;
     }
 }