private DeviceDTO ToDTO(device s)
        {
            DeviceDTO dto = new DeviceDTO();

            dto.device_ID = s.device_ID;
            if (s.department != null)
            {
                dto.device_dept = s.department.dept_name;
            }
            dto.device_info = s.device_info;
            dto.device_mark = s.device_mark;
            dto.device_name = s.device_name;
            return(dto);
        }
 public int AddNew(string device_ID, string device_name)
 {
     using (MyContext ctx = new MyContext())
     {
         var device = ctx.devices.SingleOrDefault(d => d.device_ID == device_ID);
         if (device == null)
         {
             device s = new device();
             s.device_ID   = device_ID;
             s.device_name = device_name;
             s.device_dept = null;
             s.device_mark = 0;
             ctx.devices.Add(s);
             ctx.SaveChanges();
             return(1);
         }
         else
         {
             return(-1);
         }
     }
 }