Question

我是MVC的新手，我正在尝试使用CRUD创建一个自动递增ID。我用id：

创建了我的模型

    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int BookingId { get; set; }

和我的控制员：

 public ActionResult Create()
    {
        ViewBag.OpticianId = new SelectList(db.Opticans, "OpticianId", "UserId");
        ViewBag.PatientId = new SelectList(db.Patients, "PatientId", "HCN");
        ViewBag.PracticeId = new SelectList(db.Practices, "PracticeId", "PracticeName");
        ViewBag.AppointmentTime = new SelectList(db.Times, "AppointmentTime", "AppointmentTime");
        return View();
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include = "BookingId,Date,PracticeId,AppointmentTime,OpticianId,PatientId")] Booking booking)
    {
        if (ModelState.IsValid)
        {
            db.Bookings.Add(booking);
            db.SaveChanges();
            return RedirectToAction("Index");

            }

        ViewBag.OpticianId = new SelectList(db.Opticans, "OpticianId", "UserId", booking.OpticianId);
        ViewBag.PatientId = new SelectList(db.Patients, "PatientId", "HCN", booking.PatientId);
        ViewBag.PracticeId = new SelectList(db.Practices, "PracticeId", "PracticeName", booking.PracticeId);
        ViewBag.AppointmentTime = new SelectList(db.Times, "AppointmentTime", "AppointmentTime", booking.AppointmentTime);
        return View(booking);
    }

我已从视图中删除了预订ID，但当我尝试添加新预订时，我收到以下异常：

'System.Data.Entity.Infrastructure.DbUpdateException'

StackTrace“at   System.Data.Entity.Internal.InternalContext.SaveChanges（）\ r \ n at   System.Data.Entity.Internal.LazyInternalContext.SaveChanges（）\ r \ n at   System.Data.Entity.DbContext.SaveChanges（）\ r \ n at   CSCOpticians.Controllers.BookingsController.Create（预订）   c：\ Users \ User \ Documents \ Visual Studio   2013 \项目\ CSCOpticians \ CSCOpticians \ \控制器BookingsController.cs：行   89 \ r \ n在lambda_method（Closure，ControllerBase，Object []）\ r \ n
  在System.Web.Mvc.ActionMethodDispatcher.Execute（ControllerBase   controller，Object []参数）\ r \ n at   System.Web.Mvc.ReflectedActionDescriptor.Execute（ControllerContext   controllerContext，IDictionary 2 parameters)\r\n at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary 2   参数）\ r \ n at   System.Web.Mvc.Async.AsyncControllerActionInvoker.ActionInvocation.InvokeSynchronousActionMethod（个）\ r \ n   在   System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39（IAsyncResult的   asyncResult，ActionInvocation innerInvokeState）\ r \ n at   System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult 2.CallEndDelegate(IAsyncResult asyncResult)\r\n at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase 1.End（个）\ r \ n   在System.Web.Mvc.Async.AsyncResultWrapper.End [TResult]（IAsyncResult）   asyncResult，Object tag）\ r \ n at   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod（IAsyncResult的   asyncResult）\ r \ n at   System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.b__3d（个）\ r \ n   在   System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters。＆lt;＆gt; c__DisplayClass46.b__3f（）“string

Answer 1

您已在视图中移除了 BookingID ，但也删除了 Bind

中的BookingID

public ActionResult Create([Bind(Include = "Date,PracticeId,AppointmentTime,OpticianId,PatientId")] Booking booking)

自动递增Id MVC5

1 个答案: