OData 和插入 (AddLink) 多对多关系答案

【问题标题】：OData and inserting (AddLink) many-to-many relationshipsOData 和插入 (AddLink) 多对多关系
【发布时间】：2011-06-11 12:03:04
【问题描述】：

好吧，伙计们，这让我发疯了。我得到了以下（odata）实体，它表示一个页面结构，其中每个页面都可以有任何孩子和任何父母。（基本上是一个所有节点都可以连接的图）。在数据库中，它由两个表Page <-> PagePage <-> Page 的多对多关系表示。

问题是，我只是无法插入包含关系的新实体。我尝试的最后一件事是：

    Page page = new Page()
    {
        Id = Guid.NewGuid(),
        Title = "New Page",
        Created = DateTime.Now,
        LastChanged = DateTime.Now,
        IsRedirected = false,
        Position = 0,
        Html = "Add your HTML here.",
        Parent = { parent }
    };

    this.Context.AddToPages(page);
    this.Context.AddLink(parent, "Children", page);
    parent.Children.Add(page);
    this.Context.SaveChanges();

我想不出其他可以尝试的方法。有人破解过这个吗？

编辑 1：这是数据库图中的图片：

编辑 2：异常详情：

System.Data.Services.Client.DataServiceRequestException was unhandled
  Message=An error occurred while processing this request.
  Source=System.Data.Services.Client
  StackTrace:
       at System.Data.Services.Client.DataServiceContext.SaveResult.HandleBatchResponse()
       at System.Data.Services.Client.DataServiceContext.SaveResult.EndRequest()
       at System.Data.Services.Client.DataServiceContext.SaveChanges(SaveChangesOptions options)
       at System.Data.Services.Client.DataServiceContext.SaveChanges()
       at PortfolioManagementConsole.Models.PageViewModel.SaveChanges(Object parameter) in C:\Users\Daniel\documents\visual studio 2010\Projects\PortfolioManagementService\PortfolioManagementConsole\Models\PageViewModel.cs:line 59
       at PortfolioManagementConsole.Common.RelayCommand.Execute(Object parameter) in C:\Users\Daniel\documents\visual studio 2010\Projects\PortfolioManagementService\PortfolioManagementConsole\Common\RelayCommand.cs:line 52
       at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
       at System.Windows.Controls.Primitives.ButtonBase.OnClick()
       at System.Windows.Controls.Button.OnClick()
       at Telerik.Windows.Controls.RadButton.OnClick() in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Controls\Buttons\RadButton.cs:line 348
       at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
       at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
       at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
       at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
       at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
       at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
       at System.Windows.Input.InputManager.ProcessStagingArea()
       at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
       at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
       at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
       at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
       at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
       at System.Windows.Threading.Dispatcher.Run()
       at System.Windows.Application.RunDispatcher(Object ignore)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run(Window window)
       at System.Windows.Application.Run()
       at PortfolioManagementConsole.App.Main() in C:\Users\Daniel\documents\visual studio 2010\Projects\PortfolioManagementService\PortfolioManagementConsole\obj\x86\Debug\App.g.cs:line 0
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.Data.Services.Client.DataServiceClientException
       Message=<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
  <code></code>
  <message xml:lang="de-CH">An error occurred while processing this request.</message>
</error>
       Source=System.Data.Services.Client
       StatusCode=500
       StackTrace:
            at System.Data.Services.Client.DataServiceContext.SaveResult.<HandleBatchResponse>d__1e.MoveNext()
       InnerException:

【问题讨论】：

你得到什么错误？还是只是实体似乎没有插入？
context.SaveChanges() 方法上有一个 DataServiceRequestException。
还有异常的消息？
这就是问题所在，它只是“处理此请求时发生错误。”。堆栈跟踪给了我一个“System.Data.Services.Client.DataServiceContext.SaveResult.HandleBatchResponse()”，内部异常给出了一个“状态代码 500”、相同的消息和“TargetSite {Boolean MoveNext()}”
好的，这就是您在客户端收到的错误。服务器的代码是否在您的控制之下？你能看看它为什么返回这个错误吗？

标签： wpf odata wcf-data-services

【解决方案1】：

您的 WCF 数据服务服务器未返回详细的错误消息，这无助于您确定从服务器返回的确切错误消息。按照以下说明启用来自服务器的详细错误消息： http://blogs.msdn.com/b/phaniraj/archive/2008/06/18/debugging-ado-net-data-services.aspx 。启用此功能后，您应该能够看到服务器抛出的错误消息。

通过查看您的模型，您需要另一个从子节点到父节点的链接。在 SaveChanges 之前将此行添加到代码中：

this.Context.SetLink(page, "Parent", parent);

为了帮助更好地理解这一点，以下是我博客上的一些链接，我详细介绍了如何使用 WCF 数据服务客户端处理关联：

1 到多个关联

http://blogs.msdn.com/b/phaniraj/archive/2008/10/23/working-with-associations-in-ado-net-data-services-part-2.aspx

1 对 1 关联

http://blogs.msdn.com/b/phaniraj/archive/2008/07/02/working-with-relations-in-ado-net-data-services-beta-1.aspx

【讨论】：