Vb.net ADO.NET数据服务，带有EF实现每具体类型表（TPCT）继承

我使用的SQL数据源在多个表中有重复数据。我无法控制数据库。对于我的项目，我使用VS2008创建了一个EF模型和一个ADO.NET数据服务，该服务公开了EF模型和ADO.NET数据服务。我还有一个使用该服务的.NET客户端应用程序

现在，这些db表有大量公共字段，在向服务发送insert请求之前，我需要在客户机中添加这些字段。因此，为了避免重复代码，我在EF模型中创建了一个抽象基类，并将所有公共属性放在其中。此基类的实体集名称为OrderEntries。从中继承的一个实体称为oOrdh。它映射到一个db表。为了公开这个实体，我创建了一个WebGet服务方法，因为查询使用OfType方法，该方法不支持到ATOM的转换；因此，我不能在我的客户中使用它。方法如下：

<WebGet()> _
Public Function Orders() As IQueryable(Of OEORDH)
    Dim results = From x In Me.CurrentDataSource.OrderEntries.OfType(Of OEORDH)()
    Return results
End Function

---

为了获得更有意义的错误消息，请尝试将[System.ServiceModel.ServiceBehaviorIncludeExceptionDetailInFaults=true]放在数据服务类的顶部。您可以使用$filter=isofMyNS.oOrdh基本上请求服务器上的OfType查询。它不完全相同，但结果应该相同。有关更多详细信息，请参阅：谢谢Vitek。我将查看文档为了获得更有意义的错误消息，请尝试将[System.ServiceModel.ServiceBehaviorIncludeExceptionDetailInFaults=true]放在数据服务类的顶部。您可以使用$filter=isofMyNS.oOrdh基本上请求服务器上的OfType查询。虽然不完全相同，但结果应该相同。有关更多详细信息，请参阅：谢谢Vitek。我去查一下文件

<link rel="self" title="Orders" href="Orders" />
  <m:error>
    <m:code></m:code>
    <m:message xml:lang="en-US">An error occurred while processing this request.</m:message>
  </m:error>

System.ServiceModel.Channels.CommunicationObject.ThrowIfAborted()
System.ServiceModel.Channels.InputQueueChannel`1.EndDequeue(IAsyncResult result, TDisposable& item)
System.ServiceModel.Channels.ReplyChannel.EndTryReceiveRequest(IAsyncResult result, RequestContext& context)
System.ServiceModel.Dispatcher.ReplyChannelBinder.EndTryReceive(IAsyncResult result, RequestContext& requestContext)
System.ServiceModel.Dispatcher.ErrorHandlingReceiver.EndTryReceive(IAsyncResult result, RequestContext& requestContext)
System.ServiceModel.Dispatcher.ChannelHandler.AsyncMessagePump(IAsyncResult result)
System.ServiceModel.Dispatcher.ChannelHandler.OnAsyncReceiveComplete(IAsyncResult result)
System.ServiceModel.Diagnostics.Utility.AsyncThunk.UnhandledExceptionFrame(IAsyncResult result)
System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously)
System.ServiceModel.Channels.InputQueue`1.AsyncQueueReader.Set(Item item)
System.ServiceModel.Channels.InputQueue`1.Shutdown(CommunicationObject communicationObject)
System.ServiceModel.Channels.InputQueueChannel`1.OnClosing()
System.ServiceModel.Channels.CommunicationObject.Abort()
System.ServiceModel.Dispatcher.ReplyChannelBinder.Abort()
System.ServiceModel.Channels.ServiceChannel.OnAbort()
System.ServiceModel.Channels.CommunicationObject.Abort()
System.Data.Services.DelegateBodyWriter.OnWriteBodyContents(XmlDictionaryWriter writer)
System.ServiceModel.Channels.BodyWriter.WriteBodyContents(XmlDictionaryWriter writer)
System.ServiceModel.Channels.BodyWriterMessage.OnWriteBodyContents(XmlDictionaryWriter writer)
System.ServiceModel.Channels.Message.OnWriteMessage(XmlDictionaryWriter writer)
System.ServiceModel.Channels.Message.WriteMessage(XmlDictionaryWriter writer)
System.ServiceModel.Channels.HttpStreamMessageEncoderFactory.HttpStreamMessageEncoder.WriteMessage(Message message, Stream stream)
System.ServiceModel.Channels.HttpStreamMessageEncoderFactory.HttpStreamMessageEncoder.WriteMessage(Message message, Int32 maxMessageSize, BufferManager bufferManager, Int32 messageOffset)
System.ServiceModel.Channels.WebMessageEncoderFactory.WebMessageEncoder.WriteMessage(Message message, Int32 maxMessageSize, BufferManager bufferManager, Int32 messageOffset)
System.ServiceModel.Channels.HttpOutput.SerializeBufferedMessage(Message message)
System.ServiceModel.Channels.HttpOutput.Send(TimeSpan timeout)
System.ServiceModel.Channels.HttpRequestContext.OnReply(Message message, TimeSpan timeout)
System.ServiceModel.Activation.HostedHttpContext.OnReply(Message message, TimeSpan timeout)
System.ServiceModel.Channels.RequestContextBase.Reply(Message message, TimeSpan timeout)
System.ServiceModel.Channels.RequestContextBase.Reply(Message message)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.Reply(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessageCleanup(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage4(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage3(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage2(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage1(MessageRpc& rpc)
System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.Dispatch(MessageRpc& rpc, Boolean isOperationContextSet)
System.ServiceModel.Dispatcher.ChannelHandler.DispatchAndReleasePump(RequestContext request, Boolean cleanThread, OperationContext currentOperationContext)
System.ServiceModel.Dispatcher.ChannelHandler.HandleRequest(RequestContext request, OperationContext currentOperationContext)
System.ServiceModel.Dispatcher.ChannelHandler.AsyncMessagePump(IAsyncResult result)
System.ServiceModel.Dispatcher.ChannelHandler.OnAsyncReceiveComplete(IAsyncResult result)
System.ServiceModel.Diagnostics.Utility.AsyncThunk.UnhandledExceptionFrame(IAsyncResult result)
System.ServiceModel.AsyncResult.Complete(Boolean completedSynchronously)
System.ServiceModel.Channels.InputQueue`1.AsyncQueueReader.Set(Item item)
System.ServiceModel.Channels.InputQueue`1.EnqueueAndDispatch(Item item, Boolean canDispatchOnThisThread)
System.ServiceModel.Channels.InputQueue`1.EnqueueAndDispatch(T item, ItemDequeuedCallback dequeuedCallback, Boolean canDispatchOnThisThread)
System.ServiceModel.Channels.InputQueueChannel`1.EnqueueAndDispatch(TDisposable item, ItemDequeuedCallback dequeuedCallback, Boolean canDispatchOnThisThread)
System.ServiceModel.Channels.SingletonChannelAcceptor`3.Enqueue(QueueItemType item, ItemDequeuedCallback dequeuedCallback, Boolean canDispatchOnThisThread)
System.ServiceModel.Channels.HttpChannelListener.HttpContextReceived(HttpRequestContext context, ItemDequeuedCallback callback)
System.ServiceModel.Activation.HostedHttpTransportManager.HttpContextReceived(HostedHttpRequestAsyncResult result)
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.HandleRequest()
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.BeginRequest()
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequest(Object state)
System.ServiceModel.PartialTrustHelpers.PartialTrustInvoke(ContextCallback callback, Object state)
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.OnBeginRequestWithFlow(Object state)
System.ServiceModel.Channels.IOThreadScheduler.CriticalHelper.WorkItem.Invoke2()
System.ServiceModel.Channels.IOThreadScheduler.CriticalHelper.WorkItem.Invoke()
System.ServiceModel.Channels.IOThreadScheduler.CriticalHelper.ProcessCallbacks()
System.ServiceModel.Channels.IOThreadScheduler.CriticalHelper.CompletionCallback(Object state)
System.ServiceModel.Channels.IOThreadScheduler.CriticalHelper.ScheduledOverlapped.IOCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped)
System.ServiceModel.Diagnostics.Utility.IOCompletionThunk.UnhandledExceptionFrame(UInt32 error, UInt32 bytesRead, NativeOverlapped* nativeOverlapped)
System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)