Question

当我第一次保存实体对象时，它完美地工作，但是在对同一个对象的第二次尝试时，它失败了DbUpdateConcurrencyException。我在“LastUpdated”属性上设置了Concurrency Mode到Fixed，这是一个DateTime，只要应用程序正在运行，就只维护一个Context实例。

在保存我的对象之前，我会自动更新“并发”（DatMaj）属性，这是我的保存方法（这是一个简化版本，但它仍然崩溃）：

    public virtual bool Save(IDbEntity pEntityToSave)
    {
        pEntityToSave.DatMaj = DateTime.Now;
        var result = ContextManager.Context.SaveChanges();

        //With this the DbUpdateConcurrencyException problem disappears, but it is a unnecessary hit to the database.
        //if (result > 0)
        //    Reload(pEntityToSave);

        return (result > 0);
    }

第一次运作良好。但是如果我编辑它并在几秒钟后再次保存它，则会抛出DbUpdateConcurrencyException。

真正奇怪的是，如果我记录实体框架生成的SQL，在第二次尝试时，我看到：

UPDATE [flux].[EXO_PTN_Partenaire]
SET [PTN_DatMaj] = @0
WHERE (([PTN_IdPartenaire] = @1) AND ([PTN_DatMaj] = @2))

-- @0: '17/12/2013 18:04:20' (Type = DateTime2)

-- @1: '2' (Type = Int64)

-- @2: '17/12/2013 18:04:03' (Type = DateTime2)

-- Executing at 17/12/2013 18:04:20 +01:00

-- Completed in 1 ms with result: 0

正如您所看到的，它显示Completed in 1 ms with result: 0但是如果我直接在数据库上手动执行完全相同的查询，它就可以工作。

如果在try...catch...中我调用ex.Entries.Single().Reload();并再次保存，则可以使用完全相同的过滤器来记录SQL查询。我不知道为什么它似乎无法执行（我怀疑它并没有真正执行它），而我可以这样做。
我错过了什么？这是一种缓存问题吗？我认为实体框架在保存之后重置了对象状态（状态，原始值...），但可能不完全。

解决问题的一个简单解决方法是在Reload()之后使用SaveChanges()，但我觉得这对数据库来说是无用的。还有另一种解决方法吗？

我在SQL Server 2008 R2数据库上使用C＃4.0（WPF）和Entity Framework 6（DbContext）

更新：根据要求，堆栈跟踪

System.Transactions Critical: 0 : <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Critical"><TraceIdentifier>http://msdn.microsoft.com/TraceCodes/System/ActivityTracing/2004/07/Reliability/Exception/Unhandled</TraceIdentifier><Description>Unhandled exception</Description><AppDomain>PS.vshost.exe</AppDomain><Exception><ExceptionType>System.Data.Entity.Infrastructure.DbUpdateConcurrencyException, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType><Message>Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.</Message><StackTrace>   at System.Data.Entity.Internal.InternalContext.SaveChanges()
   at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
   at System.Data.Entity.DbContext.SaveChanges()
   at ...DS.BaseDS`1.Save(IDbEntity pEntityToSave) in ...:line 38
   at ...BS.BaseBS`1.Save(TEntity pEntity) in ...:line 26
   at ...PS.ViewModel.BaseViewModel`2.SaveCurrentEntity() in ...:line 129
   at ...PS.ViewModel.FileViewModel.Enregistrer_Execute() in...:line 69
   at ...PS.ViewModel.FileViewModel.&amp;lt;InitializeCommands&amp;gt;b__6(Object x) in ...:line 51
   at ...WPF.DelegateCommand.Execute(Object parameter) in ...:line 84
   at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
   at System.Windows.Controls.Primitives.ButtonBase.OnClick()
   at System.Windows.Controls.Button.OnClick()
   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&amp;amp; handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean&amp;amp; handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean&amp;amp; 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&amp;amp; msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   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 ...PS.App.Main() in ...: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()</StackTrace><ExceptionString>System.Data.Entity.Infrastructure.DbUpdateConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries. ---&amp;gt; System.Data.Entity.Core.OptimisticConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.
   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ValidateRowsAffected(Int64 rowsAffected, UpdateCommand source)
   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.&amp;lt;Update&amp;gt;b__2(UpdateTranslator ut)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction, Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update(Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;SaveChangesToStore&amp;gt;b__b()
   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;&amp;gt;c__DisplayClass9.&amp;lt;SaveChanges&amp;gt;b__6()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
   at System.Data.Entity.Internal.InternalContext.SaveChanges()
   --- End of inner exception stack trace ---
   at System.Data.Entity.Internal.InternalContext.SaveChanges()
   at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
   at System.Data.Entity.DbContext.SaveChanges()
   at ...DS.BaseDS`1.Save(IDbEntity pEntityToSave) in ...:line 38
   at ...BS.BaseBS`1.Save(TEntity pEntity) in ...:line 26
   at ...PS.ViewModel.BaseViewModel`2.SaveCurrentEntity() in ...:line 129
   at ...PS.ViewModel.FileViewModel.Enregistrer_Execute() in ...:line 69
   at ...PS.ViewModel.FileViewModel.&amp;lt;InitializeCommands&amp;gt;b__6(Object x) in ...:line 51
   at ...WPF.DelegateCommand.Execute(Object parameter) in...:line 84
   at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
   at System.Windows.Controls.Primitives.ButtonBase.OnClick()
   at System.Windows.Controls.Button.OnClick()
   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&amp;amp; handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean&amp;amp; handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean&amp;amp; 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&amp;amp; msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   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 ...PS.App.Main() in ...: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()</ExceptionString><DataItems><Data></Data></DataItems><InnerException><ExceptionType>System.Data.Entity.Core.OptimisticConcurrencyException, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</ExceptionType><Message>Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.</Message><StackTrace>   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ValidateRowsAffected(Int64 rowsAffected, UpdateCommand source)
   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.&amp;lt;Update&amp;gt;b__2(UpdateTranslator ut)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction, Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update(Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;SaveChangesToStore&amp;gt;b__b()
   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;&amp;gt;c__DisplayClass9.&amp;lt;SaveChanges&amp;gt;b__6()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
   at System.Data.Entity.Internal.InternalContext.SaveChanges()</StackTrace><ExceptionString>System.Data.Entity.Core.OptimisticConcurrencyException: Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.
   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ValidateRowsAffected(Int64 rowsAffected, UpdateCommand source)
   at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.&amp;lt;Update&amp;gt;b__2(UpdateTranslator ut)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction, Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update(Boolean throwOnClosedConnection)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;SaveChangesToStore&amp;gt;b__b()
   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy)
   at System.Data.Entity.Core.Objects.ObjectContext.&amp;lt;&amp;gt;c__DisplayClass9.&amp;lt;SaveChanges&amp;gt;b__6()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
   at System.Data.Entity.Internal.InternalContext.SaveChanges()</ExceptionString></InnerException></Exception></TraceRecord>

Answer 1

不确定，但是如果将它添加到modifiesEntities两次：

if (pEntityToUpdate != null)
    modifiedEntities.Add(pEntityToUpdate);

..我希望有些问题。看起来'if'应该测试别的东西。该实体是否具有IDENITY列？如果是这样，那么测试应该与设定的相反。

干杯 -

保存两次时抛出DbUpdateConcurrencyException

1 个答案: