c# - 替代数据库存储数据？

Question

我的应用程序使用的是 SQL Server Compact Edition(本地数据库)。但是当我在使用 Entity Framework 时，我一直遇到一个非常烦人的 UpdateException。我的数据库只有两个小表，外键关系将它们链接在一起。所以我想问是否有数据库的替代方案？或者这是唯一的选择？
更新:
Here是EDMX图。
这是异常的堆栈跟踪: System.Windows.Markup.XamlParseException was unhandled
Message=Cannot create instance of 'MainWindow' defined in assembly 'AssignmentOrganizer, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. Exception has been thrown by the target of an invocation. Error in markup file 'AssignmentOrganizer;component/MainWindow.xaml' Line 1 Position 9.
Source=PresentationFramework
LineNumber=1
LinePosition=9
StackTrace:
at System.Windows.Markup.XamlParseException.ThrowException(String message, Exception innerException, Int32 lineNumber, Int32 linePosition, Uri baseUri, XamlObjectIds currentXamlObjectIds, XamlObjectIds contextXamlObjectIds, Type objectType)
at System.Windows.Markup.XamlParseException.ThrowException(ParserContext parserContext, Int32 lineNumber, Int32 linePosition, String message, Exception innerException)
at System.Windows.Markup.BamlRecordReader.ThrowExceptionWithLine(String message, Exception innerException)
at System.Windows.Markup.BamlRecordReader.CreateInstanceFromType(Type type, Int16 typeId, Boolean throwOnFail)
at System.Windows.Markup.BamlRecordReader.GetElementAndFlags(BamlElementStartRecord bamlElementStartRecord, Object& element, ReaderFlags& flags, Type& delayCreatedType, Int16& delayCreatedTypeId)
at System.Windows.Markup.BamlRecordReader.BaseReadElementStartRecord(BamlElementStartRecord bamlElementRecord)
at System.Windows.Markup.BamlRecordReader.ReadElementStartRecord(BamlElementStartRecord bamlElementRecord)
at System.Windows.Markup.BamlRecordReader.ReadRecord(BamlRecord bamlRecord)
at System.Windows.Markup.BamlRecordReader.Read(Boolean singleRecord)
at System.Windows.Markup.TreeBuilderBamlTranslator.ParseFragment()
at System.Windows.Markup.TreeBuilder.Parse()
at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
at System.Windows.Application.LoadBamlStreamWithSyncInfo(Stream stream, ParserContext pc)
at System.Windows.Application.LoadComponent(Uri resourceLocator, Boolean bSkipJournaledProperties)
at System.Windows.Application.DoStartup()
at System.Windows.Application.<.ctor>b__0(Object unused)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at System.Threading.ExecutionContext.runTryCode(Object userData)
at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(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, Boolean isSingleParameter)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
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 AssignmentOrganizer.App.Main() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\AssignmentOrganizer\AssignmentOrganizer\obj\x86\Debug\App.g.cs:line 0
at System.AppDomain._nExecuteAssembly(Assembly 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)
at System.Threading.ThreadHelper.ThreadStart()
InnerException: System.Reflection.TargetInvocationException
Message=Exception has been thrown by the target of an invocation.
Source=mscorlib
StackTrace:
at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache)
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.Windows.Markup.BamlRecordReader.CreateInstanceFromType(Type type, Int16 typeId, Boolean throwOnFail)
InnerException: System.Data.UpdateException
Message=An error occurred while updating the entries. See the InnerException for details.
Source=System.Data.Entity
StackTrace:
at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
at System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache)
at System.Data.Objects.ObjectContext.SaveChanges(Boolean acceptChangesDuringSave)
at System.Data.Objects.ObjectContext.SaveChanges()
at AssignmentOrganizer.App_Data.AssignmentRepository.CreateAssignment(Assignment assignmentToCreate) in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\AssignmentOrganizer\AssignmentOrganizer\App_Data\AssignmentRepository.cs:line 20
at AssignmentOrganizer.MainWindow..ctor() in C:\Users\Mohit\Documents\Visual Studio 2010\Projects\AssignmentOrganizer\AssignmentOrganizer\MainWindow.xaml.cs:line 34
InnerException: System.Data.EntityCommandCompilationException
Message=An error occurred while preparing the command definition. See the inner exception for details.
Source=System.Data.Entity
StackTrace:
at System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree)
at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(UpdateTranslator translator, Dictionary 2 标识符值) 在 System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator 转换器、EntityConnection 连接、字典 2 identifierValues, List 1 generatedValues) 在 System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager，IEntityAdapter 适配器) 内部异常:System.NotSupportedException Message=SQL Server Compact 不支持服务器生成的键和服务器生成的值。 源=System.Data.SqlServerCe.Entity 堆栈跟踪: 在 System.Data.SqlServerCe.SqlGen.DmlSqlGenerator.GenerateReturningSql(StringBuilder commandText、DbModificationCommandTree 树、ExpressionTranslator 转换器、DbExpression 返回) 在 System.Data.SqlServerCe.SqlGen.DmlSqlGenerator.GenerateInsertSql(DbInsertCommandTree 树，列表 1& parameters, Boolean isLocalProvider)
at System.Data.SqlServerCe.SqlGen.SqlGenerator.GenerateSql(DbCommandTree tree, List 1& 参数，CommandType& commandType，Boolean isLocalProvider) 在 System.Data.SqlServerCe.SqlCeProviderServices.CreateCommand(DbProviderManifest providerManifest，DbCommandTree commandTree) 在 System.Data.SqlServerCe.SqlCeProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest，DbCommandTree 命令树) 在 System.Data.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree 命令树) 在 System.Data.Common.DbProviderServices.CreateCommand(DbCommandTree 命令树) 在 System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree 命令树) 内部异常:`

Answer 1

总是有选择的。问题是它们是否比数据库更好。您可以将数据存储在 XML 或您自己的文件格式等中。然后您必须编写适当的查询、更新代码等。这可能没问题 - 但我们不能说没有更多信息。

但是，在考虑其他解决方案之前，我会深入了解您看到异常的原因。当您更改存储层时，您可能会发生一些您没有真正预料到的行为，这些行为同样会伤害您 - 并且在那时可能更难诊断。弄清当前方法无效的原因后，您就能更好地了解它是否值得改变。