asp.net-mvc-3 - 无法将文件附加为数据库/底层提供程序打开失败

Question

我有一个使用 Entity Framework 的 MVC3 应用程序。我大约有一年没有使用这个应用程序了。最近，我在一台新电脑上打开它并尝试在 Debug模式下运行并在调试中遇到以下异常/堆栈跟踪。主要的异常(exception)似乎是“无法将文件附加为数据库”和“底层提供程序在打开时失败”。我在堆栈溢出上搜索了这些错误，发现的答案似乎与这种情况不符。例如，“无法将文件附加为数据库”的答案之一表明旧版本的数据库可能位于本地数据库上，但当我浏览到 localdb 时，我在本地数据库中看不到任何数据库在 Visual Studio 。

我正在寻找有关接下来要调查哪些内容以解决此问题的指导。有什么建议吗？

失败的实际代码是:

            var currentHunt = (from ph in this.repo.GetAllPuzzleHunts()
                           orderby ph.PuzzleHuntId descending
                           select ph).FirstOrDefault();

这是 Web 应用程序第一次尝试通过 Entity Framework 从数据库获取数据。

FWIW 这台机器有 Entity Framework 6.0，我使用的是 Visual Studio 2012。

异常/堆栈跟踪如下:

System.Data.DataException was unhandled by user code
  HResult=-2146233087
  Message=An exception occurred while initializing the database. See the InnerException for details.
  Source=EntityFramework
  StackTrace:
       at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
       at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization()
       at System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c)
       at System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase()
       at System.Data.Entity.Internal.InternalContext.Initialize()
       at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
       at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
       at System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator()
       at System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator()
       at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
       at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__0.MoveNext()
       at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
       at GutolMvcApp.Controllers.HomeController.Index() in c:\Users\jordanat\Documents\Visual Studio 2012\Projects\Gutol\Gutol\GutolMvcApp\Controllers\HomeController.cs:line 25
       at lambda_method(Closure , ControllerBase , Object[] )
       at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
       at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
       at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41()
       at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
  InnerException: System.Data.Entity.Core.EntityException
       HResult=-2146233087
       Message=The underlying provider failed on Open.
       Source=EntityFramework
       StackTrace:
            at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
            at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection()
            at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__9()
            at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
            at System.Lazy`1.CreateValue()
            at System.Lazy`1.LazyInitValue()
            at System.Lazy`1.get_Value()
            at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
            at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__1[TResult](IEnumerable`1 sequence)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[TResult](Expression expression)
            at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
            at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
            at System.Data.Entity.Internal.EdmMetadataRepository.QueryForModelHash(Func`2 createContext)
            at System.Data.Entity.Internal.InternalContext.QueryForModelHash()
            at System.Data.Entity.Internal.ModelCompatibilityChecker.CompatibleWithModel(InternalContext internalContext, ModelHashCalculator modelHashCalculator, Boolean throwIfNoMetadata)
            at System.Data.Entity.Internal.InternalContext.CompatibleWithModel(Boolean throwIfNoMetadata)
            at System.Data.Entity.Database.CompatibleWithModel(Boolean throwIfNoMetadata)
            at System.Data.Entity.CreateDatabaseIfNotExists`1.InitializeDatabase(TContext context)
            at System.Data.Entity.Internal.InternalContext.<>c__DisplayClasse`1.<CreateInitializationAction>b__d()
            at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
       InnerException: System.Data.SqlClient.SqlException
            HResult=-2146232060
            Message=Cannot attach the file 'C:\Users\...\Visual Studio 2012\Projects\Gutol\Gutol\GutolMvcApp\App_Data\PuzzleCollateral.mdf' as database 'PuzzleCollateral'.

感谢您的帮助!

Answer 1

尝试这样:

https://stackoverflow.com/a/16339164/1390999

Open the "Developer Command Propmpt for VisualStudio" under your start/programs menu. Run the following commands:

sqllocaldb.exe stop v11.0

sqllocaldb.exe delete v11.0

之后，尝试启动您的 MVC 应用程序