我最近在服务器上部署了应用程序，但我遇到了Entity框架6的问题。它以这种方式失败了。在部署/配置cheange之后首次注意我收到此错误：
[ConfigurationErrorsException: The 'DbProviderFactories' section can only appear once per config file.]
System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) +834506
System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object& result, Object& resultRuntimeObject) +836240
System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
System.Configuration.BaseConfigurationRecord.GetSection(String configKey) +69
System.Configuration.ConfigurationManager.GetSection(String sectionName) +140
System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) +43
System.Data.Common.DbProviderFactories.Initialize() +218
System.Data.Common.DbProviderFactories.GetProviderTable() +9
System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +146
System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) +83
System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type, Object key) +179
System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type, Object key) +71
System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService(IDbDependencyResolver resolver, Object key) +84
System.Data.Entity.Core.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) +691
System.Data.Entity.Core.EntityClient.EntityConnection..ctor(String connectionString) +141
System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, AppConfig config) +186
System.Data.Entity.Internal.LazyInternalConnection.Initialize() +95
System.Data.Entity.Internal.LazyInternalConnection.CreateObjectContextFromConnectionModel() +16
System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +408
System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +26
System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +72
System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +68
System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +85
MobileDeviceDB.Controllers.AuthController.ShowIndex(LoginModel data) +1060
lambda_method(Closure , ControllerBase , Object[] ) +79
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +261
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +34
System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +124
System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +839035
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15
System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +33
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +839620
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +65
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +51
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +42
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +51
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288
刷新后我得到了这个例外：
[ArgumentException: Unable to find the requested .Net Framework Data Provider. It may not be installed.]
System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +282
[ArgumentException: The ADO.NET provider with invariant name 'System.Data.SqlClien' is either not registered in the machine or application config file, or could not be loaded. See the inner exception for details.]
System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.<GetService>b__0(ArgumentException e, String n) +58
System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +414
System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) +83
System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type, Object key) +179
System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type, Object key) +71
System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService(IDbDependencyResolver resolver, Object key) +84
System.Data.Entity.Core.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) +691
System.Data.Entity.Core.EntityClient.EntityConnection..ctor(String connectionString) +141
System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, AppConfig config) +186
System.Data.Entity.Internal.LazyInternalConnection.Initialize() +95
System.Data.Entity.Internal.LazyInternalConnection.CreateObjectContextFromConnectionModel() +16
System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +408
System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +26
System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +72
System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +68
System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +85
MobileDeviceDB.Controllers.AuthController.ShowIndex(LoginModel data) +1060
lambda_method(Closure , ControllerBase , Object[] ) +79
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +261
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +34
System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +124
System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +839035
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15
System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +33
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +839620
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +65
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +51
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +42
System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +51
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288
关于第一个例外 - 我的web.config中没有DbProviderFactories部分
关于第二个 - 我发现的唯一的事情是它可能是由于缺少＆＃34; EntityFramework.SqlServer.dll＆＃34;，但这不是我的情况 - 它就在那里
答案 0 :(得分：0)
所以我想出了出路 - 问题出现在第一个异常中（第二个只是覆盖它并搞砸了所有） - 在挖掘之后我发现.NET 4的machine.config有两个DbProviderFactories，其中一个他们空了