得到错误的实体框架的SaveChanges在

Question

我得到这个错误：

An exception of type 'System.Data.Entity.Infrastructure.DbUpdateConcurrencyException' occurred in EntityFramework.dll but was not handled in user code

Additional information: 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.

dbContext.Productos.Add(producto); 
dbContext.Entry(producto).State = System.Data.Entity.EntityState.Modified; 
dbContext.SaveChanges(); 
} 

关于什么是错在这里的任何想法？

谢谢。

我的堆栈跟踪是：

[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.] 
    System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.ValidateRowsAffected(Int64 rowsAffected, UpdateCommand source) +232 
    System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update() +493 
    System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.<Update>b__2(UpdateTranslator ut) +32 
    System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update(T noChangesResult, Func`2 updateFunction) +272 
    System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update() +143 
    System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesToStore>b__35() +34 
    System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction(Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) +448 
    System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction) +219 
    System.Data.Entity.Core.Objects.<>c__DisplayClass2a.<SaveChangesInternal>b__27() +71 
    System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +213 
    System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction) +408 
    System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options) +39 
    System.Data.Entity.Internal.InternalContext.SaveChanges() +320 

[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.] 
    System.Data.Entity.Internal.InternalContext.SaveChanges() +366 
    System.Data.Entity.Internal.LazyInternalContext.SaveChanges() +56 
    System.Data.Entity.DbContext.SaveChanges() +52 
    Clase5.Data.ProductoRepositorio.Insertar(Producto producto) in c:\Users\Juan\Downloads\Clase_5_-_Codigo_fuente\Clase5\Clase4\Data\ProductoRepositorio.cs:27 
    Clase5.Controllers.ProductoController.TresCrearProducto(Producto producto) in c:\Users\Juan\Downloads\Clase_5_-_Codigo_fuente\Clase5\Clase4\Controllers\ProductoController.cs:43 
    lambda_method(Closure , ControllerBase , Object[]) +180 
    System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14 
    System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +211 
    System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27 
    System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28 
    System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +48 
    System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +57 
    System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +223 
    System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +10 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +48 
    System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24 
    System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43 
    System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47 
    System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10 
    System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25 
    System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 
    System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 
    System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47 
    System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9 
    System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9657896 
    System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155 

Answer 1

您已经Producto实体实施的字段级的并发。去你的Producto实体的EDMX设计者。逐一浏览每列的属性。选择视觉实体设计器中的列 - >按F4。检查物业Concurrency Mode的价值。它应该设置为无。看看下面的快照，作为我的一个实体Employee的示例。如果对于任何列，您将看到值为Fixed，那么这就是您的错误的根源。

如果你真的想做现场级别的并发，那就用RowVersion来代替。

Answer 2

你有没有设置AutoDetectChangesEnabled假？如果已经这样做，请在SaveChanges之前手动调用DetectChanges，不要直接更改输入状态。