类型'System.Data.Entity.Infrastructure.DbUpdateException'的例外

时间：2015-09-22 13:26:59

标签： c# asp.net-mvc entity-framework

我是mvc的新手，我尝试对我的控制器进行简单的Ajax调用，因此我可以在创建视图中使用日期和时间选择器。

您可以看到我之前请求帮助的thread。但现在我遇到了一个新问题。

我在尝试保存数据时遇到此错误： EntityFramework.dll中出现“System.Data.Entity.Infrastructure.DbUpdateException”类型的异常，但未在用户代码中处理 

 public ActionResult CreateEvent(string createSammantrade, string createStartTime, string createEndTime, string createLokal)
    {
        Sammantrade sammantrade = new Sammantrade();


        sammantrade.sSammantrade = createSammantrade;
        sammantrade.sStartTid = Convert.ToDateTime(createStartTime);
        sammantrade.sSlutTid = Convert.ToDateTime(createEndTime);
        sammantrade.lID = Int32.Parse(createLokal);

        if (ModelState.IsValid)
        {
            db.Sammantrade.Add(sammantrade);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        ViewBag.lID = new SelectList(db.Lokal, "lID", "lLokal", sammantrade.lID);
        return View(sammantrade);
    }

编辑：

System.Data.Entity.Infrastructure.DbUpdateException was unhandled by user code
HResult=-2146233087
Message=An error occurred while updating the entries. See the inner exception for details.
Source=EntityFramework
StackTrace:
vid System.Data.Entity.Internal.InternalContext.SaveChanges()
vid System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
vid System.Data.Entity.DbContext.SaveChanges()
vid VLVision.Controllers.SammantradesAdminController.CreateEvent(String createSammantrade, String createStartTime, String createEndTime, String createLokal) 
vid lambda_method(Closure , ControllerBase , Object[] )
vid System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
vid System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
vid System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
vid System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>
b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
vid System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
vid System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
vid System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
vid System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>
b__3d()
vid System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>
b__3f()
InnerException:
HResult=-2146233087
Message=An error occurred while updating the entries. See the inner exception for details.
Source=EntityFramework
StackTrace:
vid System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
vid System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.<Update>
b__2(UpdateTranslator ut)
vid System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction)
vid System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update()
vid System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesToStore>
b__35()
vid System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
vid System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction)
vid System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass2a.<SaveChangesInternal>
b__27()
vid System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
vid System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction)
vid System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
vid System.Data.Entity.Internal.InternalContext.SaveChanges()
InnerException:
Class=16
ErrorCode=-2146232060
HResult=-2146232060
LineNumber=1
Message=The INSERT statement conflicted with the FOREIGN KEY constraint "FK_Sammantrade_Lokal". The conflict occurred in database "VLVision", table "dbo.Lokal", column 'lID'.
The statement has been terminated.
Number=547
Procedure=""
Server=localhost\SQLExpress
Source=.Net SqlClient Data Provider
State=0
StackTrace:
vid System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
vid System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
vid System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
vid System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
vid System.Data.SqlClient.SqlDataReader.TryConsumeMetaData()
vid System.Data.SqlClient.SqlDataReader.get_MetaData()
vid System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
vid System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds, Boolean describeParameterEncryptionRequest)
vid System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite)
vid System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
vid System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
vid System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
vid System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
vid System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.<Reader>b__c(DbCommand t, DbCommandInterceptionContext`1 c)
vid System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)
vid System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext)
vid System.Data.Entity.Internal.InterceptableDbCommand.ExecuteDbDataReader(CommandBehavior behavior)
vid System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior)
vid System.Data.Entity.Core.Mapping.Update.Internal.DynamicUpdateCommand.Execute(Dictionary`2 identifierValues, List`1 generatedValues)
vid System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
InnerException:

2 个答案:

答案 0 :(得分：1)

EntityFramework是对数据库（通常是SQL Server）的抽象。当您在EF中遇到异常时，通常是因为框架抓住了较低级别SQLException，并且＃34;包裹了＃34;它作为InnerException，然后重新开始。因此，当您查找EF异常时，请记住，您应该打开那些InnerExceptions以找出问题的真正来源（通常是某种SQLException，并提供更有帮助的消息）

在这种情况下，希望你现在明白你正在尝试使用外键表中不存在的外键值。

至于你的MVC代码，@ Steve Muecke是正确的，你不需要总是声明字符串类型作为你的动作方法参数类型。当然，他们通过HTTP作为文本进入，但MVC的ModelBinder是强大的工具，能够将这些文本值转换为DateTime s，int，甚至包含其他基元的复杂类型和结构

db实例似乎也是DbContext，并且它是Controller类的私有属性。你是怎么处理它的？除非你有某种机制可以处理它，比如一个属性，好吧。否则，您应该在每个操作方法的DbContext语句中包装using构造和用法，或者使用IoC容器处理DbContext注入和处理。

这会更好：

if (ModelState.IsValid)
{
    using (var db = new MyDbContext())
    {
        db.Sammantrade.Add(sammantrade);
        db.SaveChanges();
    } // the using block will dispose of the DbContext here.

    return RedirectToAction("Index");
}

答案 1 :(得分：0)

从InnerException的{​​{1}}可以看出，主要错误是：

  

INSERT语句与FOREIGN KEY约束冲突   ＆＃34; FK_Sammantrade_Lokal＆＃34 ;.冲突发生在数据库＆＃34; VLVision＆＃34;中，   table＆＃34; dbo.Lokal＆＃34;，column＆＃39; lID＆＃39;

因此，您将无效值传递给字段：DbUpdateException，这段代码中的引用表lID中不存在该值：

dbo.Lokal
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