多個DataReader錯誤，在本地工作，但不在發佈版本

Question

當在本地運行時，此工作正常，但在發佈並運行後，我得到「已經有一個與此命令關聯的打開的DataReader，必須先關閉它。

是否有一種合適的方法使用相同的集合數據在不同的表上生成多個對象？

這可能本質上是處理這種情況的錯誤方法。

我基本上使用來自一個對象窗體的信息來創建另一個對象。

Localhost和發佈的版本使用相同的連接字符串。我試過設置MARS真

[HttpPost] 
    [ValidateAntiForgeryToken] 
    [ActionFilters.AuditInventory] 
    public ActionResult Create([Bind(Include = "CheckoutID,Date,Provider,Injection,Patient,Chart,Location,Lot,Restocked,Authorized,Accountable,Quantity")] CheckOutInjectionViewModel checkOutInjectionViewModel) 
    { 
     foreach (var i in db.Inventories) 
     { 
      if (i.Location_Injection.Bottle == null) 
      { 
       if (i.Location_Injection.Location.Location == checkOutInjectionViewModel.Location && i.Location_Injection.Injection.Injection == checkOutInjectionViewModel.Injection) 
       { 
        i.Quantity -= checkOutInjectionViewModel.Quantity; 
       } 
      } 
     } 



     if (ModelState.IsValid) 
     { 
      db.CheckedOutInjections.Add(checkOutInjectionViewModel); 
      db.SaveChanges(); 
      var injection = new Injections 
      { 
       Accountable = checkOutInjectionViewModel.Accountable, 
       Date = checkOutInjectionViewModel.Date, 
       Injection = checkOutInjectionViewModel.Injection, 
       Location = checkOutInjectionViewModel.Location, 
       MySignature = checkOutInjectionViewModel.MySignature, 
       Provider = checkOutInjectionViewModel.Provider, 
       Quantity = checkOutInjectionViewModel.Quantity, 
      }; 
      db.InjectionsAggregate.Add(injection); 
      db.SaveChanges(); 
      return RedirectToAction("Index"); 
     } 

     return View(checkOutInjectionViewModel); 
    } 

堆棧跟蹤

[InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.] 
    System.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command) +2076159 
    System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async) +328 
    System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +161 
    System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +121 
    System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +202 
    System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch(TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) +104 
    System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.Reader(DbCommand command, DbCommandInterceptionContext interceptionContext) +505 
    System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +37 

[EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details.] 
    System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.ExecuteStoreCommands(EntityCommand entityCommand, CommandBehavior behavior) +126 
    System.Data.Entity.Core.Objects.Internal.ObjectQueryExecutionPlan.Execute(ObjectContext context, ObjectParameterCollection parameterValues) +1047 
    System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction(Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) +469 
    System.Data.Entity.Core.Objects.<>c__DisplayClass7.<GetResults>b__5() +205 
    System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +238 
    System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption) +349 
    System.Data.Entity.Core.Objects.DataClasses.EntityReference`1.Load(MergeOption mergeOption) +188 
    System.Data.Entity.Core.Objects.DataClasses.RelatedEnd.DeferredLoad() +449 
    System.Data.Entity.Core.Objects.Internal.LazyLoadBehavior.LoadProperty(TItem propertyValue, String relationshipName, String targetRoleName, Boolean mustBeNull, Object wrapperObject) +131 
    System.Data.Entity.Core.Objects.Internal.<>c__DisplayClass7`2.<GetInterceptorDelegate>b__2(TProxy proxy, TItem item) +151 
    System.Data.Entity.DynamicProxies.Inventory_AAF69D7ACE3EC0D7440AC81F5B4FEF9AA1625FB9547A97AF87B7EEE3DB9F6C07.get_Location_Injection() +39 
    Hughston_Injections.Controllers.CheckOutInjectionViewModelsController.Create(CheckOutInjectionViewModel checkOutInjectionViewModel) +123 
    lambda_method(Closure , ControllerBase , Object[]) +139 
    System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +209 
    System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +35 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +39 
    System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +67 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +42 
    System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() +72 
    System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +386 
    System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +386 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +42 
    System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +30 
    System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +186 
    System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +38 
    System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +29 
    System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +65 
    System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +53 
    System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36 
    System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +38 
    System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +44 
    System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +65 
    System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +38 
    System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +399 
    System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +157 

Answer 1

這是我想到了，我繼續從我發佈的服務器上運行時，它僅接收打開的DataReader錯誤的解決方案到，一切工作正常在本地運行。

將所有內容轉換爲sql命令後，我必須做的最後一件事就是移動引用db上下文（在控制器中聲明）的foreach循環，並且必須在保存對新上下文實例的更改之後例如嘗試仍然會導致失敗。

[HttpPost] 
    [ValidateAntiForgeryToken] 
    [ActionFilters.AuditInventory] 
    public ActionResult Create([Bind(Include = "CheckoutID,Date,Provider,Injection,Patient,Chart,Location,Lot,Restocked,Authorized,Accountable,Quantity")] CheckOutInjectionViewModel checkOutInjectionViewModel) 
    { 
     if (ModelState.IsValid) 
     { 
      StringBuilder sb = null; 
      using (SqlConnection conn = new SqlConnection("CONNECTION_STRING")) 
      { 
       try 
       { 
        sb = new StringBuilder("INSERT INTO Injections VALUES ("); 
        sb.Append("'" + (checkOutInjectionViewModel.Date.HasValue ? checkOutInjectionViewModel.Date.Value.ToString("yyyy-MM-dd") : "1999-01-01") + "',"); 
        sb.Append("'" + checkOutInjectionViewModel.Provider + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Quantity.ToString() + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Accountable + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Location + "', "); 
        sb.Append("NULL,"); 
        sb.Append("'" + checkOutInjectionViewModel.Injection + "');"); 

        sb.Append("INSERT INTO CheckOutInjectionViewModels VALUES ("); 
        sb.Append("'" + (checkOutInjectionViewModel.Date.HasValue ? checkOutInjectionViewModel.Date.Value.ToString("yyyy-MM-dd") : "1999-01-01") + "',"); 
        sb.Append("'" + checkOutInjectionViewModel.Patient + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Chart + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Lot + "', "); 
        sb.Append("'FALSE',"); 
        sb.Append("NULL,"); 
        sb.Append("'FALSE',"); 
        sb.Append("'" + checkOutInjectionViewModel.Provider + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Injection + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Location + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Accountable + "', "); 
        sb.Append("'" + checkOutInjectionViewModel.Quantity.ToString() + "', "); 
        sb.Append("NULL);"); 

        conn.Open(); 


        var context = new ApplicationDbContext(); 
        context.Database.ExecuteSqlCommand(sb.ToString()); 
        context.SaveChanges(); 

        foreach (var i in db.Inventories) 
        { 
         if (i.Location_Injection.Bottle == null) 
         { 
          if (i.Location_Injection.Location.Location == checkOutInjectionViewModel.Location && i.Location_Injection.Injection.Injection == checkOutInjectionViewModel.Injection) 
          { 
           i.Quantity -= checkOutInjectionViewModel.Quantity; 
          } 
         } 
        } 

       } 
       catch (Exception ex) 
       { 
        ViewBag.Error = ex.Message + Environment.NewLine + sb.ToString(); 
        ViewBag.Locations = new SelectList(db.Locations, "Location", "Location"); 
        ViewBag.Providers = new SelectList(db.Providers, "Provider", "Provider"); 
        ViewBag.Injections = new SelectList(db.Injections, "Injection", "Injection"); 
        ViewBag.Accountables = new SelectList(db.Accountables, "Accountable", "Accountable"); 
       } 
       finally 
       { 
        conn.Close(); 
       } 
       return RedirectToAction("Index"); 
      } 
     } 
     return View(checkOutInjectionViewModel); 
    }