沃梦达 / 编程技术 / 编程语言 / C#/.NET开发 / 正文

c# – ASP.NET Web窗体和MySql实体框架：“不支持嵌套事务”

C#/.NET开发
2023-11-22

我有一个ASP.NET Web表单应用程序,使用.Net Connector for MySql Entity Framework.我以前使用MySql创建了一个Web应用程序,但从未遇到过这个问题.我目前每天获得大约20000次页面浏览量,并且每天大约有10次“嵌套交...

我有一个ASP.NET Web表单应用程序,使用.Net Connector for MySql Entity Framework.

我以前使用MySql创建了一个Web应用程序,但从未遇到过这个问题.

我目前每天获得大约20000次页面浏览量,并且每天大约有10次“嵌套交易”错误不受支持.

我无法弄清楚它为什么会发生,为什么它只会偶尔发生一次.

在主页面预加载事件中,我获得用户的整数ID并将其保存到公共变量：

using (var entity = new Entities())
                {
                    var user = entity.my_aspnet_users.Single(i => i.name == Context.User.Identity.Name);
                    UserID = user.id;
                    if (HttpContext.Current.Request.Url.AbsolutePath != "###" && HttpContext.Current.Request.Url.AbsolutePath != "###")
                    {
                        if (user.Player == null)
                            Response.Redirect("###", true);
                        else
                            PlayerID = user.Player.PlayerID;
                    }
                }

然后在页面上：

using (var entity = new Entities())
                            if (entity.Players.Count(i => ###) == 1)
                            {
                                var user = entity.my_aspnet_users.Single(i => i.id == Master.UserID);
                                if (user.Player == null)
                                {
                                    user.Player = entity.Players.Single(i => ###);
                                    entity.SaveChanges();
                                }
                                Response.Redirect("###", false);
                            }

SaveChanges()会抛出错误.我不知道为什么它有时只会发生.当用户在网站上注册时,我有时也会得到相同的错误,尽管所有这些似乎都是随机且罕见的.

无论如何,我认为在MySql中允许嵌套事务？我需要设置一个设置吗？我的MySql实例是5.6.17,我相信使用默认参数 – 在Amazon RDS中设置.

‘User.Identity.Name’是否访问数据库？你知道我在哪里可以解决这个问题吗？

如果有帮助,这里是一些例外的堆栈跟踪：

**Exception on example code:**
System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.Data.Entity.Core.EntityException: An error occurred while starting a transaction on the provider connection. See the inner exception for details. ---> System.InvalidOperationException: Nested transactions are not supported.

at MySql.Data.MySqlClient.ExceptionInterceptor.Throw(Exception exception)

at MySql.Data.MySqlClient.MySqlConnection.Throw(Exception ex)

at MySql.Data.MySqlClient.MySqlConnection.BeginTransaction(IsolationLevel iso)

at MySql.Data.MySqlClient.MySqlConnection.BeginDbTransaction(IsolationLevel isolationLevel)

at System.Data.Common.DbConnection.BeginTransaction(IsolationLevel isolationLevel)

at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.b__0(DbConnection t, BeginTransactionInterceptionContext c)

at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext,TResult](TTarget target, Func`3 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed)

at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.BeginTransaction(DbConnection connection, BeginTransactionInterceptionContext interceptionContext)

at System.Data.Entity.Core.EntityClient.EntityConnection.<>c__DisplayClassf.b__d()

at System.Data.Entity.Infrastructure.DefaultExecutionStrategy.Execute[TResult](Func`1 operation)

at System.Data.Entity.Core.EntityClient.EntityConnection.BeginDbTransaction(IsolationLevel isolationLevel)

--- End of inner exception stack trace ---

at System.Data.Entity.Core.EntityClient.EntityConnection.BeginDbTransaction(IsolationLevel isolationLevel)

at System.Data.Entity.Core.EntityClient.EntityConnection.BeginTransaction()

at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)

at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction)

at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass2a.b__27()

at System.Data.Entity.Infrastructure.DefaultExecutionStrategy.Execute[TResult](Func`1 operation)

at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction)

at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)

at System.Data.Entity.Internal.InternalContext.SaveChanges()

at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()

at System.Data.Entity.DbContext.SaveChanges()

at ###.Account.###.ButtonSubmit###_Click(Object sender, EventArgs e)

at System.Web.UI.WebControls.Button.OnClick(EventArgs e)

at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)

at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)

at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)

at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.HandleError(Exception e)

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.ProcessRequest()

at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)

at System.Web.UI.Page.ProcessRequest(HttpContext context)

at ASP.account_###.ProcessRequest(HttpContext context)

at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)



**Exception on creating a user:**
System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.InvalidOperationException: Nested transactions are not supported.

at MySql.Data.MySqlClient.ExceptionInterceptor.Throw(Exception exception)

at MySql.Data.MySqlClient.MySqlConnection.Throw(Exception ex)

at MySql.Data.MySqlClient.MySqlConnection.BeginTransaction(IsolationLevel iso)

at MySql.Data.MySqlClient.MySqlConnection.BeginTransaction()

at MySql.Web.Security.MySQLMembershipProvider.GetUser(Object providerUserKey, Boolean userIsOnline)

at MySql.Web.Security.MySQLMembershipProvider.GetUser(String username, Boolean userIsOnline)

at MySql.Web.Security.MySQLMembershipProvider.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status)

at System.Web.UI.WebControls.CreateUserWizard.AttemptCreateUser()

at System.Web.UI.WebControls.CreateUserWizard.OnNextButtonClick(WizardNavigationEventArgs e)

at System.Web.UI.WebControls.Wizard.OnBubbleEvent(Object source, EventArgs e)

at System.Web.UI.WebControls.CreateUserWizard.OnBubbleEvent(Object source, EventArgs e)

at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)

at System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e)

at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)

at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)

at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)

at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.HandleError(Exception e)

at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

at System.Web.UI.Page.ProcessRequest()

at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)

at System.Web.UI.Page.ProcessRequest(HttpContext context)

at ASP.register_aspx.ProcessRequest(HttpContext context)

at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

解决方法:

你可能遇到了this bug in MySQL Connector/NET.

什么触发了这个bug：

>代码调用执行查询A.
>启动查询A的事务1
>执行查询A并导致MySQL出错
>事务1未回滚
>代码调用执行查询B.
>启动查询B的事务2
> MySQL Connector / NET抛出异常

错误是第4点：事务1在发生错误后保持打开(或者至少连接器仍然确信它保持打开状态).由于连接池,调用查询A和查询B的代码可以完全不相关.此外,如果第4点和第5点之间的时间足够长,则回滚事务,因此稀有性和随机性.

不幸的是,MySQL还没有修复.我所知道的唯一解决方法是下载Connector / NET的源代码并自行修复/构建它.

本文标题为：c# – ASP.NET Web窗体和MySql实体框架：“不支持嵌套事务”

上一篇： 使用SqlDataReader的DateTime2到C#DateTime
下一篇： Oracle自定义类向导无法从Oracle用户定义的数据类型生成自定义c#类

基础教程推荐

学习HTML
学习jQuery
学习Laravel
学习CSS3
学习Vue.js
学习Bootstrap5
学习ThinkPHP
学习AJAX
猜你喜欢
最新文章
热门文章
编程基础
热门标签
网站首页 HTML/CSS 菜单 Layui Yii2