Question

我有一个使用TransactionScope的函数。当我使用两个dbContext时，它会崩溃。错误消息是：

System.Data.EntityException: Error underlying provider Open. ---> System.Transactions.TransactionException: The operation is not valid for the state of the transaction. in System.Transactions.TransactionState.EnlistPromotableSinglePhase (InternalTransaction tx, IPromotableSinglePhaseNotification promotableSinglePhaseNotification, Transaction AtomicTransaction, Guid promoterType) in System.Transactions.Transaction.EnlistPromotableSinglePhase (IPromotableSinglePhaseNotification promotableSinglePhaseNotification, Guid promoterType) in System.Transactions.Transaction.EnlistPromotableSinglePhase (IPromotableSinglePhaseNotification promotableSinglePhaseNotification) in System .Data.SqlClient.SqlInternalConnection.EnlistNonNull (Transaction tx) in System.Data.SqlClient.SqlInternalConnection.Enlist (Transaction tx)
in System.Data.ProviderBase.DbConnectionInternal.ActivateConnection (Transaction transaction) in System.Data.ProviderBase.DbConnectionPool.PrepareConnection (DbConnection owningObject, DbConnectionInternal obj, Transaction transaction) in System.Data.ProviderBase.DbConnectionPool.TryGetConnection (DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout , allowCreate Boolean, Boolean onlyOneCheckConnection, DbConnectionOptions UserOptions, DbConnectionInternal & connection) in System.Data.ProviderBase.DbConnectionPool.TryGetConnection (DbConnection owningObject, TaskCompletionSource1 retry, DbConnectionOptions
  UserOptions, DbConnectionInternal & connection) in
  System.Data.ProviderBase.DbConnectionFactory.TryGetConnection (DbConnection
  owningConnection, TaskCompletionSource1 retry, DbConnectionOptions UserOptions, DbConnectionInternal oldConnection, DbConnectionInternal & connection) in System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal (DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions UserOptions) in
  System.Data.SqlClient.SqlConnection.TryOpenInner (TaskCompletionSource1 retry) in System.Data.SqlClient.SqlConnection.TryOpen (TaskCompletionSource`1 retry) in System.Data.SqlClient.SqlConnection.Open () in System.Data.EntityClient.EntityConnection. OpenStoreConnectionIf (Boolean openCondition, DbConnection storeConnectionToOpen, DbConnection originalConnection, String ExceptionCode, attemptedOperation String, Boolean & closeStoreConnectionOnFailure)

代码

public void example(int c, IEnumerable<int> pi, string comm)
{
    using (var transactionScope = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = IsolationLevel.RepeatableRead }))
    {
        var idsList = pi.ToList();
        foreach (var playlist in Context.pl.Where(p => idsList.Contains(p.pid) && p.c== c&& p.stat== 1))
        {
            playlist.TimestampAuthorized = null;

            var pl = "sss";
            notif.generateNotifForUser((new Notification(1, 1, pl, 2, 2)));
        }
        Context.SaveChanges();
        transactionScope.Complete();
    }
}

问题发生在Context.SaveChanges(); 如果我对该行notif.generateNotifForUser();发表评论，则可行。在这个函数中，我也做context.saveChanges();

由于

Answer 1

// code before unchanged
foreach (var playlist in Context.pl.Where(p => idsList.Contains(p.pid) && p.c== c&& p.stat== 1).ToList()) // added ToList
// code after unchanged

问题与您尝试使用开放式连接进行两件事有关。迭代pl DbSet结果以及您在generateNotifForUser中正在进行的操作，这是您可能从DbContext获取/执行其他操作的内容（基于您的更新，您正在进行SaveChanges调用）。要解决此问题，请在Lamda语句的末尾添加ToList，以强制在迭代开始之前立即完整地显示查询结果。然后，连接将不再打开，允许您继续在代码的其他部分使用DbContext。这也假设你没有在方法链中进一步犯下类似的错误。

Answer 2

编辑：

通知方法似乎导致错误，因为它也在调用Context.SaveChanges

您只需要拨打Context.SaveChanges一次

我会删除通知方法中的Context.SaveChanges，只在事务范围结束时调用一次。

使用TransactionScope和两个DBContext，得到错误

2 个答案: