事务回滚错误（此 SqlTransaction 已完成；它不再可用）

Question

我正在尝试测试第一个事务，如果它是成功的，那么我尝试第二个事务，如果第二个事务也是一个成功，那么我将两个都提交，如果第二个事务失败，我需要回滚首先。

所以我有以下函数，它返回一个可以是状态之一的字典：

0（表示事务失败但设法回滚）-> sql 事务

1（表示事务成功）-> sql事务

-1（表示事务失败并且没有设法回滚）-> sql 事务

Public Function execDBTrans_valMod(transactionName As String, ByVal emailSubject As String, ByVal emailBody As String, ByVal queryString As String, Optional ByVal connectionString As String = "SQLConnectionHere") As Dictionary(Of Integer, SqlTransaction)
        Dim trans_dict As New Dictionary(Of Integer, SqlTransaction)

        Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings(connectionString).ToString) 'LATEST EXEC
            connection.Open()

            Dim command As New SqlCommand(queryString, connection)
            Dim transaction As SqlTransaction = connection.BeginTransaction(transactionName)
            command.Transaction = transaction

            Try
                command.CommandTimeout = 3600 'Used for large updates
                command.ExecuteNonQuery()
                'transaction.Commit() DO NOT COMMIT so that we can commit only after we verify that pbSite can be inserted

                trans_dict.Add(1, transaction)
                Return trans_dict
            Catch dbTrans_ex As Exception
                Try
                    transaction.Rollback()

                    trans_dict.Add(0, transaction)
                    Return trans_dict
                Catch dbTrans2_ex As Exception

                    trans_dict.Add(-1, transaction)
                    Return trans_dict
                    ' This catch block will handle any errors that may have occurred on the server that would cause the rollback to fail, such as a closed connection.
                End Try
            End Try

        End Using
    End Function

然后我在函数中有以下代码：

Dim transPB_dict = execDBTrans_valMod("transPB", failSubject, failBody, buildInsert)
If transPB_dict.ContainsKey(1) Then 'SUCCESS

    Dim transPBsite_dict = execDBTrans_valMod("transPBsite", failSubject, failBody, buildInsert_PBsite)

    If transPBsite_dict.ContainsKey(1) Then
        transPB_dict.Item(1).Commit()
        transPBsite_dict.Item(1).Commit()
        Return True
    Else 'Failed to create the tables for this user so rollback all the tables that were created in the previous transaction (all the old tables in panelbase)
        transPB_dict.Item(1).Rollback() 'THIS THROWS THE ERROR This SqlTransaction has completed; it is no longer usable

        Return False
    End If

Else
        Return False
End if

我还没有提交第一个事务，为什么我尝试回滚时却说sqlTransaction已经完成...？

感谢您的帮助！

Answer 1

当你退出 USING 块时

Using connection As New SqlConnection...
End Using

您的连接已关闭并被释放，并且针对该连接的任何待处理事务都已提交。您不能针对多个连接进行相同的事务。

只需创建和打开一次连接。将此连接（和事务）传递给将要处理 SQL 的方法。然后，当一切都完成后，您可以提交您的事务并关闭/释放您的连接。

处理跨多个 SQL 命令的单个连接将提高程序的速度，因为每个连接都会产生开销，从而减慢您的速度。

Answer 2

因为您的连接在execDBTrans_valMod 中打开和关闭。
当连接关闭时，与该连接关联的事务结束。

如果您需要在第二个命令失败时回滚第一个命令，您只需要一个事务。
连接和事务应该由命令执行器的调用者管理。

你需要这样的东西：

Public Sub execDBTrans_valMod(ByVal transaction As SqlTransaction, ByVal emailSubject As String, ByVal emailBody As String, ByVal queryString As String)
    Using command As New SqlCommand(queryString, transaction.Connection, transaction)
        Try
            command.CommandTimeout = 3600 'Used for large updates
            command.ExecuteNonQuery()
        Catch ex As Exception
            ' Do something with emailSubject and emailBody??
            ' Then rethrow ex to be caught by the caller.
            Throw
        End Try
    End Using
End Sub

和调用者：

Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("SQLConnectionHere").ToString)
    connection.Open()
    Using transaction As SqlTransaction = connection.BeginTransaction()
        Try
            execDBTrans_valMod(transaction, failSubject, failBody, buildInsert)
            execDBTrans_valMod(transaction, failSubject, failBody, buildInsert_PBsite)
            transaction.Commit()
            Return True
        Catch ex As Exception
            Try
                transaction.Rollback()
            Catch exRollback As Exception
                ' Do logging or something when rollback failed.
            End Try
            Return False
        End Try
    End Using
End Using