OdbcTransaction.Rollback 方法的VB.NET例子

下面的示例创建一个 OdbcConnection 和一个 OdbcTransaction 。此示例还演示如何使用 BeginTransaction、Commit 和 Rollback 等方法。

Public Sub ExecuteTransaction(ByVal connectionString As String)

    Using connection As New OdbcConnection(connectionString)
        Dim command As New OdbcCommand()
        Dim transaction As OdbcTransaction

        ' Set the Connection to the new OdbcConnection.
        command.Connection = connection

        ' Open the connection and execute the transaction.
        Try
            connection.Open()

            ' Start a local transaction.
            transaction = connection.BeginTransaction()

            ' Assign transaction object for a pending local transaction.
            command.Connection = connection
            command.Transaction = transaction

            ' Execute the commands.
            command.CommandText = _
                "Insert into Region (RegionID,RegionDescription) VALUES (100,'Description')"
            command.ExecuteNonQuery()
            command.CommandText = _
                "Insert into Region (RegionID,RegionDescription) VALUES (101,'Description')"
            command.ExecuteNonQuery()

            ' Commit the transaction.
            transaction.Commit()
            Console.WriteLine("Both records are written to database.")

        Catch ex As Exception
            Console.WriteLine(ex.Message)
            ' Try to rollback the transaction
            Try
                transaction.Rollback()

            Catch
                ' Do nothing here; transaction is not active.
            End Try
        End Try
        ' The connection is automatically closed when the
        ' code exits the Using block.
    End Using
End Sub