OleDbTransaction.Rollback-Methode

Führt einen Rollback einer noch ausstehenden Transaktion aus.

Namespace: System.Data.OleDb
Assembly: System.Data (in system.data.dll)

Syntax

'Declaration
Public Overrides Sub Rollback
'Usage
Dim instance As OleDbTransaction

instance.Rollback

public override void Rollback ()

public:
virtual void Rollback () override

public void Rollback ()

public override function Rollback ()

Ausnahmen

Hinweise

Ein Rollback der Transaktion kann nur ausgeführt werden, wenn die Transaktion noch aussteht (nach dem Aufruf von BeginTransaction, jedoch vor dem Aufruf von Commit). Ein Rollback wird für die Transaktion ausgeführt, wenn sie verworfen wird, bevor Rollback oder Commit aufgerufen werden.

Beispiel

Im folgenden Beispiel werden eine OleDbConnection und eine OleDbTransaction erstellt. Darüber hinaus wird die Verwendung der Methoden BeginTransaction, Commit und Rollback veranschaulicht.

Public Sub ExecuteTransaction(ByVal connectionString As String)

    Using connection As New OleDbConnection(connectionString)
        Dim command As New OleDbCommand()
        Dim transaction As OleDbTransaction

        ' Set the Connection to the new OleDbConnection.
        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

public void ExecuteTransaction(string connectionString)
{
    using (OleDbConnection connection =
               new OleDbConnection(connectionString))
    {
        OleDbCommand command = new OleDbCommand();
        OleDbTransaction transaction = null;

        // Set the Connection to the new OleDbConnection.
        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 (Exception ex)
        {
            Console.WriteLine(ex.Message);
            try
            {
                // Attempt to roll back the transaction.
                transaction.Rollback();
            }
            catch
            {
                // Do nothing here; transaction is not active.
            }
        }
        // The connection is automatically closed when the
        // code exits the using block.
    }

using System;
using System.Data;
using System.Data.OleDb;

class Class1
{
    static void Main()
    {
    }

    public void ExecuteTransaction(string connectionString)
    {
        using (OleDbConnection connection =
                   new OleDbConnection(connectionString))
        {
            OleDbCommand command = new OleDbCommand();
            OleDbTransaction transaction = null;

            // Set the Connection to the new OleDbConnection.
            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 (Exception ex)
            {
                Console.WriteLine(ex.Message);
                try
                {
                    // Attempt to roll back the transaction.
                    transaction.Rollback();
                }
                catch
                {
                    // Do nothing here; transaction is not active.
                }
            }
            // The connection is automatically closed when the
            // code exits the using block.
        }

Plattformen

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

OleDbTransaction-Klasse
OleDbTransaction-Member
System.Data.OleDb-Namespace

Weitere Ressourcen

Durchführen von Transaktionen