OleDbTransaction.Rollback Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Data.OleDb
Assembly:
System.Data.OleDb.dll
Assembly:
System.Data.dll
Pacchetto:
System.Data.OleDb v8.0.1
Pacchetto:
System.Data.OleDb v9.0.0-rc.2.24473.5
Origine:
OleDbTransaction.cs
Origine:
OleDbTransaction.cs

Esegue il rollback di una transazione da uno stato in sospeso.

public:
 override void Rollback();
public:
 virtual void Rollback();
public override void Rollback ();
public void Rollback ();
override this.Rollback : unit -> unit
abstract member Rollback : unit -> unit
override this.Rollback : unit -> unit
Public Overrides Sub Rollback ()
Public Sub Rollback ()

Implementazioni

Rollback()

Eccezioni

Exception

Si è verificato un errore durante il tentativo di eseguire il commit della transazione.

InvalidOperationException

È già stato eseguito il rollback o il commit della transazione.

-oppure-

La connessione non funziona.

Esempio

Nell'esempio seguente viene creato un oggetto OleDbConnection e un oggetto OleDbTransaction. Viene inoltre illustrato come usare i BeginTransactionmetodi , e CommitRollback .

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.
    }
}

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

Commenti

Il rollback della transazione può essere eseguito solo da uno stato in sospeso (dopo BeginTransaction essere stato chiamato, ma prima Commit di essere chiamato). Verrà eseguito il rollback della transazione nel caso in cui venga eliminato prima Commit o Rollback venga chiamato.

Si applica a

Vedi anche