OleDbConnection.BeginTransaction Método

Definição

Namespace:

System.Data.OleDb

Assembly:

System.Data.OleDb.dll

Pacote:

System.Data.OleDb v8.0.0

Inicia uma transação de banco de dados.

Sobrecargas

BeginTransaction()	Inicia uma transação de banco de dados com o valor IsolationLevel atual.
BeginTransaction(IsolationLevel)	Inicia uma transação de banco de dados com o nível de isolamento especificado.

BeginTransaction()

Origem:

OleDbConnection.cs

Inicia uma transação de banco de dados com o valor IsolationLevel atual.

public:
 System::Data::OleDb::OleDbTransaction ^ BeginTransaction();

public System.Data.OleDb.OleDbTransaction BeginTransaction ();

override this.BeginTransaction : unit -> System.Data.OleDb.OleDbTransaction

Public Function BeginTransaction () As OleDbTransaction

Retornos

OleDbTransaction

Um objeto que representa a nova transação.

Exceções

InvalidOperationException

Não há suporte para transações paralelas.

Exemplos

O exemplo a seguir cria um OleDbConnection e um OleDbTransaction. Ele também demonstra como usar os BeginTransactionmétodos , Commite Rollback .

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 with ReadCommitted isolation level.
            transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted);

            // 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 with ReadCommitted isolation level.
            transaction = connection.BeginTransaction(IsolationLevel.ReadCommitted)

            ' 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

Comentários

Você deve confirmar ou reverter explicitamente a transação usando o Commit método ou Rollback . Para garantir que o modelo de gerenciamento de transações .NET Framework Data Provider for OLE DB seja executado corretamente, evite usar outros modelos de gerenciamento de transações, como os fornecidos pela fonte de dados.

Confira também

• Conectando-se a fontes de dados

BeginTransaction(IsolationLevel)

Origem:

OleDbConnection.cs

Inicia uma transação de banco de dados com o nível de isolamento especificado.

public:
 System::Data::OleDb::OleDbTransaction ^ BeginTransaction(System::Data::IsolationLevel isolationLevel);

public System.Data.OleDb.OleDbTransaction BeginTransaction (System.Data.IsolationLevel isolationLevel);

override this.BeginTransaction : System.Data.IsolationLevel -> System.Data.OleDb.OleDbTransaction

Public Function BeginTransaction (isolationLevel As IsolationLevel) As OleDbTransaction

Parâmetros

isolationLevel

IsolationLevel

O nível de isolamento em que a transação deve ser executada.

Retornos

OleDbTransaction

Um objeto que representa a nova transação.

Exceções

InvalidOperationException

Não há suporte para transações paralelas.

Exemplos

O exemplo a seguir cria um OleDbConnection e um OleDbTransaction. Ele também demonstra como usar os BeginTransactionmétodos , um Commite Rollback .

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

Comentários

Você deve confirmar ou reverter explicitamente a transação usando o Commit método ou Rollback . Para garantir que o modelo de gerenciamento de transações .NET Framework Data Provider for OLE DB seja executado corretamente, evite usar outros modelos de gerenciamento de transações, como os fornecidos pela fonte de dados.

Observação

Se você não especificar um nível de isolamento, o nível de isolamento padrão para o provedor subjacente será usado. Para especificar um nível de isolamento com o BeginTransaction método , use a sobrecarga que usa o isolationLevel parâmetro .

Confira também

• Conectando-se a fontes de dados