Sdílet prostřednictvím


OleDbConnection.BeginTransaction Metoda

Definice

Spustí transakci databáze.

Přetížení

BeginTransaction()

Spustí transakci databáze s aktuální IsolationLevel hodnotou.

BeginTransaction(IsolationLevel)

Spustí databázovou transakci se zadanou úrovní izolace.

BeginTransaction()

Zdroj:
OleDbConnection.cs
Zdroj:
OleDbConnection.cs
Zdroj:
OleDbConnection.cs

Spustí transakci databáze s aktuální IsolationLevel hodnotou.

public:
 System::Data::OleDb::OleDbTransaction ^ BeginTransaction();
public System.Data.OleDb.OleDbTransaction BeginTransaction ();
override this.BeginTransaction : unit -> System.Data.OleDb.OleDbTransaction
member this.BeginTransaction : unit -> System.Data.OleDb.OleDbTransaction
Public Function BeginTransaction () As OleDbTransaction

Návraty

Objekt představující novou transakci.

Výjimky

Paralelní transakce nejsou podporovány.

Příklady

Následující příklad vytvoří a OleDbConnectionOleDbTransaction. Ukazuje také, jak používat BeginTransactionmetody , Commita 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

Poznámky

Musíte explicitně potvrdit nebo vrátit zpět transakce pomocí Commit metody nebo Rollback . Chcete-li se ujistit, že zprostředkovatel dat rozhraní .NET Framework pro model správy transakcí OLE DB funguje správně, nepoužívejte jiné modely správy transakcí, například ty, které poskytuje zdroj dat.

Viz také

Platí pro

BeginTransaction(IsolationLevel)

Zdroj:
OleDbConnection.cs
Zdroj:
OleDbConnection.cs
Zdroj:
OleDbConnection.cs

Spustí databázovou transakci se zadanou úrovní izolace.

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
member this.BeginTransaction : System.Data.IsolationLevel -> System.Data.OleDb.OleDbTransaction
Public Function BeginTransaction (isolationLevel As IsolationLevel) As OleDbTransaction

Parametry

isolationLevel
IsolationLevel

Úroveň izolace, pod kterou by měla transakce běžet.

Návraty

Objekt představující novou transakci.

Výjimky

Paralelní transakce nejsou podporovány.

Příklady

Následující příklad vytvoří a OleDbConnectionOleDbTransaction. Ukazuje také, jak používat BeginTransactionmetody , Commita .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

Poznámky

Musíte explicitně potvrdit nebo vrátit zpět transakce pomocí Commit metody nebo Rollback . Chcete-li se ujistit, že zprostředkovatel dat rozhraní .NET Framework pro model správy transakcí OLE DB funguje správně, nepoužívejte jiné modely správy transakcí, například ty, které poskytuje zdroj dat.

Poznámka

Pokud nezadáte úroveň izolace, použije se výchozí úroveň izolace pro příslušného poskytovatele. Pokud chcete zadat úroveň izolace pomocí BeginTransaction metody , použijte přetížení, které přebírá isolationLevel parametr .

Viz také

Platí pro