SqlCeTransaction.Rollback-Methode

Führt einen Rollback einer noch ausstehenden Transaktion aus.

Namespace:  System.Data.SqlServerCe
Assembly:  System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)

Syntax

'Declaration
<SecurityTreatAsSafeAttribute> _
<SecurityCriticalAttribute> _
<SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode := True)> _
Public Overrides Sub Rollback
'Usage
Dim instance As SqlCeTransaction

instance.Rollback()

[SecurityTreatAsSafeAttribute]
[SecurityCriticalAttribute]
[SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode = true)]
public override void Rollback()

[SecurityTreatAsSafeAttribute]
[SecurityCriticalAttribute]
[SecurityPermissionAttribute(SecurityAction::Assert, UnmanagedCode = true)]
public:
virtual void Rollback() override

[<SecurityTreatAsSafeAttribute>]
[<SecurityCriticalAttribute>]
[<SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode = true)>]
abstract Rollback : unit -> unit 
[<SecurityTreatAsSafeAttribute>]
[<SecurityCriticalAttribute>]
[<SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode = true)>]
override Rollback : unit -> unit 

public override function Rollback()

Implementiert

IDbTransaction.Rollback()

Ausnahmen

Ausnahme	Bedingung
Exception	Fehler beim Ausführen eines Commits der Transaktion.
InvalidOperationException	Es wurde bereits ein Commit bzw. ein Rollback für die Transaktion ausgeführt. -oder- Die Verbindung ist unterbrochen.

Hinweise

Ein Rollback der Transaktion kann nur ausgeführt werden, wenn die Transaktion noch aussteht (nach dem Aufruf der BeginTransaction-Methode, jedoch vor dem Aufruf der Commit-Methode).

Beispiele

Im folgenden Beispiel werden eine SqlCeConnection-Klasse und eine SqlCeTransaction-Klasse erstellt. Darüber hinaus wird die Verwendung der Methoden BeginTransaction, Commit und Rollback veranschaulicht.

Dim conn As New SqlCeConnection("Data Source = AdventureWorks.sdf;")
conn.Open()

' Start a local transaction; SQL Mobile supports the following 
' isolation levels: ReadCommitted, RepeatableRead, Serializable
'
Dim tx As SqlCeTransaction = conn.BeginTransaction(IsolationLevel.ReadCommitted)

' By default, commands run in auto-commit mode; 
'
Dim cmd1 As SqlCeCommand = conn.CreateCommand()

' You may create multiple commands on the same connection
'
Dim cmd2 As SqlCeCommand = conn.CreateCommand()

' To enlist a command in a transaction, set the Transaction property
'
cmd1.Transaction = tx

Try
    cmd1.CommandText = "INSERT INTO FactSalesQuota " & _
        "(EmployeeKey, TimeKey, SalesAmountQuota) " & _
        "VALUES (2, 1158, 150000.00)"

    cmd1.ExecuteNonQuery()

    ' Auto-commited because cmd2 is not enlisted in a transaction
    '
    cmd2.CommandText = "INSERT INTO FactSalesQuota " & _
        "(EmployeeKey, TimeKey, SalesAmountQuota) " & _
        "VALUES (3, 1157, 15000.00)"

    cmd2.ExecuteNonQuery()

    ' Commit the changes to disk if everything above succeeded;
    ' Use Deferred mode for optimal performance; the changes will 
    ' be flashed to disk within the timespan specified in the 
    ' ConnectionString 'FLUSH INTERVAL' property; 
    '
    tx.Commit(CommitMode.Deferred)

    ' Alternatively, you could use:
    ' tx.Commit(CommitMode.Immediate);
    '
    ' or use default (Deferred) commit mode:
    ' tx.Commit()

Catch e As Exception
    ' Handle errors here
    '
    tx.Rollback()
Finally
    conn.Close()
End Try

SqlCeConnection conn = new SqlCeConnection("Data Source = AdventureWorks.sdf;");
conn.Open();

// Start a local transaction; SQL Mobile supports the following 
// isolation levels: ReadCommitted, RepeatableRead, Serializable
//
SqlCeTransaction tx = conn.BeginTransaction(IsolationLevel.ReadCommitted);

// By default, commands run in auto-commit mode; 
//
SqlCeCommand cmd1 = conn.CreateCommand();

// You may create multiple commands on the same connection
//
SqlCeCommand cmd2 = conn.CreateCommand();

// To enlist a command in a transaction, set the Transaction property
//
cmd1.Transaction = tx;

try
{
    cmd1.CommandText = "INSERT INTO FactSalesQuota " +
        "(EmployeeKey, TimeKey, SalesAmountQuota) " +
        "VALUES (2, 1158, 150000.00)";

    cmd1.ExecuteNonQuery();

    // Auto-commited because cmd2 is not enlisted in a transaction
    //
    cmd2.CommandText = "INSERT INTO FactSalesQuota " +
        "(EmployeeKey, TimeKey, SalesAmountQuota) " +
        "VALUES (3, 1157, 15000.00)";

    cmd2.ExecuteNonQuery();

    // Commit the changes to disk if everything above succeeded;
    // Use Deferred mode for optimal performance; the changes will 
    // be flashed to disk within the timespan specified in the 
    // ConnectionString 'FLUSH INTERVAL' property; 
    //
    tx.Commit(CommitMode.Deferred);

    // Alternatively, you could use:
    // tx.Commit(CommitMode.Immediate);
    //
    // or use default (Deferred) commit mode:
    // tx.Commit()
}
catch (Exception)
{
    // Handle errors here
    //
    tx.Rollback();
}
finally
{
    conn.Close();
}

Siehe auch

Verweis

SqlCeTransaction Klasse

System.Data.SqlServerCe-Namespace

Commit

BeginTransaction