Metodo SqlCeTransaction.Rollback

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

Spazio dei nomi  System.Data.SqlServerCe
Assembly:  System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)

Sintassi

'Dichiarazione
<SecurityTreatAsSafeAttribute> _
<SecurityCriticalAttribute> _
<SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode := True)> _
Public Overrides Sub Rollback
'Utilizzo
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()

Implementa

IDbTransaction.Rollback()

Eccezioni

Osservazioni

È possibile eseguire solo il rollback della transazione da uno stato in sospeso, dopo la chiamata al metodo BeginTransaction, ma prima di chiamare il metodo Commit.

Esempi

Nell'esempio seguente vengono create una classe SqlCeConnection e una classe SqlCeTransaction. Vengono inoltre illustrate le modalità di utilizzo dei metodi BeginTransaction, Commit e Rollback.

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();
}

Vedere anche

Riferimento

SqlCeTransaction Classe

Spazio dei nomi System.Data.SqlServerCe

Commit

BeginTransaction