SqlCeConnection.BeginTransaction Method (IsolationLevel)
Inicia una transacción de base de datos con el valor IsolationLevel actual.
Espacio de nombres: System.Data.SqlServerCe
Ensamblado: System.Data.SqlServerCe (en system.data.sqlserverce.dll)
Sintaxis
'Declaración
Public Function BeginTransaction ( _
isolationLevel As IsolationLevel _
) As SqlCeTransaction
public SqlCeTransaction BeginTransaction (
IsolationLevel isolationLevel
)
public:
SqlCeTransaction^ BeginTransaction (
IsolationLevel isolationLevel
)
public SqlCeTransaction BeginTransaction (
IsolationLevel isolationLevel
)
public function BeginTransaction (
isolationLevel : IsolationLevel
) : SqlCeTransaction
Parámetros
- isolationLevel
Nivel de aislamiento de transacción de esta conexión.
Valor devuelto
Un objeto que representa la nueva transacción.
Notas
Se debe confirmar o deshacer explícitamente la transacción mediante el método Commit o Rollback.
Ejemplo
En el siguiente ejemplo se crea SqlCeConnection y SqlCeTransaction y, a continuación, se muestra la forma de utilizar los métodos BeginTransaction, Commit y 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();
}
Seguridad para subprocesos
Todos los miembros (Compartidos en Microsoft Visual Basic) de este tipo son seguros para la ejecución de subprocesos. No se garantiza que los miembros de instancia sean seguros para subprocesos.
Plataformas
Plataformas de desarrollo
Windows Vista, Windows Mobile 5.0, Windows XP Professional with Service Pack 2 (SP2), Windows Server 2003, Windows Mobile 2003 for Pocket PC, Windows CE 5.0
Información de la versión
.NET Framework y NET Compact Framework
Se admite en 3.5
.NET Framework
Se admite en 3.0
.NET Compact Framework y .Net Framework
Se admite en 2.0
Vea también
Referencia
SqlCeConnection Class
SqlCeConnection Members
System.Data.SqlServerCe Namespace
Commit
Rollback