OleDbTransaction.Rollback 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
从挂起状态回滚事务。
public:
override void Rollback();
public:
virtual void Rollback();
public override void Rollback ();
public void Rollback ();
override this.Rollback : unit -> unit
abstract member Rollback : unit -> unit
override this.Rollback : unit -> unit
Public Overrides Sub Rollback ()
Public Sub Rollback ()
实现
例外
在尝试提交事务时出错。
示例
以下示例创建 OleDbConnection 和 OleDbTransaction。 它还演示如何使用 BeginTransaction、 Commit和 Rollback 方法。
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
注解
事务只能在调用 Commit) 之前BeginTransaction从挂起状态 (回滚。 如果事务在之前释放 Commit
或 Rollback
被调用,则会回滚该事务。