Transaction 属性

获取或设置执行 SqlCeCommand 的事务。

命名空间：  System.Data.SqlServerCe
程序集：  System.Data.SqlServerCe（在 System.Data.SqlServerCe.dll 中）

语法

声明
Public Property Transaction As SqlCeTransaction
    Get
    Set
用法
Dim instance As SqlCeCommand
Dim value As SqlCeTransaction

value = instance.Transaction

instance.Transaction = value

public SqlCeTransaction Transaction { get; set; }

public:
property SqlCeTransaction^ Transaction {
    SqlCeTransaction^ get ();
    void set (SqlCeTransaction^ value);
}

member Transaction : SqlCeTransaction with get, set

function get Transaction () : SqlCeTransaction
function set Transaction (value : SqlCeTransaction)

属性值

类型：System.Data.SqlServerCe. . :: . .SqlCeTransaction
SqlCeTransaction 。默认值为 nullNothingnullptrunitnull 引用（在 Visual Basic 中为 Nothing）。

注释

如果 Transaction 属性已设置为特定值，而命令正在执行过程中，则不能设置该属性。如果设置了一个 SqlCeTransaction 对象的事务属性，而该对象没有与 SqlCeCommand 对象连接到相同的 SqlCeConnection，则在下次执行语句时将引发异常。

如果在将 SqlCeTransaction 设置为 null Nothing nullptr unit null 引用（在 Visual Basic 中为 Nothing） 的情况下运行 SqlCeCommand，则该命令将以自动提交模式运行；因此每个语句都在其自身的事务中运行。

示例

Dim conn As New SqlCeConnection("Data Source = MyDatabase.sdf; Password ='<pwd>'")
conn.Open()

' Start a local transaction
'
Dim tx As SqlCeTransaction = conn.BeginTransaction()

' 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 Shippers ([Company Name]) VALUES ('Northwind Traders')"
    cmd1.ExecuteNonQuery()

    ' Auto-commited because cmd2 is not enlisted in a transaction
    '
    cmd2.CommandText = "INSERT INTO Employees ([Last Name], [First Name]) VALUES ('Decker', 'Barbara')"
    cmd2.ExecuteNonQuery()

    ' This will cause referential constraint violation
    '
    cmd1.CommandText = "DELETE FROM Products WHERE [Product ID] = 1"
    cmd1.ExecuteNonQuery()

    ' Commit the changes to disk if everything above succeeded
    '
    tx.Commit()
Catch
    tx.Rollback()
Finally
    conn.Close()
End Try

SqlCeConnection conn = new SqlCeConnection("Data Source = MyDatabase.sdf; Password ='<pwd>'");
conn.Open();

// Start a local transaction
//
SqlCeTransaction tx = conn.BeginTransaction();

// 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 Shippers ([Company Name]) VALUES ('Northwind Traders')";
    cmd1.ExecuteNonQuery();

    // Auto-commited because cmd2 is not enlisted in a transaction
    //
    cmd2.CommandText = "INSERT INTO Employees ([Last Name], [First Name]) VALUES ('Decker', 'Barbara')";
    cmd2.ExecuteNonQuery();

    // This will cause referential constraint violation
    //
    cmd1.CommandText = "DELETE FROM Products WHERE [Product ID] = 1";
    cmd1.ExecuteNonQuery();

    // Commit the changes to disk if everything above succeeded
    //
    tx.Commit();
}
catch (Exception)
{
    tx.Rollback();
}
finally
{
    conn.Close();
}

请参阅

参考

SqlCeCommand类

SqlCeCommand 成员

System.Data.SqlServerCe 命名空间