SqlCeConnection.Open 方法
使用 ConnectionString 所指定的属性设置打开数据库连接。
命名空间: System.Data.SqlServerCe
程序集: System.Data.SqlServerCe(在 System.Data.SqlServerCe.dll 中)
语法
声明
<SecurityCriticalAttribute> _
<SecurityTreatAsSafeAttribute> _
Public Overrides Sub Open
用法
Dim instance As SqlCeConnection
instance.Open()
[SecurityCriticalAttribute]
[SecurityTreatAsSafeAttribute]
public override void Open()
[SecurityCriticalAttribute]
[SecurityTreatAsSafeAttribute]
public:
virtual void Open() override
[<SecurityCriticalAttribute>]
[<SecurityTreatAsSafeAttribute>]
abstract Open : unit -> unit
[<SecurityCriticalAttribute>]
[<SecurityTreatAsSafeAttribute>]
override Open : unit -> unit
public override function Open()
实现
异常
异常 | 条件 |
---|---|
InvalidOperationException | 连接已打开。 |
SqlCeException | 在打开连接时出现连接级别的错误。 |
注释
此方法可创建一个到数据源的新连接。
备注
如果 SqlCeConnection 超出范围,则不会将其关闭。必须通过调用 Close 或 Dispose 显式关闭该连接。
示例
下面的示例创建一个 SqlCeConnection 并打开它,执行一个查询,然后关闭此连接。
Dim conn As SqlCeConnection = Nothing
Try
conn = New SqlCeConnection("Data Source = MyDatabase.sdf; Password ='<pwd>'")
conn.Open()
Dim cmd As SqlCeCommand = conn.CreateCommand()
cmd.CommandText = "INSERT INTO Customers ([Customer ID], [Company Name]) Values('NWIND', 'Northwind Traders')"
cmd.ExecuteNonQuery()
Finally
conn.Close()
End Try
SqlCeConnection conn = null;
try
{
conn = new SqlCeConnection("Data Source = MyDatabase.sdf; Password ='<pwd>'");
conn.Open();
SqlCeCommand cmd = conn.CreateCommand();
cmd.CommandText = "INSERT INTO Customers ([Customer ID], [Company Name]) Values('NWIND', 'Northwind Traders')";
cmd.ExecuteNonQuery();
}
finally
{
conn.Close();
}