在config.web中保存数据库连接串

在asp中有多种方法保存数据库连接串，asp+提供了另一种新方式:config.web。quickstart中的许多demo都是直接将连接串写在程序中。这对于demo用途是没有问题，但在实际使用中是不行的。

本文示范如何使用config.web来存储连接串。在每页asp.net中你只需用
调出来就可以直接使用了。这样做的好处一是安全，二是方便，改密码时只需改一个地方即可。

废话少说，这里就是code:(放在该application的根目录下)

Config.web
<configuration>
        <appsettings>
                <add key="MyConn" value="server=localhost;uid=sa;pwd=mypassword;Database=somedatabase"/>
        </appsettings>
</configuration>

Somepage.aspx
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SQL" %>

<script language="VB" runat="server">

Sub Page_Load(Src As Object, E As EventArgs)

'This is the meat of calling the DSN out of the config.web

'Setting a local variable to hold the connection string variable
Dim MyConnection As SQLConnection
Dim Config as HashTable

'Setting a local variable to hold the connection string
Config = Context.GetConfig("appsettings")
MyConnection = New SQLConnection(Config("MyConn"))

'Setting a command object to insert some data into a database
Dim MyCommand As SQLCommand

dim parm1 as string = "SomeTextValue"
dim parm2 as string = "SomeTextValue2"

Dim InsertCmd As String = "Insert into tablename values (@parm1, @parm2)"

'Using the connection string
MyCommand = New SQLCommand(InsertCmd, MyConnection)

MyCommand.Parameters.Add(New SQLParameter("@Parm1", SQLDataType.VarChar, 50))
MyCommand.Parameters("@Parm1").Value = Parm1

MyCommand.Parameters.Add(New SQLParameter("@Parm2", SQLDataType.VarChar, 50))
MyCommand.Parameters("@Parm2").Value = Parm2

MyCommand.ActiveConnection.Open()
MyCommand.Execute()
MyCommand.ActiveConnection.Close()

End Sub
</script>