您正在看的.Net是:数据库连接字在Web.config里的用法。 在asp.net中的WEB程序的设置中我们必须用到Web.config来存储数据库连接字.事实上这是个 很好的做法,因为可以省去我们很多的麻烦还可以帮助我们避免不必要的错位,是的很多情况下 我就是这样做.它通过XML来记录这些信息.具体的是在<appSettings>....</appSettings>这个 标记中来记录的.这里请看一个ORACLE的例子如下: <appSettings>     <add key=ORACLEConnectionString value=Provider=OraOLEDB.Oracle.1; Persist Security Info=False;Password=blah;User ID=greg;Data Source=sph; />     <add key=SQLConnectionString value=data source=SQL1;initial catalog=ID_V; integrated security=SSPI;persist security info=False;workstation id=TH03D374; packet size=4096/>   <appSettings> 而在你的应用程序中你只要这样写,就可以了,如下: string conn = ConfigurationSettings.AppSettings[OracleConnectionString]; OleDbConnection myConnection = new OleDbConnection(conn); 很轻松是吗?不必每次都输入同样的连接字,也不要记住那些讨厌的信息了,只需要起一个好记的 名字就可以. 好了下面我在来给出其他的一些连接字 MYSQL的连接字: ConnectionString = Data Source=localhost; +                               Database=MYSQLDatabase; +                               User ID=myUsername; +                               Password=myPassword; +                               Command Logging=false; OLE DB的: IBM AS/400 OLE DB 的 VB.NET Dim oOleDbConnection As OleDb.OleDbConnection Dim sConnString As String = _            Provider=IBMDA400.DataSource.1; & _            Data source=myAS400DbName; & _            User Id=myUsername; & _            Password=myPassword oOleDbConnection = New OleDb.OleDbConnection(sConnString) oOleDbConnection.Open()   JET OLE DB 的 VB.NET Dim oOleDbConnection As OleDb.OleDbConnection Dim sConnString As String = _          Provider=Microsoft.Jet.OLEDB.4.0; & _          Data Source=C:\myPath\myJet.mdb; & _          User ID=Admin; & _          Password= oOleDbConnection = New OleDb.OleDbConnection(sConnString) oOleDbConnection.Open()   Oracle OLE DB 的 VB.NET Dim oOleDbConnection As OleDb.OleDbConnection Dim sConnString As String = _          Provider=OraOLEDB.Oracle; & _          Data Source=MyOracleDB; & _          User ID=myUsername; & _      &nbs