数据库连接

在Web.config中，数据库连接的种类：
1、

1 <connectionStrings>
2     <add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\NORTHWND.MDF;Integrated Security=True;Connect Timeout=30;User Instance=True"
3       providerName="System.Data.SqlClient" />
4   </connectionStrings>

前台System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString()；
2、

1  <appSettings>
2     <add key="ConnectionString" value="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Data.MDF;Integrated Security=True;User Instance=True" />
3   </appSettings>

前台System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();