http://zhanglei1286.blog.163.com/blog/static/1895797120091112113019600/
在后台代码里：
SQL 2000:
static string StrConn = "server=.;uid=sa;pwd=sa;database=MyCUDS";
SQL2005:
con = new SqlConnection(@"Server=.\SQLExpress;Database=db_CMS;Persist Security Info=True;User ID=sa;Password=Masslong");
在web.config里：
sql 2000:
<connectionStrings>
<add name="RateSystemConnectionString" connectionString="Data Source=.;Initial atalog=RateSystem;
User ID=sa Pwd=sa" providerName="System.Data.SqlClient" />
</connectionStrings>
sql 2005:
<connectionStrings>
<add name="BookShopConnectionString" connectionString="Data Source=.\SQLEXPRESS;
Initial Catalog=BookShop;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>
/////////////////////////////////////////////
<connectionStrings>
<add name="ConnectionString" providerName="System.Data.SqlClient" connectionString="Data Source=(local);Initial Catalog=dbname;User ID=sa;Password=1"/>
</connectionStrings>
DBHelper.cs获得字符串
string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
(*注：Data Source可以用Server代替，Initial Catalog表示数据库名，可以用Database代替，(local)表示本地连接，如果是远程连接，可以用远程主机名或IP来表示)
<appSettings>
<add key="ConnectionString" value="Data Source=(local);Initial Catalog=dbname;User ID=sa;Password=1"/>
</appSettings>
<appSettings>
<add key="ConnectionString" value="server=192.168.1.1;database=shop;uid=sa;pwd=*"/>
</appSettings>
DBHelper.cs获得字符串
string connectionString =ConfigurationManager.AppSettings["ConnectionString"];
