asp.net web.config 設定 sql 連線字串

參考引用來源:Store connection string in web.config
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Store connection string in web.config

Connection string in .NET 2.0 config file
In the appSettings location, add a key named whatever you like to reference your connection string to.

＜appSettings＞
＜add key="myConnectionString" value="server=localhost;database=myDb;uid=myUser;password=myPass;" /＞
＜/appSettings＞
To read the connection string from code, use the ConfigurationSettings class.

string connStr = ConfigurationSettings.AppSettings("myConnectionString");
Now you have the connection string loaded from web.config into your string variable in code.

Connection string in .NET 3.5 (and above) config file
Do not use appsettings in web.config. Instead use the connectionStrings section in web.config.

＜connectionStrings＞
＜add name="myConnectionString" connectionString="server=localhost;database=myDb;uid=myUser;password=myPass;" /＞
＜/connectionStrings＞
To read the connection string into your code, use the ConfigurationManager class.

string connStr = ConfigurationManager.ConnectionStrings["myConnectionString"].ConnectionString;