Работа с ConnectionString в ADO.Net 2.0
C помощью класса SqlConnectionStringBuilder стало еще удобнее работать со строками соединения.
1)
SqlConnectionStringBuilder conStrbuilder = new SqlConnectionStringBuilder();
conStrbuilder.DataSource = serverName;
conStrbuilder.UserID = uid;
conStrbuilder.Password = pwd;
SqlConnection c = new SqlConnection (conStrbuilder.ConnectionString);
2)
conStrbuilder = new SqlConnectionStringBuilder (configConnectionString);
conStrbuilder.Pooling = false;
//More connection string changes
SqlConnection c = new SqlConnection (conStrbuilder.ConnectionString);
Источник: http://blogs.msdn.com/dataaccess/archive/2005/03/30/403926.aspx