Database Connection Strings for ASP.NET (web.config)

<connectionStrings>
  <add name="OracleConnectionString"
       connectionString="Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=127.0.0.1)(PORT=1521)))(CONNECT_DATA=(SERVER=127.0.0.1)(SID=ORCLSID)));User Id=scott;Password=tiger;"
       providerName="Oracle.DataAccess.Client" />
</connectionStrings>

<add name="OracleConnectionString"
     connectionString="Data Source=127.0.0.1:1521/orcl;User ID=scott;Password=tiger;"
     providerName="Oracle.DataAccess.Client" />

<add name="MSSQLConnectionString"
     connectionString="Data Source=127.0.0.1;Initial Catalog=Northwind;User ID=sa;Password=YourPassword;"
     providerName="System.Data.SqlClient" />

<add name="MSSQLConnectionString"
     connectionString="Server=127.0.0.1;Database=Northwind;uid=sa;pwd=YourPassword;"
     providerName="System.Data.SqlClient" />

<add name="MSSQLConnectionString"
     connectionString="Data Source=YOUR-PC\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=true"
     providerName="System.Data.SqlClient" />

<add name="MySqlConnectionString"
     connectionString="Server=127.0.0.1;Port=3306;Database=dbname;Uid=root;Pwd=YourPassword;"
     providerName="MySql.Data.MySqlClient" />

// needs a reference to System.Configuration
string connectionString =
    System.Configuration.ConfigurationManager.ConnectionStrings["MSSQLConnectionString"].ConnectionString;

using (var connection = new System.Data.SqlClient.SqlConnection(connectionString))
{
    connection.Open();
    // run your commands here
}