This connection string would create a data source called ConnectSQL, used to connect to the database TestDB hosted on a SQL Server instance named Serv001\instance:
<connectionStrings>
<add name="ConnectSQL" connectionString="Data Source=Serv001\instance; Encrypt=Mandatory;
Database=TestDB;User Id=username;Password=password"
providerName="System.Data.SqlClient"/>
</connectionStrings>
Similarly, this example would connect to the same database, but it would use integrated security instead of database user authentication:
<connectionStrings>
<add name="ConnectSQL" connectionString="Data Source=Serv001\instance; Encrypt=Mandatory;
Database=TestDB;Integrated Security=true;"
providerName="System.Data.SqlClient"/>
</connectionStrings>