Connecting with external sql server in Umbraco 7 MVC

Hello, I am newby with Umbraco and it has been hard for me to get updated info about how to connect with external database and render non-umbraco info into my umbraco views.

May I use a secondary connectionstring and ApplicationContex?
Or make another MVC project in the same solution and share the DLL?
Or must use web services to do that?

How do I approach to this need?

Thx,
Karl


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/57416-connecting-with-external-sql-server-in-umbraco-7-mvc