Finding by SQL

If you’d like to use your own SQL to find records in a table you can use find_by_sql. The find_by_sql method will return an array of objects even the underlying query returns just a single record. For example you could run this query:

Client.find_by_sql("SELECT * FROM clients INNER JOIN orders ON clients.id = orders.client_id ORDER clients.created_at desc")

find_by_sql provides you with a simple way of making custom calls to the database and retrieving instantiated objects.

More at http://guides.rubyonrails.org/v2.3.11/active_record_querying.html