Thanks for the answer! Unfortunately, what I needed to do back then were more complex than that (say, I need to perform query on top of subquery, e.g. "SELECT

Thanks for the answer! Unfortunately, what I needed to do back then were more complex than that (say, I need to perform query on top of subquery, e.g. "SELECT ... FROM (SELECT ...) AS a HAVING ... GROUP BY ..." sort of thing) which seems to be something ActiveRecord wasn't designed for. In the end, I solve the problem by using Arel with an ActiveModel and unwrap all the data manually.