Rails way of writing this Mysql query - mysql

Question

I have a Mysql query which is this:
actors_to_delete = find_by_sql("SELECT * FROM `dvd_role` a
LEFT JOIN `dvd_actor2role` b ON a.id = b.`roleId`
LEFT JOIN `dvd_actor` c ON b.`actorId` = c.`id`
WHERE role LIKE '%uncredited%'
GROUP BY c.id")
I've written it the Railsy way like this:
actors_to_delete = Role.joins("LEFT JOIN `dvd_actor2role` ON dvd_role.id = dvd_actor2role.`roleId`").joins("LEFT JOIN `dvd_actor` ON dvd_actor2role.`actorId` = dvd_actor.`id`").where("dvd_role.role LIKE '%uncredited%'").group("dvd_actor.id")
What I'm wondering (apart from the fact that what is really the difference between these 2 queries, they both do the same thing, so why favour the Railsy way over the more straightforward sql way?) is how do I write it with the relations that are already established in Rails.
If I try do something like this:
Actor.actor2role.role.where("role LIKE ?", '%uncredited%')
I'll get undefined method actor2role because, even though the relationships have been established in Rails, they work for an instance of Actor, not the model itself.
So, in conclusion, just wondering what the best way to do it is. Coming from PHP and Mysql I tend to write a lot of these things out the sql way and am trying to change my evil ways :)
Edit
I also have another problem and that's the fact that in the sql query I get all the info from all 3 tables, the Rails way gives me only the dvd_role table for some reason.
How can I get the data from the other 2 table as well?
I was able to do the latter by adding .select("*") in the beginning. Is this the appropriate way:
actors_to_delete = Role.select("*").joins("LEFT JOIN `dvd_actor2role` ON dvd_role.id = dvd_actor2role.`roleId`").joins("LEFT JOIN `dvd_actor` ON dvd_actor2role.`actorId` = dvd_actor.`id`").where("dvd_role.role LIKE '%uncredited%'").group("dvd_actor.id")