How can I join these tables?

rubyonrails-talk
1

A bit of a re-post, but I've cleaned up the question.

--MODELS-- class Unit < ActiveRecord::Base   has_many :rooms

class Room < ActiveRecord::Base   belongs_to :unit   has_many :rentals   has_many :people, :through => :rentals

class Person < ActiveRecord::Base   has_many :rentals   has_many :rooms, :through => :rentals

class Rental < ActiveRecord::Base   belongs_to :room, :person

--QUESTION-- Using only the unit.id, how can I get the associated person.id?

Person.find_by_sql(...)

AR finders don't supplant SQL, think of them as convenience methods for the simple cases..

Isak