Querying through associations with Ruby on Rails

Question

I have a question about doing a query through a few associations using Ruby on Rails.

This question involves querying across three models. (Event, Fight, Fighters). The important parts of the models are as follows:

• An event has multiple fights.
• Each fight has two fighters: fighter1 and fighter2.

What I need to write is a function to retrieve a list of all fights that have a given fighter. However, this needs to be done through the Event model due to some weird localization thing we have running.

Is there an easy way to do this?

Answer 1

Assuming

class Event
  has_many :fights
end

class Fight
  has_many :fighters
end

Then you can do:

events = Event.joins(:fights => :fighters).where("fighters.name = 'sally'")
fights = events.inject([]){|a,e| a = a + e.fights; a }