Rails - associate two different fields from one model as one association

Question

I have two fields on my Game model, home_team_id and away_team_id.

I would like to associate these two fields as the teams tied to the Game.

These teams can belong to more than one game so I have on my Team model

has_many :games

I'm not sure what to put on my Game model.

has_many :teams

doesn't work because it doesn't know to look for home_team_id and away_team_id. Is there a way to tell it that there are two different keys for teams?

I've also tried this but it doesn't work either.

has_one :away_team, :class_name => 'Team', :foreign_key => 'id'
has_one :home_team, :class_name => 'Team', :foreign_key => 'id'

In the end I just want to be able to run @game.teams in the console and get the home and away teams returned.

Answer 1

Assuming that you have created your Game migration like:

class CreateGames < ActiveRecord::Migration
  def change
    create_table :games do |t|
      t.integer :home_team_id
      t.integer :away_team_id

      t.timestamps
    end
  end
end

You can archive it by specifying your model like:

class Game < ActiveRecord::Base
  belongs_to :away_team, class_name: 'Team', foreign_key: 'away_team_id'
  belongs_to :home_team, class_name: 'Team', foreign_key: 'home_team_id'

  def teams
    [away_team, home_team]
  end
end