I've read multiple questions about this, but have yet to find an answer that works for my situation.
I have 3 models: Apps
, AppsGenres
and Genres
Here are the pertinent fields from each of those:
Apps
application_id
AppsGenres
genre_id
application_id
Genres
genre_id
The key here is that I'm not using the id
field from those models.
I need to associate the tables based on those application_id
and genre_id
fields.
Here's what I've currently got, but it's not getting me the query I need:
class Genre < ActiveRecord::Base
has_many :apps_genres, :primary_key => :application_id, :foreign_key => :application_id
has_many :apps, :through => :apps_genres
end
class AppsGenre < ActiveRecord::Base
belongs_to :app, :foreign_key => :application_id
belongs_to :genre, :foreign_key => :application_id, :primary_key => :application_id
end
class App < ActiveRecord::Base
has_many :apps_genres, :foreign_key => :application_id, :primary_key => :application_id
has_many :genres, :through => :apps_genres
end
For reference, here is the query I ultimately need:
@apps = Genre.find_by_genre_id(6000).apps
SELECT "apps".* FROM "apps"
INNER JOIN "apps_genres"
ON "apps"."application_id" = "apps_genres"."application_id"
WHERE "apps_genres"."genre_id" = 6000
UPDATED Try this:
class App < ActiveRecord::Base
has_many :apps_genres, :foreign_key => :application_id
has_many :genres, :through => :apps_genres
end
class AppsGenre < ActiveRecord::Base
belongs_to :genre, :foreign_key => :genre_id, :primary_key => :genre_id
belongs_to :app, :foreign_key => :application_id, :primary_key => :application_id
end
class Genre < ActiveRecord::Base
has_many :apps_genres, :foreign_key => :genre_id
has_many :apps, :through => :apps_genres
end
With query:
App.find(1).genres
It generates:
SELECT `genres`.* FROM `genres` INNER JOIN `apps_genres` ON `genres`.`genre_id` = `apps_genres`.`genre_id` WHERE `apps_genres`.`application_id` = 1
And query:
Genre.find(1).apps
generates:
SELECT `apps`.* FROM `apps` INNER JOIN `apps_genres` ON `apps`.`application_id` = `apps_genres`.`application_id` WHERE `apps_genres`.`genre_id` = 1