Question

class Upload < ActiveRecord::Base
    has_many :comments
end

class Gallery < Upload
    has_many :images
end

class MusicAlbum < Upload
    has_many :audio_tracks
end

Should this work as expected? Will Gallery and MusicAlubm models inherit :comments association from their parent (Upload) and add their own?

Answer 1

Yes, the models are just classes, and when inherited they get all the methods from parent class. So, as both Gallery and MusicAlbum are descendants from Upload model, they will have the has_many :comments association, and both will get data from uploads db table (which needs to have a type column to support STI for this model)

A nice simple STI example can be found here