HABTM Polymorphic Relationship
No, you can’t do that, there’s no such thing as a polymorphic has_and_belongs_to_many association. What you can do is create a middle model. It would probably be something like this: class Subscription < ActiveRecord::Base belongs_to :attendee, :polymorphic => true belongs_to :event end class Event < ActiveRecord::Base has_many :subscriptions end class User < ActiveRecord::Base has_many :subscriptions, … Read more