app/models/subscribe.rb
class Subscribe < ActiveRecord::Base
belongs_to :subscription, :counter_cache => true, :validate => true
belongs_to :work, :class_name => 'Manifestation', :validate => true
validates_associated :subscription, :work
validates_presence_of :subscription, :work, :start_at, :end_at
validates_uniqueness_of :work_id, :scope => :subscription_id
end
# == Schema Information
#
# Table name: subscribes
#
# id :integer not null, primary key
# subscription_id :integer not null
# work_id :integer not null
# start_at :datetime not null
# end_at :datetime not null
# created_at :datetime
# updated_at :datetime
#