app/models/favorite.rb
# == Schema Information
#
# Table name: favorites
#
# id :integer not null, primary key
# lacquer_id :integer
# user_id :integer
# created_at :datetime
# updated_at :datetime
#
class Favorite < ActiveRecord::Base
belongs_to :lacquer
belongs_to :user
validates :user, :lacquer, presence: true
end