class Categorization < ActiveRecord::Base belongs_to :post belongs_to :category belongs_to :named_category, :class_name => 'Category', :foreign_key => :named_category_name, :primary_key => :name belongs_to :author has_many :post_taggings, :through => :author, :source => :taggings belongs_to :author_using_custom_pk, :class_name => 'Author', :foreign_key => :author_id, :primary_key => :author_address_extra_id has_many :authors_using_custom_pk, :class_name => 'Author', :foreign_key => :id, :primary_key => :category_id end class SpecialCategorization < ActiveRecord::Base self.table_name = 'categorizations' default_scope { where(:special => true) } belongs_to :author belongs_to :category end