class Comment < ActiveRecord::Base scope :containing_the_letter_e, :conditions => "comments.body LIKE '%e%'" scope :for_first_post, :conditions => { :post_id => 1 } scope :for_first_author, :joins => :post, :conditions => { "posts.author_id" => 1 } belongs_to :post, :counter_cache => true def self.what_are_you 'a comment...' end def self.search_by_type(q) self.find(:all, :conditions => ["#{QUOTED_TYPE} = ?", q]) end end class SpecialComment < Comment def self.what_are_you 'a special comment...' end end class VerySpecialComment < Comment def self.what_are_you 'a very special comment...' end end