class Post < ActiveRecord::Base belongs_to :author do def greeting "hello" end end belongs_to :author_with_posts, :class_name => "Author", :include => :posts has_many :comments, :order => "body" do def find_most_recent find(:first, :order => "id DESC") end end has_one :very_special_comment has_one :very_special_comment_with_post, :class_name => "VerySpecialComment", :include => :post has_many :special_comments has_and_belongs_to_many :categories has_and_belongs_to_many :special_categories, :join_table => "categories_posts" def self.what_are_you 'a post...' end end class SpecialPost < Post; end; class StiPost < Post has_one :special_comment, :class_name => "SpecialComment" end