Hello, is there something wrong with using has_one to implement Class Table Inheritance ? Eg. class Person < ActiveRecord::Base # attributes : eg. name, string end class Contact < Person # attributes : has_one :Person belongs_to :Company end Of course for a such simple case I could use Single Table Inheritance but this is only an example and I don't like too much the fact of mixing in a single table a bunch of inrelated and unused properties. Your advice is welcome, thanks -- Posted via http://www.ruby-forum.com/.