people table like this
id int not null auto_increment,
type varchar not null
/* common attributes */
name varchar not null,
email varchar not null,
/* attributes for type=Customer */
balance decimal(10,2),
/* attributes for type=Employee */
=================
model
class person < activerecord::Base
end
class Customer < Person
end
class Employee < Person
end
============
this is a segnment on ‘agile web development with rails’
my silly question is though the autoer note which attribute belong who,
but in the real world, real code, how can I know which is private
attribute for customer or employee?