Question

I’m trying to create a model for a comic book which has 1 writer and 1 artist. These are both instances of a Person. However how do I show this in my migration?

class CreateComics < ActiveRecord::Migration
   def self.up
     create_table :comics do |t|
       t.column :name, :string      
       t.column :writer_id, :integer, :null => false
       t.column :artist_id, :integer, :null => false
     end
   end
...

How do I say :writer_id should map to :person_id or is this kind of renaming frowned upon?

Answer 1

You create the mapping in your model class using the class_name and foreign_key option.

belongs_to :writer, :class_name => "Person", :foreign_key => "writer_id"
belongs_to :artist, :class_name => "Person", :foreign_key => "artist_id"