class AddNumberToComics < ActiveRecord::Migration
  def self.up
    add_column :comics, :number, :integer, :null => false
    
    number = 1
    Comic.ordered.each do |comic|
      comic.number = number
      comic.save
      number += 1
    end
  end

  def self.down
    remove_column :comics, :number
  end
end