Rails migrationでカラムを追加する場所を指定する方法 ref: http://qiita.com/masamitsu-konya/items/c4f75fc02347de9f8b0f

20131202155637_add_column_to_users.rb

class AddColumnToUsers < ActiveRecord::Migration
  def change
    add_column :users, :work_time, :time, :after => :necessary_time
  end
end

file0.txt

r g migration AddColumnToUsers work_time:time
invoke  active_record
create  db/migrate/20131202155637_add_column_to_users.rb

file2.txt

rake db:migrate