class CreateNotifications < ActiveRecord::Migration class OldNotification < ActiveRecord::Base end class Notification < ActiveRecord::Base end def self.up rename_table :notifications, :old_notifications create_table :notifications do |t| t.column :content_id, :integer t.column :user_id, :integer t.column :created_at, :datetime t.column :updated_at, :datetime end OldNotification.reset_column_information Notification.reset_column_information if $schema_generator OldNotification.find(:all).each do |on| Notification.create!(on.attributes) end end drop_table :old_notifications end def self.down remove_column :notifications, :id rename_column :notifications, :user_id, :notify_user_id rename_column :notifications, :content_id, :notify_content_id end end