class AlterUserActivitiesNews < ActiveRecord::Migration def up UserActivity.all.each do |activity| if activity.act_type == 'News' if activity.act activity.created_at = activity.act.created_on activity.updated_at = activity.act.respond_to?("updated_on") ? activity.act.updated_on : activity.act.created_on activity.save else activity.destroy end end end end def down end end