class RemoveMessageFromPostAction < ActiveRecord::Migration[4.2] def up remove_column :post_actions, :message end def down add_column :post_actions, :message, :text execute "UPDATE post_actions SET message = p.raw FROM post_actions pa LEFT JOIN posts p ON p.id = pa.related_post_id WHERE post_actions.id = pa.id AND pa.related_post_id IS NOT NULL;" end end