class UpdatePtLocales < ActiveRecord::Migration[5.2] class User < ApplicationRecord # Dummy class, to make migration possible across version changes end disable_ddl_transaction! def up User.where(locale: 'pt').in_batches.update_all(locale: 'pt-PT') end def down User.where(locale: 'pt-PT').in_batches.update_all(locale: 'pt') end end