User.update_all("mail_notification = 'selected'","EXISTS (SELECT 1 FROM #{Member.table_name} WHERE #{Member.table_name}.mail_notification = #{connection.quoted_true} AND #{Member.table_name}.user_id = #{User.table_name}.id)")
User.update_all("mail_notification = 'only_my_events'","mail_notification NOT IN ('all', 'selected')")