select u.user_name, A.c from user as u 

    join (

        select ug.ug_user, ug.ug_group, count(*) as c

            from revision as r 

            join page as p on r.rev_page = p.page_id 

            join actor as ac on ac.actor_id = r.rev_actor 

            join user_groups as ug on ac.actor_user = ug.ug_user

        where p.page_namespace = 4 and p.page_title like '頁面存廢討論/記錄/%'

            -- and ug.ug_group = 'patroller'

        group by ug.ug_user

        order by count(*) desc

    ) A on u.user_id = A.ug_user;