select z.순위,z.팀명,z.경기수,sum(b."승패합"/c."승패차") as "나누기"
from football z,
(select a.순위,a.팀명,a.경기수,sum(a."승"+a."패") as "승패합"
from football a
where a."경기수"='36'
group by a.순위,a.팀명,a.경기수) b --승패합
,
(select a.순위,a.팀명,a.경기수,sum(a."승"-a."패") as "승패차"
from football a
where a."경기수"='36'
group by a.순위,a.팀명,a.경기수) c --승패차
group by z.순위,z.팀명,z.경기수