select
a.FIRST_LOGIN
,count(member_code) as  MEMBER_CNT
from
(select
member_code,
substr(min(login_datetime),1,10) as FIRST_LOGIN
from
access_log
where
substr(login_datetime,1,7) = '2023-08'
group by
member_code
) a
group by
a.FIRST_LOGIN
order by
FIRST_LOGIN desc
;