Oracle Calendar

 
select sum(decode(day,'1',no)) 일,
  sum(decode(day,'2',no)) 월,
  sum(decode(day,'3',no)) 화,
  sum(decode(day,'4',no)) 수,
  sum(decode(day,'5',no)) 목,
  sum(decode(day,'6',no)) 금,
  sum(decode(day,'7',no)) 토
from (
          select rownum no, b.mm||b.dd yyyymmdd, to_char(to_date(b.mm||b.dd,'yyyymmdd'),'d') day ,
                    ceil((rownum + 7 - to_number(to_char(to_date(b.mm||b.dd,'yyyymmdd'),'d'))) / 7) week
          from
              (
                select '200712' mm, lpad(rownum,2,'0') dd
                from dict
                where rownum <= 31 
              ) b
          where to_char(last_day(to_date(b.mm||'01','yyyymmdd')),'dd') >= b.dd
          ) x
group by week ;