select a.class_no from a where amt in (select max(amt) from a where oper_date='2002-02-11');
select b.class_no, max(amt) from ( select class_no, sum(amt) as amt from a where oper_date = '2002/2/11' grup by class_no)
select a.class_no,max(amt) from a where oper_date='2002/2/11' group by a.class_no
select a.class_no,max(amt) from a where to_char(oper_date,'yyyy/mm/dd')='2002/02/11' group by a.class_no
select b.class_no, amt from ( select class_no, sum(amt) amt from a where oper_date like '2002-02-11%' grup by class_no order by amt desc) where rownum=1;
oper_date='2002-02-11');
from (
select class_no, sum(amt) as amt
from a
where oper_date = '2002/2/11'
grup by class_no)
where to_char(oper_date,'yyyy/mm/dd')='2002/02/11'
group by a.class_no
from (
select class_no, sum(amt) amt
from a
where oper_date like '2002-02-11%'
grup by class_no order by amt desc) where rownum=1;