Oracle 分组 取第一条记录

id        apply_id
1         1
2         1
3         1
4         2
5         2
6         3
7         3
8         3

取出
id        apply_id
3         1
5         2
8         3

select alx_a.id
from
(select id,apply_id,rownum rid from 表) alx_a,
(select id,apply_id,rownum rid from 表) alx_b
where alx_a.apply_id = alx_b.apply_id and alx_a.id <= alx_b.id
group by alx_a.id,alx_a.apply_id
having count(*) = 1