ORACLE怎么写先排序后分组的前5位

Question

select *
from (select a.*,
row_number() over(partition by ordered order by cdate desc) px
from (select a.*, b.user_name username
from view_hjzx a, gjjx.sys_users b
where a.userid = b.userid(+)
and a.HANDSET like '%15901054535%') a)
where px <= 5 order by cdate desc
数据是好几种分类，标识是ORDERED，然后我想达到的目的是，最大的日期的ORDERED作为一组，显示前五条，然后按日期排序，第二大的ORDERED前五条，第三大的前五条，日期带领5条组号，不知道怎么写，目前的写法有个问题就是后排序，假设第二组有个日期大于第一组他会跑上去，很苦恼
604790441欢迎指导

Answer 1

    select *
    from (select a.*,
    row_number() over(partition by ordered order by cdate desc) px,
    FIRST_VALUE(cdate) OVER (partition by ordered order by cdate desc
                             ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
                            ) ordered_date
    from (select a.*, b.user_name username
    from view_hjzx a, gjjx.sys_users b
    where a.userid = b.userid(+)
    and a.HANDSET like '%15901054535%') a)
    where px <= 5
    order by ordered_date DESC, ORDERED DESC, cdate desc