Oracle，使用desc和rownum的顺序获得顶行

Question

该查询给了我无效的标识符错误，我知道这是因为子查询将只能访问高一层的数据。

select *
from   t2_callerid_plan cp
where  cp.subsrefnum in (
       select *
       from   (
              select vsap.subsrefnum
              from   prv_internet_responses_vsap vsap
              where  vsap.subsrefnum = cp.subsrefnum
              order by vsap.id desc
       )
       where rownum = 1
);

现在，我在徘徊是否有办法创建可以在子查询中使用查询数据时仅返回最新行的查询？

Answer 1

您可以使用ROW_NUMBER() ：

SELECT * FROM ( 
    SELECT cp.*,
           ROW_NUMBER() OVER(PARTITION BY cp.subsrefnum ORDER BY vsap.id desc) as rnk
    from t2_callerid_plan cp
    JOIN  prv_internet_responses_vsap vsap
     ON vsap.subsrefnum = cp.subsrefnum) p
WHERE p.rnk = 1

Answer 2

您可以尝试以下方法：

  select *
from   t2_callerid_plan cp
inner join
(
 select vsap.subsrefnum,ROW_NUMBER()  OVER (PARTITION BY subsrefnum ORDER BY vsap.id desc) rn
              from   prv_internet_responses_vsap vsap 
)vsap
on    vsap.subsrefnum = cp.subsrefnum and vsap.rn=1