Question

Id  user_id   Name
--- --------  ------
1      1        A
2      1        B
3      1        C
4      2        D
5      2        E
6      2        F

这是我的用户表，我想使用user_id降序获取2行。我想要类似的输出。

Id  user_id   Name
--- --------  ------
2      1        B
3      1        C
5      2        E
6      2        F

预先感谢

Answer 1

使用row_number()：

select Id, user_id, Name
from (select t.*, row_number() over (partition by user_id order by id desc) as seqnum
      from t
     ) t
where seqnum <= 2
order by user_id, id

Answer 2

我认为您严格需要ANCIer方法。您应该尝试下面的相关子查询-

SELECT Id, user_id, Name
FROM  T T2
WHERE (SELECT  COUNT(*)
       FROM    T T3
       WHERE T2.user_id = T3.user_id
       AND T2.Id <= T3.Id) <= 2

Fiddle.

我想获取2条具有相同ID的记录

2 个答案: