)编写第二个最小(最小)id(如果存在)的查询
CUSTOMER(ID,CASE_ID,NAME,STATE)
1,100,Alex,NY
2,100,Alex,VA
3,100,Alex,CT
4,100,Tom,PA
5,102,Peter,MO
6,103,Dave,TN
.
.
.
如何为每组case_id (
请尝试:
SELECT
ID,
CASE_ID
FROM
(
SELECT
*,
ROW_NUMBER() OVER(PARTITION BY CASE_ID ORDER BY ID) Rn
FROM CUSTOMER
)x
WHERE Rn=2
您可以使用窗口函数:
with cte as (
select ID, CASE_ID, ROW_NUMBER() over (partition by CASE_ID order by ID) rn
from CUSTOMER
)
select ID, CASE_ID
from cte
where rn = 2
或者您可以使用exists子句来删除第一行(即在存在值较低的行时获取最小值):
select MIN(ID) ID, CASE_ID
from CUSTOMER c
where exists (select 1 from CUSTOMER c2 where c2.ID < c.ID and c2.CASE_ID = c.CASE_ID)
group by CASE_ID
或者,另一种写法:
select MIN(ID) ID, CASE_ID
from CUSTOMER c
where c.ID > (select MIN(ID) from CUSTOMER c2 where c2.CASE_ID = c.CASE_ID)
group by CASE_ID