SQL 获取最小值或最大值对应的数据

Question

这是我的数据结构

ID_组	日期	价格
1个	20/11/2022	3个
1个	19/11/2022	4个
2个	18/11/2022	42
2个	19/11/2022	2个
1个	21/11/2022	2个

我想制作一个表格以便以这种格式获取我的数据：

ID_组	最高价	最大价格日期	最低价格	最低价格日期
1个	4个	19/11/2022	3个	20/11/2022
2个	42	18/11/2022	2个	19/11/2022

这是我现在拥有的：

select ID_group,
max(price) MaxPrice,
'' MaxPriceDate,
min(price) MinPrice,
'' MinPriceDate
from table
group by ID_group

Answer 1

我们可以在这里使用ROW_NUMBER以及旋转逻辑：

WITH cte AS (
    SELECT t.*, ROW_NUMBER() OVER (PARTITION BY ID_group ORDER BY Price) rn1,
                ROW_NUMBER() OVER (PARTITION BY ID_group ORDER BY Price DESC) rn2
    FROM yourTable t
)

SELECT
    ID_group,
    MAX(CASE WHEN rn2 = 1 THEN Price END) AS MaxPrice,
    MAX(CASE WHEN rn2 = 1 THEN "Date" END) AS MaxPriceDate,
    MAX(CASE WHEN rn1 = 1 THEN Price END) AS MinPrice,
    MAX(CASE WHEN rn1 = 1 THEN "Date" END) AS MinPriceDate
FROM cte
GROUP BY ID_group
ORDER BY ID_group;