寻找SQL-Server函数以识别最小/最大行并从这些行中提取信息

Question

想象这种格式的数据：

Customer, Object, Price
[William, Orange, 100p
William, Apple, 80p
William, Banana 60p
Casper, Cola, 150p
Casper, Beer, 120p
Casper, Peanuts, 200p]

我有兴趣为每个买家提取最便宜的商品以及实际商品。

输出应该看起来像这样。

Customer, MostExpItem, MostExpCost, LeastExpItem, LeastExpCost
William, Orange, 100p, Banana, 60p
Casper, Peanuts, 200p, Beer, 120p

任何指针？我可以使用group by轻松提取最小值/最大值。此问题是否需要子查询？

Answer 1

您可以使用窗口功能：

select
    customer,
    max(object) filter(where price = most_exp_price) most_exp_item,
    most_exp_price,
    max(object) filter(where price = less_exp_price) less_exp_item,
    less_exp_price
from (
    select 
        t.*, 
        max(price) over(partition by customer) most_exp_price,
        min(price) over(partition by customer) less_exp_price
    from mytable t
) t
where price in (max_price, min_price)
group by customer