LeetCode（数据库）- 每件商品的最新订单

Posted 2021-11-08 程序员牧码

题目链接：点击打开链接

题目大意：略。

解题思路：略。

AC 代码

-- 解决方案(1)
WITH t AS(SELECT order_id, order_date, product_id, DENSE_RANK() OVER(PARTITION BY product_id ORDER BY order_date DESC) rk
FROM Orders)

SELECT product_name, t.product_id, order_id, order_date
FROM t JOIN Products USING(product_id)
WHERE rk = 1
ORDER BY product_name, t.product_id, order_id

-- 解决方案(2)
select product_name, o.product_id, order_id, order_date
from Orders o left join Products p
using(product_id)
where (product_id, order_date) in
(
    select product_id, max(order_date) order_date
    from Orders
    group by product_id
)
order by product_name, product_id, order_id