LeetCode（数据库）- 每个产品在不同商店的价格

Posted 2021-12-25 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

SELECT product_id, 'store1' store, store1 price FROM Products WHERE store1 IS NOT NULL
UNION ALL
SELECT product_id, 'store2' store, store2 price FROM Products WHERE store2 IS NOT NULL
UNION ALL
SELECT product_id, 'store3' store, store3 price FROM Products WHERE store3 IS NOT NULL