| comments | true | |
|---|---|---|
| difficulty | 中等 | |
| edit_url | https://github.com/doocs/leetcode/edit/main/solution/1000-1099/1070.Product%20Sales%20Analysis%20III/README.md | |
| tags |
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销售表 Sales:
+-------------+-------+ | Column Name | Type | +-------------+-------+ | sale_id | int | | product_id | int | | year | int | | quantity | int | | price | int | +-------------+-------+ (sale_id, year) 是这张表的主键(具有唯一值的列的组合)。 product_id 是产品表的外键(reference 列)。 这张表的每一行都表示:编号 product_id 的产品在某一年的销售额。 一个产品可能在同一年内有多个销售条目。 请注意,价格是按每单位计的。
编写解决方案,选出每个售出过的产品 第一年 销售的 产品 id、年份、数量 和 价格。
- 对每个
product_id,找到其在Sales表中首次出现的最早年份。 - 返回该产品在该年度的 所有 销售条目。
返回一张有这些列的表:product_id,first_year,quantity 和 price。
结果表中的条目可以按 任意顺序 排列。
示例 1:
输入: Sales 表: +---------+------------+------+----------+-------+ | sale_id | product_id | year | quantity | price | +---------+------------+------+----------+-------+ | 1 | 100 | 2008 | 10 | 5000 | | 2 | 100 | 2009 | 12 | 5000 | | 7 | 200 | 2011 | 15 | 9000 | +---------+------------+------+----------+-------+ 输出: +------------+------------+----------+-------+ | product_id | first_year | quantity | price | +------------+------------+----------+-------+ | 100 | 2008 | 10 | 5000 | | 200 | 2011 | 15 | 9000 | +------------+------------+----------+-------+
# Write your MySQL query statement below
SELECT
product_id,
year AS first_year,
quantity,
price
FROM Sales
WHERE
(product_id, year) IN (
SELECT
product_id,
MIN(year) AS year
FROM Sales
GROUP BY product_id
);# Write your MySQL query statement below
WITH
T AS (
SELECT
*,
RANK() OVER (
PARTITION BY product_id
ORDER BY year
) AS rk
FROM Sales
)
SELECT product_id, year AS first_year, quantity, price
FROM T
WHERE rk = 1;