1、题目描述
Write an SQL query that selects the product id, year, quantity, and price for the first year of every product sold.
The query result format is in the following example:
Sales table:
| sale_id | product_id | year | quantity | price |
|---|---|---|---|---|
| 1 | 100 | 2008 | 10 | 5000 |
| 2 | 100 | 2009 | 12 | 5000 |
| 7 | 200 | 2011 | 15 | 9000 |
Product table:
| product_id | product_name |
|---|---|
| 100 | Nokia |
| 200 | Apple |
| 300 | Samsung |
Result table:
| product_id | first_year | quantity | price |
|---|---|---|---|
| 100 | 2008 | 10 | 5000 |
| 200 | 2011 | 15 | 9000 |
来源：力扣（LeetCode）
2、解题思路
和Product table没什么关系
1# 首先增加子表，查询product_id最早出售年份select product_id,min(`year`) as min1 from sales group by product_id
2# 然后2表联查
3、提交记录
select s.product_id,`year` as first_year, quantity,price
from sales s,
(select product_id,min(`year`) as min1
from sales
group by product_id) gro
where s.product_id=gro.product_id and s.`year`=gro.min1
1340ms
