【SQL】1327. 列出指定时间段内所有的下单产品

前述

知识点：sql中用JOIN USING 简化JOIN ON

题目描述

leetcode 题目：1327. 列出指定时间段内所有的下单产品

Code

写法一

先过滤，再连表

-- 写法一：先过滤再连表
select B.product_name, A.summ as unit
from(
    select product_id,
        sum(unit) as summ
    from Orders
    where order_date between '2020-02-01' and '2020-02-29'
    group by product_id
    having summ >= 100
) A
left join Products B
on A.product_id = B.product_id;

写法二

先连表，再过滤

-- 写法二：先连表再过滤
select product_name, sum(unit) as unit
from Products P
left join Orders O
using(product_id)
-- where order_date between '2020-02-01' and '2020-02-29'
-- where order_date >= '2020-02-01' and order_date <='2020-02-29'
-- where year(order_date) = 2020 and month(order_date) = 02
where order_date like '2020-02%'
group by O.product_id
having sum(unit) >= 100;

不同的过滤条件写法，都行。