题解 | #返回购买 prod_id 为 BR01 的产品
返回购买 prod_id 为 BR01 的产品的所有顾客的电子邮件（一）
https://www.nowcoder.com/practice/962b16554fbf4b99a87f4d68020c5bfb
题解 | #返回购买 prod_id 为 BR01 的产品的所有顾客的电子邮件（一）#
select
cust_email
from
(SELECT
cust_id
FROM
((select
order_num
from
OrderItems
where
prod_id = "BR01") as oi
join Orders using(order_num))
) AS ooc
JOIN Customers USING(cust_id)
数据量大的话 这样对表做删减 效率会不会更快些 哈哈哈哈哈 笑死了怎么复杂怎么来
cust_email
from
(SELECT
cust_id
FROM
((select
order_num
from
OrderItems
where
prod_id = "BR01") as oi
join Orders using(order_num))
) AS ooc
JOIN Customers USING(cust_id)
数据量大的话 这样对表做删减 效率会不会更快些 哈哈哈哈哈 笑死了怎么复杂怎么来
