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
select cust_email
from Customers
where cust_id in(select cust_id
from Orders
where order_num in (
select order_num from OrderItems where prod_id = 'BR01'));
牛客报错 unknown database test
莫名其妙，过段时间就通过了
可能是牛客服务器出错了？
