题解 | #prod_id为BR01的顾客的电子邮件（一）#
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 OrderItems join Orders on OrderItems.order_num = Orders.order_num
where OrderItems.prod_id = 'BR01'
)
