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
    OrderItems ori
    join Orders ord on ori.order_num = ord.order_num
    join Customers cus on ord.cust_id = cus.cust_id
where
    prod_id = 'BR01'