题解 | #返回购买的产品的所有顾客的电子邮件（二）#
返回购买 prod_id 为 BR01 的产品的所有顾客的电子邮件（二）
https://www.nowcoder.com/practice/c7aa73afc41f4dfc925baebdd175c345
SELECT cust_email
FROM Customers c
WHERE c.cust_id IN
(
SELECT o.cust_id
FROM Orders o
INNER JOIN OrderItems oi ON o.order_num = oi.order_num
WHERE prod_id = 'BR01'
)
