题解 | 返回prod_id为BR01的所有顾客的电子邮件
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 c.cust_email from Customers c where c.cust_id in ( select o.cust_id from Orders o left join OrderItems oi on oi.order_num = o.order_num where oi.prod_id = 'BR01' )