题解 | #返回购买 有顾客的电子邮件（二）#

select
  cust_email
from
  Customers
  inner join Orders on Customers.cust_id = Orders.cust_id
  inner join OrderItems on OrderItems.order_num = Orders.order_num
where
  prod_id = 'BR01'

出现了莫名其妙的bug，代码一字未动，一次不通过，一次可通过