从不订购的客户
https://leetcode-cn.com/problems/customers-who-never-order/
子查询
select
????Name?as?Customers
from
????Customers
where
????Id?not?in?(
????????select
????????????distinct?CustomerId
????????from
????????????Orders
????)
原文：https://www.cnblogs.com/wudanyang/p/13124512.html