题目描述
leetcode 题目:1045. 买下所有产品的客户 思路
先按照customer_id 分组排序再看去重后的product_key 数量是否和Product表中的product_key 数量一致
select customer_id
from Customer A
group by customer_id
having count(distinct(A.product_key)) …
四,驱动的注册
1,struct device_driver结构体
/**
* struct device_driver - The basic device driver structure
* name: Name of the device driver.
* bus: The bus which the device of this driver belongs to.
* owner: The module own…