题目描述

leetcode题目：1407. 排名靠前的旅行者

Code

写法一

先过滤，再连表

-- 写法一：先过滤再连表
select name, ifnull(summ, 0) as travelled_distance
from Users
left join(select user_id, sum(distance) as summfrom Ridesgroup by user_id
) A
on Users.id = A.user_id
order by summ desc, name asc;

写法二

先连表，再过滤

-- 写法二：先连表再过滤
select  name, ifnull(sum(distance), 0) as travelled_distance
from Users U 
left join Rides R
on U.id = R.user_id
group by R.user_id
order by travelled_distance desc, name;