Problem: 1321. 餐馆营业额变化增长

👨‍🏫 参考题解

Code

select a.visited_on,sum(b.amount) as amount, round(sum(b.amount) / 7,2) as average_amount
from 
    (select distinct visited_on from customer) a 
    join customer b
    on datediff(a.visited_on, b.visited_on) 
    between 0 and 6
where 
    a.visited_on >= (select min(visited_on) from customer) + 6
group by a.visited_on
order by a.visited_on