[SQL문제풀기] 레스토랑 웨이터의 팁 분석

문제

solvesql.com

https://solvesql.com/problems/tip-analysis/

내가 작성한 정답

select day, time, round(avg(tip),2) avg_tip, round(avg(size),2) avg_size
from tips
group by day, time
order by 1 asc, 2 asc