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https://solvesql.com/problems/restaurant-vip/
https://solvesql.com/problems/restaurant-vip/
solvesql.com
select total_bill,tip,sex,smoker,day,time,size
from (
select *, rank() over(PARTITION by day order by total_bill desc) as rk
from tips
)
where rk = 1
가장 큰 컬럼을 찾으면 되는거라 rank나 row_number() 윈도우 함수 쓰는게 편하다고 생각해서 풀이함
윈도우 함수를 안쓴다면 서브쿼리에 in , max 함수 써도 충분하다 생각!
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