August 2022
Beginner to intermediate
436 pages
9h 43m
Korean
Content preview from SQL로 시작하는 데이터 분석
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61
2
장
데이터 준비
order_amount ntile
------------ -----
4.99 1
9.99 1
11.99 2
12.99 2
14.99 3
19.99 4
23.49 5
34.99 6
55.98 7
59.99 8
89.99 9
99.99 10
이 방법을 활용하면 다음 코드와 같이 서브쿼리에서
ntile
함수로 각 행의
N
분위수 값을 계산
하고, 외부쿼리에서
min
함수와
max
함수를 사용해 구간별 범위를 확인할 수도 있습니다.
SELECT
ntile
,
min
(order_amount)
as
lower_bound
,
max
(order_amount)
as
upper_bound
,
count
(order_id)
as
orders
FROM
(
SELECT
customer_id, order_id, order_amount
,ntile(10)
over
(
order
by
order_amount)
as
ntile
FROM
orders
) a
GROUP
BY
1
;
이와 관련된 함수로
percent
_
rank
함수가 있습니다.
percent
_
rank
함수는 각 데이터의 백
분위수 값을 반환합니다. 인자 없이 괄호만 사용하며, 필요시
PARTITION
BY
절과
ORDER
BY
절도 같이 사용합니다.
percent_rank() over (partition by... ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.