August 2022
Beginner to intermediate
436 pages
9h 43m
Korean
Content preview from SQL로 시작하는 데이터 분석
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265
5
장
텍스트 분석
true false false true 2571
true false true false 3041
true false true true 2491
true true false false 3440
true true false true 2064
true true true false 2684
true true true true 5293
쿼리 수행 결과를 보면, 각 레코드에서 언급하는
UFO
목격 방향의 분포가 한눈에 보이게끔
BOOLEAN
타입 값이 행렬 형태로 출력됐습니다.
이렇게 모든 조합에 대해 확인하면 전체 데이터의 분포를 확인하기 편리하고,
BI
도구나 시각
화 도구에서 데이터를 활용하기도 좋습니다. 하지만 이 데이터를 요약하고 각 문자열에 대한
집계를 수행하면 더 유용한 경우도 있습니다. 이번에는 각 방향이 언급된 개수를 계산해봅시다
(필드의 타입이 문자열이 아니라 판매량 등의 숫자 타입인 경우에는
sum
함수로 합계를 구하
거나
avg
함수로 평균값을 구할 수도 있습니다 ).
SELECT
count
(
case
when
description
ilike
‘%south%’
then
1
end
)
as
south
,
count
(
case
when
description
ilike
‘%north%’
then
1
end
)
as
north
,
count ...
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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.