ํ”„๋กœ๊ทธ๋ž˜๋จธ์Šค SQL - GROUP BY

2021. 5. 30. 23:15ใ†๐Ÿ’ป ๊ฐœ๋ฐœ/SQL

1. ๊ณ ์–‘์ด์™€ ๊ฐœ๋Š” ๋ช‡ ๋งˆ๋ฆฌ ์žˆ์„๊นŒ 

https://programmers.co.kr/learn/courses/30/lessons/59040

 

์ฝ”๋”ฉํ…Œ์ŠคํŠธ ์—ฐ์Šต - ๊ณ ์–‘์ด์™€ ๊ฐœ๋Š” ๋ช‡ ๋งˆ๋ฆฌ ์žˆ์„๊นŒ

ANIMAL_INS ํ…Œ์ด๋ธ”์€ ๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ์˜ ์ •๋ณด๋ฅผ ๋‹ด์€ ํ…Œ์ด๋ธ”์ž…๋‹ˆ๋‹ค. ANIMAL_INS ํ…Œ์ด๋ธ” ๊ตฌ์กฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์œผ๋ฉฐ, ANIMAL_ID, ANIMAL_TYPE, DATETIME, INTAKE_CONDITION, NAME, SEX_UPON_INTAKE๋Š” ๊ฐ๊ฐ ๋™๋ฌผ์˜ ์•„์ด๋””

programmers.co.kr

1. ๋ฌธ์ œ 

๋™๋ฌผ ๋ณดํ˜ธ์†Œ์— ๋“ค์–ด์˜จ ๋™๋ฌผ ์ค‘ ๊ณ ์–‘์ด์™€ ๊ฐœ๊ฐ€ ๊ฐ๊ฐ ๋ช‡ ๋งˆ๋ฆฌ์ธ์ง€ ์กฐํšŒํ•˜๋Š” SQL๋ฌธ์„ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”. ์ด๋•Œ ๊ณ ์–‘์ด๋ฅผ ๊ฐœ๋ณด๋‹ค ๋จผ์ € ์กฐํšŒํ•ด์ฃผ์„ธ์š”.

ํ…Œ์ด๋ธ” ANIMAL_INS
์‹คํ–‰๊ฒฐ๊ณผ

 

2. ํ’€์ด๊ณผ์ •

๊ณ ์–‘์ด์™€ ๊ฐœ๋ฅผ ๊ฐ๊ฐ ์นด์šดํŒ…ํ•ด์•ผํ•ด์„œ animal_type์„ ๊ทธ๋ฃนํ™”ํ•ด์ฃผ๊ณ , Cat์ด ๋จผ์ €์™€์•ผํ•˜๋ฏ€๋กœ ์˜ค๋ฆ„์ฐจ์ˆœ ์ •๋ ฌํ•ด์ค€๋‹ค.

select animal_type, count(animal_type)
from animal_ins
group by animal_type
order by animal_type