(SQL) 프로그래머스 - 입양 시각 구하기(1)

https://school.programmers.co.kr/learn/courses/30/lessons/59412

프로그래머스

 

아이디어

• HOUR (Oracle은 EXTRACT와 CAST)를 이용하여 DATETIME에서 시간을 추출한 후 그룹화
• HAVING 및 BETWEEN을 이용하여 9시 부터 21시까지만 출력

 

코드

MySQL

SELECT HOUR(DATETIME) AS HOUR, COUNT(*) AS COUNT
FROM ANIMAL_OUTS
GROUP BY HOUR
HAVING HOUR BETWEEN 9 AND 19
ORDER BY HOUR
;

 

Oracle

SELECT EXTRACT(HOUR FROM CAST(DATETIME AS TIMESTAMP)) HOUR, COUNT(*) COUNT
FROM ANIMAL_OUTS
GROUP BY EXTRACT(HOUR FROM CAST(DATETIME AS TIMESTAMP))
HAVING EXTRACT(HOUR FROM CAST(DATETIME AS TIMESTAMP)) BETWEEN 9 AND 19
ORDER BY 1
;