level 2. 입양 시각 구하기(1)

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

코딩테스트 연습 - 입양 시각 구하기(1)

-- 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 HOUR, COUNT(*) AS COUNT
    FROM (
        SELECT TO_CHAR(datetime, 'HH24') AS HOUR
        FROM ANIMAL_OUTS
    )
    WHERE HOUR BETWEEN 9 AND 19
    GROUP BY HOUR
    ORDER BY HOUR