[GROUP BY] - 입양시각 구하기(1)

[문제 설명]

[출력 예상]

-- Mysql
-- 풀이 1

SELECT DATE_FORMAT(DATETIME, '%H') as 'HOUR', COUNT(*) as 'COUNT'
FROM ANIMAL_OUTS
GROUP BY HOUR
HAVINH HOUR >= 9 and HOUR <= 19
ORDER BY HOUR asc

-- Mysql
-- 풀이 2

SELECT HOUR(DATETIME) as 'HOUR', count(*) as 'COUNT'
FROM ANIMAL_OUTS
GROUP BY HOUR
HAVING HOUR between 9 and 19
ORDER BY HOUR asc

 

 

[oracle / mysql 비교]

https://atoz-develop.tistory.com/entry/Oracle%EC%9D%98-TOCHAR-%ED%95%A8%EC%88%98%EC%99%80-%EB%8C%80%EC%9D%91%EB%90%98%EB%8A%94-MySQL-%ED%95%A8%EC%88%98

Oracle의 TO_CHAR 함수와 대응되는 MySQL 함수