코딩테스트 연습 > GROUP BY > 월별 잡은 물고기 수 구하기 https://school.programmers.co.kr/learn/courses/30/lessons/293260
group by로 "월" 단위로 묶는다.
SELECT COUNT(*) AS FISH_COUNT, MONTH(TIME) AS MONTH FROM FISH_INFO GROUP BY MONTH ORDER BY MONTH ASC