프로그래머스 고득점 키트 _ GROUP BY_MYSQL
https://programmers.co.kr/learn/challenges?selected_part_id=17044
1. 고양이와 개는 몇마리 있을까?
select ANIMAL_TYPE, count(ANIMAL_TYPE) as count
from ANIMAL_INS
group by ANIMAL_TYPE
order by ANIMAL_TYPE
2. 동명 동물수 찾기
select NAME, count(NAME)
from ANIMAL_INS
group by NAME
having NAME != ''
and count(NAME) > 1
order by NAME
3. 입양 시각 구하기
select hour(DATETIME) as 'HOUR', count(hour(DATETIME)) as 'COUNT'
from ANIMAL_OUTS
where hour(DATETIME) between 9 and 19
group by hour(DATETIME)
4. 입양 시각 구하기 2
아직 못품