[SQL_Level3] 특정 조건을 만족하는 물고기별 수와 최대 길이 구하기

문제 설명

문제

예시

나의 풀이

# case 사용
select count(*) as FISH_COUNT, max(LENGTH) as MAX_LENGTH, FISH_TYPE
from FISH_INFO
group by FISH_TYPE
having avg(case when LENGTH is null then 10 else LENGTH end) >= 33
order by FISH_TYPE

# ifnull() 사용
select count(*) as FISH_COUNT, max(LENGTH) as MAX_LENGTH, FISH_TYPE
from FISH_INFO
group by FISH_TYPE
having avg(ifnull(LENGTH,10)) >= 33
order by FISH_TYPE