특정 물고기를 잡은 총 수 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/298518

프로그래머스

[문제]

FISH_INFO 테이블에서 잡은 BASS와 SNAPPER의 수를 출력하는 SQL 문을 작성해주세요.

컬럼명은 'FISH_COUNT`로 해주세요.

 

[나의 풀이]

SELECT COUNT(*) FISH_COUNT
FROM FISH_INFO I JOIN FISH_NAME_INFO N
ON I.FISH_TYPE = N.FISH_TYPE
WHERE FISH_NAME REGEXP 'BASS|SNAPPER'

 

[다른 풀이]

SELECT count(*) FISH_COUNT
FROM FISH_INFO I
INNER JOIN FISH_NAME_INFO N
ON I.FISH_TYPE = N.FISH_TYPE 
WHERE FISH_NAME IN ('BASS', 'SNAPPER')

 

SELECT
    COUNT(*) AS FISH_COUNT
FROM
    FISH_INFO
WHERE
    FISH_TYPE IN (
    	SELECT 
        	FISH_TYPE 
        FROM 
        	FISH_NAME_INFO 
        WHERE FISH_NAME IN ('BASS', 'SNAPPER')
    )

서브쿼리를 사용한 방법