[SELECT] 조건에 맞는 회원수 구하기

문제 설명

 

 

문제

 

예시

 

해결

SELECT COUNT(USER_ID) USERS
FROM USER_INFO
WHERE AGE BETWEEN 20 AND 29
AND JOINED LIKE '2021%';

SELECT count(USER_ID) USERS
FROM USER_INFO
WHERE YEAR(JOINED) = 2021 AND AGE BETWEEN 20 AND 29;