[SELECT/LEVEL1] 조건에 맞는 회원수 구하기 (MySQL/Oracle)

MySQL

SELECT COUNT(*) USERS
 FROM USER_INFO
WHERE AGE >= 20
  AND AGE <= 29
  AND YEAR(JOINED) = 2021

 

Oracle

SELECT COUNT(*) USERS
 FROM USER_INFO
WHERE (AGE >= 20 AND AGE <= 29)
  AND TO_CHAR(JOINED, 'YYYY') = '2021'