(프로그래머 – ORACLE) 연령 없이 회원 수 결정

CREATE 문

CREATE TABLE USER_INFO  (
USER_ID		NUMBER		NOT NULL,
GENDER		NUMBER		NULL,
AGE		NUMBER		NULL,
JOINED		DATE		NOT NULL
)

• 내 솔루션

SELECT
    COUNT(USER_ID) AS USERS
FROM USER_INFO
WHERE AGE IS NULL;