oracle developer 문제풀이6. COUNT

문제1. 실적도 없이 놀고 있는 두 직원은 누구인지 목록을 출력하는 쿼리를 작성하라.

SELECT name AS 놈팽이
FROM tstaff
WHERE score IS NULL;

문제2. 성취도가 80점 이상인 직원이 몇 명이 되는지 조사하라.

SELECT COUNT(*)
FROM tstaff
WHERE score >= 80;