- 그룹별로 집계
SELECT MAJOR, COUNT(MID) FROM MEMBERS GROUP BY MAJOR;
- 그룹별로 집계(함수 사용)
SELECT SUBSTR(NAME, 1, 1), COUNT(MID) FROM MEMBERS
GROUP BY SUBSTR(NAME, 1, 1)
- WHERE 절에서는 집계 함수를 사용할 수 없음
SELECT SUBSTR(NAME, 1, 1), COUNT(MID) FROM MEMBERS
WHERE COUNT(MID) < 10
GROUP BY SUBSTR(NAME, 1, 1)
-- GROUP BY를 끝낸후 조건 조회(조건에 집계함수가 필요한 경우)
SELECT SUBSTR(NAME, 1, 1), COUNT(MID) FROM MEMBERS
GROUP BY SUBSTR(NAME, 1, 1)
HAVING COUNT(MID) < 10