서브쿼리를 값처럼 쓸 수 있음 (WHERE절 활용)

SELECT MEMBER_NAME, REVIEW_TEXT, DATE_FORMAT(REVIEW_DATE,'%Y-%m-%d') FROM REST_REVIEW R
JOIN MEMBER_PROFILE M
ON R.MEMBER_ID = M.MEMBER_ID
WHERE R.MEMBER_ID = (SELECT RR.MEMBER_ID FROM REST_REVIEW RR
                    JOIN MEMBER_PROFILE MM
                    ON RR.MEMBER_ID = MM.MEMBER_ID
                    GROUP BY RR.MEMBER_ID
                     ORDER BY COUNT(RR.MEMBER_ID) DESC
                    LIMIT 1)
ORDER BY REVIEW_DATE ASC, REVIEW_TEXT ASC

WHERE 절의 대상값으로 서브쿼리에서 1개 값만 추출하여 활용함.