조건에 맞는 사용자 정보 조회하기
SELECT USER_ID, NICKNAME, CONCAT(CITY, ' ', STREET_ADDRESS1, ' ', STREET_ADDRESS2) 전체주소, CONCAT(SUBSTRING(TLNO, 1, 3), '-', SUBSTRING(TLNO, 4, 4), '-', SUBSTRING(TLNO, 8, 4)) 전화번호 FROM USED_GOODS_USER WHERE USER_ID IN (SELECT WRITER_ID FROM USED_GOODS_BOARD GROUP BY WRITER_ID HAVING COUNT(*)>=3) ORDER BY USER_ID DESC https://school.programmers.co.kr/learn/courses/30/lessons/164670