프로그래머스_조건에 맞는 사용자 정보 조회하기

CONCAT, SUBSTR 중요!

SELECT B.USER_ID, B.NICKNAME, 
CONCAT(CITY,SPACE(1),STREET_ADDRESS1,SPACE(1),STREET_ADDRESS2) AS 전체주소, 
CONCAT(SUBSTR(TLNO,1,3),'-',SUBSTR(TLNO,4,4),'-',SUBSTR(TLNO,8,4)) AS 전화번호
FROM USED_GOODS_BOARD A JOIN USED_GOODS_USER B
ON A.WRITER_ID=B.USER_ID
GROUP BY B.NICKNAME
HAVING COUNT(B.NICKNAME)>=3
ORDER BY USER_ID DESC