프로그래머스 - 조건에 맞는 사용자 정보 조회하기

내풀이

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

• 살짝 어려웠다 substr은 (col_name, 몇번째부터, 몇개를)