[프로그래머스 / SQL] GROUP BY문제 (조건에 맞는 사용자와 총 거래금액 조회하기)

 

https://school.programmers.co.kr/learn/courses/30/lessons/164668

프로그래머스

 

명시적 조인 (JOIN) 활용 - 일반적

SELECT    
    A.USER_ID, 
    A.NICKNAME, 
    SUM(B.PRICE) AS TOTAL_SALES
FROM USED_GOODS_USER A
JOIN USED_GOODS_BOARD B ON A.USER_ID = B.WRITER_ID
WHERE B.STATUS = 'DONE'
GROUP BY A.USER_ID, A.NICKNAME
HAVING SUM(B.PRICE) >= 700000
ORDER BY TOTAL_SALES;

 

 

암시적 조인 : WHERE 절에서 조인 조건을 명시하여 두 테이블을 연결 

SELECT    
    A.USER_ID, 
    A.NICKNAME, 
    SUM(PRICE) AS TOTAL_SALES
FROM USED_GOODS_USER A, USED_GOODS_BOARD B
WHERE A.USER_ID = B.WRITER_ID
AND STATUS = 'DONE'
GROUP BY A.USER_ID, A.NICKNAME
HAVING SUM(PRICE) >= 700000
ORDER BY TOTAL_SALES;