SQL 프로그래머스 164673 조건에 부합하는 중고거래 댓글 조회하기

 

 

select USED_GOODS_BOARD.TITLE, USED_GOODS_BOARD.BOARD_ID, USED_GOODS_REPLY.REPLY_ID, USED_GOODS_REPLY.WRITER_ID, USED_GOODS_REPLY.CONTENTS, date_format(USED_GOODS_REPLY.CREATED_DATE, '%Y-%m-%d') as CREATED_DATE
from USED_GOODS_BOARD
         inner join USED_GOODS_REPLY
                    on USED_GOODS_BOARD.BOARD_ID = USED_GOODS_REPLY.BOARD_ID
where USED_GOODS_BOARD.CREATED_DATE like '2022-10%'
order by USED_GOODS_REPLY.CREATED_DATE, USED_GOODS_BOARD.TITLE

 

 

1.컬럼명이 겹칠 때만 테이블명을 명시하면 된다.

겹쳐서 명시해야하는 컬럼명들 BOARD_ID, WRITER_ID, CONTENTS, CREATED_DATE

2.as 별칭을 사용하여 나타내자

 

이에 대해 수정한 쿼리문

select TITLE, B.BOARD_ID, REPLY_ID, R.WRITER_ID, R.CONTENTS, date_format(R.CREATED_DATE, '%Y-%m-%d') as CREATED_DATE
    from USED_GOODS_BOARD as B
        inner join USED_GOODS_REPLY as R
        on B.BOARD_ID = R.BOARD_ID
    where B.CREATED_DATE like '2022-10%'
order by R.CREATED_DATE, TITLE