[sql, oracle] 계정별 마지막 row

SELECT membr_seq, book
    FROM (SELECT membr_seq, book
            , ROW_NUMBER() OVER(PARTITION BY membr_seq ORDER BY dt DESC) rn
        FROM book_t
    )
WHERE rn = 1

 

ROW_NUMBER() OVER(PARTITION BY membr_seq ORDER BY dt DESC) rn  
membr_seq별로 dt의 내림차순으로 번호를 매겨서
번호의 1을 조회한다.