[JOIN/LEVEL3] 오랜 기간 보호한 동물(1) (MySQL/Oracle)

MySQL

SELECT A.NAME
, A.DATETIME
FROM ANIMAL_INS A LEFT OUTER JOIN ANIMAL_OUTS B
ON A.ANIMAL_ID = B.ANIMAL_ID
WHERE B.ANIMAL_ID IS NULL
ORDER BY A.DATETIME
LIMIT 3

---

Oracle

SELECT *
FROM (SELECT A.NAME AS NAME
        , A.DATETIME AS DATETIME
        FROM ANIMAL_INS A, ANIMAL_OUTS B
        WHERE A.ANIMAL_ID = B.ANIMAL_ID(+)
        AND B.datetime IS NULL
        ORDER BY A.DATETIME
      )
WHERE ROWNUM < 4
;