[SQL문제풀기] 오랜 기간 보호한 동물(1)

문제

MYSQL

내가 작성한 정답

SELECT I.NAME, I.DATETIME
FROM ANIMAL_INS I
LEFT JOIN ANIMAL_OUTS O ON I.ANIMAL_ID = O.ANIMAL_ID
WHERE O.ANIMAL_ID IS NULL
ORDER BY I.DATETIME 
LIMIT 3;

ORACLE

내가 작성한 정답

#1
SELECT I.NAME, I.DATETIME
FROM ANIMAL_INS I
LEFT JOIN ANIMAL_OUTS O ON I.ANIMAL_ID = O.ANIMAL_ID
WHERE O.ANIMAL_ID IS NULL
ORDER BY I.DATETIME 
FETCH FIRST 3 ROWS ONLY;

#2
SELECT NAME, DATETIME
FROM(SELECT I.NAME, I.DATETIME
    FROM ANIMAL_INS I
    LEFT JOIN ANIMAL_OUTS O ON I.ANIMAL_ID = O.ANIMAL_ID
    WHERE O.ANIMAL_ID IS NULL
    ORDER BY I.DATETIME )
WHERE ROWNUM <= 3;