레벨 3
JOIN
https://programmers.co.kr/learn/courses/30/lessons/59043
INNER JOIN으로 해결
ffSELECT INS.ANIMAL_ID, INS.NAME
FROM ANIMAL_INS INS
INNER JOIN ANIMAL_OUTS OUTS
ON INS.ANIMAL_ID = OUTS.ANIMAL_ID
WHERE INS.DATETIME > OUTS.DATETIME
ORDER BY INS.DATETIME