👩‍💻 문제

https://school.programmers.co.kr/learn/courses/30/lessons/59042#qna

🙋‍♀️ 답변

SELECT AO.ANIMAL_ID, AO.NAME
FROM ANIMAL_INS AI
RIGHT JOIN ANIMAL_OUTS AO
ON AI.ANIMAL_ID = AO.ANIMAL_ID
WHERE AI.ANIMAL_ID IS NULL
ORDER BY 1;

🤔