-- USING OUTER JOIN SELECT o.ANIMAL_ID, o.NAME FROM ANIMAL_INS AS i RIGHT OUTER JOIN ANIMAL_OUTS AS oON i.ANIMAL_ID = o.ANIMAL_ID WHERE i.ANIMAL_ID is null ORDER BY o.ANIMAL_ID-- USING NOT EXIST SELECT o.ANIMAL_ID, o.NAME FROM ANIMAL_OUTS AS o WHERE NOT EXISTS (SELECT 1 FROM ANIMAL_INS AS i WHERE i.ANIMAL_ID = o.ANIMAL_ID) ORDER BY o.ANIMAL_ID prompt 이해하기 - OUTS 에는 있지만 INS에는 존재 ..