left join , on

SELECT A.ID, A.NAME
FROM A
LEFT JOIN B
ON A.ID = B.ID
WHERE ~
ORDER BY ~

//animal_outs 테이블에는 있지만 , animal_ins 테이블에는 없는 경우
SELECT animal_id, name
FROM animal_outs
WHERE animal_id NOT IN
( SELECT animal_id FROM animal_ins )