[solvesql] 작품이 없는 작가 찾기

SELECT a.artist_id, a.name
FROM artists a LEFT OUTER JOIN artworks_artists aa ON a.artist_id = aa.artist_id
WHERE a.death_year IS NOT NULL AND aa.artwork_id IS NULL

- LEFT OUTER JOIN 활용 : 차집합

- IS (NOT) NULL 활용