问题10
数据库中有多少部电影既是爱情片又是喜剧片？
选项：
373 484 262 595
这是我的代码：

SELECT movies.title
FROM movies
LEFT JOIN genremap ON movies.movie_id = genremap.movie_id

UNION

SELECT genres.genre_id
FROM genres
LEFT JOIN genres ON genremap.genre_id = genres.genre_id
WHERE genres.genre_name = "Comedy" OR genres.genre_name = "Romance" 
ORDER BY movies.title
LIMIT 50;

我也试过了，但它返回了一个错误：

SELECT m.title, g.genre_id, gs.genre_name
FROM genremap AS g
LEFT JOIN movies AS m ON m.movie_id = g.movie_id

UNION

SELECT gs.genre_id
FROM genres AS gs
LEFT JOIN genres ON g.genre_id = gs.genre_id
WHERE gs.genre_name = "Comedy" OR gs.genre_name = "Romance" 
ORDER BY movies.title
LIMIT 50;