1、查询属于Action分类的所有电影id
select b.film_id from category a join film_category b on a.category_id=b.category_id where a.name='Action';2、查询以上电影id对应的title,description
select title,description from film where film_id in (select b.film_id from category a join film_category b on a.category_id=b.category_id where a.name='Action');