首先，查询出Action的类别id

select category_id from category where name = 'Action';-- 返回1

第二，拿着Action的类别id，去查询属于该类别的电影id

select film_id from film_category where category_id = (select category_id from category where name = 'Action');

第三，去film表中查询

select title,description from film
where film_id in (
select film_id from film_category
where category_id = (
select category_id from category where name = 'Action'
)
)
;