题解 | #使用子查询的方式找出属于Action分类的所有电影对应的title,description#

选择出电影分类为Action的电影分类id

SELECT c.category_id
FROM category AS c
WHERE c.name='Action'

根据电影分类id确定电影id

SELECT *
FROM film_category AS fc
WHERE fc.category_id IN
(
    SELECT c.category_id
    FROM category AS c
    WHERE c.name='Action'
)

根据电影id确定电影title,description

SELECT f.title, f.description
FROM film AS f
WHERE f.film_id IN
   (
   SELECT fc.film_id
   FROM film_category AS fc
   WHERE fc.category_id IN
      (
       SELECT c.category_id
       FROM category AS c
       WHERE c.name='Action'
       ) 
    )