首先三张表内连接,条件为film表的描述信息包含robot也就是 like '%robot%',还有一个隐含条件(所有分类的电影数量>=5) SELECT t3.name, count(t1.film_id) FROM film AS t1 inner JOIN film_category AS t2 on t1.film_id=t2.film_id INNER join category AS t3 ON t2.category_id=t3.category_id where t1.description LIKE '%robot%' and t2.category_id IN (select category_id from film_category group by category_id having count(film_id)>=5)