题解 | #查找描述信息中包含robot的电影对应的分类名称以及电影数目，而且还需要该分类对应电影数量>=5部#

应该先找到每个电影分类下电影总数量大于5的category_id

select c.name,
       count(fc.film_id)
from film f,category c,film_category fc
where f.description like '%robot%'
and f.film_id=fc.film_id
and fc.category_id=c.category_id
and c.category_id in (select category_id
                      from film_category
                      group by category_id
                       having count(film_id)>=5)