--直接用多表相连接的方式，直接取出描述含有robot的电影名字
--然后再用分类的ID连接film_category表，查找分类中包含5部以上电影的分类
select c.name,count(f.film_id) count
from film f,category c,film_category fc
where f.film_id = fc.film_id
and fc.category_id = c.category_id
and f.description like '%robot%'
and c.category_id in(select category_id
from film_category
group by category_id
having count(film_id) >= 5)