【第一次遇到结合文本正则进行筛选】
【思路】难！到完整写出来花了蛮久的！

【代码如下】
select t2.name, count(t2.film_id) from
(select t1.film_id, t1.title, t1.description, c.name from
(select f., fc.category_id from film as f left join film_category as fc on f.film_id = fc.film_id) as t1
left join
category as c
on t1.category_id = c.category_id
where t1.description like '%robot%'
and t1.category_id in (select t1.category_id from (select f., fc.category_id from film as f left join film_category as fc on f.film_id = fc.film_id) as t1 group by category_id having count(film_id) >= 5)
) as t2
group by t2.name