Ejercicios agrupados

Mostrar la categoría con más películas

Mostrar los cinco clientes que más han gastado

Mostrar los países que tengan menos de 10 clientes

Mostrar los actores que han trabajado en más de 20 películas

Mostrar los actores que han trabajado en 5 o más  películas de acción

select name,count(film_id) total
from category join film_category using (category_id)
join film using (film_id)
group by category_id
order by total desc
limit 1

select first_name, last_name, sum(amount) total
from customer join payment using (customer_id)
group by customer_id
order by total desc limit 5

select country,count(customer_id) total
from customer join address using (address_id)
join city using (city_id)
join country using (country_id)
group by country_id
having total<10

select first_name,last_name, count(film_id) total
from actor join film_actor using (actor_id)
join film using (film_id)
group by actor_id
having total>20

select first_name,last_name, count(film_id) total
from actor join film_actor using (actor_id)
join film using (film_id)
join film_category using (film_id)
join category using (category_id)
where name='action'
group by actor_id
having total>=5