[SQL_self_cross_joins]FilipaA

SQL_self_cross_joins.sql

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+-- 1. Get all pairs of actors that worked together.
+select * from film_actor;
+
+select distinct concat(ac1.first_name, ' ', ac1.last_name) AS actor1, 
+				concat(ac2.first_name, ' ', ac2.last_name) AS actor2, 
+                f.title
+from sakila.film_actor a1
+	join sakila.film_actor a2 on a1.film_id = a2.film_id and a1.actor_id <> a2.actor_id 
+	left join sakila.film f on a1.film_id = f.film_id
+	left join sakila.actor ac1 on a1.actor_id=ac1.actor_id
+	left join sakila.actor ac2 on a2.actor_id = a2.actor_id
+order by f.title
+;
+
+-- 2.Get all pairs of customers that have rented the same film more than 3 times.
+SELECT * from sakila.customer;
+SELECT * from sakila.rental;
+SELECT * from sakila.inventory;
+SELECT* from sakila.film;
+
+select c1.customer_id,
+       c2.customer_id,
+       count(*) as number_of_rentals
+from sakila.rental ren
+	join sakila.customer c1 on ren.customer_id = c1.customer_id
+	join sakila.inventory i on ren.inventory_id = i.inventory_id
+	join sakila.film f on i.film_id = f.film_id
+	join sakila.inventory i1 on f.film_id = i1.film_id
+	join sakila.rental ren1 on i1.inventory_id = ren1.inventory_id and ren.rental_id > ren1.rental_id
+	join sakila.customer c2 on ren1.customer_id = c2.customer_id
+group by 1, 2
+having number_of_rentals > 3
+order by number_of_rentals desc;
+
+
+
+-- 3.Get all possible pairs of actors and films.
+select f.title, a.first_name, a.last_name
+from sakila.actor a
+	cross join sakila.film b
+order by 1;