lab solved

day3_lab_sql_joins.sql

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+/*day3 lab joins*/
+
+/* challenge task 1*/
+select count(film_id) as number_of_films, c.name
+from film f
+inner join film_category fc
+using(film_id)
+inner join category c
+using(category_id)
+group by c.name;
+
+/* challenge task 2*/
+select store_id, ci.city, co.country
+from store s
+inner join address a using(address_id)
+inner join city ci using(city_id)
+inner join country co using(country_id);
+
+/* challenge task 3*/
+select store.store_id, sum(amount) as revenue
+from payment p
+inner join customer c using(customer_id)
+inner join staff using(staff_id)
+inner join store on staff.store_id=store.store_id
+group by store.store_id;
+
+/* challenge task 4*/
+select round(avg(f.length), 2) as average_runtime, c.name
+from film f
+inner join film_category fc using(film_id)
+inner join category c using(category_id)
+group by c.name;
+
+/* bonus task 5*/
+select avg(f.length) as avg_length, c.name
+from film f
+inner join film_category using(film_id)
+inner join category c using(category_id)
+group by c.name
+order by avg_length desc
+limit 3;
+
+/* bonus task 6*/
+select f.title, count(f.film_id) as frequency
+from film f
+inner join inventory i using(film_id)
+inner join rental r using(inventory_id)
+group by f.title
+order by frequency desc
+limit 10;
+
+/* bonus task 7*/
+select store_id, f.title
+from store s
+inner join inventory i using(store_id)
+inner join film f using(film_id)
+where s.store_id = 1 and f.title like 'Academy Dinosaur';
+
+/* bonus task 8*/
+select distinct f.title,
+	case
+		when isnull(i.film_id) then 'NOT available' else 'Available' end as availability
+from film f
+left join inventory i using(film_id)
+group by f.title, availability
+order by f.title;