Ricardo Santos - joins

joins.sql

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+#1 List the number of films per category.
+USE sakila;
+
+SELECT c.name, COUNT(*)
+FROM category c
+LEFT JOIN film_category fc
+ON c.category_id = fc.category_id
+GROUP BY c.name;
+
+#2 Retrieve the store ID, city, and country for each store.
+
+SELECT store_id, city, country
+FROM store s
+LEFT JOIN address a 
+ON s.address_id = a.address_id
+LEFT JOIN city c
+ON a.city_id = c.city_id
+LEFT JOIN country co
+ON c.country_id = co.country_id;
+
+#3 Calculate the total revenue generated by each store in dollars.
+
+SELECT s.store_id, sum(p.amount)
+FROM payment p
+LEFT JOIN staff s
+ON p.staff_id = s.staff_id
+LEFT JOIN store st
+ON s.store_id = st.store_id
+GROUP BY s.store_id;
+
+#4 Determine the average running time of films for each category.
+SELECT c.name, AVG(f.length)
+FROM film f
+LEFT JOIN film_category fc
+ON f.film_id = fc.film_id
+LEFT JOIN category c
+ON fc.category_id = c.category_id
+GROUP BY c.name
+;
+#Bonus:
+#Identify the film categories with the longest average running time.
+SELECT c.name, AVG(f.length)
+FROM film f
+LEFT JOIN film_category fc
+ON f.film_id = fc.film_id
+LEFT JOIN category c
+ON fc.category_id = c.category_id
+GROUP BY c.name
+ORDER BY AVG(f.length) DESC
+LIMIT 3
+;
+#Display the top 10 most frequently rented movies in descending order.
+SELECT f.title, count(*)
+FROM rental r
+LEFT JOIN inventory i
+ON r.inventory_id = i.inventory_id
+LEFT JOIN film f
+ON i.film_id = f.film_id
+GROUP BY f.title
+ORDER BY count(*) DESC
+LIMIT 10;
+
+#Determine if "Academy Dinosaur" can be rented from Store 1.
+
+SELECT *
+FROM film f
+LEFT JOIN inventory i
+ON f.film_id = i.film_id
+WHERE f.title = "Academy Dinosaur" AND i.store_id = 1;
+
+#Provide a list of all distinct film titles, along with their availability status in the inventory. Include a column indicating whether each title is 'Available' or 'NOT available.' Note that there are 42 titles that are not in the inventory, and this information can be obtained using a CASE statement combined with IFNULL."
+
+SELECT DISTINCT f.title,
+CASE 
+	WHEN i.film_id IS NOT NULL THEN "Available"
+    ELSE "Not Available"
+END AS Availability
+FROM film f
+LEFT JOIN inventory i
+ON f.film_id = i.film_id;