From 5cb6dffb511db42b1509d8376d3aa98d8f81b542 Mon Sep 17 00:00:00 2001
From: Ricardo Higginson <ricardo.higginson@scalapay.com>
Date: Tue, 7 Jul 2026 20:30:22 +0200
Subject: [PATCH] lab solved

---
 lab_solved.sql | 106 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 lab_solved.sql

diff --git a/lab_solved.sql b/lab_solved.sql
new file mode 100644
index 0000000..da7d808
--- /dev/null
+++ b/lab_solved.sql
@@ -0,0 +1,106 @@
+
+-- List the number of films per category.
+SELECT
+    c.name AS category,
+    COUNT(fc.film_id) AS number_of_films
+FROM category c
+JOIN film_category fc
+    ON c.category_id = fc.category_id
+GROUP BY c.name
+ORDER BY number_of_films DESC;
+
+-- Retrieve the store ID, city, and country for each store.
+SELECT
+    s.store_id,
+    ci.city,
+    co.country
+FROM store s
+JOIN address a
+    ON s.address_id = a.address_id
+JOIN city ci
+    ON a.city_id = ci.city_id
+JOIN country co
+    ON ci.country_id = co.country_id;
+    
+-- Calculate the total revenue generated by each store in dollars.
+SELECT
+    s.store_id,
+    SUM(p.amount) AS total_revenue
+FROM store s
+JOIN staff st
+    ON s.store_id = st.store_id
+JOIN payment p
+    ON st.staff_id = p.staff_id
+GROUP BY s.store_id
+ORDER BY total_revenue DESC;
+
+-- Determine the average running time of films for each category.
+
+SELECT
+    c.name AS category,
+    ROUND(AVG(f.length), 2) AS average_running_time
+FROM category c
+JOIN film_category fc
+    ON c.category_id = fc.category_id
+JOIN film f
+    ON fc.film_id = f.film_id
+GROUP BY c.name
+ORDER BY average_running_time DESC;
+
+-- Identify the film categories with the longest average running time.
+
+SELECT
+    c.name AS category,
+    ROUND(AVG(f.length), 2) AS average_running_time
+FROM category c
+JOIN film_category fc
+    ON c.category_id = fc.category_id
+JOIN film f
+    ON fc.film_id = f.film_id
+GROUP BY c.name
+ORDER BY average_running_time DESC
+LIMIT 1;
+
+
+-- Display the top 10 most frequently rented movies in descending order.
+
+SELECT
+    f.title,
+    COUNT(r.rental_id) AS rental_count
+FROM film f
+JOIN inventory i
+    ON f.film_id = i.film_id
+JOIN rental r
+    ON i.inventory_id = r.inventory_id
+GROUP BY f.title
+ORDER BY rental_count DESC
+LIMIT 10;
+
+-- Determine if "Academy Dinosaur" can be rented from Store 1.
+
+SELECT
+    f.title,
+    CASE
+        WHEN COUNT(i.inventory_id) > 0 THEN 'Available'
+        ELSE 'NOT available'
+    END AS availability
+FROM film f
+LEFT JOIN inventory i
+    ON f.film_id = i.film_id
+    AND i.store_id = 1
+WHERE f.title = 'ACADEMY DINOSAUR'
+GROUP BY f.title;
+
+-- 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
+    f.title,
+    CASE
+        WHEN IFNULL(COUNT(i.inventory_id), 0) > 0 THEN 'Available'
+        ELSE 'NOT available'
+    END AS availability
+FROM film f
+LEFT JOIN inventory i
+    ON f.film_id = i.film_id
+GROUP BY f.title
+ORDER BY f.title;
\ No newline at end of file