From e75867541b94ceeacaa5268f7805dd6c2ff68390 Mon Sep 17 00:00:00 2001
From: Valeria Acevedo <valeriaacevedo@Valerias-MacBook-Air.local>
Date: Sat, 16 May 2026 16:18:19 +0200
Subject: [PATCH] lab done

---
 lab-sql-subqueries .sql | 102 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 lab-sql-subqueries .sql

diff --git a/lab-sql-subqueries .sql b/lab-sql-subqueries .sql
new file mode 100644
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+++ b/lab-sql-subqueries .sql	
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+# Challenge
+# Write SQL queries to perform the following tasks using the Sakila database:
+
+#Determine the number of copies of the film "Hunchback Impossible" that 
+# exist in the inventory system.
+
+SELECT COUNT(*) AS total_copies
+FROM inventory
+WHERE film_id = (
+    SELECT film_id
+    FROM film
+    WHERE title = 'Hunchback Impossible'
+);
+
+# List all films whose length is longer than the average length of 
+#all the films in the Sakila database.
+
+SELECT title, length
+FROM film
+WHERE length > (
+    SELECT AVG(length)
+    FROM film
+);
+
+#Use a subquery to display all actors who appear in the film "Alone Trip".
+SELECT first_name
+FROM actor
+WHERE actor_id IN (
+    SELECT actor_id
+    FROM film_actor
+    WHERE film_id = (
+        SELECT film_id
+        FROM film
+        WHERE title = 'Alone Trip'
+    )
+);
+
+# Sales have been lagging among young families, and you want to target family movies for a promotion. 
+# Identify all movies categorized as family films.
+SELECT title
+FROM film
+WHERE film_id IN (
+    SELECT film_id
+    FROM film_category
+    WHERE category_id = (
+        SELECT category_id
+        FROM category
+        WHERE name = 'Family'
+    )
+);
+
+# Retrieve the name and email of customers from Canada using both subqueries and joins. 
+# To use joins, you will need to identify the relevant tables and their primary and foreign keys.
+
+SELECT title
+FROM film
+WHERE film_id IN (
+    SELECT film_id
+    FROM film_category
+    WHERE category_id = (
+        SELECT category_id
+        FROM category
+        WHERE name = 'Family'
+    )
+);
+
+# Determine which films were starred by the most prolific actor in the Sakila database. 
+# A prolific actor is defined as the actor who has acted in the most number of films. 
+# First, you will need to find the most prolific actor and then use that actor_id to find the different films that he or she starred in.
+SELECT first_name, email
+FROM customer
+WHERE address_id IN (
+    SELECT address_id
+    FROM address
+    WHERE city_id IN (
+        SELECT city_id
+        FROM city
+        WHERE country_id = (
+            SELECT country_id
+            FROM country
+            WHERE country = 'Canada'
+        )
+    )
+);
+
+# Find the films rented by the most profitable customer in the Sakila database. 
+# You can use the customer and payment tables to find the most profitable customer, i.e., 
+# the customer who has made the largest sum of payments.
+
+SELECT title
+FROM film
+WHERE film_id IN (
+    SELECT film_id
+    FROM film_actor
+    WHERE actor_id = (
+        SELECT actor_id
+        FROM film_actor
+        GROUP BY actor_id
+        ORDER BY COUNT(film_id) DESC
+        LIMIT 1
+    )
+);
\ No newline at end of file