Gabriel_sql-subqueries.sql

sql-subqueries.sql

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+USE sakila;
+
+-- 1
+SELECT COUNT(*) AS copies
+FROM inventory
+WHERE film_id = (
+    SELECT film_id
+    FROM film
+    WHERE title = 'HUNCHBACK IMPOSSIBLE'
+);
+
+-- 2
+SELECT title, length
+FROM film
+WHERE length > (
+    SELECT AVG(length)
+    FROM film
+);
+
+-- 3
+SELECT first_name, last_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'
+    )
+);
+
+-- 4
+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'
+    )
+);
+
+-- 5
+SELECT first_name, last_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'
+        )
+    )
+);
+
+-- 6
+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(*) DESC
+        LIMIT 1
+    )
+);
+
+-- 7
+SELECT title
+FROM film
+WHERE film_id IN (
+    SELECT film_id
+    FROM inventory
+    WHERE inventory_id IN (
+        SELECT inventory_id
+        FROM rental
+        WHERE customer_id = (
+            SELECT customer_id
+            FROM payment
+            GROUP BY customer_id
+            ORDER BY SUM(amount) DESC
+            LIMIT 1
+        )
+    )
+);
+
+-- 8
+SELECT customer_id, SUM(amount) AS total_spent
+FROM payment
+GROUP BY customer_id
+HAVING SUM(amount) > (
+    SELECT AVG(total_spent)
+    FROM (
+        SELECT SUM(amount) AS total_spent
+        FROM payment
+        GROUP BY customer_id
+    ) AS avg_table
+);