SQLize Online / PHPize Online  /  SQLtest Online

/* Relative share of each film category in – the total number of rentals (relative_rentals_count) – the total rental revenue (USD) (relative_rental_amount) */ SELECT c.name AS category, SUM(p.amount) / ( SELECT SUM(amount) FROM payment ) AS relative_rental_amount, COUNT(*) / ( SELECT COUNT(*) FROM payment ) AS relative_rentals_count FROM payment AS p -- start with the biggest table once JOIN rental AS r ON r.rental_id = p.rental_id JOIN inventory AS i ON i.inventory_id = r.inventory_id JOIN film_category AS fc ON fc.film_id = i.film_id JOIN category AS c ON c.category_id = fc.category_id GROUP BY c.category_id ORDER BY relative_rental_amount DESC; ; show status like 'Last_query_cost';