W3School TIY Editor

SELECT customers.customer_name, SUM(order_details.quantity * products.price) FROM order_details INNER JOIN products ON order_details.product_id = products.product_id INNER JOIN orders ON order_details.order_id = orders.order_id INNER JOIN customers ON orders.customer_id = customers.customer_id GROUP BY customers.customer_id, customers.customer_name HAVING SUM(order_details.quantity * products.price) >= 1000;