SELECT
    customer_id,
    customer_name,
    COUNT(rental_id)+COUNT(payment_id) AS discount_point,
    CASE
        WHEN COUNT(rental_id)+COUNT(payment_id) < 41 THEN '10%'
        WHEN COUNT(rental_id)+COUNT(payment_id) > 59 THEN '30%'
        ELSE '20%'
    END AS discount
FROM customer_derived
GROUP BY customer_id, customer_name
ORDER BY customer_id, customer_name;