CREATE TABLE Payments (customer_id VARCHAR, amount_paid INT)

What is the maximum total amount paid by a customer? List the customer id and amount.
SELECT customer_id, SUM(amount_paid) FROM Payments GROUP BY customer_id ORDER BY SUM(amount_paid) DESC LIMIT 1
SELECT "customer_id", SUM("amount_paid") FROM "Payments" GROUP BY "customer_id" ORDER BY SUM("amount_paid") DESC NULLS LAST LIMIT 1