with my_cte as ( (SELECT first_name, order_date, SUM(total_order_cost) AS total_order_cost FROM (SELECT first_name, order_date, total_order_cost FROM customers AS c INNER JOIN orders AS o ON c.id = o.cust_id ORDER BY 1 , 2) AS t GROUP BY 1 , 2); SELECT * FROM my_cte WHERE total_order_cost = (SELECT MAX(total_order_cost) FROM my_cte WHERE order_date BETWEEN '2019-02-01' AND '2019-05-01');