Create a query to get the customer with the most numbers of orders - am wondering which one is a more efficient query?
SELECT c.customer_id, c.first_name || ' ' || c.last_name as Name,
count(o.customer_id) as Orders
FROM customer c
JOIN customer_order o
ON c.customer_id = o.customer_id
GROUP BY c.customer_id, c.first_name, c.last_name
ORDER BY 3 DESC
FETCH FIRST 1 ROWS ONLY;
OR
SELECT c.customer_id, c.first_name || ' ' || c.last_name as Name,
ORDER_COUNT
FROM (
SELECT customer_id, count(customer_id) order_count
FROM customer_order
GROUP BY customer_id
ORDER BY order_count DESC
FETCH FIRST 1 ROWS ONLY) o
JOIN customer c
ON c.customer_id = o.customer_id;
Thank you!
