SQL: INNER JOIN vs LEFT JOIN when counting orders per customer

-- ======================================================================
-- Q: INNER JOIN vs LEFT JOIN: list customers and their number of orders,
-- including those with none.
--
-- With INNER JOIN, customers without orders are lost. Use COUNT(o.id) and not
-- COUNT(*), because COUNT(*) also counts the row with NULL as 1.
-- ======================================================================

SELECT c.id, c.name, COUNT(o.id) AS orders
FROM customer c
LEFT JOIN "order" o ON o.customer_id = c.id
GROUP BY c.id, c.name
ORDER BY orders DESC;