I've 2 tables: Clients and Orders. A person has numerous orders as well as an order goes to some customer. An order could be approved (marked with a area approved_at). I wish to retrieve all of the clients with no approved order. Including clients with no order and clients with orders that are not approved (approved_at = null). Can One do that in one query without subqueries?

SELECT ..., COUNT(Orders.id) AS cnt
FROM Customers
LEFT JOIN Orders ON (Customers.id = Orders.Customer_id) AND (Orders.approved_at is null)
HAVING cnt = 0
SELECT c.*
FROM Customers c
LEFT JOIN Orders o ON c.ID = o.CustomerID
WHERE o.ID IS NULL OR c.Approved_at IS NULL