SELECT customer_name FROM customers EXCEPT SELECT t1.customer_name FROM customers AS t1 JOIN customer_orders AS t2 ON t1.customer_id  =  t2.customer_id
What are the names of customers who never made an order.
SELECT customer_name FROM customers EXCEPT SELECT t1.customer_name FROM customers AS t1 JOIN customer_orders AS t2 ON t1.customer_id = t2.customer_id
select customer_name from customers except select t1 . customer_name from customers as t1 join customer_orders as t2 on t1 . customer_id = t2 . customer_id
What are the names of customers who never made an order .