SELECT count(*) FROM Customers WHERE customer_id NOT IN ( SELECT customer_id FROM Customer_Payments );
List the number of customers that did not have any payment history.
SELECT count ( * ) FROM Customers WHERE customer_id NOT IN ( SELECT customer_id FROM Customer_Payments ) ;
select count ( * ) from customers where customer_id not in ( select customer_id from customer_payments )
List the number of customers that did not have any payment history .