Find the ids of customers without first notification of loss record.
select customer_id from customers except select t1.customer_name from customers as t1 join first_notification_of_loss as t2 on t1.customer_id = t2.customer_id
Show me their names.
select customer_name from customers except select t1.customer_name from customers as t1 join first_notification_of_loss as t2 on t1.customer_id = t2.customer_id