what is the customer name of customer id 1
select customer_name from customers where customer_id = 1
what is the customer name of customer id 2
select customer_name from customers where customer_id = 2
what is the customer name of customer id 3
select customer_name from customers where customer_id = 3
find the name of the customers who have at most two orders
select t2.customer_name from orders as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t2.customer_id having count ( * ) < = 2