What is the customer ID of the customer with the most number of accounts?
select t1.customer_id from accounts as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t1.customer_id order by count ( * ) desc limit 1
What is the customer first name of the customer with the most number of accounts?
select t2.customer_first_name from accounts as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t1.customer_id order by count ( * ) desc limit 1
What is the customer last name of the customer with the most number of accounts?
select t2.customer_last_name from accounts as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t1.customer_id order by count ( * ) desc limit 1