Show the first name and last name for the customer with account name 900.
select t2.customer_first_name, t2.customer_last_name from accounts as t1 join customers as t2 on t1.customer_id = t2.customer_id where t1.account_name = "900"
What is a login name of Dee A Larkin?
select login_name from customers where customer_first_name = "Dee" and customer_middle_initial = "A" and customer_last_name = "Larkin"
Final question is How many customers in the table?
select count ( customer_id ) from customers