show the customer ids and first names without a credit card
select customer_id, customer_first_name from customers except select t1.customer_id, t2.customer_first_name from customers_cards as t1 join customers as t2 on t1.customer_id = t2.customer_id where card_type_code = "Credit"
show the customer ids, first name and last name without a Debit card
select customer_id, customer_first_name ,customer_last_name from customers except select t1.customer_id, t2.customer_first_name,t2.customer_last_name from customers_cards as t1 join customers as t2 on t1.customer_id = t2.customer_id where card_type_code = "Debit"
show the customer ids and card number
select customer_id, card_number from customers_cards