SELECT customer_id ,  count(*) FROM Customers_cards GROUP BY customer_id ORDER BY count(*) DESC LIMIT 1
What is the customer id with most number of cards, and how many does he have?
SELECT customer_id , count ( * ) FROM Customers_cards GROUP BY customer_id ORDER BY count ( * ) DESC LIMIT 1
select customer_id , count ( * ) from customers_cards group by customer_id order by count ( * ) desc limit value
What is the customer id with most number of cards , and how many does he have ?