CREATE TABLE Customers_cards (card_type_code VARCHAR2)

What is the card type code with most number of cards?
SELECT card_type_code FROM Customers_cards GROUP BY card_type_code ORDER BY COUNT(*) DESC LIMIT 1
SELECT "card_type_code" FROM "Customers_cards" GROUP BY "card_type_code" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY