text: CREATE TABLE Customers_cards (card_type_code VARCHAR) -- 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 CREATE TABLE Customers_cards (card_type_code VARCHAR) -- Show card type codes with at least 5 cards. SELECT card_type_code FROM Customers_cards GROUP BY card_type_code HAVING COUNT(*) >= 5 CREATE TABLE Customers_cards (card_type_code VARCHAR, customer_id VARCHAR) -- Show all card type codes and the number of customers holding cards in each type. SELECT card_type_code, COUNT(DISTINCT customer_id) FROM Customers_cards GROUP BY card_type_code CREATE TABLE Customers_cards (customer_id VARCHAR); CREATE TABLE Customers (customer_first_name VARCHAR, customer_id VARCHAR); CREATE TABLE Customers (customer_id VARCHAR, customer_first_name VARCHAR, card_type_code VARCHAR) -- Show the customer ids and firstname 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" CREATE TABLE Customers_Cards (card_type_code VARCHAR) -- Show all card type codes. SELECT DISTINCT card_type_code FROM Customers_Cards CREATE TABLE Customers_Cards (card_type_code VARCHAR) -- Show the number of card types. SELECT COUNT(DISTINCT card_type_code) FROM Customers_Cards