text: CREATE TABLE Customers_cards (customer_id VARCHAR) -- Show all customer ids and the number of cards owned by each customer. SELECT customer_id, COUNT(*) FROM Customers_cards GROUP BY customer_id CREATE TABLE Customers_cards (customer_id VARCHAR) -- 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 CREATE TABLE Customers_cards (customer_id VARCHAR); CREATE TABLE Customers (customer_first_name VARCHAR, customer_last_name VARCHAR, customer_id VARCHAR) -- Show id, first and last names for all customers with at least two cards. 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 GROUP BY T1.customer_id HAVING COUNT(*) >= 2 CREATE TABLE Customers_cards (customer_id VARCHAR); CREATE TABLE Customers (customer_first_name VARCHAR, customer_last_name VARCHAR, customer_id VARCHAR) -- What is the customer id, first and last name with least number of accounts. 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 GROUP BY T1.customer_id ORDER BY COUNT(*) LIMIT 1 CREATE TABLE Customers_cards (card_type_code VARCHAR) -- Show all card type codes and the number of cards in each type. SELECT card_type_code, COUNT(*) FROM Customers_cards GROUP BY card_type_code