CREATE TABLE Customers_Cards (card_id NUMBER, customer_id NUMBER, card_type_code VARCHAR2, card_number VARCHAR2, date_valid_from DATETIME, date_valid_to DATETIME, other_card_details VARCHAR2)
CREATE TABLE Accounts (account_id NUMBER, customer_id NUMBER, account_name VARCHAR2, other_account_details VARCHAR2)
CREATE TABLE Customers (customer_id NUMBER, customer_first_name VARCHAR2, customer_last_name VARCHAR2, customer_address VARCHAR2, customer_phone VARCHAR2, customer_email VARCHAR2, other_customer_details VARCHAR2)
CREATE TABLE Financial_Transactions (transaction_id NUMBER, previous_transaction_id NUMBER, account_id NUMBER, card_id NUMBER, transaction_type VARCHAR2, transaction_date DATETIME, transaction_amount DOUBLE PRECISION, transaction_comment VARCHAR2, other_transaction_details VARCHAR2)

, I want to list from high to low by the total number of card number.
SELECT card_type_code, SUM(card_number) FROM Customers_Cards GROUP BY card_type_code ORDER BY SUM(card_number) DESC
SELECT "card_type_code", SUM("card_number") FROM "Customers_Cards" GROUP BY "card_type_code" ORDER BY SUM("card_number") DESC