CREATE TABLE customers (customer_id NUMBER, customer_first_name CLOB, customer_last_name CLOB, customer_address CLOB, customer_phone CLOB, customer_email CLOB, other_customer_details CLOB)
CREATE TABLE financial_transactions (transaction_id NUMBER, previous_transaction_id NUMBER, account_id NUMBER, card_id NUMBER, transaction_type CLOB, transaction_date TIME, transaction_amount NUMBER, transaction_comment CLOB, other_transaction_details CLOB)
CREATE TABLE customers_cards (card_id NUMBER, customer_id NUMBER, card_type_code CLOB, card_number CLOB, date_valid_from TIME, date_valid_to TIME, other_card_details CLOB)
CREATE TABLE accounts (account_id NUMBER, customer_id NUMBER, account_name CLOB, other_account_details CLOB)

What are the different card types, and how many cards are there of each?
SELECT card_type_code, COUNT(*) FROM customers_cards GROUP BY card_type_code
SELECT "card_type_code", COUNT(*) FROM "customers_cards" GROUP BY "card_type_code"