payment table records each payment made
by a customer, with information such as the amount and the
rental being paid for (when applicable).
payment_id: A surrogate primary key used to uniquely identify each payment.
customer_id: The customer whose balance the payment is being applied to. This is a foreign key reference to the
staff_id: The staff member who processed the payment. This is a foreign key reference to the
rental_id: The rental that the payment is being applied to. This is optional because some payments are for outstanding fees and may not be directly related to a rental.
amount: The amount of the payment.
payment_date: The date the payment was processed.
last_update: When the row was created or most recently updated.