11. Calculating Interest

CREATE FUNCTION `ufn_calculate_future_value`(`sum` DECIMAL(10, 4),
                                            yearly_interest_rate DOUBLE,
                                            number_of_years INT)
RETURNS DECIMAL(10, 4)
DETERMINISTIC

BEGIN
    RETURN `sum` * (POW((1 + yearly_interest_rate), number_of_years));
END;

CREATE PROCEDURE `usp_calculate_future_value_for_account`(account_id INT, interest_rate DOUBLE(19,4))

BEGIN

    SELECT a.id, ah.first_name, ah.last_name, a.balance,
    `ufn_calculate_future_value`(a.balance, interest_rate, 5)
    FROM accounts AS a
    JOIN account_holders AS ah
    ON a.account_holder_id = ah.id
    WHERE a.id = account_id;

END;