CREATE TABLE view_product_availability (product_id DECIMAL, booking_id DECIMAL, status_date TIME, available_yn TEXT)
CREATE TABLE bookings (booking_id DECIMAL, customer_id DECIMAL, booking_status_code TEXT, returned_damaged_yn TEXT, booking_start_date TIME, booking_end_date TIME, count_hired TEXT, amount_payable DECIMAL, amount_of_discount DECIMAL, amount_outstanding DECIMAL, amount_of_refund DECIMAL)
CREATE TABLE customers (customer_id DECIMAL, coupon_id DECIMAL, good_or_bad_customer TEXT, first_name TEXT, last_name TEXT, gender_mf TEXT, date_became_customer TIME, date_last_hire TIME)
CREATE TABLE payments (payment_id DECIMAL, booking_id DECIMAL, customer_id DECIMAL, payment_type_code TEXT, amount_paid_in_full_yn TEXT, payment_date TIME, amount_due DECIMAL, amount_paid DECIMAL)
CREATE TABLE products_for_hire (product_id DECIMAL, product_type_code TEXT, daily_hire_cost DECIMAL, product_name TEXT, product_description TEXT)
CREATE TABLE products_booked (booking_id DECIMAL, product_id DECIMAL, returned_yn TEXT, returned_late_yn TEXT, booked_count DECIMAL, booked_amount DECIMAL)
CREATE TABLE discount_coupons (coupon_id DECIMAL, date_issued TIME, coupon_amount DECIMAL)

What are the first name, last name, and gender of all the good customers? Order by their last name.
SELECT first_name, last_name, gender_mf FROM customers WHERE good_or_bad_customer = 'good' ORDER BY last_name
SELECT "first_name", "last_name", "gender_mf" FROM "customers" WHERE "good_or_bad_customer" = 'good' ORDER BY "last_name" NULLS FIRST