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
good customers refers to good_or_bad_customer = 'good'; first name, last name, and gender refers to first_name, last_name, and gender_mf respectively; order by their last name refers to ORDER BY last_name;