Show me the first name of all students.
select first_name from students
What are their monthly rentals?
select t1.first_name, t2.monthly_rental from students as t1 join student_addresses as t2 on t1.student_id = t2.student_id
What about each student's average rentals across different address?
select t2.first_name, avg(t1.monthly_rental) from student_addresses as t1 join students as t2 on t1.student_id = t2.student_id group by t2.first_name
Give me the id and first name of the student with the highest of them.
select t1.student_id, t2.first_name from student_addresses as t1 join students as t2 on t1.student_id = t2.student_id group by t1.student_id order by avg(monthly_rental) desc limit 1