Q8_m

select s.name
from students s 
    inner join packages p1 on s.id = p1.id
    inner join friends f on s.id = f.id
    inner join packages p2 on f.friend_id = p2.id
    /* double inner join to get both the salaries of the person and his/her friend*/
where p1.salary < p2.salary
order by p2.salary asc;