What are the names of all users?
select name from useracct
Only show the target users.
select distinct t1.name from useracct as t1 join trust as t2 on t1.u_id = t2.target_u_id
Order them by increasing trust score.
select t1.name from useracct as t1 join trust as t2 on t1.u_id = t2.target_u_id order by trust
Who has the lowest trust score?
select t1.name from useracct as t1 join trust as t2 on t1.u_id = t2.target_u_id order by trust limit 1