-- Database schema
| Highschooler : ID [ INT ] primary_key , name [ TEXT ] , grade [ INT ] | Friend : student_id [ INT ] primary_key Friend.student_id = Highschooler.ID , friend_id [ INT ] Friend.friend_id = Highschooler.ID | Likes : student_id [ INT ] primary_key Likes.student_id = Highschooler.ID , liked_id [ INT ] Likes.liked_id = Highschooler.ID |
-- -- Show names of all high school students who do not have any friends.

SELECT name FROM Highschooler EXCEPT SELECT T2.name FROM Friend AS T1 JOIN Highschooler AS T2 ON T1.student_id  =  T2.id;