Consider a database name "db_name" whose attributes are intern_id (primary key), subject.
Intern_id = {1, 2, 3, 4, 5, 6}
Subject = {sql, oop, sql, oop, c, c++}
If these are one to one relation then what will be the output of the following MySQL statement?

SELECT intern_id
FROM db_name
WHERE subject IN (c, c++);