scholarshipsDistribution

My solution:

CREATE PROCEDURE scholarshipsDistribution() 
BEGIN 
  SELECT candidate_id AS student_id 
  FROM   candidates 
  WHERE  candidate_id NOT IN (SELECT DISTINCT candidate_id AS id 
                              FROM   candidates, 
                                     detentions 
                              WHERE  candidate_id = student_id 
                              ORDER  BY candidate_id); 
END