How many athletes from Malaysia have won a medal?
Malaysia refers to region_name = 'Malaysia'; athletes won a medal refer to competitor_id where medal_id <> 4;
SELECT COUNT(T3.person_id) FROM medal AS T1 INNER JOIN competitor_event AS T2 ON T1.id = T2.medal_id INNER JOIN games_competitor AS T3 ON T2.competitor_id = T3.id INNER JOIN person_region AS T4 ON T3.person_id = T4.person_id INNER JOIN noc_region AS T5 ON T4.region_id = T5.id WHERE T5.region_name = 'Malaysia' AND T1.id != 4