UPDATE courses SET discipline = null WHERE id_course = 'course170';
UPDATE courses SET discipline = null WHERE id_course = 'course32';
UPDATE courses SET discipline = null WHERE id_course = 'course157';
UPDATE courses SET discipline = null WHERE id_course = 'course67';
UPDATE courses SET discipline = null WHERE id_course = 'course51';
UPDATE courses SET discipline = null WHERE id_course = 'course162';
UPDATE courses SET discipline = null WHERE id_course = 'course30';
UPDATE courses SET discipline = null WHERE id_course = 'course8';
UPDATE courses SET discipline = null WHERE id_course = 'course103';
UPDATE courses SET discipline = null WHERE id_course = 'course121';
