UPDATE courses SET discipline = null WHERE id_course = 'course123';
UPDATE courses SET discipline = null WHERE id_course = 'course32';
UPDATE courses SET discipline = null WHERE id_course = 'course50';
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UPDATE courses SET discipline = null WHERE id_course = 'course164';
UPDATE courses SET discipline = null WHERE id_course = 'course41';
UPDATE courses SET discipline = null WHERE id_course = 'course51';
UPDATE courses SET discipline = null WHERE id_course = 'course174';
UPDATE courses SET discipline = null WHERE id_course = 'course4';
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UPDATE courses SET discipline = null WHERE id_course = 'course126';
UPDATE courses SET discipline = null WHERE id_course = 'course160';
UPDATE courses SET discipline = null WHERE id_course = 'course91';
