how to get this information from tables [closed]

SELECT jour,heure_debut,
          heure_fin,nom_ens,nom_mod,nom_salle
          FROM cours,enseignant,modules,salles,specialite,promotion
          WHERE cours.id_ens=enseignant.id_ens and 
          cours.id_salle=salles.id_salle AND 
          cours.id_mod=modules.id_mod
          and(SELECT id_cours FROM cours WHERE cours.id_promo = 
              (SELECT id_promo FROM promotion WHERE promotion.id_speci = 
               (SELECT id_speci FROM specialite WHERE specialite.nom_speci='2MGL')
               AND promotion.niveau=2) );