-- question 1
select nom, prenom,intitule, credits from etudiant e 
join inscription i on e.idetu=i.idetu 
join cours c on c.idcours=i.idcours;
 
-- question 2
select nom, prenom,intitule, credits from etudiant e 
left join inscription i on e.idetu=i.idetu 
left join cours c on c.idcours=i.idcours;
-- question 3
select nom, prenom,intitule, credits from etudiant e 
right join inscription i on e.idetu=i.idetu 
right join cours c on c.idcours=i.idcours;
 
-- question 4
select nom, prenom,intitule, credits from etudiant e cross join cours;
 
-- question 5
select nom, prenom, note, intitule from etudiant e 
join inscription i on e.idetu=i.idetu
join cours c on c.idcours=i.idcours; 
-- question 6
select nom, prenom, note, intitule from etudiant e 
left join inscription i on e.idetu=i.idetu
left join cours c on c.idcours=i.idcours
where i.idcours is null; 
 
-- question 7
select nom, prenom, note, intitule from etudiant e 
right join inscription i on e.idetu=i.idetu
right join cours c on c.idcours=i.idcours
where i.idetu is null;

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