-- Query 28

SELECT
    consommation.numcons AS 'numéro',
    consommation.libcons AS 'libellé consommation'
FROM consommation
WHERE NOT EXISTS (
    SELECT comprend.numcons
    FROM comprend
    WHERE comprend.numcons = consommation.numcons
);

/* == RESULT ==
"Numéro","Libellé Consommation"
150,"Jus de tomate"
300,"Cocktail"
*/