create view V_TOTAL_PANIER as
    select
        PAN.idUser ,
        sum(PAN.quantite*ART.prix) as TOTAL
    from
        panier as PAN
        inner join 
            articles as ART 
        on ART.idArticle = PAN.idArticle
    group by
        PAN.idUser;

select TOTAL 
from V_TOTAL_PANIER 
where idUser = 1