drop view Historique_Avril;

create view Historique_Avril
(Identifiant_Client,Nom_Client,Avril_HT,Avril_TTC)
as select 
f.Identifiant_Client,
f.Nom_Client,
f.Prix_HT,
f.Prix_TTC
from Facture f
	where to_char(f.Date_Commande,'MM')= '04'
	order by f.Identifiant_Client; 