-- requete pour remplir le champ site_id 
update materiels set site_id = NULL where lieu_stockage is NULL;
update materiels set site_id ="1" where lieu_stockage like "Belin%";
update materiels set site_id ="2" where lieu_stockage like "Roche%";
update materiels set site_id ="3" where lieu_stockage like "Tarbes%";