<asp:AccessDataSource ID="AccessDataSource1" runat="server"
DataFile="~/App_Data/db.mdb" SelectCommand="SELECT foto.idfoto, foto.file, immobile.prezzo, immobile.contratto, immobile.tipologia FROM foto left JOIN immobile on (foto.idfoto = immobile.id)
where immobile.contratto = ?">
<SelectParameters>
    <asp:querystringparameter name="Contratto" type="String" querystringfield="contratto" />
  </SelectParameters>
</asp:AccessDataSource>