declare
    cursor curCli is select numero_cli, count(*) from Commandes where date_cde between '21/11/09' and sysdate group by numero_cli order by 2 desc;
    tabCli curCli%rowtype;
    cpt number;

begin
    cpt := 0;
    open curCli;
    if curCli%isopen then
        while cpt < 3 loop
            fetch curCli into tabCli;
            dbms_output.put_line(tabCli.numero_cli);
            cpt := cpt + 1;
        end loop;
    end if;
    close curCli;
end;
/