Query con parametri Oracle in c#

Usa invece i due punti (:login ).

 string sqlCmd = @"SELECT  r.row_id AS resp_id,
                                    r.name AS resp_name
                            FROM    srb.s_resp r,
                                    srb.s_per_resp pr,
                                    srb.s_contact c,
                                    srb.s_user u
                            WHERE   r.row_id = pr.resp_id
                                    AND u.row_id = c.row_id
                                    AND c.person_uid = pr.per_id
                                    AND UPPER(u.login) = :login
                                    ORDER BY r.name";