Request over partition and join

Hello,

I'm trying to get a report using partition and joins.

The involved tables are:

ligne_ordres with
- non unique composite key titre_id, date_ord, numero_ordre,
operation_id
- foreign key titre_id to table titres
- foreign key operation_id to table operations

titres with
- field societe

operations with
- field libelle

I need to get the following report:

id   societe   date_ord   numero_ordre   libelle  ppb  pf   ppn  tpb
tf  tpn

With the following code I get:

id   titre_id  date_ord   numero_ordre   operation_id  ppb  pf  ppn
tf  tpn

How to integrate societe and libelle into the report instead of
titre_id and operation_id?

[code]
WITH calculate_parts AS (
    SELECT id, titre_id, date_ord, numero_ordre, operation_id,
          CASE
            WHEN operation_id != 2 and operation_id != 21 and
operation_id != 23 THEN
              prix_brut
            ELSE
              -round(quantite * cumpb - 0.005, 2)
           END AS prix_brut,
           CASE
             WHEN operation_id != 2 and operation_id != 21 and
operation_id != 23 THEN
               frais
             ELSE
               -round(quantite * cump, 2) + round(quantite * cumpb, 2)
           END AS frais,
           CASE
             WHEN operation_id != 2 and operation_id != 21 and
operation_id != 23 THEN
             prix_net
           ELSE
             -round(quantite * cump, 2)
           END AS prix_net
    FROM ligne_ordres
    WHERE date_ord >= '2011-03-01')
SELECT DISTINCT ON(titre_id, date_ord, numero_ordre, operation_id)
   id, titre_id, date_ord, numero_ordre, operation_id,
   SUM(prix_brut) OVER (PARTITION BY titre_id, date_ord, numero_ordre,
operation_id) AS ppb,
   SUM(frais) OVER (PARTITION BY titre_id, date_ord, numero_ordre,
operation_id) AS pf,
   SUM(prix_net) OVER (PARTITION BY titre_id, date_ord, numero_ordre,
operation_id) AS ppn,
   SUM(prix_brut) OVER () AS tpb,
   SUM(frais) OVER () AS tf,
   SUM(prix_net) OVER () as tpn
FROM calculate_parts
ORDER BY titre_id, date_ord, numero_ordre, operation_id, id
[/code]

Thanks in advance for any help.

Cheers,
Michèle