diff --git a/PostgreSQL/src/functions.sql b/PostgreSQL/src/functions.sql
index aa09a51..8eb6dbf 100644
--- a/PostgreSQL/src/functions.sql
+++ b/PostgreSQL/src/functions.sql
@@ -2,14 +2,17 @@
 CREATE OR REPLACE FUNCTION pieces_membre(int) RETURNS TABLE(id_piece int, quantite_piece int)
 AS 
 $$ 
-SELECT id_piece, quantite_contenir * quantite_enregistrer as quantite_pieces_possedees
-FROM enregistrer
-NATURAL JOIN boites
-NATURAL JOIN contenir
-WHERE id_membre=$1
-UNION
-(SELECT id_piece, quantite_acheter as quantite_pieces_possedees
-  FROM acheter WHERE id_membre=$1);
+SELECT id_piece, SUM(quantite_pieces_possedees) FROM (
+  SELECT id_piece, quantite_contenir * quantite_enregistrer as quantite_pieces_possedees
+  FROM enregistrer
+  NATURAL JOIN boites
+  NATURAL JOIN contenir
+  WHERE id_membre=$1
+  UNION
+  (SELECT id_piece, quantite_acheter as quantite_pieces_possedees
+    FROM acheter WHERE id_membre=$1)
+  )
+  GROUP BY id_piece
 $$
 LANGUAGE SQL;
 ;