Probleme SUM et DISTINCT

bonjour

je souhaite faire la somme de la colonne DL_Qte sans doublon dans la colonne DO_Piece

repertoire = ThisWorkbook.Path & "\"

Dim rs As New ADODB.Recordset

Set cnn = New ADODB.Connection

cnn.Open "DRIVER={Microsoft Access Driver (*.mdb)};DBQ=" & repertoire & "BDDTEST.mdb"

rs.Open "SELECT COUNT(*)AS Nb ,SUM(DL_Qte) AS Nb1 FROM Import ", cnn '---------------------------- ligne OK

'rs.Open "SELECT COUNT(*)AS Nb ,SUM(DL_Qte) AS Nb1 FROM (SELECT DISTINCT DO_Piece FROM Import) ", cnn '-------------------ne fonctionne pas

Cells(2, 2) = rs("Nb")

Cells(3, 2) = rs("Nb1")

rs.Close

cnn.Close

bonsoir

essaie avec la clause group by

"SELECT COUNT(do_piece) AS Nb ,SUM(DL_Qte) AS Nb1 FROM  FROM Import GROUP BY do_piece ", cnn