>
> I have this :
>
> SELECT date_trunc('month', f.date_creation) as mois,
> sum(f.montant_ttc / d.taux) as facture,
> (SELECT sum(f2.montant_ttc / d2.taux) as facture2
> FROM facture AS f2 JOIN devise AS d2 USING (id_devise)
> WHERE date_trunc('month', f2.date_creation)
> <= date_trunc('month', f.date_creation))
> FROM facture AS f JOIN devise AS d USING (id_devise)
> GROUP BY date_trunc('month', f.date_creation)
>
> which does not work... telling me that
>
> "Sub-SELECT uses un-GROUPed attribute f.date_creation from outer
query"
> Which is not really true, but some way is...
>
> What I want is to get the sum of the month, and the sum of the month
and
> the previous.
>
> If someone has a clue, something, anything... :)
>
Try
... GROUP BY mois ;
Regards, Christoph