Re: problem with subselect

> |> 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)
> |> <=3D 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)
> |>=20
> |> which does not work... telling me that
> |>=20
> |> "Sub-SELECT uses un-GROUPed attribute f.date_creation from outer
> | query"
> |> Which is not really true, but some way is...
> |>=20
> |> What I want is to get the sum of the month, and the sum of the
month
> | and
> |> the previous.
> |>=20
> |> If someone has a clue, something, anything... :)
> |>=20
> | Try
> | ... GROUP BY mois ;
>
> Already tried, not working either.
>
I should have had a closer look:
The WHERE clause is causing the error.
I can't see any quick solution, but what often helped me is
First try to word the query as a view and do the GROUPing then on the
view.

Regards, Christoph