using count in other column

Hi,

I made up a query to make a count for each item for each month/year:
SELECT"Artnr_ID", to_char("Date_plan","YYYY") AS "Jaar",
to_char("Date_plan","MM") AS "Maand", Count("tblArtnrs"."Artikelnr") AS
"Monthly_count", "val1","val2","val3"
FROM (("tblAnalyses" INNER JOIN "tblStudies" ON "tblAnalyses"."Studie_ID" =
"tblStudies"."Studie_ID") INNER JOIN "tblFichenr" ON
"tblStudies"."ID_fichenr" = "tblFichenr"."ID") INNER JOIN "tblArtnrs" ON
"tblFichenr"."ID_Art_nrs" = "tblArtnrs"."Artnr_ID"
GROUP BY "tblArtnrs"."Artnr_ID", to_char("Date_plan","YYYY") ,
to_char("Date_plan","MM"), "val1","val2","val3";

Now I want to use the "Monthly_count" value for further calculations with
other columns.
I tried to use 
"Monthly_count"+ "val1" + "Monthly_count" * "val2" + "Monthly_count" *"val3"
But "Monthly_count" is not recognised in my calculations.

How can this be solved?

Thanks

Bart

-- 
View this message in context: http://www.nabble.com/using-count-in-other-column-tp24622738p24622738.html
Sent from the PostgreSQL - sql mailing list archive at Nabble.com.