In my SELECT statement I fetch data from a view, and I have the 2 following errors: 1.When I use Aggregate function AVG, it returns "Aggregate function calls may not be nested" 2. When I use my PL/PGSQL function "HO()" it returns "Attribute req_preminter.datedemande must be GROUPed or used in an aggregate function" It must be a commun mistake I'm sure,but I'm not very good at big queries (I thought I was once for all succesfull by creating views...) ; I've read that subselect fct shoud be used instead, but how, and what is a grouped attribute ? Can somebody help me ? ---------------------------------------------- Here is my queries, if interested ---------------------------------------------- CREATE VIEW Req_PremInter AS SELECT Demande.demandeID, to_char(datedemande, 'MMYYYY') AS Mois, Demande.Datedemande AS Datedemande, Min(Intervention.DateInter) AS DateInter FROM Demande INNER JOIN Intervention ON Demande.demandeID = Intervention.Demande GROUP BY Demande.demandeID, to_char(datedemande, 'MMYYYY'), Demande.Datedemande; QUERY with AVG: -------------------------- SELECT Req_PremInter.Mois AS Mois, Avg(to_number(dateinter,99)) AS Delai FROM Req_PremInter GROUP BY Req_PremInter.Mois ORDER BY Req_PremInter.Mois; QUERY with HO (PL/PGSQL function) ------------------------- SELECT Req_PremInter.Mois AS Mois, HO(datedemande, dateinter, '12/12/2000', '12/12/2000')/24 AS Delai FROM Req_PremInter GROUP BY Req_PremInter.Mois ORDER BY Req_PremInter.Mois; Final QUERY (what I really what to run) -------------------------------------------------------- SELECT Req_PremInter.Mois AS Mois, Avg(HO(datedemande,'12/12/2000',dateinter,datedemande)/24) AS Delai FROM Req_PremInter GROUP BY Req_PremInter.Mois ORDER BY Req_PremInter.Mois;
