Pint the generated SQL print db(db.donation.id>0)._select(sum)
try execute the same command from pgsql shell. What do you get? Massimo On Nov 25, 7:41 pm, Bruno Rocha <[email protected]> wrote: > Hi, > > I was using sum() to calculate the amount of donations received in > (http://natalanimal.com.br/init/default/extrato), but I've found a limit > problem, I don't know if it is a PostgreSQL limit or sum() expression limit. > * > * > *#----FIRST WAY, USING SUM()* > > In my model I have a field "db.donation.total" for each donation, to > calculate this I did: > > sum = db.donation.total.sum() > total = db(db.donation.id>0).select(sum) > > I got total as Rows object which has a key "SUM(donation.total)" inside > _extra field as <Row {'_extra': <Row {'SUM(donation.total)': 515.0}>}> > > In this case it is returning *515.0* as result. > > *#---SECOND WAY LOOPING THROUGHT THE TABLE* > > Now I will make the same operation looping throught the values > > rows = db(db.donation.id>0).select() > total = float(0) > for row in rows: total += row.total > > In this case it is returning *590.0* as result > > *#---MY CONCLUSION* > > I figured out that the first way using sum() is limiting the rows of the > sum, in this example sum() is considering only 35 rows when I have 41 rows. > > why this is missing 6 rows in this case? I tried lot of times with the same > result set. > > Thanks > > -- > > Bruno Rochahttp://about.me/rochacbruno/bio
