That's a good point. Thanks Jeff.
The reason they are none, or have a null value, is because there are
actually no related records in the related table.
Two Tables:
Participants (contains all potential participants)
Data (contains actual participant activity)
If there is a way to convert those nulls to zeroes, that would work
perfectly.
Here's my query, (I'm using the stable release version of django,
otherwise I'd use "annotate" which I found is present in the
development version).
contest = Participant.objects.extra(select={
'contest_stats': """
SELECT SUM(amt)
FROM contest_data
WHERE contest_data.participant_id = region_participant.id
"""
}).order_by('-contest_stats')
Thanks,
J
On Jun 30, 9:28 am, Jeff FW <jeff...@gmail.com> wrote:
> Any reason not to make the total 0 instead of None? Null in database
> (or None in Python) has a special meaning, and it doesn't always make
> sense to sort a list of (mostly) integers with some null values.
>
> -Jeff
>
> On Jun 30, 2:01 am, J <jobce...@gmail.com> wrote:
>
> > Hello,
>
> > I developed an app for an online contest.
>
> > In this app, I requested a queryset with totals from a related table,
> > and wanted to display the top ten participants. So, I sorted the
> > queryset on the totals field, descending. Some participants didn't have
> > any items, so the total for these was "None".
>
> > When using sqlite, this appeared as I wanted, with the objects having
> > "None" at the bottom, and thus not included in the top ten.
>
> > However, after uploading this app to the production site, which has a
> > postgres db, the None participants appeared at the top of the list (!),
> > and THEN came the largest items successively decreasing as expected. My
> > top-ten program failed.
>
> > Any ideas?
>
> > Thanks,
> > J
>
> > PS: Examples:
>
> > Developement, sqlite, working:
> > AR003 147
> > CH005 69
> > CO001 50
> > CO031 50
> > CH029 49
> > AR004 None
> > AR029 None
>
> > Production, postgres, not working:
> > CO217 None
> > CO024 3000
> > PE017 1400
> > VE025 988
> > CO013 930
> > PE203 628
> > CH016 523
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