Re: Stuck at filtering/slicing

On Wed, 2011-05-25 at 02:59 -0700, Michel30 wrote:
> Hello all,
>
> I have the following model:
>
> class Documentrevision(models.Model):
> docrevid = models.AutoField(primary_key=True,
> db_column='DocRevID')
> documentid = models.ForeignKey(Document, db_column='DocumentID')
> submitterid = models.ForeignKey('Author', db_column='SubmitterID')
> documenttitle = models.CharField(max_length=765,
> db_column='DocumentTitle')
> publicationinfo = models.TextField(db_column='PublicationInfo',
> blank=True)
> versionnumber = models.IntegerField(db_column='VersionNumber')
> abstract = models.TextField(db_column='Abstract', blank=True)
> revisiondate = models.DateTimeField(null=True,
> db_column='RevisionDate', blank=True)
> timestamp = models.DateTimeField(db_column='TimeStamp')
> obsolete = models.IntegerField(null=True, db_column='Obsolete',
> blank=True)
> keywords = models.CharField(max_length=720, db_column='Keywords',
> blank=True)
> note = models.TextField(db_column='Note', blank=True)
> demanaged = models.IntegerField(null=True, db_column='Demanaged',
> blank=True)
>
> Now I want to retrieve all entries that match obsolete=0, then order
> on revisiondate and docrevid and last get only the highest
> versionnumber for each group of documentid.
>
> I got this far:
> found_entries =
> Documentrevision.objects.filter(obsolete=0).order_by('-revisiondate','-
> docrevid')
>
> This gives me all versionnumbers though: I've been trying several ways
> to slice, group , do for-loops and can't get it to work..
> Any ideas are greatly appreciated :-)
> Thanks
>

DocumentRevision.objects.values('documentid').annotate(Max('docrevid)').filter(...)

Should do the trick.

--

Jani Tiainen

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To post to this group, send email to django-users@googlegroups.com.
To unsubscribe from this group, send email to django-users+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/django-users?hl=en.