Thanks Malcolm. I couldn't find a ticket for this particular
enhancement so I created http://code.djangoproject.com/ticket/2400.
On 7/22/06, Malcolm Tredinnick <[EMAIL PROTECTED]> wrote:
>
> On Sat, 2006-07-22 at 19:43 +1000, Matthew Flanagan wrote:
> > Hi,
> >
> > I have the following simplified models. Then I create a number of IP
> > addresses and interfaces, with not all IP addresses being related to
> > an interface.
> >
> > class IPAddress(models.Model):
> > address = models.CharField(maxlength=15)
> >
> > class Admin: pass
> >
> > class Interface(models.Model):
> > name = models.CharField(maxlength=15)
> > ipaddress = models.ForeignKey(IPAddress)
> >
> > class Admin: pass
> >
> > Then when I try:
> >
> > >>> IPAddress.objects.filter(interface__isnull=False)
> >
> > I get a list of IPAddresses that have related interfaces.
> >
> > Then if I try:
> >
> > >>> IPAddress.objects.filter(interface__isnull=True)
> >
> > I get an empty list when I expected to be getting the IP addresses
> > that are not related to any interfaces. Right?
> >
> > Ultimately I'd like to do this:
> >
> > class Interface(models.Model):
> > name = models.CharField(maxlength=15)
> > ipaddress = models.ForeignKey(IPAddress,
> > limit_choices_to={'interface__isnull':True})
> >
> > class Admin: pass
> >
> > so that the admin will only should "free" ip addresses not ones that
> > ae already used.
> >
> > Is this a bug? Am I doing the wrong lookup?
>
> It's not a bug. But it could be argued it's a missing feature. Because
> the reverse relation does not exist yet, you cannot query against it. We
> would need to special case this type of situation. For the moment, you
> will need to construct a custom SQL query if you want to do this (it's
> not too painful).
>
> If there's not a ticket for it already (it came up in [1]), maybe file
> an enhancement request.
>
> [1]
> http://groups.google.com/group/django-users/browse_frm/thread/98b7aedf8f9d806c/385833fa2b597afe?lnk=gst&rnum=1#385833fa2b597afe
>
> Regards,
> Malcolm
>
>
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
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 [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/django-users
-~----------~----~----~----~------~----~------~--~---
