On Wed, Jan 28, 2009 at 4:44 PM, Malcolm Tredinnick < malc...@pointy-stick.com> wrote:
> > On Wed, 2009-01-28 at 06:49 -0800, Aaron Lee wrote: > > I tried doing that but it didn't work, the order of names within the > > PersonAdmin still shows the Name according to pk order. > > Firstly, realise that your question doesn't have a "correct" answer. > Ordering by multi-valued fields always have that problem. For example: > > Person1 > - Name.name = 'a' > - Name.name = 'c' > Person2 > - Name.name = 'b' > What I want to achieve is when I edit Person1 in the admin interface, I want to order the Name.name i.e. 'a', 'c' instead of according to 'a','c''s primary key in Name. So I am a bit confused why Person2 comes into the picture. Think about a person can have multiple names e.g. screenname, nickname, username etc ... I believe that's a legitimate use of ManyToManyField? > > Now, depending upon which "name" value is chosen for Person1, it might > sort ahead of or behind Person2. However, things are even worse than > that. What will happen, in fact, is that the SQL results will include > Person1 twice -- once for name='a' and once for name='c', since any > ordering columns are part of the select result. > > However, if you're certain that the group of things you are selecting > don't have multiple entries in the related many-to-many table (in which > case, why are you using a ManyToManyField and not a ForeignKey?), you > can order by any related field you like: > > class Person(models.Model): > ... > class Meta: > ordering = ['name__name'] > > This is documented in the order_by() documentation for querysets (since > Meta.ordering is just an order_by() application): > > http://docs.djangoproject.com/en/dev/ref/models/querysets/#order-by-fields > > 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 django-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
