#11154 is really about another issue; it has nothing to do with model equality.
I'll try to submit a new patch with a release not in the next days as requested by anssi. Le lundi 16 juillet 2012 17:44:06 UTC-4, Daniel Sokolowski a écrit : > > I would also throw this ticket into the mix - > https://code.djangoproject.com/ticket/11154, it's related and has bit me > in > the past. > > -----Original Message----- > From: Anssi K��ri�inen > Sent: Monday, July 16, 2012 3:07 PM > To: Django developers > Subject: Model equality in inheritance cases > > I was looking through some old tickets, and spotted a case which I had > worked on some time ago. The case is about model instance equality in > different inheritance situations. There are three different cases to > consider (assuming primary keys match): > - should a proxy model be equal to its proxy parent? > - should a inherited model be equal to its parent instance? > - what to do in model multi-inheritance cases. > > My take is that proxy models should be equal to their parent > instances, otherwise inherited models should not equal their parent > instances. The reasons for this are backwards compatibility, > performance and achieving correctness for all cases. > > I won't go into details of what kind of problems multitable multi- > inheritance causes for achieving correctness. Suffice to say that it > is possible to construct cases where is it very hard to tell if two > models should be equal or not. Refer to ticket #16458 for more > details. > > The backwards compatibility issue is in my opinion enough to say "no" > to the multitable-inheritance case. Django has one use in admin which > downright breaks when child models are equal to their parent models. > User code could have similar problems, too. > > Writing a patch for proxy model equality is straightforward. Writing a > patch which takes all the corner cases of multitable multi-inheritance > in account is not trivial at all. > > So, I propose to go forward with proxy model equality. Doing something > to this long standing issue would be welcome in any case. > > For more dirty details, see ticket #16458. Tickets #11892 and #14492 > are related. > > - Anssi > > -- > You received this message because you are subscribed to the Google Groups > "Django developers" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/django-developers?hl=en. > > > Daniel Sokolowski > Web Engineer > Danols Web Engineering > http://webdesign.danols.com/ > > -- You received this message because you are subscribed to the Google Groups "Django developers" group. To view this discussion on the web visit https://groups.google.com/d/msg/django-developers/-/eO41x26agEIJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
