On Sat, 2008-06-28 at 13:23 -0700, felix wrote: > > Contact > Company(Contact) > Person(Contact) > > If I have a Contact it might be a Person or a Company and I'm looking > for the best way to find out. > Especially in cases where I'm listing these objects, doing a separate > trial and error database query (as I show below) isn't the best > solution. > > Actually it might be nice if the top parent class table had a > content_type field (or similar to avoid coupling to > contrib.contenttypes) so we could easily deduce the leaf class.
This has been discussed on this list before. It would be nice, but it's not something that's going to happen by default. The reason is that it breaks inheriting from third-party classes (since you would have to modify the table of the third-paty model in the database). You could implement this yourself by having a secondary table to track the relations. Or you can manually include a type_code attribute in your parent model (since it's something you have created yourself). The latter case is the most natural in the situations where it makes sense to somehow treat the parent class as just a proxy for the child. This might all sound horrible, but that's the way life goes. Relational databases and object-oriented inheritance have some mismatches (search for "Vietnam of computer science" on the web as a starting point) that can't really be overcome. Anything to try and meld them is a hack on some level. 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?hl=en -~----------~----~----~----~------~----~------~--~---
