I had now a similar problem and started to write a generic solution which is certainly not perfect, but works for me. Here is a detailed description:
http://lino.saffre-rumma.net/autodoc/lino.test_apps.1.html Looking forward to any comments. Luc On 7.11.2010 17:19, ringemup wrote: > Thank you for the pointer to ticket #11618, Stefan. At this point, I > don't care if the workaround is ugly -- if it actually works, at least > I'll be able to move forward with this project. I'll test it out and > check back in to confirm whether it does. > > > On Nov 7, 9:03 am, Stefan Foulis <stefan.fou...@gmail.com> wrote: >> As far as I know there is no existing api to convert a 'Place' into a >> 'Restaurant' with multi-table inheritance in django. There is a ticket >> about this [1]. And in another ticket [2] that is marked as a >> duplicate but seems to have an example of how to solve this problem >> until there is a standard api for the operation. Translated to the >> Restaurant example this would be: >> >> restaurant = Restaurant(place_ptr = place) >> for f in place._meta.local_fields: setattr(restaurant, f.name, >> getattr(place, f.name)) >> restaurant.save() >> >> [1]http://code.djangoproject.com/ticket/7623 >> [2]http://code.djangoproject.com/ticket/11618 >> >> On Nov 4, 9:25 pm, ringemup <ringe...@gmail.com> wrote: >> >>> I have an existing model that I want to extend using multi-table >>> inheritance. I need to create a child instance for each parent >>> instance in the database, but I can't figure out how. I've scoured >>> google and haven't come up with anything other than Ticket #7623[1]. >>> Here are some of the things I've tried... >> >>> Let's adapt the Place / Restaurant example from the docs: >> >>> class Place(models.Model): >>> name = models.CharField(max_length=50) >>> address = models.CharField(max_length=80) >> >>> class Restaurant(Place): >>> place = models.OneToOneField(Place, parent_link=True, >>> related_name='restaurant') >>> serves_hot_dogs = models.BooleanField() >>> serves_pizza = models.BooleanField() >> >>> I want to do the following, in essence: >> >>> for place in Place.objects.all(): >>> restaurant = Restaurant(**{ >>> 'place': place, >>> 'serves_hot_dogs': False, >>> 'serves_pizza': True, >>> }) >>> restaurant.save() >> >>> Of course, doing this tries to also create a new Place belonging to >>> the new Restaurant, and throws an error because no values have been >>> specified for the name and address fields. I've also tried: >> >>> for place in Place.objects.all(): >>> restaurant = Restaurant(**{ >>> 'serves_hot_dogs': False, >>> 'serves_pizza': True, >>> }) >>> place.restaurant = restaurant >>> place.save() >> >>> This, however, doesn't create any records in the restaurant table. >> >>> Any suggestions? >> >>> [1]http://code.djangoproject.com/ticket/7623 >> >> > -- 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.
