> It isn't very clear from that sentence which of the two methods Django > uses to delete those child records, but looking at the code, it seems > to be method #2. Since it's using the more-efficient batch delete, no > custom delete methods are being called, no signals are being sent, > which is exactly the problem you're having. > > The solution is to override the delete method (or respond to the > pre_delete signal), on your *parent* model, in this case > 'Participant'. That way, when you delete the Participant, you can > delete all related Data records by hand. I had a quick glance at the code and I came to the opposite conclusion.
A comment [1] in the delete() method in the QuerySet class says: "# Collect all the objects to be deleted in this chunk, and all the # objects that are related to the objects that are to be deleted." This collection is then passed to the delete_objects [2] function where the SQL magic happens and it definitely sends signals. Confused as I was, I just tried it. I have a Video model which haa a VideoHost model as foreign key. I defined a function that prints its parameter and attached it to the post_delete signal: >>> def print_sig(*args,**kwargs): ... for x in args: print str(x) ... for k,v in kwargs.items(): print k,v >>> dispatcher.connect(print_sig, signal=signals.post_delete) Then I deleted one VideoHost[3]: >>> VideoHost.objects.all()[0].delete() All related Videos got deleted as well, and signals got sent: instance Video 1 on YouTube signal <object object at 0xb7d8f4a8> sender <class 'videosite.videos.models.Video'> instance Video 2 on YouTube signal <object object at 0xb7d8f4a8> sender <class 'videosite.videos.models.Video'> instance Video 3 on YouTube signal <object object at 0xb7d8f4a8> sender <class 'videosite.videos.models.Video'> instance YouTube signal <object object at 0xb7d8f4a8> sender <class 'videosite.videos.models.VideoHost'> It seems signals are the way to go, or did I miss something? Regards, Daniel [1] http://code.djangoproject.com/browser/django/trunk/django/db/models/query.py#L276 [2] http://code.djangoproject.com/browser/django/trunk/django/db/models/query.py#L680 [3] OMG, I deleted YouTube! :) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" 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-users?hl=en -~----------~----~----~----~------~----~------~--~---
