On Sep 16, 5:49 pm, Steven <[EMAIL PROTECTED]> wrote: > I just got started with Django (I'm using v1.0).. and have been trying > (unsuccessfully) to add this line to my first model "author = > models.ForeignKey(User)"... (see my models.py below). Everytime I do > so and sync I get the following message: > > ^[[31;1mError: One or more models did not validate: > ^[[31;1mauth.message: Accessor for field 'user' clashes with related > field 'User.message_set'. Add \ > a related_name argument to the definition for 'user'. > ^[[0m^[[31;1mmusables.message: Accessor for field 'author' clashes > with related field 'User.message\ > _set'. Add a related_name argument to the definition for 'author'. > ^[[0m > > The odd thing is I decided to copy my model (see below it is called > MessageV2) and then it worked fine? Is there something "magical" > about the first model you define in a file? Is Django storing some > extra state somewhere.. btw.. i've been "DROP TABLE"ing all my tables > before manage.py syncdb ? > > Steven > > ===== models.py ====== > > from django.db import models > from django.contrib.auth.models import User > > # Create your models here. > > class Message(models.Model): > sent_date = models.DateTimeField() > subject = models.CharField(max_length = 100) > body = models.TextField() > slug = models.SlugField(max_length = 100) > # author = models.ForeignKey(User) # uncommenting this causes the > problem > def __unicode__(self): > return self.subject > > class MessageV2(models.Model): > sent_date = models.DateTimeField() > subject = models.CharField(max_length = 100) > body = models.TextField() > slug = models.SlugField(max_length = 100) > author = models.ForeignKey(User) # this is where things are > confusing > > def __unicode__(self): > return self.subject
No, there's no magic, and the problem isn't to do with the position in the file - it's to do with the name of your models. As the error message states, the problem is with a name clash. When you define a ForeignKey, Django automatically creates a reverse relationship from the target model back to your original model. By default, this is given the name of your model, which in your case is Message, plus '_set' - ie message_set. However, User already has a relation with a model called Message, which is part of the contrib.auth application, so there's a clash. The error message also helpfully states the solution: add a related_name to the author definition. If you do author = models.ForeignKey(User, related_name='author_messages') things should work, and you'll be able to refer backwards from user to authors via user.author_messages.all() and so on. See the fine documentation here: http://docs.djangoproject.com/en/dev/ref/models/fields/#foreign-key-arguments -- DR. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
