Thank you for the responses this makes sense. My app is still barely past the Polls stage.. so I've just changed the name of my model and it works great. Now that its been explained the error message makes a lot of sense.
Hmm... I'm wondering if there is a more friendly error message that could be displayed.. or a newbie warning in the docs "don't use these model names: X, Y, Z if you're going to define User as a ForeignKey..if you do make sure you define related_name". Maybe in practice model name collisions (with ForiegnKey(User)) don't happen often except for silly newbies. Although it does seem like there would be a chance that 2 different django apps might collide though... and if they were both "3rd party apps" ideally one wouldn't want to patch them i.e. add related_name. Has that happened to anyone? Steven On Sep 16, 10:45 am, "Karen Tracey" <[EMAIL PROTECTED]> wrote: > On Tue, Sep 16, 2008 at 12:49 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 > > When you define a ForeignKey, the target model acquires an accessor to > retrieve the set of models with ForeignKey values that specify it. The name > of that accessor is the name of the model where the ForeignKey is defined > (lower-cased), plus '_set'. This is probabably explained with better words > in the documentation: > > http://docs.djangoproject.com/en/dev/topics/db/queries/#following-rel... > > Your problem is you are defining a model Message with a ForeignKey to User > when the django.contrib.auth application already has a different model > Message with ForeignKey to User, see: > > http://docs.djangoproject.com/en/dev/topics/auth/#messages > > Thus validation determines that there are going to be two different > 'message_set' accessors on User, and validation fails. You can either use > the related_name argument on your ForeignKey to change the name for the > accessor, or you can change the name of your model to something other than > Message (which is why your 2nd model works, it's not because it is the 2nd > model but rather because its name does not duplicate another model's name > that has a ForeignKey to User). > > Karen --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
