Django Reverse Accessor Clashes

Question

So here I'm having lots of problems with reverse accessor clashes. I though I was being pretty clever and DRY with my model structure to be able to use user.profile for any kind of profile, or to use provider.profile for either provider... but I'm getting clash errors all over the place.

Mind taking a look at my code and seeing if there is any way for me to finagle this so I can still user just the user.profile without needing to know which kind of profile (and likewise provider.profile without needing to know which kind of provider)? Or just telling me that what I'm trying to do is impossible and any better solutions?

class BaseProfileModel(models.Model):
    '''
    An abstract model class containing fields and/or methods relevant to all users.
    '''
    user = models.OneToOneField(User, related_name="profile", primary_key=True)
    phone = PhoneNumberField(verbose_name=_("Phone Number"))
    pic = models.ImageField(upload_to=get_upload_file_name,
                            width_field="width_field",
                            height_field="height_field",
                            null=True,
                            blank=True,
                            verbose_name=_("Profile Picture")
                           )
    height_field = models.PositiveIntegerField(null=True, default=0)
    width_field = models.PositiveIntegerField(null=True, default=0)
    thumbnail = ImageSpecField(source='pic',
                                   processors=[ResizeToFill(180,180)],
                                   format='JPEG',
                                   options={'quality': 100})
    bio = models.TextField(
        verbose_name=_("About"),
        default="",
        blank=True,
        max_length=800
    )

    class Meta:
        abstract = True

    def __str__(self):
        if self.user.email:
            return self.user.email
        else:
            return self.user.username

    @property
    def is_provider(self):
        return hasattr(self, 'provider')

    def get_absolute_url(self):
        return reverse_lazy(self.profile_url_name, kwargs={'pk': self.pk})

    # Methods

class BaseHumanProfileModel(BaseProfileModel):
    '''
    Abstract base class containing fields relevant to human users
    '''
    birth_date = models.DateField(verbose_name=_("Date of Birth"))
    GENDER_CHOICES = (
        ('M', _('Male')),
        ('F', _('Female')),
        ('N', _('Not Specified')),
    )
    gender = models.CharField(
        max_length=1, choices=GENDER_CHOICES, default='N', verbose_name=_('Gender'))

    class Meta:
        abstract = True

class CustomerProfile(BaseHumanProfileModel):
    '''
    Concrete Human subclass for the consumers
    '''
    home_location = models.OneToOneField(
        Location,
        related_name='customer',
        null=True,
        blank=True,
        on_delete=models.SET_NULL
        )
    profile_url_name = 'profiles:customer_profile'

    # Methods

class Provider(models.Model):
    '''
    Class containing information needed for providers
    Other models (provider profiles, reviews, events, etc.) will use this class
    as ForeignKey to interface with functionalities related to creating and managing
    sessions/listings.
    '''
    stripe_access_token = models.TextField(blank=True, default='')

    # Methods....


class IndividualProviderProfile(BaseHumanProfileModel):
    '''
    Concrete subclass for representing the profile of an individual provider.
    '''
    provider = models.OneToOneField(Provider, related_name='profile')
    locations = models.ManyToManyField(Location, null=True, blank=True, related_name='individual_providers')
    specialties = models.CharField(
        verbose_name=_("Specialties"),
        max_length=200,
        blank=True,
    )
    certifications = models.CharField(
        verbose_name=_("Certifications"),
        max_length=200,
        blank=True,
    )
    profile_url_name = 'profiles:individual_provider_profile'

    # methods


class OrganizationProviderProfile(BaseProfileModel):
    '''
    Profile representing a provider that is an organization.
    Contains key to provider class for interfacing with session scheduling
    Also contains set of individual providers that work for the organization.
    '''
    provider = models.OneToOneField(Provider, related_name='profile')
    website = models.URLField(blank=True)
    location = models.ForeignKey(Location, related_name='organization')
    employees = models.ManyToManyField(IndividualProviderProfile, null=True, blank=True, related_name='organization')

    @property
    def locations(self):
        return Locations.objects.filter(pk=self.location.pk)

    profile_url_name = 'profiles:organization_provider_profile'

    #methods

Now when I try to sync the db I get this rather long and intense set of warnings:

CommandError: System check identified some issues:

ERRORS:
profiles.CustomerProfile.user: (fields.E304) Reverse accessor for 'CustomerProfile.user' clashes with reverse accessor for 'OrganizationProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'CustomerProfile.user' or 'OrganizationProfile.user'.
profiles.CustomerProfile.user: (fields.E304) Reverse accessor for 'CustomerProfile.user' clashes with reverse accessor for 'IndividualProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'CustomerProfile.user' or 'IndividualProviderProfile.user'.
profiles.CustomerProfile.user: (fields.E305) Reverse query name for 'CustomerProfile.user' clashes with reverse query name for 'OrganizationProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'CustomerProfile.user' or 'OrganizationProviderProfile.user'.
profiles.CustomerProfile.user: (fields.E305) Reverse query name for 'CustomerProfile.user' clashes with reverse query name for 'IndividualProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'CustomerProfile.user' or 'IndividualProviderProfile.user'.
profiles.OrganizationProfile.provider: (fields.E304) Reverse accessor for 'OrganizationProviderProfile.provider' clashes with reverse accessor for 'IndividualProviderProfile.provider'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.provider' or 'IndividualProviderProfile.provider'.
profiles.OrganizationProviderProfile.provider: (fields.E305) Reverse query name for 'OrganizationProviderProfile.provider' clashes with reverse query name for 'IndividualProviderProfile.provider'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.provider' or 'IndividualProviderProfile.provider'.
profiles.OrganizationProviderProfile.user: (fields.E304) Reverse accessor for 'OrganizationProviderProfile.user' clashes with reverse accessor for 'CustomerProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.user' or 'CustomerProfile.user'.
profiles.OrganizationProviderProfile.user: (fields.E304) Reverse accessor for 'OrganizationProviderProfile.user' clashes with reverse accessor for 'IndividualProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.user' or 'IndividualProvider.user'.
profiles.OrganizationProviderProfile.user: (fields.E305) Reverse query name for 'OrganizationProviderProfile.user' clashes with reverse query name for 'CustomerProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.user' or 'CustomerProfile.user'.
profiles.OrganizationProviderProfile.user: (fields.E305) Reverse query name for 'OrganizationProviderProfile.user' clashes with reverse query name for 'IndividualProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'OrganizationProviderProfile.user' or 'IndividualProvider.user'.
profiles.IndividualProviderProfile.provider: (fields.E304) Reverse accessor for 'IndividualProviderProfile.provider' clashes with reverse accessor for 'OrganizationProviderProfile.provider'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.provider' or 'OrganizationProviderProfile.provider'.
profiles.IndividualProviderProfile.provider: (fields.E305) Reverse query name for 'IndividualProviderProfile.provider' clashes with reverse query name for 'OrganizationProviderProfile.provider'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.provider' or 'OrganizationProviderProfile.provider'.
profiles.IndividualProviderProfile.user: (fields.E304) Reverse accessor for 'IndividualProviderProfile.user' clashes with reverse accessor for 'CustomerProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.user' or 'CustomerProfile.user'.
profiles.IndividualProviderProfile.user: (fields.E304) Reverse accessor for 'IndividualProviderProfile.user' clashes with reverse accessor for 'OrganizationProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.user' or 'OrganizationProviderProfile.user'.
profiles.IndividualProviderProfile.user: (fields.E305) Reverse query name for 'IndividualProviderProfile.user' clashes with reverse query name for 'CustomerProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.user' or 'CustomerProfile.user'.
profiles.IndividualProviderProfile.user: (fields.E305) Reverse query name for 'IndividualProviderProfile.user' clashes with reverse query name for 'OrganizationProviderProfile.user'.
    HINT: Add or change a related_name argument to the definition for 'IndividualProviderProfile.user' or 'OrganizationProviderProfile.user'.

score 73 · Accepted Answer · edited Nov 20 '15 at 18:35

73

related_name's must be unique. You're giving the same name to all the related_name's.

Try to rename them like this:

user = models.OneToOneField(User, related_name="custom_user_profile", primary_key=True)
#..
provider = models.OneToOneField(Provider, related_name='user_ind_provider_profile')
#..
provider = models.OneToOneField(Provider, related_name='user_org_provider_profile')

edited Nov 20 '15 at 18:35

rantsh

608
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answered Nov 16 '14 at 08:55

doniyor

36,596
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1

Ah dang so there's no way for me to make it so that I could use a single related name to refer to either, knowing that only one of the two would ever be assigned? Also, if you know a thing or two about django, would you mind checking out this post I made earlier http://stackoverflow.com/questions/26952212/django-models-polymorphism-and-foreign-keys and offering any input? I'm trying to decide between different ways to structure my data. – rfj001 Nov 16 '14 at 09:05
5

``related_name`` will be a unique column in db table, so a model cannot have two or more outgoing relations with the same name. – doniyor Nov 16 '14 at 09:09
Although the above code still doesn't do it for me because the related name on user could be pointing to one of any 3 concrete profile classes, which doesn't work with the DB. Basically means my whole polymorphism scheme doesn't work at all. – rfj001 Nov 16 '14 at 09:20
@rfj001 but this solves your clashing problem right? – doniyor Nov 16 '14 at 09:21
1

@rfj001 you are making things more complicated than they are. – doniyor Nov 16 '14 at 09:22
it solves the clashing between the provider field on Individual and Organization provider, but there is still clashing between all of the Profile classes on the user field, because each profile class has the same related name back to the Django User Model – rfj001 Nov 16 '14 at 09:24
@rfj001 someone could solve it for you, but i would recommend (as i learned also in this way) you to sit down and draw all models and their relations in a diagramm. this way you see the flow of relations which is 1-1 mappable to django models – doniyor Nov 16 '14 at 09:24
i updated the answer, just changed the relatedname to ``custom_user_profile`` – doniyor Nov 16 '14 at 09:26
See how the class with the OneToOneField back to `django.contrib.auth.models.User` is supposed to be my abstract subclass, from which 3 other classes inherit? When the concrete subclasses inherit this field, they each have a OneToOneField with related name "profile" with `django.contrib.auth.models.User` Thus even though it only appears once in code, the related name for the user model is really being reused in 3 cases, thus causing clashing, no matter what I decide to call the name. – rfj001 Nov 16 '14 at 09:31
you can write it only once with this : http://stackoverflow.com/questions/22538563/django-reverse-accessors-for-foreign-keys-clashing – jvo Apr 02 '15 at 08:57
If you want to have a single 'profile' attribute that returns the profile model you want, you could do it by defining a custom property called 'profile' on each model (using the @property decorator). This property could then return the required model. – seddonym Oct 28 '15 at 10:46

Django Reverse Accessor Clashes

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