djangodjango-modelsdjango-managers

Django: related_name issue


I am trying to make a query with related_name. I need to list tenants and its domain. But I am getting this error:

'TenantManager' object has no attribute 'domains'

What am I doing wrong?

models.py

class Tenant(TenantMixin):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    name = models.CharField(max_length=100)
    created_on = models.DateField(auto_now_add=True)

    objects = TenantManager()

    auto_create_schema = True
    auto_drop_schema = True


class Domain(DomainMixin):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    domain = models.CharField(max_length=253, unique=True, db_index=True)
    tenant = models.ForeignKey(settings.TENANT_MODEL, db_index=True, related_name='domains',
                               on_delete=models.CASCADE)

managers.py

class TenantManager(models.Manager):

    def list_all(self):        
        return self.domains.all()    

viewsets.py

class TenantViewSets(viewsets.GenericViewSet):

    authentication_classes = (JWTAuthentication,)
    permission_classes = [IsAuthenticated, IsAdminUser, IsSuperUser]

    def list(self, request):      
        queryset = Tenant.objects.list_all()
        serializer = Tenant.Serializer(queryset, many=True)
        return Response(serializer.data) 

serializers.py

class DomainSerializer(serializers.ModelSerializer): 
    tenant = serializers.RelatedField(read_only=True)

    class Meta:
        model = Domain
        fields = (
            "id",
            "domain",
            "tenant",
        )


class TenantSerializer(serializers.ModelSerializer): 
    domain = DomainSerializer(read_only=True)

    class Meta:
        model = Tenant
        fields = (
            "id",
            "name",
            "schema_name",
            "created_on",
            "domain",
        )

Solution

  • You can't use the related_name on a manager method like that. On the manager you can do all the usual ORM queries, like self.filter() or self.get(id=1).

    Looking at your code, if list_all() is to return all domains but then you're trying to use that queryset in a view set for tenants. If it's domain objects you actually want, change the queryset to Domain.objects.all()