Hi,
Have you tried breaking up the migrations into multiple steps?
First create User and Institute without reference to each other. Then try
additional migrations.
Also, you can simplify Institute.members using reverse relations as follows:
def members(self):
return Institute.user_set.all()
Dartos
On Friday, May 5, 2017 at 8:41:52 AM UTC-4, Tobias Dacoir wrote:
>
> I am trying to build a model (in two separate apps) which has the
> following constraints:
>
> - There can be many institutes
> - there can many users
> - each user is a member of exactly one institute
> - each institute has exactly one master user
>
> However I am running into CircularDependency errors when trying to create
> this model and database. Of course this model is a bit problematic because
> you can't have an institute without master user, but also you can't create
> a user without some default institute. How do I fix this? Should I be more
> lean on the model side and allow for a lot of blanks and null values and
> make all the exception handling somewhere else?
>
> Please tell me how to improve my model.
>
>
>>
>>> class User(AbstractBaseUser, PermissionsMixin):
>>
>> # account-related information
>> institute = models.ForeignKey(Institute, blank=True, null=True,
>> on_delete=models.SET(get_default_institute))
>> username = ...
>> ....
>>
>> This is the model in another app for the institutes
>>
>> class Institute(models.Model):
>> master_user = models.ForeignKey(settings.AUTH_USER_MODEL,
>> related_name='master_user')
>> name = models.CharField(max_length=255)
>>
>> def members(self):
>> UserModel = apps.get_model('play', 'User') # need to avoid
>> circular import
>> return UserModel.objects.filter(institute=self)
>>
>>
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