Cannot return null for non-nullable field FooType.barType [Enum]

The error occurs with graphene-django==2.0.0 with a field with choices, for example:

class Foo(models.Model):
    ONE = 1
    TWO = 2
  
    BAR_TYPES = (
        (ONE, _('one'),
        (TWO, _('two'),
    )

    bar_type = models.PositiveIntegerField(_('type'), choices=BAR_TYPES)


class FooType(DjangoObjectType):                                    
    class Meta:
        model = Foo

This error can be resolved with an explicit graphene.Field declaration:

class FooEnum(graphene.Enum):
    ONE = 1
    TWO = 2                       


class FooType(DjangoObjectType):                                    
    bar_type = graphene.Field(FooEnum)
    class Meta:
        model = Foo

Is it really necessary to duplicate the choices, though?

[prokher]

I had the same issue until I applied the following:

import django.db.models as dj_models
from enum import Enum

class MyEnum(Enum):
    VAL1 = 'Value 1'
    VAL2 = 'Value 2'
    VAL3 = 'Value 3'

    def __str__(self):
        """Allow to directly assign enum values to the model field."""
        return self.name


class MyModel(dj_models.Model):
    state = dj_models.CharField(choices=[(tag.name, tag.value) for tag in MyEnum],
                                max_length=42)

this fixed an issues for me.

I’ve got the recipe from here: http://anthonyfox.io/2017/02/choices-for-choices-in-django-charfields/

Also there are useful comments under this article: https://hackernoon.com/using-enum-as-model-field-choice-in-django-92d8b97aaa63

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.