Django REST Framework warning: `UnorderedObjectListWarning`

While creating a basic Django REST framework project with several models and the implementation of pagination, I faced this warning in terminal:

UnorderedObjectListWarning: Pagination may yield inconsistent results with an unordered object_list

I used the implementation of the DRF website the point: PageNumberPagination

I copied this into my settings.py file inside my project:

# settings.py

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
    'PAGE_SIZE': 100
}

and the above warning was popping up in terminal.

The explanation on the DRF website is, you have to order the queryset.

DRF expects an ordering of ["-created"].

The names of my attributes for the creation in my models where different, "created_time" and in the User model of Django the timestamp attribute is "date_joined". So, I had to come up with something.

---

There are two possible solutions:

1) add in the model class the ordering:

# models.py

from django.db import models

class Project(models.Model):
    created_time = models.DateTimeField(auto_now_add=True)
    name = models.CharField(max_length=100)
    description = models.TextField()
    author = models.ForeignKey()

    class Meta:
        ordering = ["created_time"]

the important part is the ordering = ["created_time"]. With this line of code you order the entries in your database by the create date and time.

2) add the .order_by() method to the queryset in the view:

# views.py

class ProjectViewSet(viewsets.ModelViewSet):

    def get_queryset(self):
        # use order_by to avoid the warning for the pagination
        return Project.objects.filter(author=self.request.user).order_by(
            "created_time"
        )

You order the queryset by the timestamp when the project was created .order_by("created_time").