#parent class

    class ObjectJourney(Base):        
        journey_type = models.ForeignKey('Journey.JourneyType')
        entry_time = models.DateTimeField(auto_now_add=True)
        exit_time = models.DateTimeField(null=True,blank=True)

#child class

    class BookingJourney(ObjectJourney):
        journey_object = models.ForeignKey('RequestBooking.Booking')
        journey_entity = models.ForeignKey(
            'UserManagement.C24customer', related_name='journeys')

Migrations file contains

    migrations.CreateModel(
                    name='BookingJourney',
                    fields=[
                        ('objectjourney_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE,
                        parent_link=True, primary_key=True, serialize=False, to='Journey.ObjectJourney')),
                    ],
                    options={
                        'abstract': False,
                    },
                    bases=('Journey.objectjourney',),
            ),

#Following are the error trails visible in terminal

    File "/home/jagdamba/testenv/lib/python3.6/site-packages/django/db/migrations/state.py", line 308, in render_multiple
        model.render(self)
    File "/home/jagdamba/testenv/lib/python3.6/site-packages/django/db/migrations/state.py", line 579, in render
        return type(self.name, bases, body)
    File "/home/jagdamba/testenv/lib/python3.6/site-packages/django/db/models/base.py", line 253, in __new__
        base.__name__,
    django.core.exceptions.FieldError: Auto-generated field 'objectjourney_ptr' in class 'BookingJourney' for parent_link to base class 'ObjectJourney' clashes with declared field of the same name.

My attempts to solve this error

    -Deleted migrations and created new migration.
    -ALso followed steps of this article...
    https://www.kidstrythisathome.com/2016/10/wtf-django-moving-models-part1.html