/Python/Django/Django pre_save get old instance

Django pre_save get old instance

@receiver(pre_save, sender=A)
def signal_product_manage_latest_version_id(sender, instance, update_fields=None, **kwargs):
    try:
        old_instance = A.objects.get(id=instance.id)
    except A.DoesNotExist:  # to handle initial object creation
        return None  # just exiting from signal
    # your code to with 'old_instance'

Source: stackoverflow.com

Similar codes

1 vote140 views1 answer
How to redirect to another page in django after login
Python Django
0 vote134 views1 answer
Create django model field based on another field
Python Django
0 vote136 views2 answers
The module in NAME could not be imported: django.contrhtmlib.auth.password_validation.UserAttributeSimilarityValidator. Check your AUTH_PASSWORD_VALIDATORS setting.
Python Django
0 vote150 views2 answers
Url namespaces for django rest router urls
Python Django
0 vote140 views2 answers
Django APIView Pagination
Python Django
0 vote144 views2 answers
Django-filter
Python Django
0 vote143 views1 answer
Django today date in template
Python Django
2 votes135 views1 answer
Django template capitalize equivalent
Python Django
0 vote130 views1 answer
Ssl django nginx
Python Django
0 vote121 views1 answer
Django check if get parameter exists
Python Django