1# when using sqlite3
2python manage.py dumpdata > datadump.json
3# after chagne db
4python manage.py makemigrations
5python manage.py migrate --run-syncdb
6python manage.py shell
7from django.contrib.contenttypes.models import ContentType
8ContentType.objects.all().delete()
9quit()
10python manage.py loaddata datadump.json