from django.db import migrations def set_map_false_for_all(apps, schema_editor): Contact = apps.get_model('contacts', 'Contact') Contact.objects.all().update(include_on_network_map=False) def noop_reverse(apps, schema_editor): pass class Migration(migrations.Migration): dependencies = [ ('contacts', '0003_contact_include_on_network_map'), ] operations = [ migrations.RunPython(set_map_false_for_all, noop_reverse), ]