import django.db.models.deletion from django.db import migrations, models import content.models class Migration(migrations.Migration): dependencies = [('content', '0015_seed_subjects')] operations = [ migrations.AddField( model_name='unit', name='subject', field=models.ForeignKey( default=content.models.default_subject_pk, on_delete=django.db.models.deletion.PROTECT, related_name='units', to='content.subject', ), ), ]