# Generated by Django 3.1.4 on 2020-12-26 14:51 from django.db import migrations def migrate_empty_units(apps, schema_editor): Unit = apps.get_model('cookbook', 'Unit') Step = apps.get_model('cookbook', 'Step') empty_units = Unit.objects.filter(name='').all() for x in empty_units: for s in Step.objects.all(): for i in s.ingredients.all(): if i.unit == x: i.unit = None i.save() x.delete() class Migration(migrations.Migration): dependencies = [ ('cookbook', '0090_auto_20201214_1359'), ] operations = [ migrations.RunPython(migrate_empty_units), ]