moviewyrm/bookwyrm/migrations/0008_work_default_edition.py

# Generated by Django 3.0.7 on 2020-11-04 18:15

from django.db import migrations, models
import django.db.models.deletion


def set_default_edition(app_registry, schema_editor):
    db_alias = schema_editor.connection.alias
    works = app_registry.get_model("bookwyrm", "Work").objects.using(db_alias)
    editions = app_registry.get_model("bookwyrm", "Edition").objects.using(db_alias)
    for work in works:
        ed = editions.filter(parent_work=work, default=True).first()
        if not ed:
            ed = editions.filter(parent_work=work).first()
        work.default_edition = ed
        work.save()


class Migration(migrations.Migration):

    dependencies = [
        ("bookwyrm", "0007_auto_20201103_0014"),
    ]

    operations = [
        migrations.AddField(
            model_name="work",
            name="default_edition",
            field=models.ForeignKey(
                null=True,
                on_delete=django.db.models.deletion.PROTECT,
                to="bookwyrm.Edition",
            ),
        ),
        migrations.RunPython(set_default_edition),
        migrations.RemoveField(
            model_name="edition",
            name="default",
        ),
    ]