Django migration to merge one table's records into another similar table (both having UUID primary keys)

0002_merge_tables.py

from django.db import migrations


def merge_foo_into_bar(apps, schema_editor):
    """ For each FooCategory, create a corresponding BarCategory (with the new type)
    and for each Foo, create a corresponding Bar.
    
    The idea is that Foo and FooCategory would be dropped in a subsequent migration.
    """
    Foo = apps.get_model('myapp', 'Foo')
    FooCategory = apps.get_model('myapp', 'FooCategory')
    Bar = apps.get_model('myapp', 'Bar')
    BarCategory = apps.get_model('myapp', 'BarCategory')

    BarCategory.objects.bulk_create([
        BarCategory(
            id=obj.id,  # since the ID is a UUID, this should be ok
            title=obj.name,
            # ...maybe additional attributes set here 
        ) for obj in FooCategory.objects.all()
    ])

    Bar.objects.bulk_create([
        Bar(
            id=obj.id,
            internal_name=obj.internal_name,  # FIXME: if this column is unique, there could be collision
            category_id=obj.category_id,  # since the FooCategory.id was preserved
            text=obj.text
        ) for obj in Foo.objects.all()
    ])


class Migration(migrations.Migration):

    dependencies = [
        ('myapp', '0001_initial'),
    ]

    operations = [
        migrations.RunPython(merge_foo_into_bar)  # not reversible
    ]