Django将具有值的现有列更改为ForeignKey

from django.db import models

class NewModel(models.Model):
    new_foreign_key = models.ForeignKey(OtherModel, on_delete=models.CASCADE)

python manage.py makemigrations

from django.db import migrations

def migrate_data(apps, schema_editor):
    NewModel = apps.get_model('your_app_name', 'NewModel')
    OldModel = apps.get_model('your_app_name', 'OldModel')

    for old_model in OldModel.objects.all():
        new_model = NewModel()
        new_model.new_foreign_key = OtherModel.objects.get(id=old_model.old_foreign_key)
        new_model.save()

class Migration(migrations.Migration):

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

    operations = [
        migrations.RunPython(migrate_data),
    ]

python manage.py migrate