[Solved]-Accessing model manager methods in datamigration

by

9👍

✅

Looks like this is not possible.

From the South documentation:

You can do a lot more with this inside a data migration; any model can
be available to you. The only caveat is that you won’t have access to
any custom methods or managers on your models, as they’re not
preserved as part of the freezing process (there’s no way to do this
generally); you’ll have to copy any code you want into the migration
itself. Feel free to make them methods on the Migration class; South
ignores everything apart from forwards and backwards.

👤Amit

4👍

Since Django 1.8, you can include model managers in migrations by adding the use_in_migrations property.

From the docs:
https://docs.djangoproject.com/en/2.0/topics/migrations/#model-managers

class MyManager(models.Manager):
    use_in_migrations = True

class MyModel(models.Model):
    objects = MyManager()
👤mattdedek

2👍

Augmenting @mattdedek’s answer with an example of use in a migration

def my_migration_function(apps, schema_editor):
    MyModel = apps.get_model('my_app_name', 'MyModel')
    MyModel.objects.create(name='foo')


class Migration(migrations.Migration):
    initial = True

    dependencies = [
        ...
    ]

    operations = [
        migrations.RunPython(my_migration_function),
    ]

Currently works in django migrations (tested on version 3.0.4)

👤ralston3

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