Multiple databases¶

Interacting with Multiple Databases¶

django-simple-history follows the Django conventions for interacting with multiple databases.

>>> # This will create a new historical record on the 'other' database.
>>> poll = Poll.objects.using('other').create(question='Question 1')

>>> # This will also create a new historical record on the 'other' database.
>>> poll.save(using='other')

When interacting with QuerySets, use using():

>>> # This will return a QuerySet from the 'other' database.
Poll.history.using('other').all()

When interacting with manager methods, use db_manager():

>>> # This will call a manager method on the 'other' database.
>>> poll.history.db_manager('other').as_of(datetime(2010, 10, 25, 18, 4, 0))

See the Django documentation for more information on how to interact with multiple databases.

Tracking User in a Separate Database¶

When using django-simple-history in app with multiple database, you may run into an issue where you want to track the history on a table that lives in a separate database to your user model. Since Django does not support cross-database relations, you will have to manually track the history_user using an explicit ID. The full documentation on this feature is in Manually Track User Model.

Tracking History Separate from the Base Model¶

You can choose whether or not to track models’ history in the same database by setting the flag use_base_model_db.

class MyModel(models.Model):
    ...
    history = HistoricalRecords(use_base_model_db=False)

If set to True, migrations and audit events will be sent to the same database as the base model. If False, they will be sent to the place specified by the database router. The default value is False.