diff --git a/docs/ref/models/instances.txt b/docs/ref/models/instances.txt index 1da38d96632..2010692d88d 100644 --- a/docs/ref/models/instances.txt +++ b/docs/ref/models/instances.txt @@ -81,7 +81,7 @@ fields are present, then ``values`` are guaranteed to be in the order to each of the missing fields. In addition to creating the new model, the ``from_db()`` method must set the -``adding`` and ``db`` flags in the new instance's ``_state`` attribute. +``adding`` and ``db`` flags in the new instance's :attr:`~Model._state` attribute. Below is an example showing how to record the initial values of fields that are loaded from the database:: @@ -853,3 +853,21 @@ Other attributes class to identify the class of object that could not be found and to allow you to catch a particular model class with ``try/except``. The exception is a subclass of :exc:`django.core.exceptions.ObjectDoesNotExist`. + +``_state`` +---------- + +.. attribute:: Model._state + + The ``_state`` attribute refers to a ``ModelState`` object that tracks + the lifecycle of the model instance. + + The ``ModelState`` object has two attributes: ``adding``, a flag which is + ``True`` if the model has not been saved to the database yet, and ``db``, + a string referring to the database alias the instance was loaded from or + saved to. + + Newly instantiated instances have ``adding=True`` and ``db=None``, + since they are yet to be saved. Instances fetched from a ``QuerySet`` + will have ``adding=False`` and ``db`` set to the alias of the associated + database.