Reverse OneToOne relationship does not save properly.

[David Hatch]

When the reverse side of a one-to-one relationship is assigned to and the model is saved, the association is not properly written to the database.

Example:

Models:

class Tag(models.Model):
    data = models.OneToOneField("Data")

class Data(models.Model):
    pass

Run:

data = Data()
t = Tag.objects.create()
data.tag = t
data.save()
# refresh from db
data = Data.objects.get(pk=data.pk)
data.tag # raises DoesNotExist

Attached is a patch including a test case which illustrates this issue.
To run the test case cd to the tests directory then...

export PYTHONPATH=`pwd`:`pwd`/..; ./runtests.py --settings=test_sqlite one_to_one_regress

test_reverse_one_to_one_save should fail.

[David Hatch]

test case

[Aymeric Augustin]

You're seeing the expected behavior. You'd need to call tag.save().

The API for 1-to-1 relationships isn't totally symmetrical -- after all it isn't at the SQL level.

[Mariusz Felisiak]

#32056 was closed as a duplicate, we can treat this as a request for a new feature.

[Mariusz Felisiak]

#34433 was closed as a duplicate.

[NKSM]

Replying to Aymeric Augustin:

You're seeing the expected behavior. You'd need to call tag.save().

The API for 1-to-1 relationships isn't totally symmetrical -- after all it isn't at the SQL level.

This should be documented here:

​https://docs.djangoproject.com/en/dev/topics/db/examples/one_to_one/.

The way it is now described is confusing.