create() does not save reverse OneToOne relationship nor raise an Exception

[Alan Rivas]

When creating an object with a reverse OneToOne relationship as an argument, the method Model.create does not set the relation but does not raise an Error either.

Example:

models:

from django.db import models

class Place(models.Model):
    pass


class Restaurant(models.Model):
    place = models.OneToOneField(
        Place,
        on_delete=models.CASCADE,
        null=True,
    )

With these models if you try this:

place = Place.objects.create()
restaurant = Restaurant.objects.create()

place.restaurant = restaurant
place.save(update_fields=["restaurant"])

You will get this error:

ValueError: The following fields do not exist in this model, are m2m fields, or are non-concrete fields: restaurant

But if you try with this code:

restaurant = Restaurant.objects.create()
place = Place.objects.create(restaurant=restaurant)

You will not get an Exception and restaurant will not be related with place either. I do understand you can't save in a reverse OneToOne relation but I think this behavior is inconsistent because of the missing Exception.

[Mariusz Felisiak]

Tentatively accepted. This is a side-effect of 8a47ba679d2da0dee74671a53ba0cd918b433e34 (see also #16508 and #18599). As far as I'm aware, we could raise an exception as we are not going to support it (see #18638).

[Mariana]

​PR

[Mariusz Felisiak <felisiak.mariusz@…>]

In e02fc588:

Fixed #34586 -- Made QuerySet.create() raise ValueError for reverse one-to-many relations.