Querying both sides of a OneToOneField at the same time is an error

[coderanger]

DB Model:

    cooking_recipe_item = models.OneToOneField(
        "Item",
        on_delete=models.SET_NULL,
        related_name="cooking_recipe_cookable",
        null=True,
        blank=True,
    )

GraphQL Model:

    cooking_recipe_item: Optional["Item"]
    cooking_recipe_cookable: Optional["Item"]

Query:

query {
  item {
    cookingRecipeItem {
      name
    }
    cookingRecipeCookable {
      name
    }
  }
}

Error:

Field Item.cooking_recipe_item cannot be both deferred and traversed using select_related at the same time.

It works fine if only one direction or the other is in the query. And it works with ForeignKeys in the same kind of configuration.

[bellini666]

Hey @coderanger ,

Hrm, I'm trying to understand your modeling there. Is it a OneToOne to the same item (self)? Because your are querying both the foreignkey and the related item in the same object.

[bellini666]

Btw, which django version are you using?

Django 4.2.2 just got released today, and one of the fixes is this: https://code.djangoproject.com/ticket/34612

I'm wondering if it has anything to do with the issue

[coderanger]

Yes, sorry it's a self-referencing field https://github.com/coderanger/farmrpg-etl2/blob/06920220df55376277462749b82bf046994a0dca/items/models.py#L39-L45 . I switched it to a FK since that works and it's easy enough to add a ...[0] in the client code but it used to be a OneToOne instead.

It's 4.2 right now, will give the new release a try and report back.

[bellini666]

@coderanger please tell me if 4.2.2 fixed the issue for you, so we can close this issue. Otherwise I'll need to investigate what might be going on here =P

[coderanger]

Apologies, got distracted. I tried it just now and it appears to work with 4.2.2 so I think we can close this out as a Django bug. If I find a new way to trigger it, I'll reopen :)