#33008: Document prefetch_related for GenericForeignKey - Object doesn't exist
behaviour
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Reporter: Martin Svoboda | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: contrib.contenttypes | Version: 3.2
Severity: Normal | Resolution:
Keywords: Documentation | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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Comment (by Martin Svoboda):
Thank you, you are right, assignment {{{ tags_2[0].content_object = None
}}} also set object_id and content_type_id is to None. However I am not
sure if "modification" of a source object is the correct behaviour for
prefetch_related.
Replying to [comment:3 Simon Charette]:
> I didn't look at the issue in detail but I assume this is happening due
to the prefetching logic performing a `tags_2[0].content_object = None`
assignment.
>
> How does the following code behaves?
>
> {{{#!python
> tags_1 = TaggedItem.objects.filter(tag='test')
> tags_1.content_object = None
> assert tags_1.object_id is None
> assert tags_1.content_type_id is None
> }}}
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Ticket URL: <https://code.djangoproject.com/ticket/33008#comment:4>
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