Opened 7 years ago

Last modified 7 years ago

#28723 closed Bug

RelatedManager.get_prefetch_queryset returns "wrong" cache_name — at Version 2

Reported by: Mike Hansen Owned by: nobody
Component: Database layer (models, ORM) Version: dev
Severity: Normal Keywords:
Cc: Triage Stage: Accepted
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Mike Hansen)

Currently, RelatedManager.get_prefetch_queryset returns self.field.related_query_name() as the cache_name. In the case where no related_name has been set on the ForeignKey, then this does not match with the through_attr used by get_prefetcher.

Using the models in tests/prefetch_related/models.py,

BookWithYear.objects.prefetch_related('bookreview_set')

will use a through_attr of "bookreview_set", but "bookreview" is what will be placed in _prefetched_objects_cache.

I think related_manager.field.remote_field.get_accessor_name() should be used instead.

I'll post a patch fixing this and adding a test case.

Change History (2)

comment:1 by Mike Hansen, 7 years ago

Has patch: set

A pull request for this can be found at ​https://github.com/django/django/pull/9259

I wasn't sure on the best location for these tests so any guidance would be helpful.

comment:2 by Mike Hansen, 7 years ago

Description: modified (diff)
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