#26801: Queryset gets corrupted when using nested Prefetch
----------------------------------------------+----------------------------
Reporter: mlubimow | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.8
Severity: Normal | Keywords: prefetch,
| queryset
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
----------------------------------------------+----------------------------
When queryset objects contains nested Prefetch objects, after first
evaluation it gets corrupted.
Im attaching simple example, to reproduce a bug you need to run these
commands:
1. Install requirements file
2. python mange.py migrate
3. python manage runserver
Open your browser on:
http://127.0.0.1:8000/
And refresh '''twice'''. First time its gonna work, next time you should
get an error:
{{{
AttributeError at /
Cannot find 'author' on UserProfile object, 'author__profile__university'
is an invalid parameter to prefetch_related()
}}}
From my limited investigation it looks like after first evaluation
prefetch_to parameter is prepended with previous prefetch_to param, which
is in this case not correct.
Temporarly, its enough to create this object (queryset) again every time
it gets used.
--
Ticket URL: <https://code.djangoproject.com/ticket/26801>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/051.e8053f5a91d5e1fd48d2ce9843610b2f%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
