#26780: Prefetch objects don't work with slices
-------------------------------------+-------------------------------------
Reporter: ludwik | Owner: nobody
Type: New feature | Status: new
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: prefetch, slicing | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by charettes):
* type: Bug => New feature
* version: 1.9 => master
* component: Uncategorized => Database layer (models, ORM)
* stage: Unreviewed => Accepted
Comment:
Tentatively accepting but as you've noticed it would require a large
refactor of the way prefetching is actually done.
I could see `Category.objects.prefetch_related(Prefetch('articles',
Article.object.order_by('-published_data')[0:3],
to_attr='latest_articles'))` being useful but the underlying prefetch
query would need to rely on subqueries, a feature the ORM is not good at
for now.
Maybe the addition of the [https://github.com/django/django/pull/6478
Subquery] expression could help here.
--
Ticket URL: <https://code.djangoproject.com/ticket/26780#comment:5>
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 django-updates+unsubscr...@googlegroups.com.
To post to this group, send email to django-updates@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/064.2ee3c90fc24b20475d248ec3dbc8d63a%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
