#28561: .order_by('foo__id') doesn't create a join
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Reporter: Marten Kenbeek | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: Documentation | Version: 1.11
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 1
UI/UX: 0 |
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The documentation on `order_by()` states:
> It is also possible to order a queryset by a related field, without
incurring the cost of a JOIN, by referring to the _id of the related
field:
> {{{
> # No Join
> Entry.objects.order_by('blog_id')
>
> # Join
> Entry.objects.order_by('blog__id')
> }}}
However, in recent versions the latter query is optimised and won't create
a join:
{{{
>>> print(Bar.objects.order_by('foo__id').query)
SELECT "foo_bar"."id", "foo_bar"."foo_id" FROM "foo_bar" ORDER BY
"foo_bar"."foo_id" ASC
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/28561>
Django <https://code.djangoproject.com/>
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