#25113: Field lookup for __not_in
-------------------------------------+-------------------------------------
Reporter: Evan Tschuy | Owner: nobody
Type: New feature | Status: closed
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution: wontfix
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Dmitry Mugtasimov):
It produce SQL like:
{{{
NOT ("jobs_job"."id" IN (SELECT U0."id" FROM "jobs_jobstatus" U0))
}}}
which may not be equivalent to
{{{
"jobs_job"."id" NOT IN (SELECT U0."id" FROM "jobs_jobstatus" U0)
}}}
regarding performance.
Also because of "weird" chained filter() behavior (
https://docs.djangoproject.com/en/dev/topics/db/queries/#spanning-multi-
valued-relationships ) you will have to do something like
{{{
Job.objects.filter(
~Q(id__in=JobStatus.objects.values_list('id',
flat=True).all()),
...
)
}}}
instead of
{{{
Job.objects.filter(...).exclude(id__in=JobStatus.objects.values_list('id',
flat=True).all()).delete()
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/25113#comment:6>
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