#28297: Same queryset result in two different queries on ORM
-------------------------------------+-------------------------------------
Reporter: Marcus Renno | Owner: Tom
Type: Bug | Status: assigned
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution:
Keywords: join, annotation, F | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 0 | UI/UX: 0
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Comment (by Tom):
Hmm, you're right Simon. I missed the OrderedDict change, and tested
initially on 1.11 (where it's not applied). With this, on master, the
results are added deterministically, but the first item is always the
incorrect join.
So I don't think my ticket fixes the issue in a convincing way. If you
extend the example in the ticket with another annotate and filter:
{{{
self.queryset = self.queryset.annotate(total=Count('steps__ingredients',
distinct=True))
self.queryset = self.queryset.filter(steps__ingredients__pk=1)
self.queryset =
self.queryset.annotate(available=Count('steps__ingredients',
distinct=True))
self.queryset = self.queryset.filter(steps__ingredients__pk=2)
self.queryset =
self.queryset.annotate(available2=Count('steps__ingredients',
distinct=True))
self.queryset =
self.queryset.filter(total=F('available')).filter(total=F('available2'))
}}}
Then `reuse` will have *three* aliases found: `[('test_app_recipe_steps',
'LEFT OUTER JOIN'), ('T6', 'INNER JOIN'), ('T10', 'INNER JOIN')]`
In this case my patch will fetch T6, and we have the same issue.
--
Ticket URL: <https://code.djangoproject.com/ticket/28297#comment:19>
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