#26517: Empty Querset Using Empty Queryset in ExpressionWrapper
-------------------------------------+-------------------------------------
Reporter: srkunze | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: 1.8
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by srkunze):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Old description:
> We use the ExpressionWrapper + annotate to annotate specific boolean
> values to all queried instances like this (minimal working example):
>
> {{{
> editable_ones = ..... # another queryset
> result =
> MyModel.objects.annotate(editable=ExpressionWrapper(Q(pk__in=editable_child_folders),
> output_field=BooleanField())
> }}}
>
> As soon as {{{editable_ones}}} is empty, {{{result}}} is also empty.
> Reading the docs, I guess this is not desired behavior
> (https://docs.djangoproject.com/en/1.9/ref/models/querysets/#annotate).
New description:
We use the ExpressionWrapper + annotate to annotate specific boolean
values to all queried instances like this (minimal working example):
{{{
editable_ones = ..... # another queryset
result =
MyModel.objects.annotate(editable=ExpressionWrapper(Q(pk__in=editable_ones),
output_field=BooleanField())
}}}
As soon as {{{editable_ones}}} is empty, {{{result}}} is also empty.
Reading the docs, I guess this is not desired behavior
(https://docs.djangoproject.com/en/1.9/ref/models/querysets/#annotate).
--
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Ticket URL: <https://code.djangoproject.com/ticket/26517#comment:1>
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