[Django] #17930: Error in Queryset with operator | (union queryset) + slice
Django
----------------------------------------------+----------------------------
Reporter: vini.gracindo@… | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.3
Severity: Normal | Keywords: queryset
Triage Stage: Unreviewed | union, slice
Easy pickings: 0 | Has patch: 0
| UI/UX: 0
----------------------------------------------+----------------------------
{{{
class Example:
name = models.CharField(max_length = 30)
public = models.BooleanField()
}}}
>>> Example.objects.create('example 1', False)
<Example: Example object>
>>> Example.objects.create('example 2', False)
<Example: Example object>
>>> Example.objects.create('example 3', True)
<Example: Example object>
>>> Example.objects.create('example 4', True)
<Example: Example object>
>>> Example.objects.create('example 5', False)
<Example: Example object>
>>> query = Example.objects.filter(public = True)
>>> if(query.count() < 3):
... query = query | Example.objects.filter(public =
False).order_by('?')[:1]
...
>>> query.count()
5
>>>
When using the union of querysets to slice it "ignores" the slice and
takes all objects where public = false.
--
Ticket URL: <https://code.djangoproject.com/ticket/17930>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage:
Keywords: queryset union, | Unreviewed
slice | Needs documentation: 0
Has patch: 0 | Patch needs improvement: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Changes (by lrekucki):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Old description:
> {{{
> class Example:
> name = models.CharField(max_length = 30)
> public = models.BooleanField()
> }}}
>
> >>> Example.objects.create('example 1', False)
> <Example: Example object>
> >>> Example.objects.create('example 2', False)
> <Example: Example object>
> >>> Example.objects.create('example 3', True)
> <Example: Example object>
> >>> Example.objects.create('example 4', True)
> <Example: Example object>
> >>> Example.objects.create('example 5', False)
> <Example: Example object>
> >>> query = Example.objects.filter(public = True)
> >>> if(query.count() < 3):
> ... query = query | Example.objects.filter(public =
> False).order_by('?')[:1]
> ...
> >>> query.count()
> 5
> >>>
>
> When using the union of querysets to slice it "ignores" the slice and
> takes all objects where public = false.
New description:
{{{
class Example:
name = models.CharField(max_length = 30)
public = models.BooleanField()
}}}
{{{
>>> Example.objects.create('example 1', False)
<Example: Example object>
>>> Example.objects.create('example 2', False)
<Example: Example object>
>>> Example.objects.create('example 3', True)
<Example: Example object>
>>> Example.objects.create('example 4', True)
<Example: Example object>
>>> Example.objects.create('example 5', False)
<Example: Example object>
>>> query = Example.objects.filter(public = True)
>>> if(query.count() < 3):
... query = query | Example.objects.filter(public =
False).order_by('?')[:1]
...
>>> query.count()
5
>>>
}}}
When using the union of querysets to slice it "ignores" the slice and
takes all objects where {{{public = false}}}.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:1>
Django
Type: Bug | Status: new
(models, ORM) | Resolution:
Keywords: queryset union, | Needs documentation: 0
slice | Patch needs improvement: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Changes (by lukeplant):
* stage: Unreviewed => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:2>
Django
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: queryset union, | Needs documentation: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Comment (by akaariai):
What should the expected output be? Maybe (pseudoquery):
{{{
select * from example
where (original_query_conditions) or pk in (select pk from example where
public = false order by random() limit 1)
}}}
Or, in this special case this could be written as:
{{{
select * from example
where (original_query_conditions) or pk = (select pk from example where
public = false order by random() limit 1)
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:3>
Django
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: queryset union, | Needs documentation: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Comment (by anonymous):
Expected:
{{{
>> query = query | Example.objects.filter(public =
False).order_by('?')[:1]
>> print query.count()
3
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:4>
Django
Reporter: vini.gracindo@… | Owner: Ian Foote
Type: Bug | Status: assigned
Component: Database layer | Version: 1.3
(models, ORM) |
Keywords: queryset union, | Triage Stage: Accepted
slice |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Ian Foote):
* owner: nobody => Ian Foote
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:5>
Django
Reporter: vini.gracindo@… | Owner: Ian Foote
Type: Bug | Status: assigned
Component: Database layer | Version: 1.3
(models, ORM) |
Severity: Normal | Resolution:
Keywords: queryset union, | Triage Stage: Accepted
slice |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Ian Foote):
* has_patch: 0 => 1
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:6>
Django
Reporter: vini.gracindo@… | Owner: Ian Foote
Type: Bug | Status: assigned
Component: Database layer | Version: 1.3
(models, ORM) |
Severity: Normal | Resolution:
Keywords: queryset union, | Triage Stage: Accepted
slice |
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* needs_better_patch: 0 => 1
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:7>
Django
Reporter: vini.gracindo@… | Owner: Ian Foote
Type: Bug | Status: assigned
Component: Database layer | Version: 1.3
(models, ORM) |
Severity: Normal | Resolution:
slice | checkin
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* needs_better_patch: 1 => 0
* stage: Accepted => Ready for checkin
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:8>
Django
Reporter: vini.gracindo@… | Owner: Ian Foote
Component: Database layer | Version: 1.3
(models, ORM) |
Keywords: queryset union, | Triage Stage: Ready for
slice | checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"e1fc07c047f8e46c2cea0120f44011fc458f1e91" e1fc07c]:
{{{
#!CommitTicketReference repository=""
revision="e1fc07c047f8e46c2cea0120f44011fc458f1e91"
Fixed #17930 -- Allowed ORing (|) with sliced QuerySets.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/17930#comment:9>