Opened 9 years ago

Closed 8 years ago

Last modified 5 years ago

#7076 closed (fixed)

qs.exclude(something=123) should not exclude objects with something=None

Reported by: Thomas Steinacher <tom@…> Owned by:
Component: Database layer (models, ORM) Version: master
Severity: Keywords: qsrf-cleanup
Cc: Triage Stage: Accepted
Has patch: yes Needs documentation: yes
Needs tests: yes Patch needs improvement: yes
Easy pickings: UI/UX:

Description

from django.db import models
class A(models.Model):
    str = models.CharField(null=True, blank=True, max_length=20)
    def __unicode__(self):
        return self.str or 'None'
In [1]: from test import models

In [2]: a = models.A.objects.create(str='a')

In [3]: b = models.A.objects.create(str=None)

In [4]: models.A.objects.exclude(str='a')
Out[4]: []

In [5]: models.A.objects.filter(str__isnull=True).exclude(str='a')
Out[5]: []

In [6]: models.A.objects.all()                                    
Out[6]: [<A: a>, <A: None>]

Expected output:

Out[4]: [<A: None>]  
Out[5]: [<A: None>]  

Tested with trunk & queryset-refactor.

Attachments (1)

7076.1.diff (1.6 KB) - added by Johannes Dollinger 8 years ago.

Download all attachments as: .zip

Change History (9)

comment:1 Changed 9 years ago by George Vilches

Keywords: qsrf-cleanup added

Changed 8 years ago by Johannes Dollinger

Attachment: 7076.1.diff added

comment:2 Changed 8 years ago by Johannes Dollinger

Has patch: set
Needs documentation: set
Needs tests: set
Owner: changed from nobody to anonymous
Patch needs improvement: set
Status: newassigned

I can reproduce this (r7573 + postgres).

It could be solved easyly by making __exact NULL-safe:

But I couldn't find something comparable for sqlite and oracle (except for (a=b OR (a IS NULL AND b IS NULL))) - and I don't know if anything depends on NULL == 1=NULL == NOT (1=NULL) and would break with FALSE == 1<=>NULL != NOT(1<=>NULL) == TRUE.

While trying to come up with a patch I found some dead code that should handle the issue for related tables (see patch, missing [JOIN_TYPE] in if final > 1 ...) and just threw in a similar weakening for the unjoined case.

This will be a backwards incompatible change.

comment:3 Changed 8 years ago by anonymous

Owner: anonymous deleted
Status: assignednew
Triage Stage: UnreviewedAccepted

comment:4 Changed 8 years ago by Jacob

milestone: 1.0

comment:5 Changed 8 years ago by Malcolm Tredinnick

Thanks for the patch, but ... one way to tell that a patch isn't quite correct is when the existing test suite doesn't pass when it's applied. :-)

This patch breaks the exclude(field__in=[]) case. I'll fix it before committing and add some tests for the issues in this ticket, but please check the test suite and include tests for any new functionality. It makes things easier.

comment:6 Changed 8 years ago by Malcolm Tredinnick

Resolution: fixed
Status: newclosed

Fixed in [7760].

comment:7 Changed 8 years ago by Malcolm Tredinnick

(In [7812]) Modified [7760] to not include a "col is not NULL" fragment for non-nullable fields.

This avoids any use of "pk is not NULL" fragment, which behave inconsistently
in MySQL. Thanks to Russell Keith-Magee for diagnosing the problem and
suggesting the easy fix.

Refs #7076.

comment:8 Changed 5 years ago by Jacob

milestone: 1.0

Milestone 1.0 deleted

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