Boolean fields return 0 and 1 when loaded through select_related

[homm]

This behavior only on mysql. SQLite always return True or False.

Models.py file:

from django.db import models

class BoolModel(models.Model):
    bool = models.BooleanField()

class Parent(models.Model):
    true = models.ForeignKey(BoolModel, related_name='trues')
    false = models.ForeignKey(BoolModel, related_name='falses')

In command line:

./manage.py shell
>>> from ex.models import *
>>> true = BoolModel.objects.create(bool=True)
>>> false = BoolModel.objects.create(bool=False)
>>> parent = Parent.objects.create(true=true, false=false)

>>> parent = Parent.objects.get()
>>> parent.true.bool
True
>>> parent.false.bool
False

>>> parent = Parent.objects.select_related('true', 'false').get()
>>> parent.true.bool
1
>>> parent.false.bool
0

As you can seen, in first case, when parent object loaded without select_related, booleans is booleans.
In second case, when object loaded with select_related, boolens are numbers.

Version 1.2 and 1.3 acts the same.

[Russell Keith-Magee]

This is because MySQL has special handling for returning boolean values; in 1.2, we added some callbacks to do the post-processing to ensure values get rectified. However, that rectification is performed with reference to the original model field. When using select_related, the original model obviously isn't being carried along for the ride.

[Adam Nelson]

Change at #15169 may be related and address this

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Ramiro Morales]

Patch, includes tests

[anonymous]

I just spent a ton of time debugging to figure out what this bug is. It causes ModelForms to have checkboxes that are all checked.

[benjaoming]

*bump* there is a patch for this! It even contains a very neat set of tests. Can it be merged and the bug closed? :)

[anonymous]

In my opinion this is a fairly significant issue. I spent all morning trying to figure out why a ModelForm (which was working perfectly locally on SQLite) had broken checkbox fields when deployed with a mysql backend.

parent = ParentModel.objects.select_related('child').get(pk=id)
# BooleanFields won't work with this form if using MySQL because their values are rendered as ints due to select_related()
child_form = ChildModelForm(instance=parent.child)

If there's no easy fix to this in Django itself I think there should at least be a warning in the documentation letting users know of this issue.

[Luke Plant <L.Plant.98@…>]

In f3a2bcdee906f7ca1434b6275fdc09b3a454cf46:

Fixed #15040 - Boolean fields return 0 and 1 when loaded through select_related

Thanks to homm for the report and ramiro for the patch.

[Luke Plant <L.Plant.98@…>]

In 142f69eb8c79ea5a54799354231b219f7c53b1cc:

[1.5.x] Fixed #15040 - Boolean fields return 0 and 1 when loaded through select_related

Thanks to homm for the report and ramiro for the patch.

Backport of f3a2bcdee906f7ca1434b6275fdc09b3a454cf46 from master

[anonymous]

I am having this problem in 1.5.1 -- 0 when using select related, but False when not. I am using mysql.

[anonymous]

The problem only occurs when using .defer()

[Tim Graham]

@anonymous, please open a new ticket with a test case if you can reproduce the issue on master. I tried the attached test based on your vague description but it passes on master and 1.5.x.

[Anssi Kääriäinen]

I am pretty sure this one was fixed in #21203 and #21126, both of which got backpatched to 1.5.

[Kyle Gibson]

I apologise if this isn't the proper place for this comment, but what would it take to get this fix backpatched to 1.4?

[Carl Meyer]

Replying to kylegibson:

I apologise if this isn't the proper place for this comment, but what would it take to get this fix backpatched to 1.4?

I'm afraid it won't be. 1.4 is in security-fix-only mode.