[Django] #27875: Manager inheritance for multi-table inheritance model behaviour
Django
-------------------------------------+-------------------------------------
Reporter: ek-init | Owner: nobody
Type: Bug | Status: new
Component: | Version: 1.10
Uncategorized |
Severity: Normal | Keywords: Manager inheritance
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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The Managers documentation says:
> Managers from base classes are always inherited by the child class,
using Python’s normal name resolution order (names on the child class
override all others; then come names on the first parent class, and so
on).
> If no managers are declared on a model and/or its parents, Django
automatically creates the objects manager.
For abstract base classes this works properly, inheriting the manager from
the base model and therefore overriding the objects manager if so
declared.
For my non-abstract inheritance example, this does not work the same way
...
{{{
#!python
class MyManager(models.Manager):
pass
class A(models.Model):
objects = MyManager()
other = MyManager()
class B(A):
pass
}}}
{{{
In [4]: B.objects.__class__
Out[4]: django.db.models.manager.Manager
In [5]: B.other.__class__
Out[5]: test_app.models.MyManager
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/27875>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
-------------------------------------+-------------------------------------
Reporter: ek-init | Owner: nobody
Component: Uncategorized | Version: 1.10
Severity: Normal | Resolution: invalid
Keywords: Manager inheritance | Triage Stage:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: new => closed
* resolution: => invalid
Comment:
You are using Django < 1.10 while reading the documentation for Django >=
1.10.
As the [https://docs.djangoproject.com/en/1.10/topics/db/managers/#custom-
managers-and-model-inheritance Django 1.10 documentation mentions]:
> In older versions, manager inheritance varied depending on the type of
model inheritance (i.e. Abstract base classes, Multi-table inheritance, or
Proxy models), especially with regards to electing the default manager.
--
Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:1>
Django
manager_inheritance_from_future
-------------------------------------+------------------------------------
Reporter: ek-init | Owner: nobody
Type: Bug | Status: new
Severity: Normal | Resolution:
Keywords: Manager inheritance | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------
* status: closed => new
* resolution: invalid =>
* stage: Unreviewed => Accepted
* component: Uncategorized => Documentation
Comment:
Actually, the behavior is as documented but only when using
`Meta.manager_inheritance_from_future=True`. The documentation needs to
mention this. I'll propose a patch.
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Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:2>
Django
manager_inheritance_from_future
-------------------------------------+------------------------------------
Type: Bug | Status: new
Severity: Normal | Resolution:
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Tim Graham):
* has_patch: 0 => 1
Comment:
My [https://github.com/django/django/pull/8104 PR] is intentionally vague
as it's difficult to tell which specific behaviors are controlled by the
attribute since there were a several manager changes spread over two
commits: 3a47d42fa33012b2156bf04058d933df6b3082d2 and
ed0ff913c648b16c4471fc9a9441d1ee48cb5420.
--
Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:3>
Django
manager_inheritance_from_future
-------------------------------------+------------------------------------
Type: Bug | Status: closed
Component: Documentation | Version: 1.10
Severity: Normal | Resolution: fixed
Keywords: Manager inheritance | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------
* status: new => closed
* resolution: => fixed
Comment:
In [changeset:"22eb15a18c16b93496f6e88ebe3a306daad492b1" 22eb15a1]:
{{{
#!CommitTicketReference repository=""
revision="22eb15a18c16b93496f6e88ebe3a306daad492b1"
[1.11.x] Fixed #27875 -- Doc'd manager_inheritance_from_future in manager
docs.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:4>
Django
manager_inheritance_from_future
-------------------------------------+------------------------------------
Type: Bug | Status: closed
Component: Documentation | Version: 1.10
Severity: Normal | Resolution: fixed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------
Comment (by Tim Graham <timograham@…>):
In [changeset:"e298ec4e947c3d300f4ef21019e59f4bc05ceabf" e298ec4]:
{{{
#!CommitTicketReference repository=""
revision="e298ec4e947c3d300f4ef21019e59f4bc05ceabf"
[1.10.x] Fixed #27875 -- Doc'd manager_inheritance_from_future in manager
docs.
Backport of 22eb15a18c16b93496f6e88ebe3a306daad492b1 from stable/1.11.x
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:5>
Django
manager_inheritance_from_future
-------------------------------------+------------------------------------
Type: Bug | Status: closed
Component: Documentation | Version: 1.10
Severity: Normal | Resolution: fixed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------
Comment (by ek-init):
Replying to [comment:1 Simon Charette]:
> You are using Django < 1.10 while reading the documentation for Django
>= 1.10.
>
> As the [https://docs.djangoproject.com/en/1.10/topics/db/managers
/#custom-managers-and-model-inheritance Django 1.10 documentation
mentions]:
>
> > In older versions, manager inheritance varied depending on the type of
model inheritance (i.e. Abstract base classes, Multi-table inheritance, or
Proxy models), especially with regards to electing the default manager.
Fixed, but I want to mention that I was using Django 1.10.5 :)
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Ticket URL: <https://code.djangoproject.com/ticket/27875#comment:6>