[Django] #27846: refresh_from_db() does not create "soft links" on model_instances that are pointed to by another model's OneToOneField
Django
pointed to by another model's OneToOneField
-------------------------------------+-------------------------------------
Reporter: Keith | Owner: nobody
Hostetler |
Type: | Status: new
Uncategorized |
Component: Database | Version: 1.10
layer (models, ORM) | Keywords: refresh_from_db
Severity: Normal | OneToOneField
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
Sorry for the poor summary, it is difficult to explain in words. I have a
project to demo this bug attached to this ticket, but I will try to
explain the bug anyway in steps and the setup.
Setup:
- 2 models (A and B)
- B has a OneToOne to A
- Both A and B have a field (ie TextField)
- Setup either a signal or override save() for A to update B's TextField
to equal that of A's on save() or post_save for signals
Steps:
- Create instance of A
- Get another copy of the instance of A via A.objects.get()
- Create instance of B using the copy of the instance of A
- Do refresh_from_db() on original instance of A
- Try to access B from A
The project I have provided is a slim version of this problem that
demonstrates it with signals, overriden save(), and basic set and save
inside the test. The basic set and save works, but the other two fail when
using the above steps.
--
Ticket URL: <https://code.djangoproject.com/ticket/27846>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
pointed to by another model's OneToOneField
-------------------------------------+-------------------------------------
Type: Uncategorized | Status: new
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage:
OneToOneField | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* Attachment "django_1_10_refresh_from_db_bug.rar" added.
Django
pointed to by another model's OneToOneField
-------------------------------------+-------------------------------------
Type: Bug | Status: new
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage:
OneToOneField | Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* type: Uncategorized => Bug
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:1>
Django
pointed to by another model's OneToOneField
-------------------------------------+-------------------------------------
Type: Bug | Status: new
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage:
OneToOneField | Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Old description:
> Sorry for the poor summary, it is difficult to explain in words. I have a
> project to demo this bug attached to this ticket, but I will try to
> explain the bug anyway in steps and the setup.
>
> Setup:
> - 2 models (A and B)
> - B has a OneToOne to A
> - Both A and B have a field (ie TextField)
> - Setup either a signal or override save() for A to update B's TextField
> to equal that of A's on save() or post_save for signals
>
> Steps:
> - Create instance of A
> - Get another copy of the instance of A via A.objects.get()
> - Create instance of B using the copy of the instance of A
> - Do refresh_from_db() on original instance of A
> - Try to access B from A
>
> The project I have provided is a slim version of this problem that
> demonstrates it with signals, overriden save(), and basic set and save
> inside the test. The basic set and save works, but the other two fail
> when using the above steps.
New description:
Sorry for the poor summary, it is difficult to explain in words. I have a
project to demo this bug attached to this ticket, but I will try to
explain the bug anyway in steps and the setup.
Setup:
- 2 models (A and B)
- B has a OneToOne to A
- Both A and B have a field (ie TextField)
- Setup either a signal or override save() for A to update B's TextField
to equal that of A's on save() or post_save for signals
Steps:
- Create instance of A
- Get another copy of the instance of A via A.objects.get()
- Create instance of B using the copy of the instance of A
- Do refresh_from_db() on original instance of A
- Try to access B from A
The project I have provided is a slim version of this problem that
demonstrates it with signals, overriden save(), and basic set and save
inside the test. The basic set and save works, but the other two fail when
using the above steps. Run the test suite to see.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:2>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
OneToOneField |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* stage: Unreviewed => Accepted
Comment:
I think this is fixable but I'm not sure without trying to write a patch.
This case may be discussed in ticket:901#comment:36 It looks like the
issue is that `refresh_from_db()`
[https://github.com/django/django/blob/a7214f0e84913a27e0b73de89d4c827ef1c53b94/django/db/models/base.py#L609-L620
clears concrete fields] but doesn't clear reverse relations.
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:3>
Django
-------------------------------------+-------------------------------------
| Kukuy
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* owner: nobody => Matvey Kukuy
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:4>
Django
-------------------------------------+-------------------------------------
Type: Bug | Status: new
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => new
* owner: Matvey Kukuy => (none)
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:5>
Django
-------------------------------------+-------------------------------------
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* owner: nobody => Paulo
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:4>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* cc: Andrey Fedoseev (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:5>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Paulo):
Hello,
What do you all think about clearing the fields cache entirely on
refresh_from_db()?
This would cover similar bugs where a many to one or many to many
relationship is cached.
The only case we can't cover is fields prefetched to custom attributes.
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:6>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* cc: Berker Peksag (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:7>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Type: Bug | Status: assigned
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution:
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* has_patch: 0 => 1
Comment:
PR: https://github.com/django/django/pull/9112
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:8>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Component: Database layer | Version: 1.10
(models, ORM) |
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"a7b5ad8b19a08d7d57302ece74f6e26d2887fd9f" a7b5ad8b]:
{{{
#!CommitTicketReference repository=""
revision="a7b5ad8b19a08d7d57302ece74f6e26d2887fd9f"
Fixed #27846 -- Made Model.refresh_from_db() clear cached relations.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:9>
Django
-------------------------------------+-------------------------------------
Reporter: Keith Hostetler | Owner: Paulo
Type: Bug | Status: closed
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution: fixed
Keywords: refresh_from_db | Triage Stage: Accepted
OneToOneField |
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Tim Graham <timograham@…>):
In [changeset:"5d3f2aa3f12747822fb1ece95f0f614eeafa47b1" 5d3f2aa]:
{{{
#!CommitTicketReference repository=""
revision="5d3f2aa3f12747822fb1ece95f0f614eeafa47b1"
[2.0.x] Fixed #27846 -- Made Model.refresh_from_db() clear cached
relations.
Backport of a7b5ad8b19a08d7d57302ece74f6e26d2887fd9f from master
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/27846#comment:10>