[Django] #26638: Allow callable in defaults argument for QuerySet.get_or_create
Django
----------------------------------------------+--------------------
Reporter: mlorant | Owner: nobody
Type: New feature | Status: new
Component: Database layer (models, ORM) | Version: master
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 1 | UI/UX: 0
----------------------------------------------+--------------------
It would be nice if `get_or_create` handles callable in the `defaults`
parameter so the defaults value are not computed at each selection.
Indeed, if your default values for insertion contains selection of related
object or any long computation, it is done at each call, even if the
object can be retrieved without insertion (and so the defaults parameter
is not used).
In term of code, I would like to do something like this:
{{{
SomeObject.objects.get_or_create(
key1=value1,
key2=value2,
defaults={
'key3': long_processing_to_get_default(),
# or even
'key3': lambda: OtherModel.objects.get(pk=request.some_value)
}
)
}}}
For backward-compatibility and ease of writing, it should still accept
values that are not callables. See the patch attached (unit tests are
missing so it is not complete!)
--
Ticket URL: <https://code.djangoproject.com/ticket/26638>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: mlorant | Owner: nobody
Type: New feature | Status: new
Component: Database layer (models, ORM) | Version: master
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Easy pickings: 1
UI/UX: 0 |
Changes (by mlorant):
* Attachment "patch26638.txt" added.
Django
Reporter: mlorant | Owner: nobody
Type: New feature | Status: new
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by mlorant):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Old description:
> It would be nice if `get_or_create` handles callable in the `defaults`
> parameter so the defaults value are not computed at each selection.
> Indeed, if your default values for insertion contains selection of
> related object or any long computation, it is done at each call, even if
> the object can be retrieved without insertion (and so the defaults
> parameter is not used).
>
> In term of code, I would like to do something like this:
>
> {{{
> SomeObject.objects.get_or_create(
> key1=value1,
> key2=value2,
> defaults={
> 'key3': long_processing_to_get_default(),
> # or even
> 'key3': lambda:
> OtherModel.objects.get(pk=request.some_value)
> }
> )
> }}}
>
> For backward-compatibility and ease of writing, it should still accept
> values that are not callables. See the patch attached (unit tests are
> missing so it is not complete!)
New description:
It would be nice if `get_or_create` handles callable in the `defaults`
parameter so the defaults value are not computed at each selection.
Indeed, if your default values for insertion contains selection of related
object or any long computation, it is done at each call, even if the
object can be retrieved without insertion (and so the defaults parameter
is not used).
In term of code, I would like to do something like this:
{{{
SomeObject.objects.get_or_create(
key1=value1,
key2=value2,
defaults={
'key3': lambda: long_processing_to_get_default(),
# or even
'key3': lambda: OtherModel.objects.get(pk=request.some_value)
}
)
}}}
For backward-compatibility and ease of writing, it should still accept
values that are not callables. See the patch attached (unit tests are
missing so it is not complete!)
--
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:1>
Django
Reporter: mlorant | Owner: nobody
Type: New feature | Status: new
(models, ORM) |
Severity: Normal | Resolution:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Easy pickings: 1 | UI/UX: 0
Description changed by mlorant:
Old description:
> It would be nice if `get_or_create` handles callable in the `defaults`
> parameter so the defaults value are not computed at each selection.
> Indeed, if your default values for insertion contains selection of
> related object or any long computation, it is done at each call, even if
> the object can be retrieved without insertion (and so the defaults
> parameter is not used).
>
> In term of code, I would like to do something like this:
>
> {{{
> SomeObject.objects.get_or_create(
> key1=value1,
> key2=value2,
> defaults={
> 'key3': lambda: long_processing_to_get_default(),
> # or even
> 'key3': lambda:
> OtherModel.objects.get(pk=request.some_value)
> }
> )
> }}}
>
> For backward-compatibility and ease of writing, it should still accept
> values that are not callables. See the patch attached (unit tests are
> missing so it is not complete!)
New description:
It would be nice if `get_or_create` handles callable in the `defaults`
parameter so the defaults value are not computed at each selection.
Indeed, if your default values for insertion contains selection of related
object or any long computation, it is done at each call, even if the
object can be retrieved without insertion (and so the defaults parameter
is not used).
In term of code, I would like to do something like this:
{{{
SomeObject.objects.get_or_create(
key1=value1,
key2=value2,
defaults={
'key3': lambda: long_processing_to_get_default(),
# or even
'key3': lambda: OtherModel.objects.get(pk=request.some_value)
}
)
}}}
For backward-compatibility and ease of writing, it should still accept
values that are not callables. ~~See the patch attached (unit tests are
missing so it is not complete!)~~ My patch is wrong in fact: it computes
the value before the selection and it consider the dict as a whole
callable instead of a single key of the dict... Anyway the implementation
inside the `except DoesNotExist` should be easy :)
--
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:2>
Django
Reporter: mlorant | Owner: nobody
Type: New feature | Status: new
(models, ORM) |
Severity: Normal | Resolution:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Easy pickings: 1 | UI/UX: 0
Comment (by ddsnowboard):
I sent a pull request that solves this
(https://github.com/django/django/pull/6650). My understanding of the
ticket is that it should evaluate the callable if and only if the object
needs to be created, and that's what the code does. Is that right?
Also, it passes all the tests under SQLite.
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:3>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Type: New feature | Status: assigned
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 1 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by ddsnowboard):
* status: new => assigned
* owner: nobody => ddsnowboard
* has_patch: 0 => 1
* needs_tests: 0 => 1
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:4>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Type: New feature | Status: assigned
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Easy pickings: 1 | UI/UX: 0
Changes (by ddsnowboard):
* needs_tests: 1 => 0
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:5>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Type: New feature | Status: assigned
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Has patch: 1 | Needs documentation: 1
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 1 | UI/UX: 0
Changes (by timgraham):
* needs_docs: 0 => 1
* stage: Unreviewed => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:6>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Type: New feature | Status: assigned
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 1
Easy pickings: 1 | UI/UX: 0
Changes (by ddsnowboard):
* cc: ddsnowboard (added)
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:7>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Type: New feature | Status: assigned
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Needs tests: 0 | Patch needs improvement: 1
Easy pickings: 1 | UI/UX: 0
Changes (by timgraham):
* needs_better_patch: 0 => 1
* needs_docs: 1 => 0
Comment:
Left comments for improvement on the PR. Please uncheck "Patch needs
improvement" after updating.
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:8>
Django
Reporter: mlorant | Owner:
| ddsnowboard
Component: Database layer | Version: master
(models, ORM) |
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 1
Changes (by Tim Graham <timograham@…>):
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"9899347641b2d3b4457cc99203a2b06504b32a16" 9899347]:
{{{
#!CommitTicketReference repository=""
revision="9899347641b2d3b4457cc99203a2b06504b32a16"
Fixed #26638 -- Allowed callable arguments for
QuerySet.get_or_create()/update_or_create() defaults.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/26638#comment:9>