[Django] #26393: Unable to filter annotations across relationships.
Django
----------------------------------------------+--------------------
Reporter: rpkilby | Owner: nobody
Type: Uncategorized | Status: new
Component: Database layer (models, ORM) | Version: 1.9
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
----------------------------------------------+--------------------
Per the title, it seems like it would make sense to be able to filter
annotations across relationships. Given the following,
{{{
from django.db import models
from django.db.models import Value as V
from django.db.models.functions import Concat
class PersonManager(models.Manager):
use_for_related_fields = True
def get_queryset(self):
queryset = super(PersonManager, self).get_queryset()
queryset = queryset.annotate(full_name=Concat(
'first_name', V(' '), 'last_name',
output_field=models.CharField()
))
return queryset
class Person(models.Model):
first_name = SubCharField(max_length=100)
last_name = SubSubCharField(max_length=100)
objects = UserManager()
class Article(models.Model):
published = models.DateTimeField()
author = models.ForeignKey(User, null=True, on_delete=models.CASCADE)
}}}
Running this:
{{{
Article.objects.filter(author__full_name="Bob, just Bob")
}}}
Produced the following traceback (snipped)
{{{
...
File "site-packages/django/db/models/query.py", line 790, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "site-packages/django/db/models/query.py", line 808, in
_filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "site-packages/django/db/models/sql/query.py", line 1243, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
File "site-packages/django/db/models/sql/query.py", line 1269, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "site-packages/django/db/models/sql/query.py", line 1192, in
build_filter
raise FieldError('Related Field got invalid lookup:
{}'.format(lookups[0]))
FieldError: Related Field got invalid lookup: full_name
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/26393>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: rpkilby | Owner: nobody
Type: Uncategorized | 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: 0 | UI/UX: 0
Changes (by rpkilby):
* cc: rpkilby@… (added)
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
--
Ticket URL: <https://code.djangoproject.com/ticket/26393#comment:1>
Django
-------------------------------------+-------------------------------------
Reporter: rpkilby | Owner: nobody
Type: Uncategorized | Status: closed
Component: Database layer | Version: 1.9
(models, ORM) |
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* status: new => closed
* resolution: => wontfix
Old description:
New description:
Per the title, it seems like it would make sense to be able to filter
annotations across relationships. Given the following,
{{{
from django.db import models
from django.db.models import Value as V
from django.db.models.functions import Concat
class PersonManager(models.Manager):
use_for_related_fields = True
def get_queryset(self):
queryset = super(PersonManager, self).get_queryset()
queryset = queryset.annotate(full_name=Concat(
'first_name', V(' '), 'last_name',
output_field=models.CharField()
))
return queryset
class Person(models.Model):
first_name = models.CharField(max_length=100)
last_name = models.CharField(max_length=100)
objects = PersonManager()
class Article(models.Model):
published = models.DateTimeField()
author = models.ForeignKey(Person, null=True,
on_delete=models.CASCADE)
}}}
Running this:
{{{
Article.objects.filter(author__full_name="Bob, just Bob")
}}}
Produced the following traceback (snipped)
{{{
...
File "site-packages/django/db/models/query.py", line 790, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "site-packages/django/db/models/query.py", line 808, in
_filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "site-packages/django/db/models/sql/query.py", line 1243, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
File "site-packages/django/db/models/sql/query.py", line 1269, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "site-packages/django/db/models/sql/query.py", line 1192, in
build_filter
raise FieldError('Related Field got invalid lookup:
{}'.format(lookups[0]))
FieldError: Related Field got invalid lookup: full_name
}}}
--
Comment:
I think you have a misunderstanding of how `use_for_related_fields` works.
The queryset in the custom manager isn't used in a query like
`Article.objects.filter(...)` is it? If I'm missing something obvious and
you have a patch demonstrating how your proposal works, then please reopen
the ticket with details.
--
Ticket URL: <https://code.djangoproject.com/ticket/26393#comment:2>
Django
-------------------------------------+-------------------------------------
Type: Uncategorized | Status: closed
Component: Database layer | Version: 1.9
(models, ORM) |
Severity: Normal | Resolution: wontfix
| Unreviewed
Has patch: 0 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Comment (by rpkilby):
Yep - I completely misunderstood how that worked. I assumed that when
filtering across relationships, the sql from the related manager was
somehow used by the primary model's manager.
--
Ticket URL: <https://code.djangoproject.com/ticket/26393#comment:3>