[Django] #19434: Some QuerySet methods not aware of fields added on "extra"
Django
----------------------------------------------+--------------------
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.4
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
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Some examples to illustrate the issue:
{{{
(Pdb) CUSTOM_SQL = "SELECT some_function(some_field) FROM some_table"
# This works
(Pdb) qs = qs.extra(select={'some_alias': CUSTOM_SQL},
order_by=['some_alias'])
# This fails
(Pdb) qs.filter(some_alias__gt=0)
*** FieldError: Cannot resolve keyword 'some_alias' into field. Choices
are: ...
# This works
(Pdb) qs.values()
[{'some_alias': 1}, {'some_alias': 2}]
# This fails
(Pdb) qs.values('some_alias')
*** FieldError: Cannot resolve keyword 'some_alias' into field. Choices
are: ...
}}}
There's a situation where half of the API supports `extra` queries
correctly, the other half fails with a `FieldError`, and there's no clear
indication to what should be the right behavior.
--
Ticket URL: <https://code.djangoproject.com/ticket/19434>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage:
Keywords: | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by hcarvalhoalves):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Comment:
Could be worked around if the ORM supported a `HAVING` clause, so `filter`
''et al'' wouldn't need to be aware of aliases, but ticket #8784 asking
for it's inclusion was marked WONTFIX. I have no idea what the solution
could be then.
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:1>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Keywords: | Needs documentation: 0
Has patch: 0 | Patch needs improvement: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Changes (by aaugustin):
* stage: Unreviewed => Accepted
Comment:
Yes, it isn't possible to filter on a field added in a
`.extra(select={...})`. I've hit this problem too.
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:2>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: | Needs documentation: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
* cc: flo@… (added)
* has_patch: 0 => 1
* version: 1.4 => master
Comment:
I've started a patch that adds support for filtering fields added by extra
and created a pull request: https://github.com/django/django/pull/735
I think something similar has been done to provide support for filtering
annotations/aggregations
{{{
qs.extra(select={'num_plus_one': 'num + 1'}
qs.filter(num_plus_one=2)
}}}
will result in following query:
{{{
SELECT (num+1) AS "num_plus_on" ...
WHERE (num+1) = 2 ....
}}}
In order to avoid quoting of the lvalue of the term in the WHERE part I
modified WhereNode.add to accept a QueryWrapper (contains the extra sql).
There's probably a much better way to add an unqouted lvalue to the
WhereNode, any suggestions/feedback are very appreciated.
{{{ qs.values('some_alias') }}} worked for me (without modification), but
I've added a test to check it.
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:3>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Keywords: | checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timo):
* stage: Accepted => Ready for checkin
Comment:
I've updated the patch with some cosmetic tweaks as well as to merge
cleanly to master (confirmed all tests pass as well). Would like someone
more familiar with the code to +1 before it gets committed.
https://github.com/django/django/pull/1242
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:4>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Keywords: | Needs documentation: 0
Has patch: 1 | Patch needs improvement: 0
Needs tests: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by timo):
* stage: Ready for checkin => Accepted
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:5>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: | Needs documentation: 0
Has patch: 1 | Patch needs improvement: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
Comment (by timo):
#21159 reported the inability to `distinct()` on `extra` columns.
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Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:6>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: new
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: | Needs documentation: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 0 |
-------------------------------------+-------------------------------------
* needs_better_patch: 0 => 1
Comment:
Patch no longer merges cleanly.
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:7>
Django
Reporter: hcarvalhoalves | Owner: nobody
Type: Bug | Status: closed
Component: Database layer | Version: master
(models, ORM) |
Keywords: QuerySet.extra | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* keywords: => QuerySet.extra
* status: new => closed
* resolution: => wontfix
Comment:
We are no longer fixing bugs with `QuerySet.extra()` per
[https://groups.google.com/d/topic/django-
developers/FojuU0syO8Y/discussion discussion on django-developers].
--
Ticket URL: <https://code.djangoproject.com/ticket/19434#comment:8>