[Django] #29391: Postgres array lookups need to call get_db_prep_value to adapt values to their db representation (FieldGetDbPrepValueMixin)

6 views
Skip to first unread message

Django

unread,
May 8, 2018, 1:21:15 PM5/8/18
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
--------------------------------------------+------------------------
Reporter: Gavin Wahl | Owner: (none)
Type: Uncategorized | Status: new
Component: contrib.postgres | Version: 2.0
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
--------------------------------------------+------------------------
I have have a model that has an ArrayField of objects that need to be
adapted to database values (EnumField from https://github.com/hzdg/django-
enumfields).

The custom array lookups in django.contrib.postgres.arrays are not
correctly calling the base fields get_db_prep_value/get_prep_value before
passing the objects to the db api.

Repro:

{{{#!python
import enum

from django.db import models
from django.contrib.postgres.fields import ArrayField


class TestEnum(enum.Enum):
VALUE_1 = 'value_1'


class EnumField(models.CharField):
def get_prep_value(self, value):
if value is None:
return None
else:
return value.value


class TestModel(models.Model):
array_of_enums = ArrayField(EnumField(max_length=20))


TestModel.objects.filter(array_of_enums__contains=[TestEnum.VALUE_1])
}}}

Currently this fails with:

{{{
Traceback (most recent call last):
File "django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: can't adapt type 'TestEnum'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "<console>", line 1, in <module>
File "django/db/models/query.py", line 226, in __repr__
data = list(self[:REPR_OUTPUT_SIZE + 1])
File "django/db/models/query.py", line 250, in __iter__
self._fetch_all()
File "django/db/models/query.py", line 1118, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "django/db/models/query.py", line 53, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch)
File "django/db/models/sql/compiler.py", line 899, in execute_sql
raise original_exception
File "django/db/models/sql/compiler.py", line 889, in execute_sql
cursor.execute(sql, params)
File "django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: can't adapt type 'TestEnum'
}}}

I expect it to succeed and generate a WHERE clause of `array_of_enums @>
ARRAY['value_1']`.

I think the fix is just to have the lookups inherit from
`FieldGetDbPrepValueMixin`.

--
Ticket URL: <https://code.djangoproject.com/ticket/29391>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

Django

unread,
May 9, 2018, 8:49:35 AM5/9/18
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
----------------------------------+------------------------------------

Reporter: Gavin Wahl | Owner: (none)
Type: Bug | Status: new
Component: contrib.postgres | Version: 2.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
----------------------------------+------------------------------------
Changes (by Tim Graham):

* type: Uncategorized => Bug
* stage: Unreviewed => Accepted


--
Ticket URL: <https://code.djangoproject.com/ticket/29391#comment:1>

Django

unread,
Feb 3, 2019, 6:36:49 PM2/3/19
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
-------------------------------------+-------------------------------------
Reporter: Gavin Wahl | Owner: vinay
| karanam
Type: Bug | Status: assigned
Component: contrib.postgres | Version: 2.0

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by vinay karanam):

* owner: (none) => vinay karanam
* status: new => assigned
* has_patch: 0 => 1


Comment:

[https://github.com/django/django/pull/10927 PR]

--
Ticket URL: <https://code.djangoproject.com/ticket/29391#comment:2>

Django

unread,
Feb 9, 2019, 6:39:16 PM2/9/19
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
-------------------------------------+-------------------------------------
Reporter: Gavin Wahl | Owner: vinay
| karanam
Type: Bug | Status: closed
Component: contrib.postgres | Version: 2.0
Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Tim Graham <timograham@…>):

* status: assigned => closed
* resolution: => fixed


Comment:

In [changeset:"5a36c81f58b8ff45d8dac052343722c54e3fa521" 5a36c81f]:
{{{
#!CommitTicketReference repository=""
revision="5a36c81f58b8ff45d8dac052343722c54e3fa521"
Fixed #29391 -- Made PostgresSimpleLookup respect
Field.get_db_prep_value().
}}}

--
Ticket URL: <https://code.djangoproject.com/ticket/29391#comment:3>

Django

unread,
Aug 21, 2019, 4:56:07 AM8/21/19
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
-------------------------------------+-------------------------------------
Reporter: Gavin Wahl | Owner: vinay
| karanam
Type: Bug | Status: closed
Component: contrib.postgres | Version: 2.0

Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Andrey Torsunov):

Which version of Django will have these changes? Thanks

--
Ticket URL: <https://code.djangoproject.com/ticket/29391#comment:4>

Django

unread,
Aug 21, 2019, 4:59:15 AM8/21/19
to django-...@googlegroups.com
#29391: Postgres array lookups need to call get_db_prep_value to adapt values to
their db representation (FieldGetDbPrepValueMixin)
-------------------------------------+-------------------------------------
Reporter: Gavin Wahl | Owner: vinay
| karanam
Type: Bug | Status: closed
Component: contrib.postgres | Version: 2.0

Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by felixxm):

3.0

--
Ticket URL: <https://code.djangoproject.com/ticket/29391#comment:5>

Reply all
Reply to author
Forward
0 new messages