#24042: Custom AutoField fields do not work correctly on postgres
-------------------------------+--------------------
Reporter: lucaswiman | Owner: nobody
Type: Uncategorized | Status: new
Component: Uncategorized | Version: master
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 1
Easy pickings: 0 | UI/UX: 0
-------------------------------+--------------------
The documentation (https://docs.djangoproject.com/en/dev/howto/custom-
model-fields/#emulating-built-in-field-types) on Field.get_internal_type
implies that it should define custom behavior and ensure that database-
correct behavior is followed. For Postgres (though not for sqlite),
specifying get_internal_type() to be "AutoField" fails to correctly set
the field, leading to errors like this:
{{{
test_auto_field (field_subclassing.tests.CustomField) ... ERROR
======================================================================
ERROR: test_auto_field (field_subclassing.tests.CustomField)
----------------------------------------------------------------------
Traceback (most recent call last):
File
"/Users/lucaswiman/opensource/django/tests/field_subclassing/tests.py",
line 128, in test_auto_field
o.save()
File "/Users/lucaswiman/opensource/django/django/db/models/base.py",
line 694, in save
force_update=force_update, update_fields=update_fields)
File "/Users/lucaswiman/opensource/django/django/db/models/base.py",
line 722, in save_base
updated = self._save_table(raw, cls, force_insert, force_update,
using, update_fields)
File "/Users/lucaswiman/opensource/django/django/db/models/base.py",
line 803, in _save_table
result = self._do_insert(cls._base_manager, using, fields, update_pk,
raw)
File "/Users/lucaswiman/opensource/django/django/db/models/base.py",
line 842, in _do_insert
using=using, raw=raw)
File "/Users/lucaswiman/opensource/django/django/db/models/manager.py",
line 131, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/Users/lucaswiman/opensource/django/django/db/models/query.py",
line 954, in _insert
return query.get_compiler(using=using).execute_sql(return_id)
File
"/Users/lucaswiman/opensource/django/django/db/models/sql/compiler.py",
line 931, in execute_sql
cursor.execute(sql, params)
File "/Users/lucaswiman/opensource/django/django/db/backends/utils.py",
line 65, in execute
return self.cursor.execute(sql, params)
File "/Users/lucaswiman/opensource/django/django/db/utils.py", line 95,
in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/Users/lucaswiman/opensource/django/django/db/backends/utils.py",
line 65, in execute
return self.cursor.execute(sql, params)
IntegrityError: null value in column "id" violates not-null constraint
DETAIL: Failing row contains (null).
}}}
The attached diff adds a regression test which fails on postgres databases
with the error above. I also fixed all other uses of isinstance(...,
AutoField) I could find in the code.
The immediate motivation for this is writing integration tests which use
django-salesforce on a CI system that uses a postgres database. I've filed
a separate issue there, though I think fixing the behavior in Django to
match the documentation would be a preferable solution. The package
maintainer for django-salesforce agrees (https://github.com/django-
salesforce/django-salesforce/issues/90#issuecomment-67932443).
'''How to Reproduce'''
Check out the master branch and apply my diff from the tests/ directory.
Run the tests with a settings file pointing to a postgres database:
{{{
PYTHONPATH=..:$PYTHONPATH ./runtests.py --verbosity=2 --failfast
field_subclassing --settings=test_postgres
}}}
It will fail with the above stack trace.
'''Testing'''
I verified that the regression test fails without the remainder of the
diff. I also verified that the tests still pass on the default test_sqlite
file.
--
Ticket URL: <https://code.djangoproject.com/ticket/24042>
Django <https://code.djangoproject.com/>
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