Strange ORM issue about django-cacheops

[Suor]

.get() referring to cacheops is ok, it's the way it works. The rest is
definitely a bug.

It would be great if you created a test for it.

[aykut]

I've created a pull request for test cases.

Here is what I faced when I was creating tests. Your test_requirements installed Django 1.6 and I get the ProductReview.DoesNotExist for my second .get. However when I downgraded Django to 1.4.10 I didn't get any exception!

I hope it helps you to fix this bug.

Cheers.

[Suor]

That works as expected (DoesNotExist on second get) on both Django 1.6 and 1.4.10.

Also, it's not really a test. There should be asserts there or something.

[Suor]

And no .get() queries all the table. There should be something wrong with your django.

[aykut]

(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ pip freeze
Django==1.4.10
ipdb==0.8
ipython==1.1.0
redis==2.8.0
simplejson==3.3.1
wsgiref==0.1.2
(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ ./run_tests.py
Creating test database for alias 'default'...
Creating test database for alias 'slave'...
.....................xxx..x...
----------------------------------------------------------------------
Ran 30 tests in 0.544s

OK (expected failures=4)
Destroying test database for alias 'default'...
Destroying test database for alias 'slave'...

(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ pip freeze
Django==1.6
ipdb==0.8
ipython==1.1.0
redis==2.8.0
simplejson==3.3.1
wsgiref==0.1.2
(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ ./run_tests.py
Creating test database for alias 'default'...
Creating test database for alias 'slave'...
...................E.xxx..x...
======================================================================
ERROR: test_62 (tests.tests.IssueTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/aykutozat/cacheops/django-cacheops/tests/tests.py", line 202, in test_62
    p2.reviews.get(status=0)  # returns the same result with p.reviews.get(status=0)
  File "/Users/aykutozat/cacheops/django-cacheops/cacheops/query.py", line 524, in get
    return self.get_queryset().inplace().get(*args, **kwargs)
  File "/Users/aykutozat/cacheops/django-cacheops/cacheops/query.py", line 416, in get
    return qs._no_monkey.get(qs, *args, **kwargs)
  File "/Users/aykutozat/cacheops/lib/python2.7/site-packages/django/db/models/query.py", line 307, in get
    self.model._meta.object_name)
DoesNotExist: ProductReview matching query does not exist.

----------------------------------------------------------------------
Ran 30 tests in 1.077s

FAILED (errors=1, expected failures=4)
Destroying test database for alias 'default'...
Destroying test database for alias 'slave'...

I don't understand what can possibly wrong with my Django? I install it with pip like you or everyone else.

[Suor]

Try clearing pip download cache and then create a fresh virtualenv. I just did, everything behaves as expected.

[Suor]

Also, create virtualenv without access to global packages.

[aykut]

Here I created a fresh virtualenv, cloned cacheops, applied my tests. Installed your requirements without pip cache. Then uninstalled Django 1.6. Installed Django 1.4.10 from source. I still didn't get the exception.

(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ pip freeze
Django==1.4.10
redis==2.8.0
simplejson==3.3.1
wsgiref==0.1.2
(cacheops)Aykuts-MacBook-Air:django-cacheops aykutozat$ ./run_tests.py
Creating test database for alias 'default'...
Creating test database for alias 'slave'...
.....................xxx..x...
----------------------------------------------------------------------
Ran 30 tests in 0.542s

OK (expected failures=4)
Destroying test database for alias 'default'...
Destroying test database for alias 'slave'...

[Suor]

Maybe Django source, from which you install 1.4.10 is altered.

[Suor]

Try installing 1.4.9 and 1.5.0

[aykut]

I still didn't get any error for 1.4.9 and 1.5.0. I even tried at one of my co-workers PC who uses ubuntu, guess what I didn't get any error again.

It is clear that there is a bug here.

[aykut]

Hi Suor,

I've opened a pull request which is a fix for this issue.

And let me please tell you the problem. You set the get_queryset to get_query_set method of ManagerMixin. So this means Manager has two methods now, get_querysetand get_query_set. And whenever you call .get_querysetfrom your .getor others, it actually calls your custom method and doesn't override default get_query_set.

Therefore, you need to call .get_query_set of django's "Manager" from .get_queryset of your "ManagerMixin". And it solves the bug.

Thanks.

[Suor]

Looks like my environment was dirty, sorry for that confusion. Anyway it's fixed now thanks to you.