Slicing on queryset not working when using .last() after queryset

[SHIVAM JINDAL]

Hi,

I am making a queryset by slicing it to return only first 2 objects but When I am using .last() on this queryset then it is not applying slicing

Pharmaceutical.objects.order_by('id').values('id')

>>> [{'id': 2L}, {'id': 3L}, {'id': 4L}, {'id': 5L}]

>>> Pharmaceutical.objects.order_by('id')[:2].values('id')

[{'id': 2L}, {'id': 3L}]

>>> Pharmaceutical.objects.order_by('id')[:2].values('id').last()

{'id': 5L} # But this should be 3

--

Thanks,

Regards

Shivam Jindal

+91 8586896112

[Vasili Korol]

I can confirm this issue on Django 1.11.15 (Python 3.4.3, MySQL 5.5.61). Calling 'last()' on a slice produces wrong result:

>>> News.objects.all().order_by('id')[:5].values('id')
<QuerySet [{'id': 1}, {'id': 2}, {'id': 3}, {'id': 4}, {'id': 5}]>

>>> News.objects.all().order_by('id')[:5][4].id

5

>>> #But calling 'last' gives us wrong id:
>>> News.objects.all().order_by('id')[:5].last()
11

понедельник, 24 сентября 2018 г., 13:49:08 UTC+2 пользователь Shivam Jindal написал:

[SHIVAM JINDAL]

I am facing this on Django 1.9, Python 2.7

--
You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-develop...@googlegroups.com.
To post to this group, send email to django-d...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-developers.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/d2a29c84-00f8-41e9-85fa-a8bf20985218%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

--

Thanks,

Regards

Shivam jindal

+91 8586896112

[Vasili Korol]

Okay, this seems to produce TypeError in Django 2.0. See here: 

https://code.djangoproject.com/ticket/22550