how to get the first element and the last element using django , Location.objects.all()

Question

this is my code.

obj_list=Location.objects.all() first_element=obj_list[0] last_element=obj_list[-1] 

then,

return render_to_response(template_name, {         'first_element':first_element,         'last_element':last_element,     }) 

and in the template:

{{ first_element.terminal_id}} {{last_element.terminal_id}} 

but it show nothing ,

what can i do ,

thanks

Answer 1

Have a look at http://docs.djangoproject.com/en/dev/topics/db/queries/#limiting-querysets

Negative indexing (i.e. Entry.objects.all()[-1]) is not supported.

Try:

first_element = Location.objects.all()[0] last_element = Location.objects.all().reverse()[0] 

-- Update 8/6/17 --

Based on @MisterRios' comment,

As of 1.6 Django supports using .first() and .last() on querysets: first_element = Location.objects.first() last_element = Location.objects.last()

Refer: https://docs.djangoproject.com/en/1.7/ref/models/querysets/#django.db.models.query.QuerySet.first