Django - how do I select a particular column from a model?

Question

I had a sniff around SO and couldn't find this, but I am sure it is here somewhere. Apologies for this potential double post!

If I have this code:

return Story.objects.filter(user=request.user.id).order_by('-create_date')

and say Story has, um, a "description" field, and I just want that description field, no need for the db to send anything else back with my result, how do I limit the query to just that?

That is, how do I generate this SQL:

select description from story where user_id = x order by create_date desc

(where x is the request.user.id value, of course)

Answer 1

Use values() or values_list().

If you use values(), You'll end up with a list of dictionaries (technically a ValuesQuerySet)

instance = MyModel.objects.values('description')[0]
description = instance['description']

If you use values_list(), you'll end up with a list of tuples

instance = MyModel.objects.values_list('description')[0]
description = instance[0]

Or if you're just getting one value like in this case, you can use the flat=True kwarg with values_list to get a simple list of values

description = MyModel.objects.values_list('description', flat=True)[0]

See the official documentation

Answer 2

Use the only method. Please read the documentation