Explain how to use QuerySet.get_or_create() with Q objects

[Mike Lissner]

This technique is useful if you want to use Q objects in conjunction with the get or create method, and it's documented in a few places around the web.

I brought this up in the forums yesterday and somebody suggested that it be documented:

​https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/django-developers/e3sJ6OiHEd0/Yrg-Z9uRAgAJ

I gave this a try, but I don't understand the documentation system and I sadly don't have time to figure it out. Seems though like a change could go here:

​https://github.com/django/django/blob/master/docs/ref/models/querysets.txt#L1886

I think something along the lines of:

get_or_create() can be used with Q objects by chaining them together like so:

An example

When this is done, the logic performs as above, but matches are made according to the query in the Q object.

I imagine this also works for update_or_create, but I'm not sure how to document that too. Maybe just a quick mention:

update_or_create() can be used with Q objects using the same technique as documented above for get_or_create()

[Dhruv Singh]

Trying to start to give my bit to the open source community.
This feels like a good small starting step.
As the description of the ticket suggests, will add an example of using Q objects with get_or_create().
Please suggest if something else is needed.

[Herbert Fortes]

I think a good place to put an example is on 'Complex lookups with Q objects' .

There has explanation on how use it with "...lookup functions that takes keyword-arguments (e.g. filter(), exclude(), get())..."

[Herbert Fortes]

Hi Dhruv Singh,

Do you still intent to make a PR to close the ticket?

I have something like this:

Differently from :meth:~django.db.models.query.QuerySet.get method, the
:meth:~django.db.models.query.QuerySet.get_or_create method must be used
with the :meth:~django.db.models.query.QuerySet.filter lookup function.
For example::

Poll.objects.filter(Q(first_name='Bryan') | Q(first_name='Bruce')).get_or_create({'last_name': 'Harrison'})

[Herbert Fortes]

​PR

[Tim Graham <timograham@…>]

In 34c52228:

Fixed #29148 -- Doc'd how to use get_or_create() with Q objects.