Thanks, Alexandr, for your effort in addressing what I personally consider
a much needed feature in the ORM. I gave your PR a try and noticed that
evaluating the same Product.objects.annotate line below twice in a row
returns two different SQL queries, the second of which results in an error.
This has not received a lot of feedback so far, so I think some code can
help. I am not sure what is the next steps; as I've understood, we need
some kind of consensus to open a ticket.
Please, don't hesitate to express your opinion on the feature and the API,
as well as the implementation to
Hello everyone.
So far, I've managed to implement joins via Subquery and OuterRef with some
caveats.
To begin with, the API looks like this
Product.objects.create(name='Pizza', country='USA', type='FOOD')
Tax.objects.create(name='USA Food Tax', amount=10, product_country='USA',
Thanks, folks, that's a very valuable insight.
I really love the idea of resolving *OuterRef* via .*join()*, it may help
overcome problems I had with reusing *Subquery*.
However, I believe *Subquery* exists apart from *QuerySet* for a reason -
to separate responsibilities, so should we mix
Great work on this, Alexandr. I've been thinking a lot about doing joins in
Django to subqueries. As you point out, when you are doing several subquery
annotations of the same subquery, just with different columns, that can
really hurt performance. Currently, I've been recommending doing a JSON
Accidentally removed gist, new one is here
https://gist.github.com/tatarinov1997/068fe786366401ed640dcbbbe5d959e4
On Monday, 6 April 2020 16:34:55 UTC+3, Alexandr Tatarinov wrote:
>
> Hello folks,
>
> Following the discussion
>
they have never made it in. Perhaps someone
with more knowledge on that matter can help.
From: django-developers@googlegroups.com
On Behalf Of Alexandr Tatarinov
Sent: Monday, April 6, 2020 3:22 AM
To: Django developers (Contributions to Django itself)
Subject: Subquery join support
Hello folks
Hello folks,
Following the discussion
https://groups.google.com/forum/#!topic/django-developers/b370mxfKCHg, I
would like to suggest adding the ability to join QuerySet with a subquery
clause to Django.
The benefits are pretty much described and discussed in the linked topic,
the only one I
