#15566: .update queries should affect Date*Field's with auto_now
-------------------------------------+-------------------------------------
Reporter: jdunck | Owner: bberes
Type: Bug | Status: assigned
Component: Database layer | Version: 1.2
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: | Needs documentation: 0
Has patch: 0 | Patch needs improvement: 0
Needs tests: 0 | UI/UX: 0
Easy pickings: 1 |
-------------------------------------+-------------------------------------
Comment (by lukeplant):
I disagree with Carl on this one. I have always interpreted
`QuerySet.update()` as a lower-level SQL construct, and would be pretty
surprised if it did anything other than update the fields that I
explicitly told it to.
I think the documentation is ambiguous - it simply doesn't state how
`QuerySet.update()` and `auto_now` interact. I had interpreted it the
other way to you - that `update()` does a SQL update of exactly the fields
you specify, and nothing more. I think either interpretation is valid, and
it is up to us to decide how to change the behaviour or clarify the docs.
I can think of ways the proposed change could break people's code. If I
had an auto_now field that was used to essentially track the last modified
timestamp of 'public' data in table, and then added some 'internal' state
data to a table, I might make use of the current behaviour of
`QuerySet.update()` to avoid triggering the `auto_now` behaviour (or
anything else that might normally run on model `save()`). In fact I have
coded some models where I have a split just like this. I can't remember if
they had `auto_now` fields, but I wouldn't have wanted them to be updated
when the internal fields were changed.
In addition, with the proposed change it's hard to see how you **would**
execute a SQL "update-these-fields-and-only-these-fields-and-don't-do
anything-special" command. I had relied on `QuerySet.update()` for that
until now. It's not hard to add a field to the update call, it's harder to
remove one.
--
Ticket URL: <https://code.djangoproject.com/ticket/15566#comment:12>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To post to this group, send email to django-updates@googlegroups.com.
To unsubscribe from this group, send email to
django-updates+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/django-updates?hl=en.
