Modify get_or_create() to use field lookups parameters for values

[Patrick Bregman]

Hi all,

First of, I'm new to this list so please tell me if there's something that can be done better. It's the best way to learn for me ;)

Recently I've been doing some reworking of an old (think Django 1.1 or 1.2) webapp of mine into the latest and greatest of Django. In the process I modified some models, and thought that get_or_create would be perfect to replace boring try / except cases. Except that it didn't really work as planned. I tried to do a get_or_create(name__iexact=value, defaults={'slug': slugify(value)}). I expected this to be smart enough to know that it should fill the field name based on the name__iexact parameter. Apparently it isn't :) In this case you'd need to add a definition for name to the defaults dict to get the value into the newly created model. I'm not sure, but I personally think this shouldn't be that hard to fix. It's basically checking (and removing) known field lookups or simply everything after a double underscore, and using that as a field name. Or at least, that's my view on it.

The big question is:
1. Is this behavior that exotic that I'm the first one to notice, or did I do a wrong search on Google?
2. Would this indeed be as easy (or comparably easy) as I think?
3. Is this behavior we actually want in Django?

If the answer to 2 and 3 are yes, I'll look into giving it a try to making a patch for this myself.

Regards,
Patrick Bregman

[gavi...@gmail.com]

I don't think this is possible to do generally. What would count__gt=1 or pub_date__month=12 do?

[Mattias Linnap]

One way to make it work in presence of field lookups would be to demand that the full values of mandatory fields must be present in the defaults dictionary.

For example:

Model.objects.get_or_create(name_iexact='hello', defaults={'name': 'Hello', 'slug': 'foo'}) or 

Model.objects.get_or_create(pub_date__month=12, defaults={'pub_date': timezone.now().date()})

[Gavin Wahl]

That is how it works now.

--
You received this message because you are subscribed to a topic in the Google Groups "Django developers" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/django-developers/EbLRpYB_1WI/unsubscribe.
To unsubscribe from this group and all its topics, send an email to django-develop...@googlegroups.com.
To post to this group, send email to django-d...@googlegroups.com.
Visit this group at http://groups.google.com/group/django-developers.

To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/dbe4723f-2a8c-4a5c-94cd-be264c1198ef%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.