On 27 Aug 2014 22:19, "Benjamin Scherrey" <[email protected]> wrote: >
> > You're right, it wasn't hard to implement as external code as I've already done so. The main reason why I propose it for inclusion into Django's codebase is because the new behavior is actually what I would have expected these two functions to do and, so far, individuals that I've polled said the same thing. When they discover what the generated SQL actually looks like they're quite surprised. > +1. I agree on the 2 points. I'm not expert enough to comment on the backwards compatibility though. > > -- Ben > > > On Thu, Aug 28, 2014 at 3:55 AM, Marc Tamlyn <[email protected]> wrote: >> >> This would be fairly significantly backwards incompatible, and any heuristic based code I think belongs in user space. >> >> It should not be too problematic to write as an external module, if it gains a lot of traction we can reconsider. >> >> Worth also noting that the json implementation in contrib.postgres is being delayed until at least postgres 9.4 and will use the jsonb data type which does have an equality operator. >> >> >> On 27 August 2014 21:04, Benjamin Scherrey <[email protected]> wrote: >>> >>> Apologies for the cross-post. I imagine this is actually where this proposal belongs. Would anyone be interested in getting an implementation of this for consideration for incorporation into some upcoming or back ported release of Django? >>> >>> -- Ben Scherrey >>> >>> ---------- Forwarded message ---------- >>> From: Benjamin Scherrey <[email protected]> >>> Date: Mon, Aug 25, 2014 at 4:58 PM >>> Subject: Improvement to objects.get_or_create and objects.update_or_create >>> To: django-users <[email protected]> >>> >>> >>> Just want to run an idea by the list for a feature improvement for the oft-used convenience functions get_or_create and update_or_create. I'll just talk about get_or_create for now on but everything I saw going forward applies to both. >>> >>> It's a common idiom to populate a dictionary and simply pass it straight on to the function when creating or updating objects. While get_or_create takes a named parameter, defaults, as the content to store/update and the normal parameters are used for both search and content. The problem is that quite often you just have a dictionary of content you want to throw into the model table and don't want to separate it out into search content vs. default content. If you don't separate it out you get a big nasty where clause on the select that tries to compare every bit of content for the item. >>> >>> For the most part this behavior is just a nuisance and probably sub-optimal db query. However, with the new json data type it will actually cause the code to break as you can't pass in a json structure as a search value in a where clause. Your app will break. >>> >>> My proposal, which I've written in my own code, is to have get_or_create automatically select the most appropriate data to use for the search clause and then to make the rest "default" data to be applied to the found or newly created object. It first tries to see if the primary key field is present in the data structure. If that's not found then it goes through the model fields and looks for any field designated as unique in the data structure. The result is a cleaner and faster SQL request and a prevention of the above mentioned error condition. If no primary key or unique field is present in the data structure then behavior will continue as currently implemented. >>> >>> Is this a change that would be welcome in the django project? If so I'd be happy to create a pull request that implements this policy and supporting unit test coverage. >>> >>> thanx, >>> >>> -- Ben >>> >>> -- >>> Chief Systems Architect Proteus Technologies >>> Chief Fan Biggest Fan Productions >>> Personal blog where I am not your demographic. >>> >>> This email intended solely for those who have received it. If you have received this email by accident - well lucky you!! >>> >>> -- >>> You received this message because you are subscribed to the Google Groups "Django developers" group. >>> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> 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/CAHN%3D9D5-9GyYAKVn4j0xB7tvvDtUtYFFMrUxc2UxPm%3DvgebA3w%40mail.gmail.com . >>> >>> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> You received this message because you are subscribed to the Google Groups "Django developers" group. >> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. >> To post to this group, send email to [email protected]. >> 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/CAMwjO1FwR6CftLacJES%2B0bnbMWmkELJmHjBQ7YTA3oGwCVT9Aw%40mail.gmail.com . >> >> For more options, visit https://groups.google.com/d/optout. > > > > > -- > Chief Systems Architect Proteus Technologies > Chief Fan Biggest Fan Productions > Personal blog where I am not your demographic. > > This email intended solely for those who have received it. If you have received this email by accident - well lucky you!! > > -- > You received this message because you are subscribed to the Google Groups "Django developers" group. > To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. > To post to this group, send email to [email protected]. > 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/CAHN%3D9D77eNhXWsbWWSETgiqkSoYKhUiTrLwZaH3_uk3Zpp5X5A%40mail.gmail.com . > > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Django developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. 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/CA%2BWjgXN6oHQRx7gFHT0uW6NMpY1SLf9XcDU_UR8gyTPxbPd_MA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
