Re: Locking / serializing access to one element in database

Hi Carsten,

Something that might help: depending on how your unique keys are set up, if the thread thinks that the object is new, it could try using .save(force_insert=True). That way it won't overwrite a different object with the same PK.

Thanks,

Collin

On Thursday, October 22, 2015 at 9:56:36 AM UTC-4, Carsten Fuchs wrote:

Am 22.10.2015 um 01:16 schrieb Simon Charette:
> I would suggest you use select_for_update()
> <https://docs.djangoproject.com/en/1.8/ref/models/querysets/#select-for-update> in a
> transaction.

This only covers the case where the object with the given ID already exists, doesn't it?

That is, if a new object is created in the except-clause, concurrent threads might
create a new object each, whereas it would presumably be expected that new_text is
(twice) added to a single common instance.

As I had the quasi exact same question a while ago (see
https://groups.google.com/forum/#!topic/django-users/SOX5Vjedy_s) but never got a reply,
I (too) am wondering how the new-object case in the except-clause could be handled?

Best regards,
Carsten

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