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Optimistic lock implementation for Django. Prevents users from doing concurrent editing.
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Django Concurrency

django-concurrency is an optimistic lock [1] implementation for Django.

Supported Django versions: 1.6.x, 1.7.x, 1.8.x, 1.9.

It prevents users from doing concurrent editing in Django both from UI and from a django command.

How it works

sample code:

from django.db import models
from concurrency.fields import IntegerVersionField

class ConcurrentModel( models.Model ):
    version = IntegerVersionField( )
    name = models.CharField(max_length=100)

Now if you try:

a = ConcurrentModel.objects.get(pk=1) = '1'

b = ConcurrentModel.objects.get(pk=1) = '2'

you will get a RecordModifiedError on

Similar projects

Other projects that handle concurrent editing are django-optimistic-lock and django-locking anyway concurrency is "a batteries included" optimistic lock management system, here some features not available elsewhere:

  • can be applied to any model; not only your code (ie. django.contrib.auth.Group)
  • handle list-editable ChangeList. (handle #11313)
  • manage concurrency conflicts in admin's actions
  • can intercept changes performend out of the django app (ie using pgAdmin, phpMyAdmin, Toads) (using TriggerVersionField)
  • can be disabled if needed (see disable_concurrency)
  • ConditionalVersionField to handle complex business rules


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