On Mon, Oct 15, 2012 at 1:50 PM, Zheng Li <dllizh...@gmail.com> wrote: > get_or_create shouldn't give duplicate entry error > anyone help. >
This is incorrect, and a common misconception: get_or_create() is not atomic. If this happens, you will get duplicate key errors: Thread A calls get_or_create(a='a', b='b') Thread B calls get_or_create(a='a', b='b') Thread A get_or_create looks for entry in DB, not found Thread B get_or_create looks for entry in DB, not found Thread B creates entry in DB Thread A get_or_create tries to create entry in DB Where I say 'thread', you could also read 'process'. If you are capable of serving multiple requests simultaneously, this can happen, even if you aren't using threads. If this is a problem for you, use a transaction aware DB instead of MySQL. It won't solve the issue, but at least you will be able to unroll the transaction. Cheers Tom -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
