On Wed, Feb 13, 2008 at 5:44 PM, Jonathan LaCour <[EMAIL PROTECTED]> wrote: > > Greetings list, > > A user recently emailed me about concurrent modifications and the > versioning extension off-list. My original intention was to allow > the user to somewhat decide how to handle concurrent modifications > on their own. The default behavior is pretty undesirable, in that > you could end up with two version rows with the same version number > in the case of concurrent writes. > > SQLAlchemy has a `version_id_col` argument that can be specified > to the mapper constructor that will use a 0-based integer version > column to watch for concurrent modification errors. I have made a > patch to the versioning extension which makes it possible to have > this capability turned on for your versioned entities, so that > ConcurrentModificationErrors will be raised in the case of these > concurrent writes. > > I am attaching a patch to this email, and I'd like to get feedback > on how I have implemented it. This was a quick job that I did > late last night when fighting off insomnia, so I am not entirely > confident in it, and I'd like to hear what people have to say about > it. > > The patch essentially adds an `enforce` keyword argument to the > `acts_as_versioned` statement. If you pass `True` the extension > will enable this new behavior. > > If I get enough positive feedback, I'll commit it to the trunk. Its > something that should really be there, I am just not confident that > I have done it "right" yet :)
Looks good (though I didn't test it). I think we should even turn it on by default (because the only reason to not have it IMO is not to add an extra column to your tables, but in this case, you already have the extra column). The only minor complaint I have is about the version which starts at 0 or 1 depending on whether you use "enforce". Could be confusing... -- Gaëtan de Menten http://openhex.org --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "SQLElixir" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlelixir?hl=en -~----------~----~----~----~------~----~------~--~---
