Upon further thought, wouldn't it be better to implement his in a playback fashion ? I mean, you would handle the first pages like an intentionally failed/rolled back transaction. The further the user goes in the process, the further you get with the queries (and you will notice any changes made by other users as then would influence the selects). That way you have no locks, and only the final input of the user does a commit, which is consistent, and requires no additional columns. Am I right if I say this is basically a special case of a multi-page form consistency problem ?
On Oct 15, 3:22 pm, mdipierro <[EMAIL PROTECTED]> wrote: > I do not think belongs to web2py but it could be a next T2 feature. > > Massimo > > On Oct 15, 4:24 am, billf <[EMAIL PROTECTED]> wrote: > > > I would like to request the ability to include a column in every table > > to be used to avoid overlapping updates, i.e. where a record has been > > updated by user B between user A selecting a record and updating/ > > deleting it. When this occurs user B's updates are invisibly undone. > > > I know that this can be hand-coded but I believe it would be a useful > > and relatively minor addition to the core - as an option on > > define_table? version=False being the default? > > > The column could be either a version_number (simpler) or a > > last_action_timestamp (perhaps more useful but more complicated?) and > > would be used to prevent a record being updated/deleted if it had been > > changed since selected. This could be achieved in SQLFORM.accepts() > > by conditionally adding " and self.table.version==version" or similar > > to the update and delete statements. The version (or timestamp) would > > be handled in much the same way as 'id'. > > > I accept that the probability of overlapping updates is small but in a > > business situation it is important for web2py to be rigorous as > > possible and this approach has negligible overhead. > > > Do people think this is desirable, do-able or dumb? > > > Bill --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to web2py@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
