On 10 nov, 05:36, Continuation <selforgani...@gmail.com> wrote: > I'm working on an auction app. > > In an Auction object I store the current_high_bid for that auction. > > When a new_bid comes in, I: > 1) retrieve the current_high_bid field of the Auction object > 2) compare it with the new_bid > 3) if the new bid is higher than current_high_bid, I update > current_high_bid to the value of the new_bid. > > but there's a (slight) chance that between steps (1) and (3) a > different user could've submitted an even higher bid which then become > the current_high_bid. In that case step 3 should not proceed. What can > I do to make sure such a situation does not arise?
Well, the SimplestSolution would be to NOT denormalize your DB. From a relational / SQL POV, you shouldn't store the "current_high_bid" in the 'auction' table, but query the 'bid' table for the currently max bid for this auction. But I guess you have some good reasons to dismiss this solution... --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
