On 10 Sep 2008, at 17:04, Maurício Linhares wrote:
> > You should be doing it like this: > > Temp.increment_counter( :counter, id ) > > This will increment the property ":counter" for the model Temp with > "id", this column must have a default value of 0 (zero) or else this > call won't work. this works because it does update foos set counter = counter + 1 and then it's the databases problem to worry about concurrent queries and so on. If what you showed was a simplification of what you're actually doing (and you can't reduce it to increment_counter) then you'll need to look into locking (either optimistic or pessimistic) Fred > > > On Wed, Sep 10, 2008 at 12:59 PM, Difei Zhao > <[EMAIL PROTECTED]> wrote: >> >> Greetings all, >> >> I have a model which holds a counter field, the field have to be >> incremented frequently to record the access frequency of the specific >> object: >> >> @obj = Temp.find(id) >> @obj.counter += 1 >> @obj.save >> >> The implementation seems quite simple, but I am worrying about the >> race condition (if there are any, I do not know whether rails is >> thread-safe) since these statements may be interleaved. Could anyone >> help about this? Thanks very much! >> >> Difei >> -- >> Posted via http://www.ruby-forum.com/. >> >>> >> > > > > -- > Maurício Linhares > http://alinhavado.wordpress.com/ (pt-br) | http:// > blog.codevader.com/ (en) > João Pessoa, PB, +55 83 8867-7208 > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" 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/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
