I see the problem here. So what you're saying is that I need some way of knowing what the parent connection object was to pass through the decorators and the execute for the nested txn's should happen on the same connection object. My follow up question is: how do people usually implement this or do they not use such decorators? Also, calling engine.connect() based on the docs should still use the connection pool right? sqlalchemy should be checking out connections from the pool and not creating new ones right?
Thanks for you help on this, Sam On Jul 15, 4:26 pm, jason kirtland <[EMAIL PROTECTED]> wrote: > SamDonaldson wrote: > >[...] > > I have defined a transaction decorator: > > def transaction(func): > > def do(*args, **kw): > > connection = engine.connect() > > transaction = connection.begin() > > try: > > # create some context here for the connection and pass it > > through to later execute > > ret = func(ctx, *args, **kw) > > transaction.commit() > > connection.close() > > return ret > > except: > > # rollback for now > > transaction.rollback() > > connection.close() > > return do > > > [...] > > The problem occurs when I nest these like this: > > > @transaction > > def blah(...) > > Do a vanilla INSERT into mysql > > > @transaction > > def blah2(...) > > Do some work here and then call blah like this: > > <work> > > id = blah(...) <--- hang happens here > > > My assumption was that sqlalchemy would handle this as nested > > transactions based on incrementing. How does this affect the > > connection pool etc..? Any help in understanding this behavior would > > be appreciated. > > With engine.connect() you are pulling a new and unrelated db connection > in each invocation of your transaction decorator. If you want each > invocation to 'nest' in the same transaction context, you'd need to > either explicitly pass along the connection or use a threadlocal engine. > > http://www.sqlalchemy.org/docs/dbengine.html#dbengine_transactions --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
