I'd certainly never do that - no matter what type of application is running, its always best to use transaction-per-logical operation, which means usually, transactions are short. If the transactions are necessarily long, a database failure in the middle means the operation just fails, but there was no option there since you needed that long running transaction.
If the app is a console app that stays open for a long time in some kind of loop, use a new Session() for each iteration of the loop, or for each 5- minute operation its doing, or whatever. So the answer is not to try/except everything, its to frame the usage of a particular transaction around the logical span of the operations you're performing. On Jan 13, 2011, at 2:47 AM, can xiang wrote: > Hi， > > sqlalchemy is such a piece of great work. I'm very happy with it, > while I indeed get a problem. > > I use sqlalchemy 0.6.6 in a non-threaded app. session is created at > module level at once. autocommit is set to False. > > I see log shows: > user = user_session.query(User).filter(User.hw_id == > args['hw_id']).first() > with the following exception: > InvalidRequestError: Can't reconnect until invalid > transaction is rolled back > > the mysql server restarted at that time. > > I check the docs, it says this may caused by a error while commit and > without rollback for that session. But the above query is single query > without a transaction and with no data commit. > > If I have to wrap all QUERY operations in try except and rollback > manually? It's so tedious and not so nice, any advice? > > -- > 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 > sqlalchemy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sqlalchemy?hl=en. > -- 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
