it sounds like you are coming up against basic transaction isolation behavior. some background is available at http://dev.mysql.com/doc/refman/5.1/en/innodb-transaction-model.html .
if you wanted to turn it off, you could use MyISAM tables or use your session with autocommit=True. Andrew wrote: > Ok... looks like I was hasty. The problem still seems fixed so far - > but my reasoning seems wrong. > It looks like the authentication request is contained within the > transaction - so I don't see why doing a select on a table within the > authentication function would cause problems. However adding a > session.rollback after that select seems to fix it... > Does anyone have any clue as to what is going on here? > Cheers, > Andrew > > On Mar 15, 2:31 pm, Andrew <ajpere...@googlemail.com> wrote: >> I may have found the problem..... >> >> It turns out this problem only occurs if I use the cherrypy auth_basic >> to provide authentication. >> In my authentication checkpassword function I was querying the user >> table without using sessions. >> Adding a session rollback, clear and close to the end of this function >> removes the problem. >> >> I had wrongly assumed that using a tool to wrap requests in >> transactions that the authentication would also be wrapped. >> >> So far so good... >> >> On Mar 15, 11:25 am, Andrew <ajpere...@googlemail.com> wrote: >> >> >> >> > Hi, I have a problem where multiple connections to a MySQL database >> > (through sqlalchemy from a cherrypy multithreaded web server) get >> > different views on the same data. >> > Scenario: >> > A user submits a form to create a new record in a >> > table >> > Cherrypy adds the record and returns an httpredirect >> > to a url that views that new record >> > The new http request fails as it does not think the >> > new record exists yet. >> > Refreshing the page after a few seconds successfully >> > finds the record. >> > More info: >> > 1)This website worked perfectly when I used sqlite as a backend. >> > 2)Even with mysql as a backend, if I query the database from a mysql >> > gui just after creating the new record via the web, then I cannot get >> > this behaviour to happen. >> > 3)Turning echo on for sqlalchemy reveals that the select statement is >> > being issued. >> > 4)This problem only seems to happen if the web page also contains >> > multiple static images that are being requested at the same time - if >> > I make the page only reference one image the problem goes away - >> > suggests some timing problem I guess. >> > 5) I am using elixir and the sqlalchemy_tool wrapper to manage the >> > session >> >> > Any help/pointers would be really appreciated. >> > Best Regards, >> > Andrew > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalch...@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 sqlalch...@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.
