Kent <jkentbo...@gmail.com> wrote:
> I'm implementing database session variables (in Oracle, > DBMS_SESSION.SET_CONTEXT(...)), in order to be able to set (from sqlalchemy) > and retrieve (from a database trigger) the application userid and URL path > during table audit triggers. > > The tricky bit is that if I set the user to 'user1', that remains in the > session in the database even when a different sqlalchemy thread grabs that > same session from the connection pool. I want to prevent the wrong > information accidentally still being in the session, so I want to be sure to > reset it when appropriate and I'm wondering whether checkout from the Pool is > the event you would recommend? > > @event.listens_for(engine, 'checkout') > def receive_checkout(dbapi_connection, connection_record, > connection_proxy): > > If the same database session is recycled from the connection pool, will it > have the same connection_record? I'd prefer to record the fact that I've set > the database session's variables on an object (such as connection_record) so > that subsequent requests can detect whether it needs to be reset. Will > connection_record correspond to a database session? For this kind of thing you normally reset the state on the “checkin” event. The connection_record does in fact follow around the DBAPI connection, however the .info dictionary is given here as the primary way to track things with a DBAPI connection. .info is available on Connection, the connection record, and the pool wrapper, and it will track the DBAPI connection for its full lifespan, until the connection is closed. So put whatever memoizations you need into the .info dictionary, and then you can pretty much set / reset the state with any of the pool events. > Thanks in advance for any advice here. > Kent > > > > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
