Read the docs on State Management and pay attention to `merge`: https://docs.sqlalchemy.org/en/14/orm/session_state_management.html
Also, to simplify this stuff a popular related pattern is to use a RevisionID or RevisionTimestamp on the objects. In the first session, you note the version information. On the second session you fetch a new object and ensure it is the same - if so, your data is safe to update. If not, the objects became out of-sync and may require more logic. On Wednesday, November 25, 2020 at 12:57:23 PM UTC-5 jens.t...@gmail.com wrote: > Hello, > > My question is regarding long-running tasks and db sessions. Currently I > have the very rare situation where a task takes longer than a db session is > valid and thus fails when it wants to write back results. Extending the TTL > of a db session is probably not a good idea. > > I think the proper approach would be to open a db session, fetch data, > close the db session, do work, open a new db session, write data, close the > db session. So, I must make sure that I fetch all data ahead of time while > the first session is active. > > Is there a way to re-associate objects that belonged to the first session > with a newly opened one? What’s the recommended approach here, does SQLA > have any magic in store to help me with very long-lived ORM objects across > db sessions? Or should I manage that data independently of their respective > ORM objects? > > Thanks! > Jens > -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/bf1d5c69-d500-4cac-bb29-026f1343a37bn%40googlegroups.com.
