On Thu, Mar 26, 2020, at 2:18 PM, Colton Allen wrote: > > You can adjust `expire_on_commit` if you're only doing short-term read-only > > actions. > > Can you expand on this? Or link to docs/blog so I can do some research. > Google hasn't helped me so far. Why would I want to expire after every commit?
because once the transaction is completed, there are other transactions going on in a database concurrently which can change the state of the objects as they are represented in the database. in order that when you next access these local objects so that they have the correct state, they are automatically expired. However this behavior is not desirable in many cases, so this flag is very commonly used to disable this behavior when you are not concerned about your objects having stale data relative to other transactions going on, when the new transaction begins. this behavior is described at: https://docs.sqlalchemy.org/en/13/orm/session_basics.html#committing > > --- > > I agree with your assessment. I think its because every time I call > "session". I'm actually saying "session_maker()". So the _flushing attribute > will be reset because its a new session instance. > > On Thursday, March 26, 2020 at 1:02:18 PM UTC-5, Jonathan Vanasco wrote: >> My first guess is two things are going on: >> >> 1. This is a behavior of `expire_on_commit` on the session. Once you commit >> on the Primary database, the object is stale. >> https://docs.sqlalchemy.org/en/13/orm/session_api.html >> >> 2. The session is then trying to read off a Secondary database, but the row >> has not yet synced. >> >> You can adjust `expire_on_commit` if you're only doing short-term read-only >> actions. However, I would explore to ensure this is trying to read off the >> other database and why. > > -- > 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/8185b96d-35cb-4973-a9cf-1e572ebd643b%40googlegroups.com > > <https://groups.google.com/d/msgid/sqlalchemy/8185b96d-35cb-4973-a9cf-1e572ebd643b%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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/2ae3206b-d8e6-43ef-a661-b52bcc88b6db%40www.fastmail.com.
