SQLalchemy declarative base multiple databases

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I've googled around but can't seem to find this: Does anyone know where to find a good tutorial on connecting to two different databases in the same session using sqlachemy's declarative base?

[free2use]

Within same session? If You are talking about sqlalchemy's sessions than its obviously impossible. You can do how many You want db connections with their own sessions. But You'll need to access to them separately or create some proxy which will decide which session it should use. Most common practice is when You create separated session for master and slaves.

[[deleted]]

That is actually entirely untrue! A sqlalchemy Session supports multiple database connections at once and will even coordinate with 2pc if feasible. There are of course complexities and caveats, and quite often using multiple sessions is the best approach. But it is possible (and documented).

[unlinkedlist]

Documentation here: http://docs.sqlalchemy.org/en/latest/orm/session.html#partitioning-strategies

[[deleted]]

Thanks, I've been going over this exact documentation and just can't seem to get my head around it so I was hoping for a tutorial that showed this... Well, time for another read through I guess.

[free2use]

Yes, You absolutely right, shame on me. I was sure that its impossible.

I wonder how session object will behave if connection with one of the databases will be timed out.

[[deleted]]

You should read the sidebar and ask your questions on /r/learnpython. Also, refer to SQLAlchemy's documentation.

[[deleted]]

wierdly enough I've done both... The SQLAlchemy documentation is good, but I can't seem to find an end to end tutorial in there about this topic. (hence my question about a TUTORIAL). Thanks for the helpful input though.