I built a simplified test-case, then tried to simplify it more into a second form -- and got a different error.
The second error message, and sqlalchemy source code lines, confirmed my initial belief this is an intentional behavior, which is not reflected in the `query` or `join` API docs. They also let me track down a callout box in the ORM tutorial noting this behavior though: when multiple entities are queried, SqlAlchemy builds the join off the first entity. -- 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 post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.