Hello, thanks for your help.
The joins Building.condition and Building.care_level are pointing the same table. The table is a single-inheritance construct. The query: session.query(Building).join(rating, Building.condition).join(care_level, Building.care_level) produces this error: sqlalchemy.exc.ArgumentError: Can't determine join between 'building' and '%(34604496 lookup)s'; tables have more than one foreign key constraint relationship between them. Please specify the 'onclause' of this join explicitly. This error can be fixed via string property names: session.query(Building).join('care_level').join('rating') This works, but with this method i have no alias names. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To view this discussion on the web visit https://groups.google.com/d/msg/sqlalchemy/-/Z-JEIbJEInkJ. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.