Hello, I'm busy to play with (joinded) inheritance in SQLAlchemy. I have to design and implement a CMS-like app and my idea was to do something like (it's the SQL script) : http://pastebin.com/m35f5227d
As you can see it's a classic inheritance situation: a base Content (abstract) which is of a certain ContentType (the polymorphic_on), and more specialized objects (News, Events, ...) inherits from this base Content class. In the manual I read that : "The table also has a column called type. It is strongly advised in both single- and joined- table inheritance scenarios that the root table contains a column whose sole purpose is that of the discriminator; it stores a value which indicates the type of object represented within the row. The column may be of any desired datatype" In my situation the so-called "type" column is the "content_type_id", which is foreign key, so for the News / Content relation in this case I would have something like : mapper(Content, contents, polymorphic_on=contents.c.content_type_id, polymorphic_identity='?????') mapper(Engineer, engineers, inherits=Employee, polymorphic_identity='?????') My question is: can I have a select() object which return a scalar for the polymorphic_identity parameters ? I guess it should be possible to put anything else than the FK value ? Thanks, Julien -- Julien Cigar Belgian Biodiversity Platform http://www.biodiversity.be Université Libre de Bruxelles (ULB) Campus de la Plaine CP 257 Bâtiment NO, Bureau 4 N4 115C (Niveau 4) Boulevard du Triomphe, entrée ULB 2 B-1050 Bruxelles Mail: [EMAIL PROTECTED] @biobel: http://biobel.biodiversity.be/person/show/471 Tel : 02 650 57 52 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
