On Jul 15, 2007, at 3:03 PM, [EMAIL PROTECTED] wrote:
> >> - Using polymorphic, joined-table inheritance ? Forget about >> polymorphic_union(), just join all the tables together using >> outerjoin(). In 0.4, even the select_table argument becomes >> optional. > i am not sure if i got this right (a month already). A-B-C works, yes. > But just explain to stupid me how would to do it for this simple tree: > A, B(A), C(B), D(A). (or anything else having at least 2 siblings > subclasses). All nodes have instances. a.outerjoin(b).outerjoin(c).outerjoin(d, a.c.id==d.c.id) ? > > This new "joined-table inheritance" term, is somewhat better > than "multiple table inh..", or as i picked it up, just "table > inheritance". its the proper term > > Also, in the docs, u still talk about polymorphical concrete > inheritance, while it does not really work. i mean, haveing some > engineer.id=2 and some other manager.id=2 would break it... there > would be 2 rows of id=2. Unless u know how to fix it. well technically i think thered be a "type" column on each table too which you might make as part of a composite primary key. that way PKs are unique within the union of all three tables. we should make that work and fix the doc for it, but also i think youre the only person to ever even attempt concrete inheritance too :) --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
