cascades work from the parent that is being deleted or is having a child removed to the child that is dependent on being attached to its parent.
so in this case Keyphrase->KeyphraseAction and Action->KeyPhraseAction both in theory need "delete, delete-orphan" cascade. In addition you can specify cascades in the database too in your foreign keys by adding "ON UPDATE DELETE" to your ForeignKey entries (assuming you are creating the schema with your table definitions). Hollister wrote: > > Mike, thanks for the quick reply. > I suspected it was a cascade issue, and have been through the docs and > tried various configs. At the risk of appearing stupid, can you point > me in the right direction? Do the cascades only need to be on the > association table, or also on the left & right parent tables? If a > parent (Keyphrase or Action) is deleted, then I want the delete to > cascade to the association (KeyphraseAction), but not vice versa. > > On Jun 3, 10:26 am, "Michael Bayer" <[email protected]> wrote: >> hollister wrote: >> >> > # mappers >> > mapper(Keyphrase, keyphrase_table) >> > mapper(Action, action_table) >> >> > mapper(KeyphraseAction, keyphrase_action_table, properties={ >> > 'keyphrase': relation(Keyphrase, >> > backref = 'keyphrase_action'), >> > 'action': relation(Action), >> > }) >> >> > # test >> > for i, action in enumerate(kp.actions): >> > print action.action_name >> > kp.actions.remove(action) # this fails! >> >> > s.commit() >> >> you need to configure cascade so that SQLA knows to delete a >> KeyphraseAction when it is deassociated from a Keyphrase. See the >> mapping >> docs for information on "delete" cascade. > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
