Thanks, I got it working. For future reference, if you have a polymorphic relationship, in order to avoid this kind of phantom object, you need to manually delete from both the parent collection and the child collection, e.g.
Project (Has Many)-> Node Parameter (Subclass)-> Node to remove a parameter from a project, you need to do both project.parameters.remove(param) project.nodes.remove(param) -Dave -----Original Message----- From: sqlalchemy@googlegroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Michael Bayer Sent: Thursday, October 26, 2006 5:43 PM To: sqlalchemy@googlegroups.com Subject: [sqlalchemy] Re: related object list not being updated on delete items dont get removed from collections when they are marked with delete(). with the exception of bi-directional relationships, SA doesnt add or remove items from collections. to do so in this case would require tracking every collection which a particular item is contained within which would add both memory and performance overhead. the usual strategy is to mark the relationship with a "delete-orphan" cascade, and then just remove the item from the collection, which will result in its getting deleted during the flush() operation. On Oct 26, 2006, at 5:13 PM, Hogarty, David A. wrote: > > I'm having a problem where phantom child objects stay attached to a > parent object after having been deleted. For example: > > def test_add_delete_parameter(self): > p = Project(name='ptest') > db.session.save(p) > db.session.flush() > p.parameters.append(Parameter(name='p1')) > p.parameters.append(Parameter(name='p2')) > p.parameters.append(Parameter(name='p3')) > db.session.flush() > id = p.parameters[-1].id > param = db.session.query(Parameter).get_by( > and_( > Parameter.c.project_id == p.id, > Parameter.c.id == id > )) > db.session.delete(param) > db.session.flush() > p2 = db.session.query(Project).get(p.id) > assert len(p2.parameters) == 2 > assert len(p.parameters) == 2 > > Both of the assertions at the bottom fail, because the project > instance > still believes it has 3 parameters attached. Is this a bug, or > should I > be deleting the parameters differently? > > -Dave > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy -~----------~----~----~----~------~----~------~--~---
