Hi, Could someone please explain what the following error means? I assume I am expecting too much magic from SQLAlchemy, but I can't see why it doesn't "just work".
I am trying to define a directed graph of related (music) artists. So I have an Artist class (nodes) and a Link class (directed arcs). The full code is available at https://github.com/andrewcooke/uykfg/blob/master/src/uykfg/music/db/network.py and https://github.com/andrewcooke/uykfg/blob/master/src/uykfg/music/db/catalogue.py but I think the essential information is below: class Link(TableBase): __tablename__ = 'music_links' src_id = Column(Integer, ForeignKey(Artist.id), primary_key=True, nullable=False) src = relationship(Artist, backref='srcs', primaryjoin=src_id==Artist.id) dst_id = Column(Integer, ForeignKey(Artist.id), primary_key=True, nullable=False) dst = relationship(Artist, backref='dsts', primaryjoin=dst_id==Artist.id) and then I ran this test: alice = Artist(name='alice') session.add(alice) bob = Artist(name='bob') session.add(bob) bob.srcs.append(alice) assert len(alice.dsts) == 1, alice.dsts where the "append" gives the error: File "/home/andrew/project/uykfg/git/env/lib/python3.2/site-packages/SQLAlchemy-0.8.0b2-py3.2.egg/sqlalchemy/orm/attributes.py", line 1066, in emit_backref_from_collection_append_event child_impl = child_state.manager[key].impl KeyError: "'src' Please - why? Thanks for reading, Andrew -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
