Still having a little trouble...here are the relevant mappings:
orm.mapper(Keyphrase, keyphrase_table, properties = {
'message':orm.relation(Message, backref='keyphrase'),
'campaign':orm.relation(Campaign, backref='keyphrase'),
'actions':orm.relation(KeyphraseAction),
})
orm.mapper(Action, action_table)
orm.mapper(KeyphraseAction, keyphrase_action_table, properties={
'action':orm.relation(Action),
'successMessage':orm.relation(Message, primaryjoin =
keyphrase_action_table.c.success_message_id == message_table.c.id),
'failureMessage':orm.relation(Message, primaryjoin =
keyphrase_action_table.c.failure_message_id == message_table.c.id),
'emailContent':orm.relation(EmailContent, primaryjoin =
keyphrase_action_table.c.email_content_id ==
email_content_table.c.id),
})
When I attempt to delete a KeyphraseAction from a Keyphrase instance
as follows:
# kp is a Keyphrase instance
for i, ka in enumerate(kp.actions):
del kp.actions[i] # this doesn't work!
It throws an error:
AssertionError: Dependency rule tried to blank-out primary key
column 'keyphrase_action.keyphrase_id' on instance
But this does work:
assoc = meta.Session.query(m.KeyphraseAction)\
.filter(and_(m.KeyphraseAction.keyphrase_id == kp.id,
m.KeyphraseAction.action_id == kp.actions[i].action.id))\
.one()
meta.Session.delete(assoc)
What am I doing wrong?
On Aug 5, 3:05 pm, Hollister <a.hollister.willi...@gmail.com> wrote:
> That was exactly the conclusion I reached before I read your reply. I
> modeled it that way and it seems to work perfectly. Guess I was just
> overthinking it.
>
> Thanks for getting back to me, Mike.
>
> On Aug 3, 11:41 pm, Michael Bayer <mike...@zzzcomputing.com> wrote:
>
> > On Aug 3, 2009, at 5:21 PM, Hollister wrote:
>
> > > I have 2 tables which are related to each other through an M:N
> > > relationship (Keyword & Action). Additionally, the relationship itself
> > > has attributes, which I have as non-key attributes in a third table
> > > (KeywordAction). I've modeled this dozens of different ways, but have
> > > yet to get exactly what I want from the model.
>
> > > At the ORM level, I want Keyword to have a property that is a
> > > collection of KeywordAction instances. Each KeywordAction instance
> > > would have a single Action instance property, so I could do things
> > > like this:
>
> > > -----------------------------------------------------------------------------------------------------------
> > > for ka in keyword.keyword_actions:
> > > if ka.status == 'open':
> > > ka.action.do_something()
>
> > > keyword.keyword_actions.append(KeywordAction(action, status = 'open'))
> > > -----------------------------------------------------------------------------------------------------------
>
> > > I've tried using the association_proxy, but I get the feeling that's
> > > not the right tool for this job.
>
> > the above example doesn't seem like it would need association proxy, a
> > simple collection of relation()s, i.e. Keyword.keyword_actions,
> > KeywordAction.action would do based on the navigation illustrated.
>
>
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