you're probably looking for delete-orphan cascade in this case, if objects
have foreign keys on their primary key columns you'd like them to be
deleted when deassociated with their parent object.
Hollister wrote:
>
> Also, the following does nothing at all (does not delete and throws no
> errors):
>
> for ka in kp.actions:
> del ka
>
> But this:
>
> del kp.actions
>
> Throws the same assertion error.
>
>
> On Aug 6, 11:01 am, Hollister <a.hollister.willi...@gmail.com> wrote:
>> 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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