On 10/28/15 1:26 PM, Chris Wilson wrote:
> OK, I hadn't thought of that, it might work but in fact I want to delete
> a Cat when it has no Houses left (House -> Cat in this case, with
> uselist=True instead of uselist=False as in the example above) and it's
> not clear that delete-orphan can reliably do this to the "one" side of
> the relationship, can it? The documentation seems to imply not:


if you want to delete an object when one of its collections are empty,
use events for that.  I have an in-depth answer to the "remove an object
when all of its many-to-many children are gone" question here:

http://stackoverflow.com/questions/9234082/setting-delete-orphan-on-sqlalchemy-relationship-causes-assertionerror-this-att/9264556#9264556





> 
>     |delete-orphan| cascade implies that each child object can only have
>     one parent at a time,
> 
> 
> So there isn't an existing mechanism other than session.delete() that I
> can see, am I missing something?
> 
> Thanks, Chris.
> 
> -- 
> 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 [email protected]
> <mailto:[email protected]>.
> To post to this group, send email to [email protected]
> <mailto:[email protected]>.
> Visit this group at http://groups.google.com/group/sqlalchemy.
> For more options, visit https://groups.google.com/d/optout.

-- 
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 [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.

Reply via email to