On Sep 19, 2008, at 11:47 AM, GHZ wrote:
> > On Sep 18, 2:54 pm, Michael Bayer <[EMAIL PROTECTED]> wrote: >> 2. more involved: catch change events and populate a >> Child.grandparent >> relation(). 0.5 has made the AttributeExtension API public which >> would be a good place to catch this event. The advantage to this is >> that your Child has a "grandparent" already set before any SQL is >> issued to the database. > > Thanks Michael, > I managed to get 2. to work.. > However I was now thinking it may be simpler to create a new relation > 'grandchildren' on the grandparent.. and add the new child to both the > parent and grandparent > > parent.children = [child] > grandparent.grandchildren = [child] > > Is there a hook for me to add to the second collection automatically > (i.e. an event when object is added to a collection)? its all the same idea, collections and scalars fire off events and AttributeExtension lets you catch them. If you put the collection/ attribute on grandparent or child, its pretty much the same thing. the other route to go is to use descriptors and custom collections for this stuff but I think AttributeExtension is simpler. --~--~---------~--~----~------------~-------~--~----~ 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?hl=en -~----------~----~----~----~------~----~------~--~---
