Update fields in table afterDelete

I have a 2 mysql tables called bin and bundle. bin HAS_MANY bundles and bundle BELONGS_TO bin

bin has a column called binValue which is the SUM(bundle.quantityOnHandPrice)  where bundle.binId=bin.id and it needs to get updated after a bundle record is deleted.

I'll do the update in the afterDelete model function using some SQL statement, but is there a better OR easier way of doing the update with AR and MySQL Cascading instead of writing SQL update statements?

Yii doesn't support automatic updating related records…

Thanx qiang