I can do as you suggest, but find my implementation a bit kludgy. In order to support the ability to revert/rollback the change I would have to include (and set as updatable) the key in the child table in the view def. Once I do this, I will have two IrKey fields in the view - ie., IrKey_A and IrKey_B.
The following works, but wonder if there is a better way:
"Replace IrKey_B with m.nKeyVal"

Michael