>David
>
>Just throwing in the following, not sure if germane or not:
>
>Would using NVL() in the "default value" of the key be of use?
>
>Terry

Terry,

If I understand you correctly, your suggestion is that the field in the parent and in the child table would be automatically filled with a chosen value when someone asks to fill it with NULL.
This could be a cosmetic improvment on the workaround I mentioned. Or did you mean anything else ?

David