Multiple Parent Keys for element/attribute in an XSD

Can I refer to multiple 'key' references for a single attribute in an XSD?

My requirement is that there is an attribute AddressID which is a reference for two other attributes of AddressID in PhysicalAddress and ForeignAddress. In effect the reference value can be either of the two specified primary keys.

I tried two entries for 'selector xpath' values, but failed. I also tried separating the xpaths with '|' in the selector xpath value (the field value remaining the same in both these cases), but am facing error at ru开发者_运维百科ntime 'Identity constraint validation error: 'duplicate keys'.'

Thanks for your time. Please let me know for any other info.

Regards, Krish