At-Most Validation for Qualified Records

Dear Experts,

We have a qualified table (Product Map) associated to the Main Table (Product). There is a qualifier field "Y/N" which is a lookup-flat field to another flat table which stores the values Y & N.

Hence the values the Y/N field may have is Y, N or blank (no value).

We need to create a validation to check that only one of the qualified records in the Product Map has the Y/N field value as Y.

I can check if At-Least one record has Y value. If it can also be checked somehow that At-Most one record has Y value, the requirement can be fulfilled.

Please let me know if you have encountered this issue and how was it solved.

We are currently using SAP MDM 5.5 SP06 Patch 05 (5.5.65.98)

Thanks a lot in Advance.

Regards,

Uday