Requisition DFF Default Value

Summary:

Hello. We are attempting to default Cost center on Requisition DFF in the Self Service Requisition Module ( Responsive module) when creating a new Requisition Line.

I would like to derive the Cost Center first for the Requester. If it is unable to fetch a value for the Requester, then I want to fetch a value for the logged-in user."

I am using below query in DFF default sql and is not working. On New Requisition line page (smart form), PARAMETER.RequesterId is blank, but am unsure why IS NULL condition is not functioning.

Please let me know if i am missing something.