Can a SharePoint Calculated field check for existence of other columns?

Question

I want to use OrderBy in SPSiteDataQuery to sort items by data, however, the field containing the date differs between the content types.

Can this be solved by sorting with a calculated field? I am currently trying to create a calculated field that checks for existence of a field (using ISERROR), if it is found it returns the value, otherwise returns a default value. Or perhaps I can create a Calculated field in parent content type, then override it's formula and field references in a child content type - would such polymorphism work?

Answer 1

As I found out - NO, it can't.