Items not included SharePoint search results if a property missing

I use an MSSQLFT query to poll Sharepoint's search through Search.asxm web service.

The query goes like this:

SELECT PreferredName, Department, AccountName, MobilePhone, WorkPhone
       Title, JobTitle开发者_如何转开发, OfficeNumber
FROM SCOPE()
WHERE 
     "scope"="People" AND JobTitle="Something"
ORDER BY
       Department, OfficeNumber

Some people do not have Depmartment attribute set and hence are not included in search results.

If I remove the "Department" part from "Order by" clause, everything works fine. Is there a way to provide "default value" for such missing property so that these people would still get included?

---

Have you tried including the Department field in the where. You might have to hack it to say something like AND (dept = '' or dept not null). In other words, any value is acceptible. That would get the rows included in the results so the Order By clause could operate on them.