Create a collection or query to check for UDA

Hi folks,
 
does anybody know how I can create a simple query to ask whether a machine has a user assigned or not? I checked the report that exists but this SQL query cannot be used for a WQL query. I got stuck trying to figure out building a query to list all machines that don't have a user assigned. I couldn't find an object class nor an attribute class. 
The reason is to have a collection with all machines without UDA to allow a different client settings policy. Any ideas? Thanks.
 
Ingrid

In the console, monitoring, Queries, make a new query, and switch to show query language (it's not there in the pull down / pick lists)
and just this to get you started:
 
select * from sms_usermachinerelationship
 
I'm guessing you'll want something like...
where sms_usermachinerelationship.uniqueusername is null
 
Test of course.  I didn't actually make a collection query...
http://msdn.microsoft.com.../library/hh949107.aspx
take a look at that for attribute names. 
 
Edit: or... just thought of this (since I didn't actually look at a cm12 console, nor am I looking now); perhaps boxes that don't have a UDA relationship simply don't have an entry in sms_usermachinerelationship at all; so maybe it'll need to be a subselect; those resourceids not in (select resourceid from sms_usermachinerelationship where uniqueusername is not null) ???  Again... just sorta dreaming this up.  Not actually doing anything in a console.

Hi Sherry,
 
it sounded pretty good an easy in first place but you were right with the second guess. Machines without an UDA relationship don't even show up in this view sms_usermachinerelationship. And machines where you remove the actual relationship still show RelationActive=1 in the view.
I think I'll have to dig around that but at least you gave me an idea where to look at and how to start. Maybe a subselect will give me the desired result.
 
Ingrid