How do I querry if fields are NULL or not set?

Thank you for answering, but I am not looking for how to do this via the gui options.  I am looking for how to query this with the rest interface. 

Here is an example:
https://jazzserver.com:9443/jazz/rpt/repository/workitem?fields=workitem/workItem[creator/name=%27Donald%27%20or%20owner/name=%27Donald%27%20and%20projectArea/name=%27PRojrect%27]/%28id|summary|target/name|state/name|creator/name|owner/name|type/name|resolution/name|parent%20%29&size=100&pos=100

I can print out the 'resolutionDate', I can also search for a specific date, but I do not know how to search for 'resolutionDate' that is NULL or NOT NULL. 

Hi Donald,
I don't have any experience with creating queries using the rest interface.  It seems like it should be possible to query for unresolved or resolved in the same way that the gui does.  https://jazz.net/forum/questions/13870/querying-for-sorted-list-of-quotunresolvedquot-work-item has an example that might help you.

He Lauren,  that example shows some language (java maybe), but I am not sure how to translate that back to the REST web query.  Also, it is a workaround of getting a value by keying off another value.  It does not answer how to do the general query of how to find NULL or NOT NULL.  I will be writing many different queries and would need to check for NULL on any field. 
Thanks for you input, and I hope we can find someone who knows this interface that can give an answer.

I wish there was, I was never able to figure it out. 

In OSLC specification, there is no mentioning about testing null value in the query capability, so I doubt that any product implementing OSLC will have such capability.