Ian, Yes, that would be very useful. One approach to implementing this is to use aggregration, e.g. count. For example,
http://example.com/requirements?oslc.where=count(rm:satisfiedBy)=0 SQL implementations can handle this. Unfortunately, the current SPARQL spec does not support aggregration. However, this could be added as an extension but that would require spec and dev work. We'd have to add an oslc.groupBy query parameter too to make aggregation useful. Regards, ___________________________________________________________________________ Arthur Ryman, PhD, DE Chief Architect, Project and Portfolio Management IBM Software, Rational Markham, ON, Canada | Office: 905-413-3077, Cell: 416-939-5063 Twitter | Facebook | YouTube [email protected] wrote on 03/01/2010 05:02:59 AM: > [image removed] > > [oslc-core] Question on oslc query - absence of properties > > Ian Green1 > > to: > > oslc-core > > 03/01/2010 05:08 AM > > Sent by: > > [email protected] > > The draft query spec. doesn't seem to support queries involving absence of > properties . For example, > > find all requirements which do not have a satisfiedBy link > > Do any ofher domains see the need for such questions to be supported by > OSLC Query? > > Does anyone see any difficulty in extending OSLC query so that such > formulations would be possible? (I think SteveS was looking at > "unsaid"/"negation by failure" at some point.) > > best wishes, > -ian > > [email protected] (Ian Green1/UK/IBM@IBMGB) > Chief Software Architect, Requirements Definition and Management > IBM Rational > > >
