Re: Targeting all subjects & objects regardless of predicate

Hi James,

You can use SPARQL query to target anything you want  - as shown in the example here https://w3c.github.io/shacl/shacl-af/#SPARQLTarget <https://w3c.github.io/shacl/shacl-af/#SPARQLTarget>.

Strictly speaking, your query would not do it. It will not catch something like this:

ex:R1 ex:p ex:R2

Where there are no triples with ex:R2 or ex:p as subjects.

> On Apr 10, 2020, at 9:43 PM, James Hudson <jameshudson3010@gmail.com> wrote:
> 
> Hello Irene,
> 
> You are correct, it does not. That was an error on my part, I missed that it does not also include all the results returned by
> 
> SELECT DISTINCT ?s
> WHERE {
>     {
>         ?s ?p ?o .
>         FILTER NOT EXISTS {
>             ?s a ?c .
>             FILTER(?c IN (rdfs:Class, rdf:Property))
>         }
>     }
> }
> 
> If I understand your comment correction regarding the SHACL Advanced Features, SHACL is capable of performing the validation check?
> 
> I would love to see how that would be written...
> 
> Regards,
> James
> 
> 
> On Fri, Apr 10, 2020 at 5:08 PM Irene Polikoff <irene@topquadrant.com <mailto:irene@topquadrant.com>> wrote:
> How does your query find resources that have no type?
> 
> As for ensuring that the type in either a class or a property, you could for example do the following:
> 
> ex:Shape1 a sh:NodeShape;
> sh:targetSubjectsOf rdf:type;
> sh:or (
> 		[
> 			sh:path rdf:type ;
> 			sh:class rdfs:Class ;
> 		]
> 		[
> 			sh:path rdf:type ;
> 			sh:class rdf:Property ;
> 		]
> 	) .
> 
> Btw, SHACL Advanced Features supports SPARQL-based targets https://w3c.github.io/shacl/shacl-af/ <https://w3c.github.io/shacl/shacl-af/>.
> 
>> On Apr 10, 2020, at 4:21 PM, James Hudson <jameshudson3010@gmail.com <mailto:jameshudson3010@gmail.com>> wrote:
>> 
>> Hello,
>> 
>> I asked a question on SO ( https://stackoverflow.com/questions/60993789/targeting-all-nodes-for-validation <https://stackoverflow.com/questions/60993789/targeting-all-nodes-for-validation> ) regarding how to verify that every node in my graph had a rdf:type and that the type was ultimately either a rdfs:Class or rdf:Property. The response I received was that it was impossible with SHACL because:
>> 
>> The problem is that none of the four built-in target types is sufficient to reach all subject/objects regardless of predicate.
>> 
>> I was just wondering why such a target type does not exist or if there were plans to include such a target type in the future...?
>> 
>> I was able to do what I needed to do with SPARQL with the following query:
>> 
>>                     {
>>                         ?s rdf:type+ ?o .
>>                         FILTER NOT EXISTS {
>>                             ?s rdf:type+ ?c .
>>                             FILTER(?c IN (rdfs:Class, rdf:Property))
>>                         }
>>                     }
>> 
>> but, I would have preferred to use SHACL.
>> 
>> Regards,
>> James
>> 
>