Re: [External] : Re: handling ("asserted") s-p-o triples and ("stated" or "reified") id-s-p-o 4-tuples in RDF/SPARQL

On Aug 13, 2024, at 5:07 AM, Thomas Lörtsch <tl@rat.io> wrote:
> 
> I always stress that I’m not good at SPARQL, but I’m trying. The following queries are my attempts at options 1-3 in standard SPARQl, asking also for eventual annotations. Given the example graph:
> 
> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
> @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
> @prefix : <http://ex.org/> .
> 
> :s :p :o1 .
> :s :p :o2 .
> :t2 rdfs:states <<( :s :p :o2 )>> ;
>     :x :y .
> :t3 rdf:reifies <<( :s :p :o3 )>> ;
>     :x :z .

…

> OPTION 2 (asserted or stated)
> =============================
> 
> SELECT *
> WHERE {
>     { :s :p ?o . }
>     UNION 
>     { ?id rdfs:states <<( :s :p ?o )>> .
>       OPTIONAL { ?id ?a ?b . } }
> }
> 
> should return
> ?id  ?o ?a ?b  
> :t1 :o1
> :t2 :o2 :x :y

Hi Thomas,

Where does :t1 come from here? I would expect the first result to have a binding only for ?o.

thanks,
.greg