CONSTRUCT a subgraph in SPARQL with propertyPath of unknown length

Asked Feb 01 '18 at 18:41

Active Mar 05 '22 at 12:22

Viewed 279 times

I am trying to extract a subgraph from a large dataset (namely Wikidata, through their Query Service ). I have found pairs of nodes that are of my interest (uses a certain property) and now I would like to CONSTRUCT a new graph, that would contain these pairs including a chain of properties and nodes, which joins them together (subclass chain).

So I have something like:

CONSTRUCT { #todo }
WHERE {
        ?s1 ex:p1 ?o1 .
        ?s2 ex:p2 ?o2 .
#OPTIONAL {?s1 rdfs:subClassOf* ?s2.} #something-like
}

Although, my actual query is a bit more complicated because I am also extracting different information from the same property (based on its string value), but it should not affect the problem.

Now I would like to copy the propertyPaths of rdfs:subClassOf, which joins those pairs, into the new graph. So I would like to put something like --

?s1 rdfs:subClassOf* ?s2 .

-- into the CONSTRUCT{} part but, of course, it's not allowed syntax.

edited Mar 05 '22 at 12:22

logi-kal

7,107
6
31
43

asked Feb 01 '18 at 18:41

jmac

1

That doesn't work, if you also need the intermediate nodes. Even with `?start :p+ ?mid . ?mid :p* ?end .` you would lose the information of the pairs. – UninformedUser Feb 01 '18 at 19:34
By the way, the property is called **rdfs** `:subClassOf` – UninformedUser Feb 01 '18 at 19:35
@AKSW thanks for the expected answer... :-/ And you are right, I corrected the subClassOf property in the original question, thanks. – jmac Feb 01 '18 at 20:56
@jmac, possibly you could figure out something using `?start :p* ?mid1 . ?mid1 :p ?mid2 . ?mid2 :p* ?end .`. – Stanislav Kralin Feb 02 '18 at 06:06
Also, `wdt:P279` is used on Wikidata instead of `rdfs:subClassOf`. – Stanislav Kralin Oct 11 '18 at 11:33

CONSTRUCT a subgraph in SPARQL with propertyPath of unknown length

0 Answers0