How to construct a list in SPARQL

Question

I have a ttl file that looks like this:

ex:Shape1
    a sh:NodeShape ;
    sh:property ex:Property-1
    rdfs:label "Shape 1"

ex:Property-1
    a sh:PropertyShape ;
    sh:path ex:property1
    sh:in (
        "Option 1"
        "Option 2"
    ) ;
    sh:name "Property 1"

ex:property1
    a owl:DatatypeProperty

After loading the above data into my triple store (which contains many shapes already), what query can I use to retrieve the same data back?

This query gets everything I need except for the list. For the list it only gives a blank node.

PREFIX sh: <http://www.w3.org/ns/shacl#>
PREFIX ex: <http://example.com/#>

CONSTRUCT {
  ?subject ?predicate ?object
}
WHERE {
  {
    bind(ex:Shape1 as ?subject)
    ex:Shape1 ?predicate ?object
  }
  UNION
  {
     ex:Shape1 sh:property ?subject .
    ?subject ?predicate ?object
  }
  UNION
  {
    ex:Shape1 sh:property/sh:path ?subject .
    ?subject ?predicate ?object
  }
}

see the Turtle specs how a list is internally serialized in RDF as a set of RDF triples: https://www.w3.org/TR/turtle/#collections — UninformedUser, Jun 07 '22 at 04:52
I've read that, and saw this similar question: https://stackoverflow.com/questions/4422197 but It is not clear to me how to construct the list when it is nested into another property. — agustaf, Jun 07 '22 at 19:26

score 0 · Answer 1 · answered Jun 14 '22 at 15:01

First of all, why do you need to query to get the same data back? Do you mean you need to get it in the same syntax and formatting?

to get the same data in the form of triples, you can simply execute SELECT * from ?s ?p ?o and it will give you all the triples. It also depends on your triplestore.

The standard query to fetch the items in your list would be the following:

PREFIX sh: <http://www.w3.org/ns/shacl#>
PREFIX ex: <http://example.com/#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?item
WHERE {
  ex:Property-1 sh:in/rdf:rest*/rdf:first ?item
}

You can read more about how the list items are stored internally. This link will be helpful. You can bind the ex:Property-1 in the same way in UNION or WHERE clause in your construct query to get the desired result.

I hope it is helpful. Good luck.

This question is related to another one: https://stackoverflow.com/q/72521705/3727991. I am trying to reconstruct a SHACL shape in a store with many other SHACL shapes. — agustaf, Jun 15 '22 at 16:36

How to construct a list in SPARQL

1 Answers1