RDFising data with SPARQL and SPIN

Question

I want to RDFising data, I need construct with a SPARQL query (I'm using SPIN) an object (Book) with two properties (Title and Author). All books have "Title" but sometime haven't "Author".

When this happens, it doesn't create this "Book", and I want create it with "Title".

I'm using GraphDB and this is the query:

prefix spif: <http://spinrdf.org/spif#>
prefix pres: <http://example.com/pruebardf/>

CONSTRUCT {
    ?rdfIRI a           pres:Book ;
            pres:Author ?author   .
}
WHERE {
     SERVICE <http://localhost:7200/rdf-bridge/1683716393221> {
         ?bookRow a                <urn:Row> ;
                  <urn:col:Author> ?author   ;
                  <urn:col:Title>  ?title    .
     }
     BIND(IRI(CONCAT("http://example.com/", spif:encodeURL(?title))) AS ?rdfIRI)
}

Is there a solution? I can use other SPARQL syntax.

Using a title as the URL is not a very good idea since titles are not sufficiently stable. Better use some natural key (eg ISBN) — Vladimir Alexiev, Jun 06 '17 at 06:32

score 0 · Accepted Answer · answered Mar 13 '17 at 12:52

Use OPTIONAL in the SERVICE part to make the pattern not fail when <urn:col:Author> is missing.

The CONSTRUCT will then simply not put in the ?rdfIRI pres:Author ?author triple but will include ?rdfIRI a pres:Book.

If you want to set ?author when it is missing in the data, look at using COALESCE.

RDFising data with SPARQL and SPIN

1 Answers1