SPARQL - INSERT property if not exists

Question

I'm currently trying to create a SPARQL query that can insert new axioms if it doesn't exist in the target graph. I'm using ONT-API that integrates Jena ARQ.

Here's my goal query on my blank ontology:

PREFIX t: <testOntologyIRI#>
INSERT DATA {
   t:testClassA t:hasProperty t:testClassB 
}

This doesn't generate the expected result: a new axiom in my blank ontology testClassA hasProperty testClassB

I've some issue with generating a new property if it doesn't exist in the target ontology.

The catch is that if I run this same query above (knowing that the property hasProperty exists in the ontology) ==> It generates implicitly the individual testClassA, testClassB and finally my goal axiom.

To counter this "issue", I wanted to create condition in my query such as:

    PREFIX t: <testOntologyIRI#>
    PREFIX owl:     <http://www.w3.org/2002/07/owl#>
    INSERT DATA {
       t:testClassA ?hasProperty t:testClassB  .
BIND(IF(EXISTS{t:hasProperty},t:hasProperty, t:hasProperty a owl:ObjectProperty) as ?hasProperty).
    }

This query is messy to me and it doesn't work. What would you recommend editing to generate automatically a property that doesn't exist in the ontology and it is needed to insert the desired axiom?

Best regards,

Answer 1

You need to use a minus condition to test the absence of a particular triple.

prefix t:<testOntologyIRI#>

insert { t:testClassA t:hasProperty t:testClassB .
         t:hasProperty rdf:type owl:Property
 }
where { minus { t:hasProperty rdf:type owl:Property }}

If the property already exists, nothing gets inserted.