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sparqljenajena-rules

Does Jena support enforcing OWL constraints during a SPARQL Update query?

I'm trying to figure out if Jena (or any other SPARQL Update server) will enforce ontological constraints. For example, I want to enforce that only entities which have type x are allowed to have property y and the value of the property must have type z. I think this is what OWL can provide, but I'm not sure. Also, specifically, will Jena ensure that if I try to write a SPARQL Update query which does not follow these rules, that update will fail to insert and an error will be returned?

Solution

  • For example, I want to enforce that only entities which have type x are allowed to have property y and the value of the property must have type z. I think this is what OWL can provide, but I'm not sure.

    What you're asking for is not what OWL provides. In OWL, you can say that:

        propertyY rdfs:domain typeX
        propertyY rdfs:domain typeZ

    but this does not mean (at least, in the way that you're expecting), that only things of type X can have values for propertyY, and that the values must be of type Z. What it means is that whenever you see an assertion that uses propertyY, like

        a propertyY b

    an OWL reasoner can infer that

        a rdf:type typeX
        b rdf:type typeZ

    The only time those inferences will be any kind of "constraint violation" is if you have some other way of inferring that a cannot be of type X, or that b cannot be of type Z. Then an OWL reasoner would recognize the inconsistency.

    I'm trying to figure out if Jena (or any other SPARQL Update server) will enforce ontological constraints. … Also, specifically, will Jena ensure that if I try to write a SPARQL Update query which does not follow these rules, that update will fail to insert and an error will be returned?

    I don't know whether Jena supports something like this out of the box, but you probably could probably either:

    1. Use an OntModel with a reasoner attached, and run your SPARQL updates against that graph. Then, you can query the graph and see whether any inconsistency is found. How this would be done would depend on how the reasoner signals inconsistencies. This might not all that hard, but remember that Jena is really RDF-based and for full OWL reasoning, you'll need another reasoner that integrates with Jena (e.g., Pellet, but there are others, too, I think).
    2. Alternatively, you might use a store that has reasoning built in, and probably has this kind of functionality already. I think that Stardog has some of these features.