Check if property is defined in jena rules

Question

In apache jena (using rules), how do I print when finding an instance that does not have a specified object property (in a single rule)?

Example (print people without a job):

[ruleNoJob: (?p rdf:type :Person) ... -> print(?p, 'does not have a job')]

score 1 · Accepted Answer · edited May 15 '16 at 20:15

1

You can use "noValue". Example code below:

[ruleNoJob: (?p rdf:type :Person), noValue(?p aa:job) -> print(?p, 'does not have a job')]

edited May 15 '16 at 20:15

JamieA

answered May 15 '16 at 19:08

Flekyy

Exactly what I needed. I kept skimming through the list of Jena built-ins and completely missed the `noValue(...)` for some reason. Thanks. – Robin Keskisarkka Mar 22 '17 at 10:52

1 Answers1