Miguel, not exactly sure, but maybe SPIN rules could help you? http://spinrdf.org/spin.html#spin-rules
Martynas On Fri, Dec 6, 2013 at 1:20 AM, Miguel Bento Alves <[email protected]> wrote: > Is it possible call a Sparql command in a rule? Can we do that with a custom > built-in function? > > An example: > > let's consider that I have the classes Student, Course and Lesson. Lesson is > related with Course. I have an ObjectProperty wasFailedBy that defines that > a given student fails to a given lesson (I list my schema and my data > example below). I want to define an ObjectProperty isDiligent that defines > that a given student is diligent to a given course. I consider that a given > student is diligent to a given course if he didn't fails more than a given > number of lessons (let's consider 1). I can't get this information with OWL > or OWL2 inference, I only can get with a Sparql command. > > I'm thinking to define my rule in this way: > > (?Student ex:isDiligent ?Course) <- > (?Student rdf:type ex:Student), > (?Course rdf:type ex:Course), > execSparql(' > prefix exa: <http://www.example.org/example#> > PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> > SELECT (COUNT(1) AS ?nCount) > WHERE { > ?V1_Student ex:failsTo ?Lesson . > ?Lesson exa:isLessonOf ?V2_Course . > }', ?Student, ?Course, ?NCount), > le(?NCount, 1). > > In my idea, the custom built-in function execSparql receives as parameters a > string with a Sparql command, a list of instanced variables to be replaced > inside the function and will return the result in the last variable passed > as parameter. I didn't implemented yet because I have doubts if this is the > better approach. My main doubts is: > Can I execute a Sparql command inside a custom built-in function using de > RuleContext? > Can I use a custom built-in function only to be an external access from the > rule and call the Sparql command, for instance via Web Service, to my > inference engine? Any better ideas? > > > <?xml version="1.0"?> > > > <!DOCTYPE rdf:RDF [ > <!ENTITY owl "http://www.w3.org/2002/07/owl#"; > > <!ENTITY exa "http://www.example.org/example#"; > > <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#"; > > <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#"; > > <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#"; > > ]> > > > <rdf:RDF xmlns="http://www.example.org/example#"; > xml:base="http://www.example.org/example#"; > xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"; > xmlns:owl="http://www.w3.org/2002/07/owl#"; > xmlns:xsd="http://www.w3.org/2001/XMLSchema#"; > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; > xmlns:exa="http://www.example.org/example#";> > > > > <!-- > > //////////////////////////////////////////////////////////////////////////// > /////////// > // > // Object Properties > // > > //////////////////////////////////////////////////////////////////////////// > /////////// > --> > > <owl:ObjectProperty rdf:about="&exa;isLessonOf"> > <rdfs:label>wasFailedBy</rdfs:label> > <rdfs:domain rdf:resource="&exa;Lesson"/> > <rdfs:range rdf:resource="&exa;Course"/> > </owl:ObjectProperty> > > > <owl:ObjectProperty rdf:about="&exa;wasFailedBy"> > <rdfs:label>wasFailedBy</rdfs:label> > <rdfs:domain rdf:resource="&exa;Lesson"/> > <rdfs:range rdf:resource="&exa;Student"/> > </owl:ObjectProperty> > > <owl:ObjectProperty rdf:about="&exa;failsTo"> > <rdfs:label>failsTo</rdfs:label> > <owl:inverseOf rdf:resource="&exa;wasFailedBy"/> > </owl:ObjectProperty> > > > <!-- > > //////////////////////////////////////////////////////////////////////////// > /////////// > // > // Classes > // > > //////////////////////////////////////////////////////////////////////////// > /////////// > --> > > <owl:Class rdf:about="&exa;Student"> > <rdfs:label>Student</rdfs:label> > </owl:Class> > > <owl:Class rdf:about="&exa;Course"> > <rdfs:label>Course</rdfs:label> > </owl:Class> > > <owl:Class rdf:about="&exa;Lesson"> > <rdfs:label>Lesson</rdfs:label> > </owl:Class> > > > > <!-- > > //////////////////////////////////////////////////////////////////////////// > /////////// > // > // Individuals > // > > //////////////////////////////////////////////////////////////////////////// > /////////// > --> > > > <owl:Thing rdf:about="&exa;Databases"> > <rdfs:label>Databases</rdfs:label> > <rdf:type rdf:resource="&exa;Course"/> > </owl:Thing> > > > > <owl:Thing rdf:about="&exa;ComputerProgramming"> > <rdfs:label>Computer Programming</rdfs:label> > <rdf:type rdf:resource="&exa;Course"/> > </owl:Thing> > > > <owl:Thing rdf:about="&exa;Michael"> > <rdfs:label>Michael</rdfs:label> > <rdf:type rdf:resource="&exa;Student"/> > </owl:Thing> > > <owl:Thing rdf:about="&exa;Richard"> > <rdfs:label>Richard</rdfs:label> > <rdf:type rdf:resource="&exa;Student"/> > </owl:Thing> > > <owl:Thing rdf:about="&exa;LessonDB1"> > <rdf:type rdf:resource="&exa;Lesson"/> > <isLessonOf rdf:resource="&exa;Databases"/> > <wasFailedBy rdf:resource="&exa;Michael"/> > </owl:Thing> > > <owl:Thing rdf:about="&exa;LessonDB2"> > <rdf:type rdf:resource="&exa;Lesson"/> > <isLessonOf rdf:resource="&exa;Databases"/> > <wasFailedBy rdf:resource="&exa;Michael"/> > <wasFailedBy rdf:resource="&exa;Richard"/> > </owl:Thing> > > <owl:Thing rdf:about="&exa;LessonCP1"> > <rdf:type rdf:resource="&exa;Lesson"/> > <isLessonOf rdf:resource="&exa;ComputerProgramming"/> > <wasFailedBy rdf:resource="&exa;Richard"/> > </owl:Thing> > > <owl:Thing rdf:about="&exa;LessonCP2"> > <rdf:type rdf:resource="&exa;Lesson"/> > <isLessonOf rdf:resource="&exa;ComputerProgramming"/> > <wasFailedBy rdf:resource="&exa;Michael"/> > <wasFailedBy rdf:resource="&exa;Richard"/> > </owl:Thing> > > </rdf:RDF> > > >
