I need to retrieve all classes available in a camera.owl file (https://github.com/quoll/mulgara/blob/master/data/camera.owl). Here is my query and I feel something wrong in it but hard to figure it out.
String queryString = "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>"
+ "PREFIX owl: <http://www.w3.org/2002/07/owl#>"
+ "PREFIX : <http://www.xfront.com/owl/ontologies/camera/#>"
+ "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>" +
"SELECT DISTINCT ?class WHERE { ?s a ?class . }";
You "feel something wrong"...that's not helpful in computer science or even any science. You should really describe what is not working next time, e.g. "doesn't return anything" or "leads to an exception" or "doesn't return what I'd expect" or ...
Your query does what you want but only for those classes that have instances. And this ontology doesn't contain any instance data.
Alternatively, you can query for all resource of type owl:Class, i.e. you work on the schema level (Note, this does only work if there are OWL classes, thus, for RDFS it wouldn't work):
PREFIX owl: <http://www.w3.org/2002/07/owl#>
SELECT ?class WHERE { ?class a owl:Class }
Related
Please help me with the SPARQL query. I have an ontology with the class 'Verse' as a subclass of owl:Thing.
The Individuals look like this:
I need to do a SPARQL query, which will retrieve all the individuals according to the Verse (class name).
I have tried this, but it seems like this query is wrong:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
SELECT ?individual ?class
WHERE {
?individual rdf:type owl:NamedIndividual .
?class rdf:type owl:Class .
}
ps: for download my ontology data, here
You can directly use the class name from your ontology.
PREFIX ontobible: <ur ontology IRI>
SELECT ?individual
WHERE {
?individual a ontobible:Verse .
}
I have setup GraphDB SE trial version and trying out inference functionality with OWL2-RL ruleset. I have built a simple SKOS knowledge with a single broader relationship. Some how, when I try to query for narrower relationship am not getting any results. Am I going wrong in the usage ?
Insertion:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
INSERT DATA {
ex:mammals rdf:type skos:Concept;
skos:prefLabel "mammals"#en;
ex:animals rdf:type skos:Concept;
skos:prefLabel "animals"#en;
skos:broader ex:mammals .
}
Query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
select * where {
?s skos:narrower ?o .
}
In the query result I don't see any response. Shouldn't it return below result -
ex:mammals skos:narrower ex:animals
I just came across this question and the OP is correct: Although the official SKOS reference explicitly states that skos:broader and skos:narrower are inverse, the actual RDF implementation does not include this statement. However, properties skos:broaderTransitive and skos:narrowerTransitive are declared as inverse.
And, although not relevant to the original question, the implementation does not state properties skos:topConceptOf and skos:hasTopConcept as inverse either.
I'm calling on http://fr.dbpedia.org/sparql
the following SPARQL query:
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
select distinct ?lcs where {
{
?lcs ^(rdf:type/rdfs:subClassOf*) <http://fr.dbpedia.org/resource/Honoré_Daumier> ,
<http://fr.dbpedia.org/resource/Auguste_Rodin>;
a owl:Class .
filter not exists {
?llcs ^(rdf:type/rdfs:subClassOf*) <http://fr.dbpedia.org/resource/Honoré_Daumier> ,
<http://fr.dbpedia.org/resource/Auguste_Rodin>;
a owl:Class ;
rdfs:subClassOf+ ?lcs .
}
}
}
On some call I've http://dbpedia.org/ontology/Person as result, on others call I'm getting http://dbpedia.org/ontology/Person and http://dbpedia.org/ontology/Agent and with others the previous answers plus http://www.w3.org/2002/07/owl#Thing
without nothing to know that a response isn't complete. How can I use the result, if it is a little randomized
The main reason for your query not working as expected is that the data the data is i) split into separate graphs and ii) not all graphs were added to the default graph.
To keep it short, the instance data is contained inside the graph http://fr.dbpedia.org whereas the schema triples will be accessible via http://dbpedia.org graph only. Sometimes, if no graph is given, then the union of some graphs is used as the default graph which will be the dataset at query time. Unfortunately, this doesn't hold for the French DBpedia endpoint, only the instance data graph will be used.
You can check this with
DESCRIBE <http://dbpedia.org/ontology/Person>
which is empty when using either no graph explicitly or the graph http://fr.dbpedia.org, but non-empty for graph http://dbpedia.org.
The way to define the default graph is using the keyword FROM. For your query, it should therefore be
prefix owl: <http://www.w3.org/2002/07/owl#>
prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
select distinct ?lcs
from <http://fr.dbpedia.org>
from <http://dbpedia.org>
where {
?lcs ^(rdf:type/rdfs:subClassOf*) <http://fr.dbpedia.org/resource/Honoré_Daumier> ,
<http://fr.dbpedia.org/resource/Auguste_Rodin>;
a owl:Class .
filter not exists {
?llcs ^(rdf:type/rdfs:subClassOf*) <http://fr.dbpedia.org/resource/Honoré_Daumier> ,
<http://fr.dbpedia.org/resource/Auguste_Rodin>;
a owl:Class ;
rdfs:subClassOf+ ?lcs .
}
}
Note, while this seems to return the correct result, you should also consider the comment from #TallTed regarding possible differences among language chapters (e.g. English vs French Wikipedia as source), release dumps (2016 vs 2018 or even the DBpedia Live) as well as Virtuoso versions used as backend.
I have a Graph Database that implements only one side of relationships in the model structures. For instance, All Broader relationships are mapped as skos:broader. All Narrower relationships are mapped as ^skos:broader (for whatever reasons they chose to do this, I have no control over this.)
I am trying to write a SPARQL Query that delivers something like
Query for all relationships of a given IRI, and their associated values.
The goal is to make a JSON or XML Representation of all the content.
Here is what I have working.
PREFIX skosxl: <http://www.w3.org/2008/05/skos-xl#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
select ?relation ?value
where
{
<CONCEPT_URI> ?r ?c
OPTIONAL {
?r rdfs:label|skosxl:prefLabel ?l
}
OPTIONAL {
?c skosxl:prefLabel/skosxl:literalForm|skosxl:literalForm ?d .
}
BIND ( if (bound(?d), ?d, ?c) as ?value )
BIND ( if (bound(?l), ?l, strafter(?r, '#')) as ?relation )
}
This works to give me all the concept relationships (IE: Broader), but it does not give me the narrower items (IE: ^broader).
Is there anyway that I can extend this generic query to produce the inverses of any relationships it finds, as well? I Tried simply adding the ^ to the ?r in the where clause but it does not like that syntactically.
Thanks,
i am working on protege 5.0 tool i downloaded the ontologies i.e doid.owl and cpr.owl which is freely downloadable from the web then i merged them. and i tried querying the ontologies using a SPARQL query the basic "select *" query is working but for retrieving the individuals, i have a query which is not working.. since cpr.owl is the benchmark i merged the ontology into that
the query is:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rs:<http://purl.obolibrary.org/obo/doid.owl>
PREFIX ab: <http://purl.org/cpr/0.9>
SELECT ?name ?age ?address
WHERE
{ ?person ab:hasDisease "heart_cancer";
ab:Name ?name ;
ab:Age ?age ;
ab:Address ?address. }