virtuoso

问题 I have a problem with generating rr:termType rr:IRI in Virtuoso. I don't know if am I doing it wrong but I followed the W3C specification. My mapping looks like this. When I generate triples with CONSTRUCT statement I still get "URL" but not IRI => <url> ( OWNER_LINK and BRAND_LINK columns). Is it something Virtuoso doesn't support or am I coding it the wrong way? DB.DBA.TTLP ( ' @prefix rr: <http://www.w3.org/ns/r2rml#> . @prefix foaf: <http://xmlns.com/foaf/0.1/> . @prefix gr: <http://purl

问题 I secured my SPARQL endpoint via SQL Accounts according to VirtSPARQLProtectSQLDigestAuthentication. Before this operation, I can get the data through the code: from SPARQLWrapper import SPARQLWrapper, JSON, DIGEST sparql = SPARQLWrapper("http://example.org/sparql") sparql.setQuery("...") sparql.setReturnFormat(JSON) results = sparql.query().convert() And after that, I use the DIGEST way to get the data, from SPARQLWrapper import SPARQLWrapper, JSON, DIGEST sparql = SPARQLWrapper("http:/

问题 What I want to do is passing data from sesame to virtuoso. Here are my codes: public static void sesame2virtuoso(String server, String repo, String graphName) throws IOException, RepositoryException { //connect sesame HTTPRepository repository = new HTTPRepository(server, repo); repository.setUsernameAndPassword(PropertiesUtil.PropValues("user"), PropertiesUtil.PropValues("password")); repository.initialize(); RepositoryConnection connection = repository.getConnection(); ValueFactory factory

问题 I am trying to query the skos:broader property for the DBPedia category "Diseases_of_oral_cavity,_salivary_glands_and_jaws". This category is available at the following URI: http://dbpedia.org/resource/Category:Diseases_of_oral_cavity,_salivary_glands_and_jaws The following query provides the desired output: PREFIX skos: <http://www.w3.org/2004/02/skos/core#> SELECT ?broaderCategory WHERE { <http://dbpedia.org/resource/Category:Diseases_of_oral_cavity,_salivary_glands_and_jaws> skos:broader

问题 I have a SPARQL CONSTRUCT like: CONSTRUCT { ?address schema:addressLocality ?city; schema:addressCountry ?country; schema:streetAddress ?addressLine; schema:postalCode ?zip; schema:addressRegion ?region. } WHERE { ?address schema:addressLocality ?city; schema:addressCountry ?country. OPTIONAL { ?address schema:streetAddress ?addressLine } OPTIONAL { ?address schema:postalCode ?zip } OPTIONAL { ?address schema:addressRegion ?region } } I'm getting fewer triples this way, than when the

问题 When using an endpoint that is hosted in Virtuoso , (like DBpedia endpoint), there are a predefined set of rules that can be used (accessible through the Inference rules link on the top right). If I need to use one of these rules I can include as the following within the query space at the endpoint: define input:inference 'ldp' However, when I try to include an external inference rules set, which is not predefined at the previous list, it triggers an error, as the following: define input

问题 Runninng this query through the DBpedia SPARQL endpoint gets me many results (with the institution column populated): select ?person ?field ?institution where { ?person a dbpedia-owl:Agent . OPTIONAL { ?person dbpprop:workInstitution ?institution . } OPTIONAL { ?person dbpprop:workInstitutions ?institution .} ?person dbpprop:field ?field . } However, adding the line FILTER(BOUND(?institution)) returns an empty result set: select ?person ?field ?institution where { ?person a dbpedia-owl:Agent

问题 UPDATE: Okay, I found it on this page: you have to run ./configure with the --enable-mono parameter. Then you'll also find out that some more dependencies are missing that aren't mentioned anywhere. Sadly, this leaves me with another problem I cannot solve. As we still have the unfinished bounty here, let's ask this. After doing ./autogen and ./configure --enable_mono (tried it on the code branches develop/6 and develop/7), I get the following error: libtool: compile: gcc -DHAVE_CONFIG_H -I.

问题 I have the following Query PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT ?type WHERE { { SELECT * WHERE { ?x rdfs:subClassOf ?type . } } OPTION (TRANSITIVE, t_distinct, t_in (?x), t_out (?type) ) . FILTER (?x = <http://dbpedia.org/ontology/Hospital>) } It works fine when i send it to Virtuoso endpoint but does not work on my Jena instance. In specific i get the following error: INFO [1] 400 Parse error: PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT ?type WHERE { {

问题 When I go to http://localhost:8890/sparql/ , there are two fields: Default Data Set Name (Graph IRI) and query . How can I list what all graphs (that go in the former field) are available in my DB? The field is not mandatory and I can just run a query against all namespaces. But I would like to know how to list the graphs available. The only non-empty graph I was able to run was http://localhost:8890/sparql For example, in a relational database environment, I believe this kind of info could