Hi to you all (and thanks for this great website since there doesn't seem to exist a forum on beginner-SPARQL-questions), i hope someone can help me on this probably totally easy-to-solve problem: I want to run a SPARQL query against the following RDF (noted in N3, the RDF/XMl sits here). This is the desription of a journal article and...
Hi I am trying to write a SPARQL query which should give me all foaf:Agents which aren't foaf:Persons. I can't see a way to apply this OPTIONAL/BOUND construct to this problem, because all the properties like rdfs:subClassOf and rdf:type are transitive and reflexive. I tried this: SELECT * WHERE { ?x rdf:type foaf:Agent OPTIONAL { ...
This is a terribly beginner series of questions, but after reading through a good 30 SPARQL tutorials I can't seem to wrap my head around what SPARQL is or how to begin using it. Is it executed on the client side? Is microsoft somehow going to be able to mess this up? Can you use a common relational database (SQL)? Are there particul...
Hi Guys. I cannot understand how can I query dbpedia.org using Jena. In the tutorials like here(Listing 4) model is initialized as follows: // Open the bloggers RDF graph from the filesystem InputStream in = new FileInputStream(new File("bloggers.rdf")); // Create an empty in-memory model and populate it from the graph Model model = M...
Hi, all. Are there any enterprise-grade database engines (Oracle, MS SQL...etc) that can handle large RDF datasets (320 million) and SPARQL queries? I guess my question is also: is SPARQL/RDF/OWL ready for serving large real-world data warehouses for an enterprise? If not, are there efficient mechanisms for adapting SPARQL/RDF against ...
Howdy, I'm making a SPARQL query against the Sesame store in localhost, using SPARQLWrapper: sparql = SPARQLWrapper('http://localhost:8080/openrdf-sesame/repositories/rep/statements') sparql.setQuery(query) sparql.setReturnFormat(JSON) results = sparql.query().convert() However, I'm getting: File "build/bdist.linux-i686/egg/...
I am using a tool called TopQuadrant to create a Symantic Web (RDF/OWL) Ontology. This tool allows for import of data from MS Excel. My spreadsheet is basically a two-column sheet with the first column being an XPATH expression and the second column being a description of that XPATH. Once I import my spreadsheet, I would like to use SP...
In this simple sparql query I get a list of subjects whose object is 42 SELECT ?v WHERE { ?v ?p 42 } If I add ?p as a variable SELECT ?v ?p WHERE { ?v ?p 42 } I will get two entities per row, the subject and the predicate. What if I wanted three entities, so including the 42? Something like: SELECT ?v ?p ?m WHERE { ?v ?p (42 as m...
Anyone have any interest in intergrating RDF and/or SPARQL with a PICK database? Has anyone tried this yet? I have some thoughts about what to try. One idea is to figure out how to create a file with a dictionary that defines some correlatives that allow data to be pulled from the file as RDF, as one or many of n-triple, turtle, n3 or XM...
Hey all. Im running a sparql query on a file that contains <User rdf:about="#RJ"> <hasName rdf:datatype="http://www.w3.org/2001/XMLSchema#string">RJ</hasName> </User> I want to return only the name i.e. 'RJ' but when i enter my query SELECT ?name FROM <example.com> WHERE { assign:RJ assign:hasName ?name . } ...
Im having a problem with RDF. I have a couple of triples defined as : <User rdf:about="#T"> <hasName rdf:datatype="http://www.w3.org/2001/XMLSchema#string">T</hasName> <hasFavourite rdf:resource="#x"/> <hasFavourite rdf:resource="#y"/> </User> Im wanting to add to the (user, hasFavourite, x) and (user, hasFavourite, y) tri...
I was reading through this question http://stackoverflow.com/questions/273218/what-is-an-rdf-triple and the excellent answers to it. Roger Federer | won | wimbledon I understand that the above sentence is a triplet. But if the sentence is Roger Federer won wimbledon in 2009, how do we represent it as a RDF triplet? This site t...
Hi, can anyone help me to figure out how to get query results back in json or xml etc when using the Arc sparql endpoint? I am using the following code to get the result of my query: $endPoint->handleQueryRequest($query); $result = $endPoint->getResult(); I have looked through the code and tried passing some paramaters - trial and...
SELECT * WHERE{ ?x rdfs:label "Chalti Ka Naam Gaadi"@en . ?x foaf:name ?z . } This works SELECT * WHERE{ ?x foaf:name "Chalti Ka Naam Gaadi" . ?x rdfs:label ?z . } This doesnt Why? Can try running it here http://dbpedia.org/snorql/ Tried adding the query link directly but doesnt work, possibly due to some markup or escap...
Is there any tool to query MongoDB using SPARQL ? I store object using an RDF schema (boo Mongo no schema ^^), and now i looking for a tool/server to query the datastore using SPARQL. I started to write a SPARQL parser, but if such as tool exists, i think i would use it. Thanks in advance. ...
hi, i have to use ROWLKit http://www.dis.uniroma1.it/quonto/?q=node/30 (1) can anybody suggest two sparql queries for the Pizza.owl ? (2) is this query valid ? PREFIX rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# PREFIX pizza: http://www.co-ode.org/ontologies/pizza/pizza.owl# SELECT * WHERE { ?p rdf:type pizza:Pizza; ...
I have a SPARQL query: PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX person: <http://www.myOntDomain/person#> PREFIX likedEvent: <http://www.myOntDomain/likedEventRule#> PREFIX event: <http://www.myOntDomain/event#> PREFIX owl: <http://www.w3.org/2002/07/owl#> PREFIX xsd: <http://www.w3.org/2001/XMLS...
I'm a firm believer in learning a platform or technology by playing with it. So I've kind of glanced at SPARQL and thus far haven't really gotten to into it because it just ... looks daunting (as does everything at first). I'd like an environment with a couple of documents that I can cross reference and query. My temptation is to do SQL...
I'd like to learn more about RDF/SPARQL implementation internals, but most of the frameworks are (necessarily) somewhat complicated by real-world performance and implementation consideratins. I am curious if there is a "reference" implementation that would be suitable as a low-level teaching tool? What is the RDF/SPARQL implementation t...
Im trying to create a Sqarql query using Jena to query dbpedia. The query is working when I use it with standalone tools (Twinkle) but when I plug it in this java code it returns an empty set. String sparqlQueryString1= "PREFIX dbont: <http://dbpedia.org/ontology/> "+ "PREFIX dbp: <http://dbpedia.org/property/>"+ ...