sparql

I am doing some searching, and learning more about SPARQL, but it is not easy like SQL. I just want to know why my query duplicates result and how to fix it. This is my SPARQL Query: PREFIX OQ:<http://www.owl-ontologies.com/Ontology1364995044.owl#> SELECT ?x ?ys ?z ?Souhaite WHERE { ?y OQ:hasnameactivite ?x. ?y OQ:AttenduActivite ?Souhaite. ?y OQ:SavoirDeActivite ?z. ?y OQ:hasnamephase ?ys. ?y OQ:Activitepour ?v. ?ro OQ:hasnamerole ?nr. ?y OQ:avoirrole ?ro. FILTER regex (?nr ,"Concepteur"). FILTER regex (?v,"Voiture"). } This gives me these results: Expected result is: While first reading your

I am trying to query the frequency of certain attributes in Wikidata , using SPARQL. For example, to find out what the frequency of different values for gender is, I have the following query: SELECT ?rid (COUNT(?rid) AS ?count) WHERE { ?qid wdt:P21 ?rid. BIND(wd:Q5 AS ?human) ?qid wdt:P31 ?human. } GROUP BY ?rid I get the following result: wd:Q6581097 2752163 wd:Q6581072 562339 wd:Q1052281 223 wd:Q1097630 68 wd:Q2449503 67 wd:Q48270 36 wd:Q44148 8 wd:Q43445 4 t152990852 1 t152990762 1 t152990752 1 t152990635 1 t152775383 1 t152775370 1 t152775368 1 ... I have the following questions regarding

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 be retrieved from system tables. As noted in comments, this query will get you a list of all Named

I'm using the sparql package in Rstudio, to query OMIM through bio2rdf. I have tested my query in yasgui and it works correctly. But from Rstudio he returns the following error: > qde <- SPARQL(endpoint,query) Opening and ending tag mismatch: hr line 5 and body Opening and ending tag mismatch: body line 3 and html Premature end of data in tag html line 1 Error: 1: Opening and ending tag mismatch: hr line 5 and body 2: Opening and ending tag mismatch: body line 3 and html 3: Premature end of data in tag html line 1 Thanks!! 来源： https://stackoverflow.com/questions/50346119/error-with-sparql-on

I'm trying to query DBPedia using SPARQL only to find company information such as a description, and a logo. I'm rather lost with devising the SPARQL Query to do this. SELECT DISTINCT ?subject ?employees ?homepage WHERE { ?subject rdf:type <http://dbpedia.org/class/yago/Company108058098> . ?subject dbpedia2:numEmployees ?employees FILTER ( xsd:integer(?employees) >= 50000 ) . ?subject foaf:homepage ?homepage . } ORDER BY DESC(xsd:integer(?employees)) LIMIT 20 I have come across the above query, which finds companies with over 50,000 emplayoees, but I don't understand such things as the rdf