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Questions tagged [linked-data]

Linked Data refers to a set of best practices for publishing data on the Web under the Semantic Web standards (RDF, SPARQL, etc.). Please consider asking your question on https://opendata.stackexchange.com, if your question is not closely related to programming or is related to a particular Linked Data dataset.

T. Berners-Lee outlines four principles of linked data in his "Linked Data" note:

  1. Use URIs as names for things
  2. Use HTTP URIs so that people can look up those names
  3. When someone looks up a URI, provide useful information, using the standards (RDF*, SPARQL)
  4. Include links to other URIs, so that they can discover more things
371 questions
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How to express untyped links?

All examples I found use some vocabulary (like FOAF) to link to another resource (knows, spouse, member,...). Is there already a way (or commonly used vocabulary) to express a general "is related to" relation-type? You may also characterize such as…
st_efan
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Failed to get server protocol; no such resource on this server

I am trying to run the following query on Sesame: PREFIX dbp-ontology: PREFIX rdf: PREFIX dbpedia-owl: PREFIX dbpedia-prop:…
kurious
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Unable to use SPARQL SERVICE with FactForge

I am trying to access FactForge from Sesame triplestore. This is the query: select * where{ SERVICE { ?s ?p ?o } } LIMIT 100 The query doesn't get executed. The same structure works with DBpedia. FactForge's SPARQL…
kurious
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JSON-LD Create Single Review for Person

How would you go about creating a review for a person? For instance if a user, submitted a review that provided both a rating and an associated bit of information about a person's/service provider's quality of service... how should that be coded…
Corey
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"Invalid Server URL" error after replacing .jar files while installing GraphDB

I was trying to install GraphDB to complement default Sesame. Following the instructions for 'Easy Install' in http://owlim.ontotext.com/display/OWLIMv54/OWLIM-SE+Installation, I copied the .war files from GraphDB distribution to my Tomcat directory…
kurious
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Sesame repository not being updated using INSERT despite no error

I am trying to update a Sesame repository with data from dbpedia. I have the following query: PREFIX owl: PREFIX xsd: PREFIX rdfs: PREFIX…
kurious
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Trouble accessing rdf data from Sponger

I am currently working on a project which uses Virtuoso Sponger. I have been having multiple issues, and I have referenced a lot of material before asking these questions. Since I am new to Virtuoso, please be patient with me. I cannot seem to…
Shivansh Singh
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kill the nearly duplicate results that came from the 1:n relations in SPARQL

Is possible to concatenate equivalent results in a SPARQL query? For instance, consider the following RDF data and desired result: knowledge base: @prefix gr:. :prod_A gr:color "Red"; gr:color…
ffa
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SPARQL select does not work as expected

If I run this query SELECT ?a ?b ?c ?g ?maxtrust WHERE { { SELECT ?a (MAX(?t) AS ?maxtrust) WHERE{ GRAPH ?g { ?a a gr:productorservicemodel } GRAPH { ?g exepo:trust ?t} } GROUP BY ?a } GRAPH ?g {?a ?b…
ffa
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How to combine multiple MySQL databases using D2RQ?

I have four different MySQL databases that I need to convert into Linked Data and then run queries on the aggregated data. I have generated the D2RQ maps separately and then manually copied them together into a single file. I have read up some…
kurious
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SPARQL algebra: Excluding nodes based on triples they have

Take this graph: :thing1 a :Foo ; :has :A ; :has :B . :thing2 a :Foo ; :has :B ; :has :A . :thing3 a :Foo ; :has :A ; :has :B ; :has :C . I want to select :thing1 and :thing2, but NOT :thing3. Here is the SPARQL query…
Blake Regalia
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sparql / dbpedia regarding extracting rdf:type person

I'd like to extract all the dpbedia entries of rdf:type person using some things called dbpedia and sparql which I barely understand. I was mostly successful with the following (varying the offset). Is there a better way? I'd like to basically get…
user3436624
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How to markup a document with RDFa when data is across multiple elements

I have the following HTML structure:
Address Line One
Address Line Two
Address Line Three
Post Code
Since the data I have is does not consistently have regions or localities,…
benjaminjosephw
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Get list of all wikipedia person entries

Q: I am trying to get list of all persons on wikipedia along with their age, birth_date, death_date(if present) and country. I am using this dbpedia query which seems to return only 50,000 results which is definitely not true. A lot of entries are…
Udit Gupta
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More than one type at once in JSON-LD notation

Is it valid by format conventions to use more then one type in JSON-LD notation? Like here: { "@context": "http://schema.org", "@type": [ "MusicalEvent", "CreativeWork" ], "name": "Name", "url":…
Evgeniy
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