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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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Does RDF store data or does it describe a data model?

I have been working with Linked-Data lately and it has been causing me a headache. Although I have read a lot of pages on the RDF format I dont understand entirely if it is used to hold data, e.g. for a database, or if it is something like a way to…
alordlord
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Virtuoso 42000 Error The estimated execution time

Using DBpedia-Live SPARQL endpoint http://dbpedia-live.openlinksw.com/sparql, I am trying to count the total number of triples associated with the instances of type owl:Thing. As the count is really big, an exception is being thrown "Virtuoso 42000…
singha
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How to represent internationalized strings in Google-friendly Schema.org

Google's Structured Data Testing Tool doesn't seem to like JSON-LD's @language in value object approach to string internationalization. For example: { "@context": "https://schema.org/", "@type": "Person", "name": [{"@language": "ar",…
EyasSH
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Problem accessing Library of Congress Linked Data using Nodejs

The Library of Congress techcenter page at http://id.loc.gov/techcenter/ gives examples accessing linked data. For example: curl -L -H 'Accept: application/json' http://id.loc.gov/vocabulary/preservationEvents/creation Running the above example…
Colin G
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How to use any owl ontology to map a large data file

I have some data let us say: "Mike": "flower" I can use some owl ontologies or I can create my own ontology using Protege to convert this data to RDF triples to be as the following: …
ananya
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Java DB Connectivity and virtuoso

During an IoT school project running for some time now I need to store json-ld data to openlink virtuoso triple store using only java and then be able to query them from a sparql endpoint of virtuoso. The data will be coming from sensors(not…
IncogniBit001
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Dbpedia Dump has missing Values?

I just downloaded some dumpfiles in .ttl format from http://wiki.dbpedia.org/downloads-2016-10. Here an Overview of the files I got in my triplestore: E:/virtuoso-opensource/vad/instance_types_de.ttl instanceTypesDe …
pyysaw
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Is SPARQL a reasoner?

I'm writing my master thesis about linked data in archives and I was wondering if you could help me with a question. I've read this book about LD and came along this sentence: SPARQL is the query language of RDF triple stores, but the query …
Xandyxoxox
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Is there a central SPARQL endpoint for the semantic web

We are going to have the semantic web. Now we have LOD cloud. Every data set has its own SPARQL endpoint. I can query the dataset triples. How can I query the whole semantic web or LOD?
Wisamx
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How to do Insert/Delete remotely through a SPARQL endpoint?

Is there a way to update data by (INSERT DATA and DELETE DATA) remotely through a SPARQL endpoint? I'm aware that we can use SERVICE to do distributed and federated query, but I got errors when i tried to use SERVICE to remotely update data…
Artemis1216
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How to deal with data quality issues in Linked Data

I have recently been exploring linked data and I keep running into one issue after the other. To overcome the performance lag while accessing external endpoints, I wanted to store data dumps locally. However, the datasets I come across mostly have…
RDangol
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Error parsing N-Triple file using RDFlib

I am trying the load the triples from a Linked data dump into my local triplestore using RDFlib. An example triple in my file: "Some detail about the subject"@EN . Snippet of the code: …
RDangol
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RDFlib count not working in SPARQL query

I am exploring python based library 'RDFlib' with native store (Sleepycat). A basic "select * ..." query works fine but COUNT does not seem to work. Here is my code: from rdflib import ConjunctiveGraph, Namespace, Literal path =…
RDangol
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Duplicated resources for the same film in the Linked Movie Database

I'm using data exposed by http://www.linkedmdb.org/, from their SPARQL endpoint and I noticed that for some films, there are two resources for example: For the film Tales of Terror there are this two…
SimCor
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SPARQL Federated Queries - Using uri returned from a query in another query

In the below query I want to use ?uri variable which identifies the DBpedia resource to obtain the DBpedia element from DBpedia SPARQL service, but it returns no result as it expects URI within <>. I also tried but again no results had…
cuneyttyler
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