linked-data

问题 I wanted to transform tabular data into linked data. I was trying to use SPARQL construct to achieve this in GraphDB 9.5 Free edition. From the tutorials in GraphDb website it says "You can press the button SPARQL from the right top corner to access SPARQL end point" . On the new version GraphDb 9.5 there is no SPARQL button after i loaded my tabular data. How do i access the SPARQL endpoint so that i can do my Construct queries? 回答1: With GraphDB 9.4 we introduced an entirely revamped

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . I want to find some great tools or styles to visualize my RDF data so that it can give viewers a shock when they access the RDF data. The problem is that the visualization tools I get now can just generate some simple styles (node,edge...) like below: They look ugly because edges take

问题 I don't quite understand why in SPARQL they haven't implemented the basic logic operators. However in most of the cases is possible to obtain the same result in a number of way. The purpose of this question is to have a quick reference for the possible way troughs that can substitute an "or" statement. Here's what I can think of: 1) UNION e.g: SELECT * WHERE { { ?s :propA ?o } UNION { ?s :propB ?o } } -not often suitable because it can became very verbose because SELECT * WHERE { { GRAPH ?g {

问题 I don't quite understand why in SPARQL they haven't implemented the basic logic operators. However in most of the cases is possible to obtain the same result in a number of way. The purpose of this question is to have a quick reference for the possible way troughs that can substitute an "or" statement. Here's what I can think of: 1) UNION e.g: SELECT * WHERE { { ?s :propA ?o } UNION { ?s :propB ?o } } -not often suitable because it can became very verbose because SELECT * WHERE { { GRAPH ?g {

问题 How to get the list of URIs under a Namespace in RDFlib? For example, we can do: from rdflib.namespace import FOAF But how do we find out what URIs are available in FOAF? In fact, there are several namespaces (RDF, RDFS, FOAF, ...), and I find it difficult to explore which URIs are within each of them, and which one to use. Say, if I want to express a belonging relationship, should I use RDFS.member or something else? Is there a standard for linked data or it's still ad-hoc? I'm new to RDFs

问题 Visitng http://dbpedia.org/resource/Cupertino shows the DBpedia RDF information about Cupertino. As you can see, it has, among others, the property and value: dbpedia-owl:type dbpedia:City However, this query on the DBpedia endpoint returns no results: SELECT ?type WHERE { dbpedia:Cupertino dbpedia-owl:type ?type } SPARQL results Why can't I retrieve the value of the dbpedia-owl:type property? 回答1: You've got an interactive webservice in front of you, and one of the most useful things that

问题 This is a follow-up question from How to prevent triples from getting mixed up while uploading to Dydra programmatically? I've created a new graph using SPARQL CONSTRUCT query. I now want to iterate over it so that I can add the statements to an RDFlib graph and then insert the data into another triplestore. I have the following questions: If SPARQL CONSTRUCT returns a graph, do I still need to iterate over the statements and add them to an RDFlib graph? I probably need to do so to be able to

问题 This question is related to What URI to use for a Sesame repository while executing a SPARQL ADD query. I'm trying to INSERT all triples from a Sesame repository into another (Dydra). There are a couple of ways to do it, such as using SERVICE clause or Dydra's GUI. However, Dydra restricts the use of SERVICE and I want an efficient way to insert the data programmatically. This is the code I have right now: queryStringUpload = 'INSERT {?s ?p ?o} WHERE GRAPH %s {?s ?p ?o}' % dataGraph sparql =

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 5 years ago . I have a large set of raw structured datasets in CSV and HDF5 format. I would usually upload these to a web server as they are, but what steps are required to incorporate this data to the semantic web? 回答1: Tim Berners-Lee defined the 5 stars of Linked Open Data. Assuming that

问题 I'm trying to copy the data from a Sesame repository to another triplestore. I tried the following query: ADD <http://my.ip.ad.here:8080/openrdf-workbench/repositories/rep_name> TO <http://dydra.com/username/rep_name> The query gets executed with output as 'true' but no triples are added. So, I tried a similar query to see if I can move data from one Sesame repository to another using SPARQL Update: ADD <http://my.ip.ad.here:8080/openrdf-workbench/repositories/source_rep> TO <http://my.ip.ad