CODEWITHSUNDEEP
sparql
patrick
patrick

Reputation: 16979

Get schema from Sparql dataset?

I downloaded Categorys (Labels) dataset in .nt format, from this page,

And I would like to figure out what is available for querying. I tried this, 

select distinct ?Category where {[] a ?Category } LIMIT 100

which is a modification of this example query

But it failed. So I need to figure out how to query this dataset. I would like to view the schema or something similar.

Upvotes: 1

Views: 639

Answers (1)

Ben Companjen
Ben Companjen

Reputation: 1443

(Assuming that by "it failed" you mean your query didn't return any results:)

The dataset you downloaded contains only triples of the pattern <.../resource/...> rdfs:label "label"@en ..
In SPARQL, the predicate a is short for rdf:type, which is not available in the file. So if you query this file, your query matches nothing.

To get an impression of the contents of the DBpedia downloads, you can look at the preview. For each download on the DBpedia 3.8 Downloads page, there is a question mark next to the link to the N-Triples, N-Quads and/or Turtle file that links to a preview of the file.

From the descriptions of the downloads it seems that the classes that are in DBpedia can be found in the Ontology Infobox Types file (see a preview of the English .nt file). Your query should return available classes if you execute it on this file.
A part of the ontology is also listed in Table 1 on page 8 of this paper (PDF).

The complete DBpedia ontology can be found here.

(Edit: added link to complete ontology.)

Upvotes: 2

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