Talk:Wikidata Query Service/Categories

Hi, is it possible to include mediawiki:pages, mediawiki:subcategories and mediawiki:HiddenCategory attributes in query results using gas:service or mediawiki:categoryTree services?

I see these attributes in dumps, but have no luck with accessing them from SPARQL queries so far...

Thank you very much in advance!

The link in the introduction (https://noc.wikimedia.org/conf/categories-rdf.dblist) is dead.

Fixed, thank you

Hi User:Smalyshev (WMF) !

Could we add the categories/sparql endpoint to the whitelist allowed for federation, so that it would be possible to make queries like

PREFIX gas: <http://www.bigdata.com/rdf/gas#>
prefix mediawiki: <https://www.mediawiki.org/ontology#> 

SELECT ?out ?depth WHERE {
    service <https://query.wikidata.org/bigdata/namespace/categories/sparql> {
        SELECT ?out ?depth WHERE {    
            SERVICE gas:service {
                gas:program gas:gasClass "com.bigdata.rdf.graph.analytics.BFS" .
                gas:program gas:linkType mediawiki:isInCategory .
                gas:program gas:traversalDirection "Reverse" .
                gas:program gas:in <https://en.wikipedia.org/wiki/Category:Ducks>. # one or more times, specifies the initial frontier.
                gas:program gas:out ?out . # exactly once - will be bound to the visited vertices.
                gas:program gas:out1 ?depth . # exactly once - will be bound to the depth of the visited vertices.
                gas:program gas:maxIterations 8 . # optional limit on breadth first expansion.
           }
       }
   }
} ORDER BY ASC(?depth)

Try it!

or

prefix mediawiki: <https://www.mediawiki.org/ontology#> 

SELECT ?out ?depth WHERE {
    service <https://query.wikidata.org/bigdata/namespace/categories/sparql> {
        SELECT ?out ?depth WHERE {    
            SERVICE mediawiki:categoryTree {
                bd:serviceParam mediawiki:start <https://en.wikipedia.org/wiki/Category:Ducks> .
                bd:serviceParam mediawiki:direction "Reverse" .
                bd:serviceParam mediawiki:depth 5 .
            }
        }
    }
} ORDER BY ASC(?depth)

Try it!

Thanks! I have some people on en-wiki who would really like some Listeria pages for a set of queries, with articles in one particular category excluded. If federation were enabled, this ought to do the trick perfectly.

Yes, I've added those to whitelist and they'll be added to the production config after deployment on Monday.

Very nice to see this up and running Stas!. I don't see Wikimedia Commons at https://noc.wikimedia.org/conf/categories-rdf.dblist . Could you please add it? It's the wiki I most often query in Petscan.

I've not added commons yet to the list because commons category list is huge, so I want to make sure the system works smoothly first. After this is ensured, we can add commons too.

1. mlwiki

Added to configs.