I'm doing some experimenting with RDF.rb and sparql-client. I ran into a
couple of problems, possibly because I'm just not understanding how to use
the APIs.
1. Distinct not working:
query = sparql.select.where([:thing, RDF.type,
:type]).order_by(:type).distinct
The query has duplicates whether distinct is called or not. The query look
right (has the distinct keyword) and executing:
query = 'SELECT DISTINCT ?type WHERE { ?thing a ?type . } ORDER BY ?type'
works properly.
2. Construct not working?
query2 = sparql.construct([:s, :s, :o]).where([:s, :p, :o]).limit(10)
doesn't return any statements. Nor does
query2 = sparql.query("construct {?s ?p o} where {?s ?p ?o} limit 10")
But if I execute the construct through RestClient.post endpoint :query =>
"construct {?s ?p o} where {?s ?p ?o} limit 10"
does return RDF/XML that I can parse into an RDF:Graph
Jim Amsden, Senior Technical Staff Member
Unleash the Labs Solution Architect for Rational EA and ADC Tools
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