SPARQL Endpoint

Access the DCAT metadata desciptions and their respective quality assessments via a SPARQL endpoint.

The endpoint API is located at http://data.wu.ac.at/sparql/.

Available Graphs

The following versions (/snapshots) of the datasets are available as named graphs:

Example Queries

Select all portals that describe transportation data, i.e., portals holding datasets that use "transportation" as a keyword:

select distinct(?p)
from <http://data.wu.ac.at/portalwatch/1703>
where {
  ?p dcat:dataset ?d.
  ?d a dcat:Dataset.
  ?d dcat:keyword "transportation".
}

List all organizations at the Austrian data portal data.gv.at and the average availability of contact email addresses in the dataset descriptions:

select ?orga avg(?v) as ?emailmetric
from <http://data.wu.ac.at/portalwatch/1703>
where {
  <http://data.gv.at> dcat:dataset ?d .
  ?d dct:publisher ?o .
  ?o foaf:name ?orga .
  ?d dqv:hasQualityMeasurement ?m .
  ?m dqv:isMeasurementOf pwq:ContactEmail .
  ?m dqv:value ?v .
}
group by ?orga

Namespaces

PREFIX dcat: <http://www.w3.org/ns/dcat#>
PREFIX dqv: <http://www.w3.org/ns/dqv#>
PREFIX prov: <http://www.w3.org/ns/prov#>
PREFIX csvw: <http://www.w3.org/ns/csvw#>
PREFIX pwq: <http://data.wu.ac.at/portalwatch/quality#>