SPARQL Endpoint

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

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

Virtuoso YASGUI

Available Graphs

The following versions (i.e. snapshots) of the datasets are available as named graphs:

  • https://data.wu.ac.at/portalwatch/ld/2040
  • https://data.wu.ac.at/portalwatch/ld/2002
  • https://data.wu.ac.at/portalwatch/ld/2001
  • https://data.wu.ac.at/portalwatch/ld/1940
  • https://data.wu.ac.at/portalwatch/ld/1937
  • https://data.wu.ac.at/portalwatch/ld/1935
  • https://data.wu.ac.at/portalwatch/ld/1934
  • https://data.wu.ac.at/portalwatch/ld/1851
  • https://data.wu.ac.at/portalwatch/ld/1849
  • https://data.wu.ac.at/portalwatch/ld/1841
  • https://data.wu.ac.at/portalwatch/ld/1839
  • https://data.wu.ac.at/portalwatch/ld/1836
  • https://data.wu.ac.at/portalwatch/ld/1832
  • https://data.wu.ac.at/portalwatch/ld/1830
  • https://data.wu.ac.at/portalwatch/ld/1821
  • https://data.wu.ac.at/portalwatch/ld/1820
  • https://data.wu.ac.at/portalwatch/ld/1812
  • https://data.wu.ac.at/portalwatch/ld/1811
  • https://data.wu.ac.at/portalwatch/ld/1808
  • https://data.wu.ac.at/portalwatch/ld/1801
  • https://data.wu.ac.at/portalwatch/ld/1751
  • https://data.wu.ac.at/portalwatch/ld/1742
  • https://data.wu.ac.at/portalwatch/ld/1731
  • https://data.wu.ac.at/portalwatch/ld/1721
  • https://data.wu.ac.at/portalwatch/ld/1711
  • https://data.wu.ac.at/portalwatch/ld/1710
  • https://data.wu.ac.at/portalwatch/ld/1701
  • https://data.wu.ac.at/portalwatch/ld/1652
  • https://data.wu.ac.at/portalwatch/ld/1650
  • https://data.wu.ac.at/portalwatch/ld/1648
  • https://data.wu.ac.at/portalwatch/ld/1641
  • https://data.wu.ac.at/portalwatch/ld/1640
  • https://data.wu.ac.at/portalwatch/ld/1638
  • https://data.wu.ac.at/portalwatch/ld/1636
  • https://data.wu.ac.at/portalwatch/ld/1631
  • https://data.wu.ac.at/portalwatch/ld/1630
  • https://data.wu.ac.at/portalwatch/ld/1627
  • https://data.wu.ac.at/portalwatch/ld/1626
  • https://data.wu.ac.at/portalwatch/ld/1624

Example Queries

Get the list of portals and respective number of datasets for a snapshot:

select ?activity ?start ?end ?portal count(?d) as ?datasets
from <https://data.wu.ac.at/portalwatch/ld/1935>
where {
  ?activity odpw:fetched ?portal ;
            prov:startedAtTime ?start ;
            prov:endedAtTime ?end .
  ?portal dcat:dataset ?d .
}
group by ?activity ?start ?end ?portal
order by desc(?datasets)

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

select distinct(?p)
from <https://data.wu.ac.at/portalwatch/ld/1935>
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 sum(?v)/count(?v) as ?emailmetric
from <https://data.wu.ac.at/portalwatch/ld/1935>
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 odpw: <http://data.wu.ac.at/ns/odpw#>
PREFIX pwq: <https://data.wu.ac.at/portalwatch/quality#>
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#>