xsd:gYear in SPARQL

[justgo129]

Hi everyone, I notice that xsd:gYear isn't supported by SPARQL. See: http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#operandDataTypes

We do have instances of xsd:gYear in our turtle, e.g. when calling out publishing for publications, e.g. http://data.globalchange.gov/article/10.1289/ehp.8430.thtml (See 4th triple)

@zednis @xgmachina Please confirm that xsd:gYear isn't supported by SPARQL, and advise whether a different suffix is needed so as to facilitate SPARQL queries. Thanks.

(nb I need to change the template to read dbpprop:pubYear in-lieu of pubDate, but that's tangential)

[zednis]

@justgo129 Where does the link you provided say that gYear isn't supported in SPARQL?

Also, what is our desired usage of gYear in SPARQL? I suspect we can return and order publications by year just fine. Do we have a query that is attempting a filter by year that isn't working?

[justgo129]

@zednis another link is: http://www.w3.org/TR/2013/REC-sparql11-query-20130321/#otherTermConstraints

While it doesn't say that xsd:gYear isn't supported by SPARQL, it's not included in the list of related xsd types that are.

We've mostly been using gYear for publication dates, similar to the above example.

[zednis]

Is there a specific operator you are concerned about? We will be able to retrieve and order by the publication years just fine. The only thing I can think of that ~might~ not work would be filter by year ranges, but even then I think it will work just fine.

Please attempt to find a SPARQL usage that is not working as intended.

[justgo129]

Sure. The aim of this SPARQL query is to return the NCA3 findings based on material published after 2009. Not a great idea for a query clearly but it's a start.

Because the URL for the query within yasgui is so long, here is the SPARQL query: PREFIX rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns# PREFIX rdfs: http://www.w3.org/2000/01/rdf-schema# PREFIX gcis: http://data.globalchange.gov/gcis.owl# PREFIX prov: http://www.w3.org/ns/prov# PREFIX cito: http://purl.org/spar/cito/ PREFIX dcterms: http://purl.org/dc/terms/ PREFIX dbpprop: http://dbpedia.org/property/ PREFIX xsd: http://www.w3.org/2001/XMLSchema# PREFIX http: http://www.w3.org/2011/http# SELECT distinct ?Finding from http://data.globalchange.gov WHERE { ?Finding a gcis:Finding . ?Finding cito:cites ?work . ?work dbpprop:pubDate ?year . FILTER (?year > xsd:gYear("2009")) }

which returns 137 entries.

Also, juxtaposing "?year" with "distinct ?Finding" results in the year's being output as: "2010-01-01T00:00:00-06:00"^^xsd:gYear which defeats the purpose of the xsd:gYear function on the penultimate line.

[zednis]

Is that number less than expected? I see 161 total findings in the report so that is 85% of the total findings.

[justgo129]

Possibly less but it's in the ballpark. Why is the xsd:gYear suffix produced: "2010-01-01T00:00:00-06:00"^^xsd:gYear

in-lieu of simply "2010?" My understanding was that xsd:gYear serves as a function to strip the xsd output. Is it a function of a bad query (which I had adapted from another source which I don't recall), or an issue with attempting to perform a query on a triple with an xsd:gYear suffix to begin with?

[zednis]

It is probably an artifact from the endpoint implementation converting the xsd:gYear to a xsd:datetime to perform comparison operations. I do not expect all SPARQL endpoints to act the same.

Also I ran the following query to find all findings that have no cited work from after 2009 and I got 24 results, so I believe the 137 results from the earlier query is accurate.

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX gcis: <http://data.globalchange.gov/gcis.owl#>
PREFIX cito: <http://purl.org/spar/cito/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX dbpprop: <http://dbpedia.org/property/>
SELECT distinct ?Finding from <http://data.globalchange.gov>
WHERE {
  ?Finding a gcis:Finding
  FILTER NOT EXISTS { ?Finding cito:cites ?work . ?work dbpprop:pubDate ?year . FILTER (?year > xsd:gYear("2009")) }
}

[justgo129]

Works for me. @bduggan or @rewolfe please feel free to close unless you'd like to continue discussing further.

[justgo129]

Having seen no objection, I've closed #112.