How Do I Gecode Data?
What?
Automatic geocoding of data in quad store.
Why?
Enable exploitation of SPARQL-GEO for geospatial oriented queries.
How?
To gecode data one should call the
rdf_geo_fill API from Conductor or iSQL:
SQL> rdf_geo_fill ();
Done. -- 282 msec.
SPARQL-GEO sample queries
- All Educational Institutions within 10km of Oxford, UK:
SELECT DISTINCT ?thing AS ?uri ?thingLabel AS ?name ?date AS ?established ?lat ?long WHERE
{
<http://dbpedia.org/resource/Oxford> geo:geometry ?sourcegeo .
?resource geo:geometry ?matchgeo .
?resource geo:lat ?lat .
?resource geo:long ?long .
FILTER ( bif:st_intersects ( ?matchgeo, ?sourcegeo, 5 ) ) .
?thing ?somelink ?resource .
?thing <http://dbpedia.org/property/established> ?date .
?thing rdfs:label ?thingLabel .
FILTER ( lang ( ?thingLabel ) = "en" )
}
- Things within close proximity of London:
SELECT DISTINCT ?resource ?label ?location WHERE
{
<http://dbpedia.org/resource/London> geo:geometry ?sourcegeo .
?resource geo:geometry ?location ; rdfs:label ?label .
FILTER ( bif:st_intersects ( ?location, ?sourcegeo, 20 ) ) .
FILTER ( lang ( ?label ) = "en" )
}
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