1.5. Tips and Tricks
1.5.1. How Can I convert triples with geo properties to geometries to use spartial query?
Assuming a Named Graph with the following triples:
... <http://linkedgeodata.org/triplify/node454640663> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://linkedgeodata.org/ontology/hostel> . <http://linkedgeodata.org/triplify/node454640663> <http://www.georss.org/georss/point> "53.2752338 -9.0443748" . <http://linkedgeodata.org/triplify/node454640663> <http://www.w3.org/2003/01/geo/wgs84_pos#long> "-9.0443748"^^<http://www.w3.org/2001/XMLSchema#decimal> . <http://linkedgeodata.org/triplify/node454640663> <http://www.w3.org/2003/01/geo/wgs84_pos#lat> "53.2752338"^^<http://www.w3.org/2001/XMLSchema#decimal> . <http://linkedgeodata.org/triplify/node280886720> <http://www.w3.org/2000/01/rdf-schema#label> "Abbey House" . <http://linkedgeodata.org/triplify/node280886720> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://linkedgeodata.org/ontology/bed_and_breakfast> . <http://linkedgeodata.org/triplify/node280886720> <http://www.georss.org/georss/point> "53.2874983 -9.0702631" . <http://linkedgeodata.org/triplify/node280886720> <http://www.w3.org/2003/01/geo/wgs84_pos#long> "-9.0702631"^^<http://www.w3.org/2001/XMLSchema#decimal> . <http://linkedgeodata.org/triplify/node280886720> <http://www.w3.org/2003/01/geo/wgs84_pos#lat> "53.2874983"^^<http://www.w3.org/2001/XMLSchema#decimal> . ...
In order to convert these triples ( with geo properties ) to geometries to use spartial query,
you need to run the DB.DBA.RDF_GEO_FILL ()
function to populate the special RDF_GEO table with the point information as detailed at
Creating Geometries From RDF Data
documentation section.
Then the geo-spatail information will be available and can be queried.
Note: RDF_GEO and associated indexes are created when the database is first created and
thus just needs to be populated with the geometry data in the RDF triples, which is what
the DB.DBA.RDF_GEO_FILL ()
function does.