Find informations about a place - sparql

Question

I'm tring to find informations about a place (ex : New York http://dbpedia.org/page/New_York). I' try to get informations suchs as nearestCity , museum)...
My request returns nothing...
String name = "New_York";
String s4 = "PREFIX g: <http://www.w3.org/2003/01/geo/wgs84_pos#>\n" +
"PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\n" +
"PREFIX onto: <http://dbpedia.org/ontology/>\n" +
"PREFIX dbpedia: <http://dbpedia.org/resource/>PREFIX dcterms: <http://purl.org/dc/terms/>\n"+
"PREFIX dp: <http://dbpedia.org/resource/>\n"+
"PREFIX dbprop: <http://dbpedia.org/property/>\n" +
"PREFIX grs: <http://www.georss.org/georss/>\n"+
"PREFIX dbpedia-oll: <http://dbpedia.org/ontology/> \n"+
"PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>PREFIX category: <http://dbpedia.org/resource/Category:>\n"+
"\n" +
"SELECT ?nearestCity \n" +
"WHERE\n" +
"{ OPTIONAL{onto:"+name+" grs:nearestCity ?nearestCity .}\n"+
" }\n" +
"LIMIT 300\n" +
"";

Answer 1

There are a couple problems with the query you are doing:
1) Some namespaces are wrong: the resource New_York has the URI: http://dbpedia.org/resource/New_York. In your query that would translate to "dbpedia:"+name instead of "onto:"+name.
2) The properties that you are looking for point to the resource New_York, not the other way around. For example, for the nearest city one, this is the query that works (note the namespaces again for the property):
SELECT ?nearestCity where {
?nearestCity <http://dbpedia.org/property/nearestCity> <http://dbpedia.org/resource/New_York>.
}LIMIT 300
(See results)
And for museum:
SELECT ?m where {
?m <http://dbpedia.org/ontology/museum> <http://dbpedia.org/resource/New_York>.
}LIMIT 300
(See results)