get latitude and longitude of a place dbpedia

You can use Jena’s ARQ to execute queries against remote SPARQL endpoints. The process is described in ARQ — Querying Remote SPARQL Services. Using ParameterizedSparqlStrings in SELECT queries To do this for different places that you might not know until it is time to execute the query, you can use a ParameterizedSparqlString to hold the query and … Read more

SPARQL: is there any path between two nodes?

While you can’t use variables in property paths, you can use a wildcard by taking advantage of the fact that for any URI, every property either is that property or isn’t. E.g., (<>|!<>) matches any property, since every property either is <> or isn’t. You can make a wildcard that goes in either direction by … Read more

Aggregating results from SPARQL query

You can GROUP BY by the variables that identify the tweet and then use GROUP_CONCAT to concatenate the hashtags into something like an array, but it will still be a string that you’ll need to parse afterward. For instance, given data like @prefix smo: <http://example.org/> . @prefix : <http://example.org/> . :tweet1 smo:tweeted_at “1” ; smo:has_hashtag … Read more