How to get all Airlines from DBpedia in Asia

Question

I'm just learning querying DBpedia. How would look query to return all Airline companies located in Asia that have income greater than X and are used by Y passengers.

Answer 1

As this is a learning question, I will show you the general process. First, we look at the Airline class in DBpedia, classes are in the ontology namespace so we find it at http://dbpedia.org/ontology/Airline. There are no owl restrictions, so we need to look at the instance level to find out what properties it has.

At the DBpedia SPARQL endpoint http://dbpedia.org/sparql, use the following query:

select distinct(?p)
{
?s ?p ?o.
?s a dbo:Airline.
}

Now we try to find a property for each of your three restrictions:

1. in Asia: look at http://dbpedia.org/property/areaServed (you probably need to add an additional step here to associate areas with continents)
2. income: choose from http://dbpedia.org/ontology/netIncome, http://dbpedia.org/ontology/operatingIncome and http://dbpedia.org/ontology/revenue
3. passengers: there is only the incorrect-looking http://dbpedia.org/property/passengers%3Csmall%3E2012%3C/small%3E_, which is only used by one carrier (Lufthansa). Either there is a more often used one in the list or you have to find this data elsewhere.