SPARQL query for finding current manager - sparql

Question

I currently have the following SPARQL query:
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX p: <http://dbpedia.org/property/>
PREFIX o: <http://dbpedia.org/ontology/>
SELECT * WHERE{
?manager p:managerclubs <http://dbpedia.org/resource/Manchester_City_F.C.>.
OPTIONAL {?manager p:cityofbirth ?city}.
OPTIONAL {?manager p:dateOfBirth ?dob}.
OPTIONAL {?manager p:image ?image}.
}
This currently returns all the managers but I want to only return the current manager, is this done via a filter or is there an alternate way of writing the query.
I also have a second question which is on the page for MCFC: http://dbpedia.org/page/Manchester_City_F.C.
How can I access the DBO data types? I assumed that simply using o: instead of p: and then calling the name of the datatype would work but this doesn't seem to be the case.
EDIT:
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX p: <http://dbpedia.org/property/>
PREFIX o: <http://dbpedia.org/ontology/>
SELECT * WHERE{
?ground p:ground <http://dbpedia.org/resource/Manchester_City_F.C.>.
OPTIONAL {?ground p:seatingCapacity ?capacity}.
OPTIONAL {?ground p:image ?image}.
}
I don't understand why the above query returns nothing in: http://dbpedia.org/sparql, from the page ground is of type dbp and there is an image and seatinCapacity for the ground.

Answer 1

You don't need to add filter in this case. You can just use the property o:manager:
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX p: <http://dbpedia.org/property/>
PREFIX o: <http://dbpedia.org/ontology/>
SELECT * WHERE{
<http://dbpedia.org/resource/Manchester_City_F.C.> o:manager ?manager
OPTIONAL {?manager p:cityofbirth ?city}.
OPTIONAL {?manager p:dateOfBirth ?dob}.
OPTIONAL {?manager foaf:depiction ?image}.
}
You may also use p:currentclub but I wouldn't recommended as its object is literal.
Regarding the second question, the capacity seams to be object of p:capacity but I don't see an p:image property, only foaf:depiction, which I also used on the query above for the managers.

Answer 2

As your first question is duly answered by Ivo, here's how your second can be improved. If you are looking for the stadium of Manchester City F.C, that fact is represented as bellow.
dbr:Manchester_City_F.C. p:ground dbr:City_of_Manchester_Stadium
You are using the relation with opposite direction. Your query should be
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX p: <http://dbpedia.org/property/>
PREFIX o: <http://dbpedia.org/ontology/>
SELECT * WHERE{
<http://dbpedia.org/resource/Manchester_City_F.C.> p:ground ?ground .
OPTIONAL {?ground p:seatingCapacity ?capacity}.
OPTIONAL {?ground p:image ?image}.
}