dbpedia sparql query returns 0 result - sparql

I’m new to query languages and linked data so thanks a lot for the help. I also have a similar question about sparql on wikidata
Wikidata sparql query returns 0 result
I would like to look up all the art movements in dbpedia with the associated artists (associated with the movement -peopleNam, famous for the movement-famousName, influence the movement-influenceName) here is my query with lots of redundant prefix (that I could not enter because of the amount of links)
SELECT ?movementName ?famousName ?peopleName ?influenceName
WHERE {
?m dc:subject <http://dbpedia.org/resource/Category:Art_movements> .
?m rdfs:label ?movementName .
FILTER(LANG(?movementName) = "en")
?m dbp:knownFor ?a .
?a rdfs:label ?famousName .
FILTER(LANG(?famousName) = "en")
?m dbp:movement ?b .
?b rdfs:label ?peopleName .
FILTER(LANG(?peopleName) = "en")
?m dbp:influencedBy ?d .
?d rdfs:label ?influenceName .
FILTER(LANG(?influenceName) = "en")
}'
When I run the query with only the movement name I get 235 results but whenever I add any other artist name, I get 0 result. Could you show me what went wrong?
A similar query is done in wikidata with some encouraging results but I haven’t tried to match the two sources yet.
Thanks

Related

i want to get the names of similar types using sparql queries from dbpedia

I need to find the names of similar types from DBpedia so I'm trying to figure out a query which can return me the names of entities which have same subject type in its dct:subject (example I want to find similar types of white house so i want to write a query for same . I'm considering the dct:subject to find them ). If there is any other approach please mention it
Previously I tried it for rdf:type but the result are not so good and some time it shows time out
I have done my problem by the query mentioned below and now i want to consider dct:subject instead of rdf:type
select distinct ?label ?resource count(distinct ?type) as ?score where {
values ?type { dbo:Thing dbo:Organization yago:WikicatIslam-relatedControversies yago:WikicatIslamistGroups yago:WikicatRussianFederalSecurityServiceDesignatedTerroristOrganizations yago:Abstraction100002137 yago:Act100030358 yago:Cabal108241798 yago:Group100031264 yago:Movement108464601 yago:PoliticalMovement108472335
}
?resource rdfs:label ?label ;
foaf:name ?name ;
a ?type .
FILTER (lang(?label) = 'en').
}
ORDER BY DESC(?score)

Classes and subclasses in OWL for SPARQL queries with inference

I have a question with OWL and SPARQL that I can't resolve. I have defined several classes, but for the question in question only 3 are the important ones: People, Men and Women; and its definitions would be the following:
<#People> a owl:Class ;
rdfs:label "People"#en .
<#Men> a owl:Class ;
rdfs:subClassOf <#People> ;
rdfs:label "Men"#en .
<#Women> a owl:Class ;
rdfs:subClassOf <#People> ;
rdfs:label "Women"#en .
And then a data in RDF for example:
<rdf:Description rdf:about="Registration#1">
<rdfs:label>ARCHEOLOGY GRADUATE</rdfs:label>
<ex:BranchKnowledge>ARTS AND HUMANITIES</ex:BranchKnowledge>
<ex:Degree>ARCHEOLOGY GRADUATE</ex:Degree>
<ex:Men rdf:datatype="http://www.w3.org/2001/XMLSchema#nonNegativeInteger">63</ex:Men>
<ex:Women rdf:datatype="http://www.w3.org/2001/XMLSchema#nonNegativeInteger">99</ex:Women>
<dcterms:coverage>2015/2016</dcterms:coverage>
</rdf:Description>
If I wanted to obtain the number of Men and Women of each data, I get it with the following query:
SELECT ?X ?degree ?branch ?men ?women
WHERE {
?X ex:Degree ?degree .
?X ex:BranchKnowledge ?branch .
?X ex:Men ?men .
?X ex:Women ?women
}
If I now want to get the total number of Men and Women inferring that both are People, I had thought that since both are subclasses of People, I could make the following query:
SELECT ?X ?degree ?branch ?people
WHERE {
?X ex:Degree ?degree .
?X ex:BranchKnowledge ?branch .
?X ex:People ?people
}
However I don't get any results.
Have I misconstructed the relationship between classes and subclasses for what I want to do or what would be the problem? (I'm working on a Virtuoso server).
You should be aware of the fact that you're using punning, i.e. the same URI for Men and Women as OWL classes and OWL data properties. I don't understand why you're doing this. Why don't you introduce properties like numberOfMen, numberOfWomen and numberOfPeople?
Next, you're using ex:People as a property, thus, you would have to define that ex:Men and ex:Women are sub-properties of ex:People.
<#People> a owl:DatatypeProperty ;
rdfs:label "People"#en .
<#Men> a owl:DatatypeProperty ;
rdfs:subPropertyOf <#People> ;
rdfs:label "Men"#en .
<#Women> a owl:DatatypeProperty ;
rdfs:subPropertyOf <#People> ;
rdfs:label "Women"#en .
And then you have to enable reasoning in the triple store if supported or use SPARQL 1.1 property paths.
But, more important, this would only lead to two rows, which means you have to do the aggregation in your SPARQL query by using the sum function, e.g.:
SELECT ?X ?degree ?branch (sum(?_people) as ?people)
WHERE {
?X ex:Degree ?degree .
?X ex:BranchKnowledge ?branch .
?p rdfs:subPropertyOf* ex:People .
?X ?p ?_people
}
GROUP BY ?X ?degree ?branch
Note, this query only works if there is just a single degree and branch, otherwise it would sum duplicate values.

SPARQL Query DBpedia Getting Multiple Values

I am new to DBPedia SPARQL Query, I am currently using the http://dbpedia.org/snorql to test queries.
My query looks like this
SELECT ?name ?school ?person
WHERE {
?person dbo:almaMater :Harvard_University .
?person foaf:name ?name .
?person dbo:birthDate ?birth .
?person dbo:country ?country .
?person dbo:almaMater ?school .
FILTER (?birth > "1980-01-01"^^xsd:date) .
} ORDER BY ?name
And below is my result
From the result above, looks like the name "Mingze Xi"#en was repeated thrice. I checked on the link under the person field and it shows that name "Mingze Xi"#en has attended Harvard University, Hangzhou ... and Zhejiang University.
Is there a way for me to query and show that under this name the person has attended these schools? I need this because there is no unique ID that I can use to indicate that this is the same person.

how to search for strings with different language code

I need to search items in two graphs with the same string, but different language codes ("xx"#en and "xx"#eng - from wordnet). obviously
"xx"#en is not equal to "xx"#eng.
it can be done with (prefix nlp suitably defined):
select * where {
?a nlp:lemma ?as .
?b rdfs:label ?bs .
filter (str(?as)=str(?bs)) .
# more code using ?a and ?b
}
However, this query takes too long and is wasteful. It should be possible to do something like:
?a nlp:lemma ?s .
?b rdfs:label ?s .
but i cannot see how - short of manually change all #eng in the wordnet triples to #en - which i would rather not do.
any solution?
thank you!
You could cut you search space down by filtering only for en and eng, but the only way to compare the string portion of a language-labeled string is to convert them to a string.
I.e. the following could be more efficient if there are language-labeled strings other than en and eng:
select * where {
?a nlp:lemma ?as .
?b rdfs:label ?bs .
filter (lang(?as) = "en" || lang(?as) = "eng")
filter (str(?as)=str(?bs)) .
# more code using ?a and ?b
}

Creating geometry object from two lat/long doubles in SPARQL

I would like to get some places from DBPedia in certain area, and that would be easy if those points would had geometry property. However, all they have is georss:point. I have converted this to two doubles, but I cannot convert them to geo:geometry object that can be supplied to location filter.
The code I have thus far:
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?name
?abstract
?ns
?ew
WHERE
{ ?m foaf:name ?name
. ?m georss:point ?coord
. ?m <http://dbpedia.org/ontology/abstract> ?abstract
. BIND( xsd:double(strbefore( ?coord, " " )) AS ?ns )
BIND( xsd:double(strafter( ?coord, " " )) AS ?ew )
BIND( geo:Point(?ew, ?ns) AS ?geo ) # <-- I have problem with this
FILTER (bif:st_intersects (?geo, bif:st_point(?geo), 10))
FILTER (LANG(?abstract) = "en")
}
If you know any way to convert those or other filtering method, please enlighten me. :)
There is not enough information here to give you a simple and clear answer.
However, I think you may be able to figure it out from the examples in the GEOSPARQL documentation for Virtuoso, the DBMS engine which hosts DBpedia. There's more here.