Why can get results with this query:
SELECT *
WHERE {
?person rdfs:label "Kirk Douglas"#en;
dbo:birthPlace ?place. # With dbp: too
}
but not with another one:
SELECT *
WHERE {
?person rdfs:label "Kirk Douglas"#en;
dbo:starring ?film.
}
I'm following tags in https://dbpedia.org/page/Kirk_Douglas
Some tip to understand it.
Thx!
In dbr:Kirk_Douglas you can read:
dbo:birthPlace dbr:Amsterdam_(city),_New_York
...
is dbo:starring of dbr:The_Light_at_the_Edge_of_the_World
dbr:Cast_a_Giant_Shadow
dbr:Two-Fisted_Tales_(film)
...
where is dbo:starring of is a way of simulating an inverse property for dbo:starring.
Indeed, in dbo:starring you can read:
rdfs:domain dbo:Work
...
rdfs:range dbo:Actor
This means that you shouldn't build triples like ?actor dbo:starring ?work, while ?work dbo:starring ?actor is a valid triple.
So your query should be something like:
SELECT *
WHERE {
?person rdfs:label "Kirk Douglas"#en .
?film dbo:starring ?person .
}
Related
I would like to have a list of all mountains names of the "dbo:firstAscentPerson" property of Lionel Terray (dbpedia: http://dbpedia.org/page/Lionel_Terray).
This below is what I have so far
select ?person ?firstAscentPerson where {
?person foaf:name "Lionel Terray"#en.
dbo:firstAscentPerson rdfs:label ?firstAscentPerson.
} LIMIT 100
The following query does what you need:
SELECT ?mountain ?mountainName ?person2 ?person2Name {
VALUES ?person1Name {"Lionel Terray"#en}
?mountain dbo:firstAscentPerson ?person1, ?person2 .
?mountain rdfs:label ?mountainName .
?person1 foaf:name ?person1Name .
FILTER (lang(?mountainName) = "en")
OPTIONAL {?person2 foaf:name ?person2Name . FILTER (lang(?person2Name) = 'en')}
}
I created this query to return all books that are notable works by George Orwell but it returns no result.
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/resource/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?name ?title where {
?person foaf:name ?name .
?title dbo:author ?person .
?title dbo:notableWork dbp:George_Orwell .
}
I cannot seem to figure out why there is no result.
I am running the query in http://dbpedia.org/snorql
Don't you have the triples about notable works in the wrong order?
Try rewriting based on this working query
SELECT *
WHERE {
:George_Orwell dbo:notableWork ?title
}
.
title
:Nineteen_Eighty-Four
:Animal_Farm
You can also bind :George_Orwell to a variable and ask more about that:
SELECT *
WHERE {
values ?author { :George_Orwell } .
?author rdfs:label ?l .
?title ?p ?author .
?title rdf:type dbo:Book .
filter (lang(?l) = "en")
}
and DESCRIBE things
describe :Animal_Farm
I'm developing my own Fuseki endpoint from some DBpedia data.
I'm in doubt on how to aggregate properties related to a single resource.
SELECT ?name ?website ?abstract ?genre ?image
WHERE{
VALUES ?s {<http://dbpedia.org/resource/Attack_Attack!>}
?s foaf:name ?name ;
dbo:abstract ?abstract .
OPTIONAL { ?s dbo:genre ?genre } .
OPTIONAL { ?s dbp:website ?website } .
OPTIONAL { ?s dbo:image ?image } .
FILTER LANGMATCHES(LANG(?abstract ), "en")
}
SPARQL endpoint: http://dbpedia.org/sparql/
This query returns 2 matching results. They are different just for the dbo:genre value. There is a way I can query the knowledge base and retrieving a single result with a list of genres?
#chrisis's query works well on the DBpedia SPARQL Endpoint, which is based on Virtuoso.
However, if you are using Jena Fuseki, you should use more conformant syntax:
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
SELECT
?name
(SAMPLE(?website) AS ?sample_website)
(SAMPLE(?abstract) AS ?sample_abstract)
(SAMPLE(?image) AS ?sample_image)
(GROUP_CONCAT(?genre; separator=', ') AS ?genres)
WHERE {
VALUES (?s) {(<http://dbpedia.org/resource/Attack_Attack!>)}
?s foaf:name ?name ;
dbo:abstract ?abstract .
OPTIONAL { ?s dbo:genre ?genre } .
OPTIONAL { ?s dbp:website ?website } .
OPTIONAL { ?s dbo:image ?image} .
FILTER LANGMATCHES(LANG(?abstract ), "en")
} GROUP BY ?name
The differences from the #chrisis's query are:
Since GROUP_CONCAT is an aggregation function, it might be used with GROUP BY only;
Since GROUP BY is used, all non-grouping variables should be aggregated (e.g. via SAMPLE);
GROUP_CONCAT syntax is slightly different.
In Fuseki, these AS in the projection are in fact superfluous: see this question and comments.
Yes, the GROUP_CONCAT() function is what you want.
SELECT ?name ?website ?abstract (GROUP_CONCAT(?genre,',') AS ?genres) ?image
WHERE{
<http://dbpedia.org/resource/Attack_Attack!> a dbo:Band ;
foaf:name ?name;
dbo:abstract ?abstract .
OPTIONAL{ <http://dbpedia.org/resource/Attack_Attack!> dbo:genre ?genre } .
OPTIONAL{ <http://dbpedia.org/resource/Attack_Attack!> dbp:website ?website} .
OPTIONAL{ <http://dbpedia.org/resource/Attack_Attack!> dbo:image ?image} .
FILTER LANGMATCHES(LANG(?abstract ), "en")
}
To get movie detail from linkedmdb, I used sparql query :
PREFIX mdb: <http://data.linkedmdb.org/resource/movie/film>
SELECT DISTINCT ?Title ?Genre ?Actor ?Country ?Director ?Year WHERE {
?film mdb:id ?uri .
?film dc:title ?Title .
?film movie:genre ?filmgenre.
?filmgenre movie:film_genre_name ?Genre .
?film movie:actor ?cast .
?cast movie:actor_name ?Actor .
?film movie:country ?Ctr .
?Ctr movie:country_name ?Country .
?film dc:date ?Year .
?film movie:director ?Drc .
?Drc movie:director_name ?Director
FILTER regex(?Title, "Kingdom of Heaven")
}
But SPARQL results shown Title same as counted Actor . How to combine the query so that Title is not repeated?
I've try using GROUP_CONCAT but not working in LinkedMDB Endpoint?
Could someone guide me?
I am trying to get the hierarchy of super and subclass of dbpedia ontolgy.
Sparql query:
SELECT DISTINCT ?superclass ?subclass
WHERE
{
?subclass a owl:Class .
?subclass rdfs:subClassOf ?superclass
}
ORDER BY ?superclass ?subclass
It gives me all classes. But when I am trying to get the counts of entity inside classes. Some classes have entity while some don't have.
Sparql query to get the count of entity inside classes.
Getting Entities:
SELECT DISTINCT ?label AS ?label
?name AS ?name
?link AS ?link
WHERE
{
?link rdf:type <http://www.wikidata.org/entity/Q12136> .
OPTIONAL { ?link foaf:name ?name }
OPTIONAL { ?link rdfs:label ?label }
FILTER( lang(?label) = "en" )
}
Not getting Entities:
SELECT DISTINCT ?label AS ?label
?name AS ?name
?link AS ?link
WHERE
{
?link rdf:type <http://www.wikidata.org/entity/Q18553493> .
OPTIONAL { ?link foaf:name ?name }
OPTIONAL { ?link rdfs:label ?label }
FILTER(lang(?label) = "en" )
}
Why some classes don't have entities? Or Am I doing something wrong? Any help please?
First of all, you are talking about classes and not ontologies. I don't know why you think that entities are instances of ontologies, especially when you're talking about individuals/instances/resources.
Second, why shouldn't there be classes that do not have instances yet?