PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX db: <http://dbpedia.org/ontology/>
PREFIX prop: <http://dbpedia.org/property/>
SELECT ?releaseDate
WHERE {
?film rdf:type db:Film;
foaf:name ?title.
?film dbp:releaseDate ?releaseDate.
FILTER regex(?releaseDate, "2016", "i").
}
Getting the release date but only two i am not sure about querying . since i am new to this.
Related
I wanted to access dbt:Cricket_by_country(value) inside of the dbp:wikiPageUsesTemplates (Property), but I am not able to access it. I am very new to the SPARQL
Below is my code
PREFIX cia: <http://www.semanticweb.org/neelc/ontologies/countries#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX dct: <http://purl.org/dc/terms/>
PREFIX dbpedia-populated-place: <http://dbpedia.org/ontology/PopulatedPlace/>
PREFIX dbcat:<http://dbpedia.org/resource/Category>
select distinct ?name , ?sizeOfTeam, ?equipment, ?TeamCountry, ?Country
where
{
?cricket dct:subject <http://dbpedia.org/resource/Category:Cricket>.
?cricket dbp:name ?name.
?cricket dbo:teamSize ?sizeOfTeam.
?cricket dbo:equipment ?equipment.
?cricket dbp:wikiPageUsesTemplate ?TeamCountry .
?cricket dbp:TeamCountry.dbt:Cricket_by_country ?Country
FILTER (LANG(?name)="en")
FILTER regex(str(?cricket), "/resource/Cricket")
}
I am trying to get actor names for a given film title (I also have the release date in hand) with my sparql query, but given the situation that multiple films have the same name, I'm trying to differentiate them with the release date. Some films don't have the release date specified, some films don't have the label specified.
I'm trying to get results when either the release date is specified and is matching, or when it is in the label of the film and is also matching.
If I can't match the date with one of these attributes, I want no results in return
Here is my current query:
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT DISTINCT ?film ?aname
WHERE {
?film a dbo:Film ;
foaf:name "A Nightmare on Elm Street"#en ;
dbo:starring ?a .
?a foaf:name ?aname
OPTIONAL
{ ?film dbo:releaseDate ?rd
BIND(year(xsd:date(?rd)) AS ?rrd)
FILTER ( ( ?rd = "1984-04-30"^^xsd:date ) || ( ?rrd = 1984) )
}
OPTIONAL
{ ?film rdfs:label ?lab
FILTER regex(?lab, "1984", "i")
FILTER ( lang(?lab) = "en" )
}
}
I think you are misusing OPTIONAL here. Instead you should be looking at UNION.
What's the difference?
SELECT ?person ?child
WHERE {
?person a :Person .
OPTIONAL {?person :hasSon ?child}
OPTIONAL {?person :hasDaughter ?child}
}
Will return every person, and optionally their sons/daughters. However this will return also people without any children at all.
Instead, something like:
SELECT ?person ?child
WHERE {
?person a :Person .
{?person :hasSon ?child}
UNION
{?person :hasDaughter ?child}
}
Will only return people who have at least one son or daughter.
Now, in your example, I have a query working like this:
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT DISTINCT ?film ?aname
WHERE {
?film a dbo:Film ;
foaf:name "A Nightmare on Elm Street"#en ;
dbo:starring ?a .
?a foaf:name ?aname
{ ?film dbp:released 1984}
UNION
{ ?film rdfs:label ?lab
FILTER regex(?lab, "1984", "i")
FILTER ( lang(?lab) = "en" )
}
}
Notice that I used the dbp:released property which seems to be working.
It seems that the property used for releases is inconsistent across films, i.e. some use dbp:released , others dbo:releaseDate.
If that's an issue, you can of course add another UNION statement in the query to deal with the different case.
One more thing:
there are many triplestores out there that have reasoning, and reasoning is something that can help deal with a variety of such situations (disambiguation, multiple properties for the same thing, etc)
I'm trying to extract some data from dbpedia using SERVICE function of SPARQL.
In fact I want to extract the names, the lat and lot of all New York theaters. To check if an instance is a theater I can use http://dbpedia.org/class/yago/Theater104417809. One example of a theater could be http://dbpedia.org/resource/Grand_Theatre_(New_York_City).
How to use service function for getting what I need in SPARQL?
** EDIT **
The query that I'm trying is the following one, but is not returning any value.
PREFIX dbpedia: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX geos: <http://www.opengis.net/ont/geosparql#>
PREFIX geof: <http://www.opengis.net/def/function/geosparql/>
PREFIX : <http://www.semanticweb.org/frubi/ontologies/2017/10/puntsWIFI#>
SELECT *
WHERE {
SERVICE <http://dbpedia.org/sparql/> {
SELECT ?teatreName ?lat ?long
WHERE {
?teatre rdf:type dbpedia:Theatre .
?teatre foaf:name ?teatreName .
?teatre geo:lat ?lat .
?teatre geo:long ?long .
?teatre dbp:city ?ciutat .
?ciutat rdfs:label "New York City"#en
}
}
}
It's not an issue with federated querying, but with your DBpedia query. dbp:city is not an object property but simply of type rdf:Property, thus it's untyped. In your case, it maps to literals which means, you have to use the literal directly. The weird thing here is, that for some reasons you have to use the datatype http://www.w3.org/1999/02/22-rdf-syntax-ns#langString explicitly instead of "New York City"#en - that's clearly not intuitive for any user. Not sure whether this happened due to the DBpedia extraction or is the expected behaviour of Virtuoso.
PREFIX dbpedia: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX geos: <http://www.opengis.net/ont/geosparql#>
PREFIX geof: <http://www.opengis.net/def/function/geosparql/>
PREFIX : <http://www.semanticweb.org/frubi/ontologies/2017/10/puntsWIFI#>
SELECT *
WHERE {
SERVICE <http://dbpedia.org/sparql/> {
SELECT ?teatreName ?lat ?long
WHERE {
?teatre rdf:type dbpedia:Theatre .
?teatre foaf:name ?teatreName .
?teatre geo:lat ?lat .
?teatre geo:long ?long .
?teatre dbp:city "New York City"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#langString>
}
}
}
I'm querying DBpedia types in SPARQL (http://dbpedia.org/sparql) by resource's label
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX : <http://dbpedia.org/resource/>
PREFIX ru: <http://ru.dbpedia.org/resource/>
PREFIX dbpedia2: <http://dbpedia.org/property/>
PREFIX dbpedia: <http://dbpedia.org/>
PREFIX dbo: <http://dbpedia.org/ontology/>
SELECT ?type ?superType WHERE { {
?res rdfs:label "HarryPotter"#en.
} UNION {
?redir dbo:wikiPageRedirects ?res .
?redir rdfs:label "HarryPotter"#en .
}
?res rdf:type ?type .
OPTIONAL {
?type rdfs:subClassOf ?superType .
}
}
It works fine.
But what if I know the exact resource - http://dbpedia.org/page/Harry_Potter? I tried something like:
?res a :Harry_Potter.
But it does not work.
How to query DBpedia types and supertypes if I know the resource URI? I can't figure out which property or operator I should use (e.g., rdfs:Resource, a, etc., which do not work)
When you write
?res a :Harry_Potter.
It doesn't work, because this means "a resource, which is of type :Harry_Potter". It is equivalent to
?res rdf:type :Harry_Potter.
:Harry_Potter identifies a resource and not the type, thus it should be used in place of ?res.
Also I think you mean Harry_Potter_(character), because that is the actual identifier and not redirect.
You query would be as simple as
SELECT ?type ?superType WHERE
{
# give me ?type of the resource
<http://dbpedia.org/resource/Harry_Potter_(character)> rdf:type ?type .
# give me ?superTypes of ?type
OPTIONAL {
?type rdfs:subClassOf ?superType .
}
}
You can just put the URI as the subject in there WHERE conditions.
SELECT ?title, ?releaseDate
WHERE {
<http://dbpedia.org/resource/Super_Mario_Bros._3> dbp:title ?title .
<http://dbpedia.org/resource/Super_Mario_Bros._3> dbo:releaseDate ?releaseDate .
}
I am trying to get some data about museum but it is not successfull. This is my code. I know the name of the museum, so I want to get data about this museum
PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX dbpprop: <http://dbpedia.org/property/>
SELECT ?abstract ?location WHERE {
?architectural_structure rdf:type dbpedia-owl:Museum .
?architectural_structure dbpedia-owl:location dbpedia:Taganrog .
?architectural_structure dbpprop:name dbpedia:Chekhov_Shop .
}
The dbpprop:name that you have selected (dbpedia:Chekhov_Shop) is in fact a string. If you look at the dbpedia page it has been defined as The Chekhov Shop. Therefore, my suggestion is to filter your query based on the name you like to be displayed:
PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX dbpprop: <http://dbpedia.org/property/>
SELECT * WHERE {
?architectural_structure rdf:type dbpedia-owl:Museum .
?architectural_structure dbpedia-owl:location dbpedia:Taganrog .
?architectural_structure dbpprop:name ?name.
Filter (str(?name)="The Chekhov Shop")
}
And if you need more information about this specific architectural structure, you start exploring. For example,
PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX dbpprop: <http://dbpedia.org/property/>
SELECT distinct * WHERE {
?architectural_structure rdf:type dbpedia-owl:Museum .
?architectural_structure dbpedia-owl:location dbpedia:Taganrog .
?architectural_structure dbpprop:name ?name.
?architectural_structure dbpprop:location ?location.
?architectural_structure dbpedia-owl:abstract ?abstract.
Filter (str(?name)="The Chekhov Shop")
}
In general, when you are faced with a triple store try to find all ?o ?p ?s and then see where you need to put a specific predicate.