I want to query all persons who lived through the entire 20th century in DBPedia.
Im using https://dbpedia.org/sparql/ to process my query. I have limited the output to 20.
The query I've tried is the following:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?personName ?birthDate ?deathDate
WHERE {
FILTER (?birthDate < "1900-01-01"^^xsd:date AND ?deathDate > "1999-12-31"^^xsd:date).
?p rdf:type dbo:Person.
?p dbp:name ?personName.
?p dbp:birthDate ?birthDate.
?p dbp:deathDate ?deathDate.
}
LIMIT 20.
In the output all person died after 1999-12-31 but they weren't born before 1900-01-01.
Why is my query wrong? How can I fix it?
Thanks in advance for you time.
This issue is due to integer values being included in the query results, and can be resolved using the DATATYPE() function in the same or a new FILTER() section.
For example:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT ?personName ?birthDate ?deathDate
WHERE
{
?person rdf:type dbo:Person;
dbp:name ?personName;
dbp:birthDate ?birthDate;
dbp:deathDate ?deathDate.
#This FILTER ensures that only xsd:date values are returned
FILTER(DATATYPE(?birthDate) = xsd:date && DATATYPE(?deathDate) = xsd:date).
FILTER (?birthDate < "1900-01-01"^^xsd:date && ?deathDate > "1999-12-31"^^xsd:date).
}
LIMIT 20
Live Query Definition
Live Query Result
DATATYPE() Documentation
Related
I can fetch several metadata fields for a particular person using the following query at https://dbpedia.org/sparql:
prefix dbpedia: <http://dbpedia.org/resource/>
prefix dbpedia-owl: <http://dbpedia.org/ontology/>
select * {
<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:birthName ?name.
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:birthDate ?birth_date}
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:deathDate ?death_date}
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:thumbnail ?thumbnail}
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:abstract ?abstract FILTER (lang(?abstract) = 'en')}
}
I've also seen query syntax that shows how to get metadata fields on many people at once:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
SELECT ?resource ?name
WHERE {
?resource rdf:type dbo:Person;
dbp:name ?name.
FILTER (lang(?name) = 'en')
}
ORDER BY ASC(?name)
LIMIT 10000 OFFSET 10000
How can I combine these two so that I can fetch the birth_date, death_date, thumbnail, and abstract (in English) for all people in DBPedia? Any pointers others can offer would be hugely helpful!
It's my first time using SPARQL.
Using DBpedia, I want to list the band names of all Rock bands from 1992
The code I've already developed runs correctly but gives 0 results. Am I filtering the date incorrectly?
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/resource/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT DISTINCT ?bandname where {
?band dbo:genre dbp:Rock_music .
?band foaf:name ?bandname .
FILTER (dbo:activeYearsStartYear >= xsd:date("1992-01-01") && dbo:activeYearsStartYear <= xsd:date("1992-12-31"))
}
I expect only the band names in a column.
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/resource/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
SELECT DISTINCT ?bandname ?date where {
?band dbo:genre dbp:Rock_music .
?band foaf:name ?bandname .
?band dbo:activeYearsStartYear ?date .
FILTER (?date >= "1992-01-01"^^xsd:dateTime && ?date <= "1992-12-31"^^xsd:dateTime)
}
This does the trick but note that dbo:activeYearsStartYear produces the year only, so FILTER is not using day/month.
I'm trying to find the nobel prize winners (http://data.nobelprize.org/snorql) born in the 20 th century and their field of study from dbpedia.
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX nobel: <http://data.nobelprize.org/terms/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
SELECT (?x as ?Label) (count(?NAME) as ?Count)
WHERE {
?Name a nobel:Laureate;
dbpprop:dateOfBirth ?Date;
rdfs:label ?NAME.
FILTER ( ?Date >= "1900-01-01"^^xsd:date )
FILTER (?Date < "2000-01-01"^^xsd:date) .
?Name owl:sameAs ?n
Service <http://dbpedia.org/sparql>
{?n dbo:field ?x} }
GROUP BY ?x
ORDER BY desc(count(?Name))
The results shows me error 400 because of dbo:field. Where is the fault?
the local file uploaded on stardog:
#prefix dbo: <http://dbpedia.org/ontology/> .
#prefix dbr: <http://dbpedia.org/resource/> .
dbr:United_States dbo:leader dbr:John_Roberts ,
dbr:Joe_Biden ,
dbr:Barack_Obama ,
dbr:Paul_Ryan .
1.query using the local file:
PREFIX dbr: <http://dbpedia.org/resource/>
PREFIX db: <http://dbpedia.org/>
PREFIX dbo: <http://dbpedia.org/ontology/>
SELECT ?person ?o
FROM <http://example.com/leaders.ttl>
WHERE{
dbr:United_States dbo:leader ?person .
SERVICE <http://dbpedia.org/sparql> { ?person dbo:abstract ?o .}
}
2.Same query using only dbpedia will give results:
PREFIX dbr: <http://dbpedia.org/resource/>
PREFIX db: <http://dbpedia.org/>
PREFIX dbo: <http://dbpedia.org/ontology/>
SELECT ?person ?o
FROM <http://example.com/leaders.ttl>
WHERE{
#dbr:United_States dbo:leader ?person .
SERVICE <http://dbpedia.org/sparql> { dbr:United_States dbo:leader ?person. ?person dbo:abstract ?o.}
}
Using the second query will result in a colum with the leaders and a column of abstract of the leaders in all languages available from dbpedia. Why does the first query where I use the local rdf file not work? The select query on the local file with dbr:United_States dbo:leader ?person . returns exactly the same column with the same leaders as running it directly on the dbpedia endpoint: dbpedia:John_Roberts, dbpedia:Joe_Biden, dbpedia:Barack_Obama, dbpedia:Paul_Ryan.
Why does the first query give no results?
I am writing SPARQL query to get all Person available in DBpedia. My query is ->
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
SELECT ?resource ?name
WHERE {
?resource rdf:type dbo:Person;
dbp:name ?name.
FILTER (lang(?name) = 'en')
}
ORDER BY ASC(?name)
It's giving around 10000 rows,when I am taking the output as HTML/csv/spreadsheet format.
But when I am giving query to get total count
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
SELECT COUNT(*)
WHERE{
?resource rdf:type dbo:Person;
dbp:name ?name.
FILTER (lang(?name) = 'en')
}
It's giving -> 1783404
Can anyone suggest a solution to get all rows of Person available in DBpedia?
DBPedia is being smart enough here to not overload its servers with large queries, and capping matches at 10000. Since you are ordering the results, you can use LIMIT and OFFSET to get result in sets of 10000. For example, to get the second set of 10000 results use this:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
SELECT ?resource ?name
WHERE {
?resource rdf:type dbo:Person;
dbp:name ?name.
FILTER (lang(?name) = 'en')
}
ORDER BY ASC(?name)
LIMIT 10000 OFFSET 10000
Actually, since DBPedia is limiting the results to 10000 matches, the LIMIT isn't really necessary.