How do I restrict my search in dbpedia using SPARQL to "Persons" only - sparql

I am using a query to output the influences of all people listed in wikipedia (where possible). I am using http://dbpedia.org/snorql/. My code so far is:
SELECT *
WHERE {
?p a
<http://dbpedia.org/ontology/Person> .
?p <http://dbpedia.org/ontology/influenced> ?influenced.
}
The problem is that the influenced output includes things like genres and political ideologies. I want to restrict it to only output "people" and "people who were influenced by those people". Thanks in advanced.

Try:
SELECT *
WHERE {
?p a
<http://dbpedia.org/ontology/Person> .
?p <dbpedia-owl:birthYear> ?birthYear.
?p <http://dbpedia.org/ontology/influenced> ?influenced.
?influenced a <http://dbpedia.org/ontology/Person>.
}
EDITED TO ADD BIRTH YEAR

Related

How to get all property from an item based on its Q number?

I want to gather all properties of a item from wikidata.
All queries I see so far assume you know properties you are looking for, but in my case, I'm not.
For example, when querying for Q1798740, I would like a returned value that looks like
[{"item": "Q1798740",
"P31": ["Q1146"],
"P17": ["Q70972"],
...
"P2043":"70 metres"}
]
and that contains all statements from the wikidata page
What query should I perform?
You need only to ask for {wd:Q1798740 ?p ?value} but it would be useful also to get the labels of the properties, which is a bit trickier:
SELECT DISTINCT ?p ?property_label ?value
WHERE
{
wd:Q1798740 ?p ?value .
?property wikibase:directClaim ?p ;
rdfs:label ?property_label .
FILTER(LANG(?property_label)="en")
}

SPARQL: How to retrieve all dog breeds and all their infobox data from dbpedia?

I would like to know how is the best sparql way to retrieve all dog breeds and all their infobox data from dbpedia.
I've tried this:
SELECT * WHERE {
{
<http://dbpedia.org/resource/Dog_type> ?p ?o
}
UNION
{
?s ?p <http://dbpedia.org/resource/Dog_type> .
?s ?p ?o .
?p ?p2 ?o2
}
}
But the result is far away from I expect like:
http://dbpedia.org/resource/Basque_Shepherd_Dog dbpedia2:coat "moderately long"^^rdf:langString
First, note that <http://dbpedia.org/resource/Dog_type> is not the class of dog breeds.
For several reasons, I suggest you do this work on DBpedia Live, rather than DBpedia [Snapshot].
Start there with a look at the description of your example breed, http://dbpedia.org/resource/Basque_Shepherd_Dog.
Then consider whether a query like the following will get you what you want --
SELECT DISTINCT *
WHERE
{
?breed a <http://dbpedia.org/class/yago/DogBreeds> ;
?p ?o
}
ORDER BY ?breed ?p ?o
LIMIT 1000

Excluding triples based on substring

I have a graph created by sponging web pages. I'm trying to write a query to exclude all triples where the subject is a web page. I can get these triples simply by
FILTER (STRENDS((STR(?i)), "html"))
but what's the best way to exclude them. Basically I need all {?s ?p ?o} minus the subset {?i ?p ?o}.
This
SELECT *
{ ?s ?p ?o
FILTER ( ! STRENDS( STR(?s), "html") )
}
filters the outcome the pattern.

How to return all S->P->O triples from a starting resource to a specified path depth?

My goal is to graphically represent the S->P->O relations within a depth two edges from the specified resource, p:Person_1. I want all relations within that path length to be returned from my query as ?s, ?p, ?o for further processing in my graphical application.
I tried the first query below which gives me my first set of ?s ?p ?o with repeats, then ?p2, ?o2, ?p3, ?o3 as additional columns in the result. I want to bind ?p2 and ?p3 to ?p, ?o2 and ?o3 to ?o.
SELECT *
WHERE {
p:Person_1 ?p ?o .
BIND("p:Person_1" as ?s)
OPTIONAL{
?o ?p2 ?o2 .
}
OPTIONAL{
?o2 ?p3 ?o3 .
}
}
Then, based on How do I construct get the whole sub graph from a given resource in RDF Graph?, I tried using CONSTRUCT to return the graph.
PREFIX p: <http://www.example.org/person/>
PREFIX x: <example.org/foo/>
construct { ?s ?p ?o }
FROM <http://localhost:8890/MYGRAPH>
where { p:Person_1 (x:|!x:)* ?s .
?s ?p ?o .
}
I am using Virtuoso and I get the error:
Virtuoso 37000 Error SP031: SPARQL compiler: Variable ?_::trans_subj_9_3 in T_IN list is not a value from some triple
I could post-process the result from my first query but I want to learn how to do this correctly with SPARQL, preferably on Virtuoso.
Update after testing the advice from #AKSW :
Both CONSTRUCT and SELECT statements work with the pattern suggested.
CONSTRUCT { ?s ?p ?o }
FROM <http://localhost:8890/MYGRAPH>
where { p:Person_1 (x:foo|!x:bar)* ?s .
?s ?p ?o .
} LIMIT 100
and:
SELECT s ?p ?o
FROM <http://localhost:8890/MYGRAPH>
where { p:Person_1 (x:foo|!x:bar)* ?s .
?s ?p ?o .
} LIMIT 100
The SELECT results in several duplicates that cannot be removed using DISTINCT, which results in an error that I assume is due to the 'datatype' of some of the returned values.
Virtuoso 22023 Error SR066: Unsupported case in CONVERT (DATETIME -> IRI_ID)
It appears some post-SPARQL processing is in order.
This gets me most of the way there. Still hoping I can find a solution for SPARQL that is like Cypher's "number of hops away" :
OPTIONAL MATCH path=s-[*1..3]-(o)
Here is a SPARQL query that works in Virtuoso. Note the SPARQL W3C standard does not support this syntax and it will fail in other triplestores.
PREFIX p: <http://www.example.org/person/>
PREFIX x: <example.org/foo/>
# CONSTRUCT {?s ?p ?o} # If you wish to return the graph
SELECT ?s ?p ?o # To return the triples
FROM <http://localhost:8890/MYGRAPH>
where { p:Person_1 (x:foo|!x:bar){1,3} ?s .
?s ?p ?o .
}LIMIT 100
See also K. Idehen's wiki entry here: http://linkedwiki.com/exampleView.php?ex_id=141
And thanks to #Joshua Taylor for advice in the same area.
Working Drafts of SPARQL 1.1 Property Paths included the {n,m} operator for handling this issue, which was implemented (and will remain supported) in Virtuoso. Here's a tweak to #tim's response.
Live SPARQL Query Results Page using the DBpedia endpoint (which is a Virtuoso instance).
Live SPARQL Query Definition Page that opens up query source code in the default DBpedia query editor.
Actual Query Example:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT DISTINCT ?s AS ?Entity
?o AS ?Category
WHERE {
?s rdf:type <http://dbpedia.org/ontology/AcademicJournal> ;
rdf:type{1,3} ?o
}
LIMIT 100
Should you be looking for LinkedIn-like presentation of Contact Networks and Degrees of Separation between individuals, here is an example using Virtuoso-specific SPARQL Extensions that solve this particular issue:
SELECT ?o AS ?WebID
((SELECT COUNT (*) WHERE {?o foaf:knows ?xx})) AS ?contact_network_size
?dist AS ?DegreeOfSeparation
<http://www.w3.org/People/Berners-Lee/card#i> AS ?knowee
WHERE
{
{
SELECT ?s ?o
WHERE
{
?s foaf:knows ?o
}
} OPTION (TRANSITIVE, t_distinct, t_in(?s), t_out(?o), t_min (1), t_max (4), t_step ('step_no') AS ?dist) .
FILTER (?s= <http://www.w3.org/People/Berners-Lee/card#i>)
FILTER (isIRI(?s) and isIRI(?o))
}
ORDER BY ?dist DESC (?contact_network_size)
LIMIT 500
Note: this approach is the only way (at the current time) to expose actual relational hops between entities in an Entity Relationship Graph that includes Transitive relations.
Live Link to Query Results
Live Link to Query Source Code
Bearing in mind that the r{n,m} operator was deprecated in the final SPARQL 1.1 (but will remain supported in Virtuoso), you can use r/r?/r? instead of r{1,3}, if you want to work strictly off the current spec:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT DISTINCT ?s AS ?Entity
?o AS ?Category
WHERE {
?s rdf:type <http://dbpedia.org/ontology/AcademicJournal> ;
rdf:type / rdf:type? / rdf:type? ?o
}
LIMIT 100
Here's a live example, against the DBpedia instance hosted in Virtuoso.

How to resolve disambiguation in Yago/DBpedia?

Assuming I am searching for an entity such as "Wizard of Oz" and know I am specifically interested in the book rather then movie or musical.
Which query/method will return correct results on most cases?
You can do that with a query like:
SELECT * WHERE {
?s <http://dbpedia.org/property/name> ?name .
?s a <http://dbpedia.org/ontology/Book> .
FILTER(regex(STR(?name), "wizard of oz", "i"))
}
You can also do that with DBpedia Lookup:
http://lookup.dbpedia.org/api/search.asmx/KeywordSearch?QueryClass=book&QueryString=wizard+of+oz
Or with DBpedia Spotlight:
http://spotlight.dbpedia.org/rest/candidates?text=wizard+of+oz+book
As every book, and only books, have an ISBN, I guess you can take Steve Harris' query and, instead of asking if it is a book, you can ask if it has an ISBN.
SELECT * WHERE {
?s <http://dbpedia.org/property/name> ?name .
?s <http://dbpedia.org/ontology/isbn> ?isbn .
FILTER(regex(STR(?name), "wizard of oz", "i"))
}