DBpedia Sparql by page template

问题

I am trying to run a query on dbpedia using SPARQL syntax, to look for all pages of a certain template. Doesn't seem to be work, I am looking for all pages with dbpprop:wikiPageUsesTemplate. Does anyone know how to correct this to properly look for templates?

SELECT ?name ?member_Of ?country ?lat ?lng ?link
WHERE {
?x dbpprop:wikiPageUsesTemplate "dbpedia:Template:Infobox_settlement" .
?x a <http://dbpedia.org/ontology/Settlement> .
?x foaf:name ?name .
?x dbpedia-owl:isPartOf ?member_Of.
?x dbpedia-owl:country ?country.
?x geo:lat ?lat .
?x geo:long ?lng .
?x foaf:isPrimaryTopicOf ?link .
}
LIMIT 2500 OFFSET 0

I've also attempted to run it just by the dbprop to no avail.

SELECT * WHERE {  ?page dbpprop:wikiPageUsesTemplate <http://dbpedia.org/resource/Template:Infobox_settlement> .  ?page dbpedia:name ?name .}

If anyone is trying to do a similar thing, it is also possible via the wiki api, where you can pagananate over all results. http://en.wikipedia.org/w/api.php?action=query&list=embeddedin&eititle=Template:Infobox_settlement

回答1:

There are at least two problems: (i) you need to use IRIs in places, and not strings; and (ii) you need to use properties that DBpedia uses.

Use IRIs

?x a <http://dbpedia.org/ontology/Settlement> .

and

?x foaf:isPrimaryTopicOf ?link .

you've demonstrated that you know that URIs need to be written in full with < and >, or abbreviated with a prefix. However,

?x dbpprop:wikiPageUsesTemplate "dbpedia:Template:Infobox_settlement" .

certainly isn't going to work. It's legal SPARQL, because a string can be the object of a triple, but you almost certainly want an IRI.

Use DBpedia's vocabulary

A query with dbpprop:wikiPageUsesTemplate like this returns no results:

select distinct ?template where {
 [] dbpprop:wikiPageUsesTemplate ?template
}

SPARQL results

That's easy enough to check, and quickly confirms that there's no data that can possibly match your query. Where did you find this property? Have you seen it used somewhere? I'm not confident that you can query DBpedia based on infobox templates. DBpedia is not the same as Wikipedia, and even if the Wikipedia API supports it, it doesn't mean that DBpedia has a counterpart. There is a note on DBpedia Data Set Properties that says:

http://xx.dbpedia.org/property/wikiPageUsesTemplate (will be changed to http://dbpedia.org/ontology/wikiPageUsesTemplate)

but that latter property doesn't seem to be in use on the endpoints either. See my answer to Syntax for Sparql query for pages with specific infobox for more details.

来源：https://stackoverflow.com/questions/27894575/dbpedia-sparql-by-page-template

标签

sparql

dbpedia