Counting in SPARQL
13,247
You might want to try this:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT (COUNT(DISTINCT ?instance) AS ?count) WHERE {
?instance a <http://dbpedia.org/ontology/Ambassador>;
<http://dbpedia.org/property/name> ?name
}
It's giving me a result of 283, which might or might not be right :).
Author by
ip.
Updated on June 04, 2022Comments
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ip. about 2 years
Ok so i have this query
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT DISTINCT (COUNT(?instance) AS ?count) WHERE { ?instance a <http://dbpedia.org/ontology/Ambassador> . }
and the result is 286. Cool. Now I want to get the number of ambassadors that have http://dbpedia.org/property/name property. But
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT DISTINCT (COUNT(?instance) AS ?count) WHERE { ?instance a <http://dbpedia.org/ontology/Ambassador> . ?instance <http://dbpedia.org/property/name> ?name }
results in 533 :(. So it is counting more because there are people which have this property one or more times. But how do I get the number of ambassadors that have this property regardless of how many times they have it. Can you do this in a single query?
Thanks.
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Kalidasan about 13 yearsNote this is using SPARQL 1.1 features: COUNT() - aggregation - and variables in SELECT.