Kingsley Idehen wrote:
> Ed Summers wrote:
>> I was just playing around w/ some SPARQL using dbpedia's endpoint and
>> noticed that:
>>
>> SELECT *
>> WHERE {
>>   ?person rdf:type <http://dbpedia.org/ontology/Person> .
>>   ?person rdfs:label ?personName .
>>   ?person <http://dbpedia.org/ontology/birthplace> ?place .
>>   ?place rdfs:label ?placeName .
>>   FILTER (lang(?personName) = "en")
>>   FILTER (lang(?placeName) = "en")
>> }
>>
>> returns some hits but this returns 0:
>>
>> SELECT COUNT(*)
>> WHERE {
>>   ?person rdf:type <http://dbpedia.org/ontology/Person> .
>>   ?person rdfs:label ?personName .
>>   ?person <http://dbpedia.org/ontology/birthplace> ?place .
>>   ?place rdfs:label ?placeName .
>>   FILTER (lang(?personName) = "en")
>>   FILTER (lang(?placeName) = "en")
>> }
>>
>> Is there something wrong here either in my query or my expectation
>> that the count query return > 0 ?
>>
>> //Ed
>>
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>>
>>   
> Ed,
> 
> It's your query, you need optionals in there. Here is a quick mod that 
> focuses on the typical culprits (rdfs:label values):
> 
> SELECT COUNT(*)
> WHERE {
>   ?person rdf:type <http://dbpedia.org/ontology/Person> .
>   optional {?person rdfs:label ?personName} .
>   ?person <http://dbpedia.org/ontology/birthplace> ?place .
>   optional {?place rdfs:label ?placeName} .
>   FILTER (lang(?personName) = "en")
>   FILTER (lang(?placeName) = "en")
> }

Kingsley, can you explain this further? If Ed's original query (no 
optionals) returns results, why would the same query with COUNT(*) 
return zero?

Lee



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