What is SPARQL

•  http://www.w3.org/TR/rdf-sparql-query/
•  http://en.wikipedia.org/wiki/SPARQL

An endpoint to play with

•  http://delicious.com/fbelleau/bio2rdf:sparql
•  http://dbpedia.org/sparql
•  http://www.semantic-systems-biology.org/biogateway/querying
•  http://atlas.bio2rdf.org/sparql

Facet browser

•  http://atlas.bio2rdf.org/fct
•  http://dbpedia.org/fct

select ?s2 as ?c1 count (*) as ?c2
where {
?s1 ?s1textp ?o1 .
?o1 bif:contains '"hexokinase"' .
?s1 a <http://purl.uniprot.org/core/Sequence> .
?s1 a <http://purl.uniprot.org/core/Citation_Statement> .
?s1 <http://purl.uniprot.org/core/memberOf> ?s2 .
} group by ?s2 order by desc 2 limit 20 offset 0

In a triple store, I have the label of the predicate.

Sample queries

select *
where {?s ?p ?o}
limit 100

select ?o count(*)
where {?s a ?o}

select ?t ?p count(*)
 where {
?s ?p ?o .
?s rdf:type ?t .
?o bif:contains "hexokinase" .
}

• bif:contains (full-text search) is not standard.
• count(*) is not standard.

select ?s ?p ?o
 where {
?s ?p ?o .
?o bif:contains "hexokinase" .
}

select ?s ?p ?o
 where {
?s ?p ?o .
?o bif:contains "hexokinase" .
?s1 ?p1 ?s .
}

?s1 ?p1 ?2 is reversing the query.