Hi,

currently I try to execute CONSTRUCT and SELECT queries via the rdfstore-js library. However, if I execute the queries, the result array is empty, although there should be values.

First I load a graph into the store.
In the second step, I add some triples to the loaded graph in the following way:
`store.graph((err, g) => {
for (let feat in featVector) {
let subject = store.rdf.createNamedNode(store.rdf.resolve("wiki:HearRate"))
let predicate = store.rdf.createNamedNode(store.rdf.resolve("property:HasValue"))
let literal = store.rdf.createLiteral("45", undefined, store.rdf.resolve("xsd:double"))
let statement = store.rdf.createTriple(subject, predicate, literal)
g.add(statement)
}

//Here I make SELECT Queries to the graph
for (let query in stateRules) {
store.execute(stateRules[query], (err, res) => {
if (err == null) {
res.forEach((triple) => {
states.push(triple.state.value)
})
}
})
}
})`

Regarding the literal expression:
let literal = store.rdf.createLiteral("45", undefined, store.rdf.resolve("xsd:double"))

I also tried these two alternatives, since I was not sure which one of them works:
let literal = store.rdf.createLiteral("45")
and let literal = store.rdf.createLiteral("45"^^xsd:double)

My select queries look like the following:

SELECT ?state
WHERE {
?state <http://localhost/Property-3AHasExpression> "HeartRate < 50".
?state <http://localhost/Property-3AHasObservationFeature> <http://localhost/HeartRate>.
<http://localhost/HeartRate> <http://localhost//Property-3AHasValue> ?heartrate.
FILTER(?heartrate < 50)
}

If I put away the FILTER expression and the HasValue statement, then it works. Therefore, I think something goes wrong as I add new triple statements to the graph with the appropriate values. My questions is now, how to make it right?
For instance, I could not find an example that shows how to add double value literals to the graph. Second, what do I have to change in the FILTER expression so that it works? Any hints and solutions regarding this issue are appreciated.

Best,
Nicole