How to Read Specific Range value of an Object Property - sparql

Question

i'm new dealing with Ontologies and finding problems to get my SPARQL Query working , trying to read value of specific Object property that has multiple Ranges Object Property Screenshot
trying this Query Return all Object Properties Execution Result , Protege Visualization
PREFIX ns: <http://www.semanticweb.org/pavilion/ontologies/2017/5/untitled-ontology-66#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT *
WHERE {
ns:star1086 ns:possesses ?z .
}
The Desired Result that i want to read only the desired Range value, Thanks in advance.

Answer 1

I think there is something wrong about your ontology.
Specifying muliple ranges to your predicate creates an intersection. Take the following statement:
?star ns:possesses ?something
Then ?something is a SpectralType and a StarTemperature and a StarCoordinates and a StarName at the same time, which is not what you want.
Instead, you should use unions. Using unions, you can state that the object of a ns:possesses statement can be either a SpectralType or a StarTemperature or a StarCoordinates or a StarName. Then, in your SPARQL query you can write the following to get only statements from a single type.
SELECT * WHERE {
ns:star1086 ns:possesses ?z .
?z a ns:SpectralType .
}
In Protégé, to write a union, open the class expression editor (by clicking on the "plus" next to "Ranges" for instance) and separate the different members with or :
SpectralType or StarTemperature or StarCoordinates or StarName
And click "OK" to create the new range.
Further considerations
Let's take a step a back and look at your ontology.
You should not use a single predicate to store all these information in the first place. Instead, I suggest you use different sub-predicates so that your graphs and queries hold more semantic value.
Furthermore, StarName and Temperature are literal values. You should not use classes for that. Use datatype properties instead.
Here is a Gist you can download and open in Protégé. It contains some sample data so you can try the following SPARQL queries.
PREFIX : <http://www.richarddegenne.com/ontology/astronomy#>
# Get all statements about :star1086
SELECT * WHERE {
:star1086 ?predicate ?object
}
# Get some statement about :star1086
SELECT * WHERE {
VALUES ?predicate {
:hasSpectralType :temperate
}
:star1086 ?predicate ?object
}
# Ask whether a given pattern is true
ASK WHERE {
:star1086 :hasSpectralType :yellowDwarf
}
# Filter stars based on their temperature
# Note: You might want to add more stars with different temperature
# if you want useful results.
SELECT ?star WHERE {
?star :temperature ?temperature
FILTER(?temperature > 5000)
}