On 04/06/17 18:47, Aya Hamdy wrote:
Hello,
I wanted to add a property called avgSpeed to an instance of a class called
FlowSensor. This property should be the average of the values of the
property vehicleSpeed attached to instances of the class Vehicle.
I read that SPARQL update allows doing this. However, I cannot reach the
syntax for doing the* averaging of values* or for building the *SPARQL
Update *query using jena with eclipse on the jena website.
If Jena indeed supports doing what I intend to do then can someone point
out some sources to guide me in my attempt?
Best Regards,
Aya
Calculate the average in a nested select so somethign like (you'll have
to fix this up):
INSERT {
<instance> :avgSpeed ?avg
}
WHERE {
SELECT (AVG(?speed) AS ?avg) {
?v rdf:type :Vehicle ;
:vehicleSpeed ?speed
}
}
By the way - it is better to more concrete in your description - actual
data for example.
