How do I make a SPARQL query to find the highest value for a property?

Question

Lets say I have a predicate like \'age\' where the values of all age triples are integer literals. What SPARQL query would return the subject with the highest age in the dat

Answer 1

You just need to do order by desc with the age predicate and then limit to just get the first one.

PREFIX ns:    
SELECT ?s ?age
WHERE { ?s ns:age ?age }
ORDER BY DESC(?age) LIMIT 1

See the semantics of order by in SPARQL here

With the next version of SPARQL , 1.1, that is already supported in some systems you can use function aggregates and do ..

SELECT (max(?age) as ?maxage)
WHERE { ?s ns:age ?age }

This is not supported in all triple stores currently.