On 26/04/12 18:15, E S wrote:
Hello,
If I am querying for a literal of type xsd:string, it appears that in Fuseki I
need to always use ^^xsd:string when querying for that literal.
For example, if I have a triple
<urn:foo:foo> rdfs:label "foo"^^xsd:string
I need to query it using
select * where {
?s ?p "foo"^^xsd:string .
}
and querying without xsd:string won't work:
select * where {
?s ?p "foo" .
}
in other words, "foo" and "foo"^^xsd:string are not equal.
Correct (currently!).
However, I can't find any specific documentation asserting that this is true. (I have found that in
the book "Learning SPARQL" by Bob DuCharme, page 133. it says that "a quoted value
is a string whether you specifically designate it xsd:string or not"). Can someone clarify
what the correct behavior is, and reference the SPARQL 1.1 spec where this is discussed? Has this
behavior ever changed in SPARQL 1 or 1.1?
This is defined in RDF, not SPARQL.
And in SPARQL
sameTerm("foo", "foo"^^xsd:string) => false
"foo" = "foo"^^xsd:string => true
i.e. string value comparison by value works.
RDF 1.1 plans to change plain literals to have a datatype of xsd:string
and so "foo" and "foo"^^xsd:string will be the same term and term-equals.
On an unrelated note, it appears that SPARQL's ORDER BY provides the order of
the character encoding (ie, case sensitive order, where 'AT' comes before
'add'), not the true alphabetical (case-insensitive) order. Is this by design?
I would think that a common use case would be to provide correct the
alphabetical ordering. Is there a way to get the alphabetical ordering?
ORDER BY lcase(?foo)
Thank you!
