or better LET ( ?var := ... ) right? ;-)
^^
This is great, so I can use
SELECT DISTINCT(?dt) WHERE {
?s ?p ?o .
LET (?dt := datatype(?o))
}
to get a simple list of all datatypes used for typed literals, at
least when using ARQ Syntax.
good hint, thanks
AndyL
On Sep 10, 2008, at 11:41 PM, Seaborne, Andy wrote:
In SPARQL, the only way a variable can get a value is from a basic
graph pattern match – everything builds up from there – and only RDF
terms in the graph can be bound so only RDF terms that occur in the
graph can be returned and then used in the CONSTRUCT.
In ARQ, in the extended syntax, there is assignment:
{
…
?s ont:firstName ?firstName .
?s ont:lastName ?lastName .
LET ( ?name = fn:concat(?firstName, “ “, ?lastName) )
}
Where fn:concat [1][2] is the XQuery/XPath Function to concatenate
strings.
There are other ways to achieve assignment; subqueries with SELECT
expressions; property functions, that give an enhanced view of the
data within strict SPARQL syntax.
A property function is custom code, made to fit into the SPARQl
syntax, that called at query execution time
PREFIX apf: <http://jena.hpl.hp.com/ARQ/property#>
prefix ont: <http://www.owl-ontologies.com/Ontology1200929459.owl
>
SELECT *
{
?s ont:firstName ?firstName .
?s ont:lastName ?lastName .
?name apf:concat (?firstName “ “ ? lastName)
}
Will bind ?name to the result of concatenting str(?firstName) the
space and str(?lastName)
Andy
[1] http://www.w3.org/TR/xpath-functions/
[2] Only in SVN : in checking this reply, I found it was wrongly
named and fixed that.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
] On Behalf Of Ricardo Almeida
Sent: 09 September 2008 15:15
To: [email protected]
Subject: SPARQL query - Construct
I,
I’m using sparql with Jena, to make some queries. I have two
ontologies (src1 and tgt), and two rdf files were I have my
instances, according to this ontologies.
<image002.png>src1:
<image010.png> person: Set of
<image011.png> personId
<image012.png><image013.png> name
addressId
addressSrc: Set of
<image014.png>
adressIdSrc
<image015.png>street
<image016.png> pobox
tgt:
employee: Set of
employee:
employeeId
firstName
lastName
addressId
addressTgt: Set of
adressIdTgt
address
I would like to use construct to obtain data from one ontology,
according to the other. Is it possible to make a concatenation (or a
split), with construct?
I made the query described above and I obtain all the first names,
but what I really wanted was to obtain the concatenation of
firstName and lastName, of tgt as the name of src1.
private String QConstructSrcFromTgt =
"CONSTRUCT { ?s rdf:type <http://www.owl-ontologies.com/Ontology1200929461.owl#Person
> .." +
" ?s <http://www.owl-ontologies.com/Ontology1200929461.owl#name
> ?firstName" +
"} FROM <http://www.owl-ontologies.com/
Ontology1200929459.owl> WHERE {?s rdf:type ?o ." +
" ?s <http://www.owl-ontologies.com/Ontology1200929459.owl#firstName
> ?firstName} ";
//" ?s <http://www.owl-ontologies.com/Ontology1200929459.owl#lasttName
> ?lastName. "+
//" FILTER regex(?lastName, \"Castro\") } ";
Thanks,
Ricardo Gabriel Soares Fernandes de Almeida.
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