- From: Dau, Frithjof <frithjof.dau@sap.com>
- Date: Mon, 15 Jun 2009 09:52:38 +0200
- To: "Samuel Pedro" <samuelcpspam@gmail.com>, <public-sparql-dev@w3.org>
Hi,
> So i can only do queries using properties like owl:sameAS,
:differentFrom, :subClass, transitive..... to object like rdfs:label,
and... ?x ????
Besides the fact that "rdfs:label" is a property: essentially yes. The
main point is stated by Lee (SPARQL expert in contrast to me):
> you have to write your query against the raw RDF triples that encode
your OWL model.
Again I recommend that you have a look at your OWL-file in an RDF
vizualizer: There you see how OWL is encoded by raw RDF triples.
Cheers
Frithjof
P.s. sorry for late answer: weekend ...
________________________________
Von: public-sparql-dev-request@w3.org
[mailto:public-sparql-dev-request@w3.org] Im Auftrag von Samuel Pedro
Gesendet: Freitag, 12. Juni 2009 20:31
An: public-sparql-dev@w3.org
Betreff: Fwd: Sparql query help
So i can only do queries using properties like owl:sameAS,
:differentFrom, :subClass, transitive..... to object like rdfs:label,
and... ?x ????
I have this class in the ontology,that have the property someValues can
i do a query that ask wich are the ingredients that "ChickenWithOnions"
have?
<owl:Class rdf:ID="ChickenWithOnions">
<rdfs:label rdf:datatype="http://www.w3.org/2001/XMLSchema#string"
>Chicken With Onions</rdfs:label> (add the label)
<rdfs:subClassOf rdf:resource="#Plates"/>
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty rdf:resource="#hasIngridients"/>
<owl:someValuesFrom>
<owl:Class>
<owl:intersectionOf rdf:parseType="Collection">
<owl:Class rdf:about="#Chicken"/>
<owl:Class rdf:about="#Onion"/>
</owl:intersectionOf>
</owl:Class>
</owl:someValuesFrom>
</owl:Restriction>
</rdfs:subClassOf>
</owl:Class>
the query should be this... (wrong tried and nothing, i'm doing again
the same mistake right?)
SELECT ?plate ?ingredient
WHERE {
?plate owl:hasIngridients ?ingredient.
?plate rdfs:label "Chicken With Onions" .
}
so the only property that i can use is the ones that says "rdfs:...."
???
2009/6/12 Dau, Frithjof <frithjof.dau@sap.com>
Hi Samuel,
with SPARQL you can essentially query subgraphs of a given
graph. In your "OWL-graph", you have a node "...#Meat". With SPARQL, you
can query other nodes and the properties which relate these nodes to you
"...#Meat"-node. Anyhow, the only property which relates your
"...#Meat"-node to ther nodes is the "rdfs:subClassOf"-property,
relating your "...#Meat"-node to its super- and subclasses (depending on
whether your "...#Meat"-node is the subject or object of a (x
rdfs:subClassOf y) triple).
I guess what you have in mind is something like: The class is
called "Meat", so let's query for that name. Nope, does not work. The
name of the class is a part of the node-URI, and you cannot query parts
of these -let's say- URI-string. So, if you want to query classes by its
names, you *must* make the name in the ontology explicit by using a
property. The most common approach is the "rdfs:label"-attribute. Iy you
use it -and you do it for your "...#Pig"-class, you explicitely relate
the name "Pig" (a literal) to the class by the rdfs:label-property. Now
you have the situation that the class is linked to its name by use of
nodes and properties, and thus you can query it.
I sugges you have a look at your ontology with an RDF-visualizer
(like IsaViz), keep in mind that you can only query for graph patterns,
and then you will hopefully understand why your initial query does not
work.
Cheers
Frithjof
________________________________
Von: public-sparql-dev-request@w3.org
[mailto:public-sparql-dev-request@w3.org] Im Auftrag von Samuel Pedro
Gesendet: Freitag, 12. Juni 2009 17:35
An: Stephane Corlosquet; Lee Feigenbaum;
public-sparql-dev@w3.org
Betreff: Re: Sparql query help
Ok, tried to send as a attachment but probably something went
wrong, i will post here:
<?xml version="1.0"?>
<rdf:RDF
xmlns:xsp="http://www.owl-ontologies.com/2005/08/07/xsp.owl#"
xmlns="http://www.owl-ontologies.com/testFood2.owl#"
xmlns:swrlb="http://www.w3.org/2003/11/swrlb#"
xmlns:swrl="http://www.w3.org/2003/11/swrl#"
xmlns:protege="http://protege.stanford.edu/plugins/owl/protege#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:owl="http://www.w3.org/2002/07/owl#"
xml:base="http://www.owl-ontologies.com/testFood2.owl">
<owl:Ontology rdf:about=""/>
<owl:Class rdf:ID="Cow">
<rdfs:subClassOf>
<owl:Class rdf:ID="RedMeat"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:ID="Chicken">
<rdfs:subClassOf>
<owl:Class rdf:ID="WhiteMeat"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:ID="Pig2">
<owl:equivalentClass>
<owl:Class rdf:ID="Pig"/>
</owl:equivalentClass>
<rdfs:subClassOf>
<owl:Class rdf:about="#RedMeat"/>
</rdfs:subClassOf>
<rdfs:label
rdf:datatype="http://www.w3.org/2001/XMLSchema#string"
>Pig2</rdfs:label>
</owl:Class>
<owl:Class rdf:ID="Onion">
<rdfs:subClassOf>
<owl:Class rdf:ID="Vegetable"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:ID="Ingredients"/>
<owl:Class rdf:about="#Pig">
<rdfs:label
rdf:datatype="http://www.w3.org/2001/XMLSchema#string"
>Pig</rdfs:label>
<rdfs:subClassOf>
<owl:Class rdf:about="#RedMeat"/>
</rdfs:subClassOf>
<owl:equivalentClass rdf:resource="#Pig2"/>
</owl:Class>
<owl:Class rdf:ID="ChickenWithTomato">
<rdfs:subClassOf>
<owl:Class rdf:ID="Plates"/>
</rdfs:subClassOf>
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty>
<owl:ObjectProperty rdf:ID="hasIngridients"/>
</owl:onProperty>
<owl:someValuesFrom>
<owl:Class>
<owl:intersectionOf rdf:parseType="Collection">
<owl:Class rdf:about="#Chicken"/>
<owl:Class rdf:ID="Tomato"/>
</owl:intersectionOf>
</owl:Class>
</owl:someValuesFrom>
</owl:Restriction>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:ID="ChickenWithOnions">
<rdfs:subClassOf rdf:resource="#Plates"/>
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty rdf:resource="#hasIngridients"/>
<owl:someValuesFrom>
<owl:Class>
<owl:intersectionOf rdf:parseType="Collection">
<owl:Class rdf:about="#Chicken"/>
<owl:Class rdf:about="#Onion"/>
</owl:intersectionOf>
</owl:Class>
</owl:someValuesFrom>
</owl:Restriction>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:about="#WhiteMeat">
<rdfs:subClassOf>
<owl:Class rdf:ID="Meat"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:about="#Tomato">
<rdfs:subClassOf>
<owl:Class rdf:about="#Vegetable"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:about="#RedMeat">
<rdfs:subClassOf>
<owl:Class rdf:about="#Meat"/>
</rdfs:subClassOf>
</owl:Class>
<owl:Class rdf:about="#Vegetable">
<rdfs:subClassOf rdf:resource="#Ingredients"/>
</owl:Class>
<owl:Class rdf:about="#Meat">
<rdfs:subClassOf rdf:resource="#Ingredients"/>
</owl:Class>
<owl:ObjectProperty rdf:ID="hasChicken">
<rdfs:subPropertyOf>
<owl:ObjectProperty rdf:ID="hasWhiteMeat"/>
</rdfs:subPropertyOf>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="hasMeat">
<rdfs:subPropertyOf rdf:resource="#hasIngridients"/>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="hasVegetable">
<rdfs:subPropertyOf rdf:resource="#hasIngridients"/>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="hasIngridients_26">
<rdfs:subPropertyOf rdf:resource="#hasIngridients"/>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="hasOnion">
<rdfs:subPropertyOf rdf:resource="#hasVegetable"/>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:about="#hasWhiteMeat">
<rdfs:subPropertyOf rdf:resource="#hasMeat"/>
</owl:ObjectProperty>
</rdf:RDF>
But think that i understand why it cant work that way.
"but I think it's pretty likely that your classes are resources
(URIs)" how i know that?
2009/6/12 Stephane Corlosquet <scorlosquet@gmail.com>
Hi Samuel,
You cannot use ?meatClass owl:Class "Pig" in your WHERE
clause because it is not a valid pattern. You should follow the {subject
property object} pattern in your WHERE clause. owl:Class is a class and
not a property.
Stephane.
On Fri, Jun 12, 2009 at 3:52 PM, Samuel Pedro
<samuelcpspam@gmail.com> wrote:
This is my owl file, i had to add labels to the
classes, and do this:
SELECT ?equivalentClass ?meatClass
WHERE {
?equivalentClass owl:equivalentClass ?meatClass
.
?meatClass rdfs:label "Pig" . (in owl file i
have Pig and Pig2)
}
and why this query doesnt work, why it only
works for labels? (I'm trying to understand sparql but...)
SELECT ?equivalentClass ?meatClass
WHERE {
?equivalentClass owl:equivalentClass ?meatClass
.
?meatClass owl:Class "Pig" .
}
2009/6/12 Lee Feigenbaum <lee@thefigtrees.net>
Samuel Pedro wrote:
Im trying to do this query...
SELECT ?subject ?object
WHERE { ?subject
owl:equivalenteClass ?object FILTER( ?object = "Meat") }
im trying to find the
equivalente Class of meat, but it doesn't return what i want, what am i
doing wrong?
if i do this...
SELECT ?subject ?object
WHERE { ?subject
owl:equivalenteClass ?object FILTER( ?object != "Meat") }
i get all the equivalent class
that there is in the owl. why?
Without seeing your data, it's hard to
say for sure, but I think it's pretty likely that your classes are
resources (URIs) and "Meat" is just a label for the class. If this is
right, you probably want a query similar to:
SELECT ?equivalentClass ?meatClass
WHERE {
?equivalentClass owl:equivalentClass
?meatClass .
?meatClass rdfs:label "Meat" .
}
The details will vary depending on what
predicate is used to give a label to your classes (in my example I
assume that it's rdfs:label). Also, note that the label needs to be
exactly "Meat" for this to work.
hope this helps,
Lee
--
--
Samuel Pedro
--
--
Samuel Pedro
--
--
Samuel Pedro
Received on Monday, 15 June 2009 07:53:19 UTC