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AW: Sparql query help

From: Dau, Frithjof <frithjof.dau@sap.com>
Date: Mon, 15 Jun 2009 09:52:38 +0200
Message-ID: <EDFFA9D51148B34FAA0B828A82AAE70C022B9747@dewdfe1g.wdf.sap.corp>
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 GMT

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