dotnetrdf-support — User Help and Support

Re: [dotNetRDF-Support] dotnetrdf question (urgent)

[Rob V. <rv...@do...>]

Hi Talal

There is no programmatic option for this since it is a Virtuoso specific 
feature and not part of any SPARQL standard.

However you should be able to get around this by doing the following:

SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new 
Uri("http://demo.openlinksw.com/sparql?should-sponge=soft"));
endpoint.HttpMode = "POST";
String query = "SELECT * FROM <http://example.org/graph> { ?s ?p ?o }";
SparqlResultSet results = endpoint.QueryWithResultSet(query);
//Do what you want with the results 

Note the use of the should-sponge=soft querystring parameter and the 
alteration of the HTTP Mode for the endpoint to POST.  Obviously you should 
insert whatever query you need into the example above.

I tested this against the endpoint you stated and it returned a HTTP 500 
error but I did the same against my local Virtuoso instance and it did work 
so it may depend on both the query and the exact configuration of the 
endpoint.

Please let me know if you need more help

Best Regards,

Rob Vesse

----------------------------------------
From: "Talal Antakyali" <tal...@gm...>
Sent: 02 May 2011 11:47
To: rv...@do...
Subject: dotnetrdf question (urgent) 

Hello...
Please execuse me because my English is very weak.
I need your help
I use dotnetrdf library to query remote RDF data using SPARQL
I am using this endpoint for my queries: http://demo.openlinksw.com/sparql 
But there is a problem: this endpoint (when using its web GUI) requires you 
to choose "Retrieve remote RDF for all missing source graphs" or otherwise 
you won't get any data as a result of your query

I couldn't find any way in dotnetrdf library to specify this option 
programmatically
Please help me
 
Thank you very much

 

Re: [dotNetRDF-Support] Ontology API example

[Rob V. <rv...@do...>]

Hi Ian

As I suggested in the previous email this does appear to be an issue with 
how the VB compiler resolves method overloads.  It appears the only 
workaround currently is to add a CObj() call around INode instances or to 
use one of the formatter accepting overloads.  For the next release I will 
add an explicit unparameterized ToString() definition to the INode 
interface which will avoid the need for the CObj() call.

If you encounter any other classes/interfaces that have this problem in VB 
please let me know so I can do the same for those classes.

Regards,

Rob Vesse

----------------------------------------
From: "Rob Vesse" <rv...@vd...>
Sent: 10 April 2011 14:58
To: dot...@li...
Subject: Re: [dotNetRDF-Support] Ontology API example 

Hi Ian

Have confirmed your issue when the code is used with VB, seems to be 
something to do with the VB compiler not implicitly casting to Object.  
Adding a CObj() call around the t.Subject, t.Object references etc does 
allow you to work around this but it is rather kludgy.

I am investigating whether there is a nicer workaround for VB and will get 
back to you when I know more.

Regards,

Rob Vesse

----------------------------------------
From: "Rob Vesse" <rv...@vd...>
Sent: 10 April 2011 11:53
To: "dotNetRDF User Help and Support" 
<dot...@li...>
Subject: re: [dotNetRDF-Support] Ontology API example 

Hi Ian

Thanks for the feedback, I have updated the example to note that 
Ontology.rdf is an example filename and you should substitute your own 
filename there.

The NullReferenceException on the GetTriplesWithSubjectPredicate() call is 
due to the fact that someclass2 is populated using the GetUriNode() method 
which returns null if there is no such node in the Graph, either check 
someclass2 for null as I have done in the updated example or use 
CreateUriNode() instead.

With regards to the formatter parameter that should be optional, INode's 
have an overload of ToString() which takes the formatter parameter to allow 
you to control exactly how the Node is converted into a String.  But they 
should also have the default ToString() method which all .Net objects have. 
 Not sure if this is some VB compiler specific issue as I do all my coding 
in C# these days and the C# compiler doesn't insist on the formatter 
parameter, will look into this and get back to you.

In the meantime if the compiler insists on the formatter parameter I would 
use an NTriplesFormatter e.g.

Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter
formatter = new VDS.RDF.Writing.Formatting.NTriplesFormatter();

If you have any further questions/issues please let me know

Rob Vesse

----------------------------------------
From: "Ian R Fry" <ia...@fr...>
Sent: 10 April 2011 11:33
To: dot...@li...
Subject: SPAM-LOW:  [dotNetRDF-Support] Ontology API example 

In the second version (showing detail Graphs and Triples) I am getting some 
errors. 
Note I have used VB.Net for a web applicaiton 
  
a)   	Console.WriteLine("Super Class: " + t.Object.ToString());
  	The tostring requires a "formatter" parameter which I have never seen 
before  
  
b) foreach (Triple t in g.GetTriplesWithSubjectPredicate(someClass, 
subClassOf))
 
gives  
Object reference not set to an instance of an object.  


I have imported all the classes.


Here is the code
 

 Dim   g1 =  New   Graph() 
 

FileLoader.Load(g, Server.MapPath( "data/Ontology.rdf"  )) 
 

 Dim   someclass2, subclassof  As   INode 
 

someclass2 = g.GetUriNode( New   Uri( "http://example.org/someClass"  )) 
 

 Dim   t1, t2  As   Triple 
 

 Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter 


subclassof = g.CreateUriNode( New   Uri(NamespaceMapper.RDFS +  
"subClassOf"  )) 
 

 For    Each   t1  In   g.GetTriplesWithSubjectPredicate(someclass2, 
subclassof)  <---- error  
 

Response.Write( "<br>Super Class: "   + t1.Object.ToString(formatter)) 
<---- compiler complains if no formatter  
 

 For    Each   t2  In   g.GetTriplesWithPredicateObject(subclassof, 
someclass) 
 

Response.Write( "<br>Sub Class: "   + t2.Subject.ToString(formatter)) 
 

 Next  
 

 Next  


   


love the product though  


   


Ian Fry  


Fry Systems   

 

Re: [dotNetRDF-Support] Writing RDF

[Rob V. <rv...@do...>]

Ah, this appears to be an omission in the library.  While RDF/XML can encode
the Base URI our writers don't currently serialize it.  Will add this for
the next release.

Regards,

Rob Vesse

> -----Original Message-----
> From: Felipe Guimarães Santos [mailto:fel...@in...]
> Sent: 11 April 2011 13:18
> To: Rob Vesse
> Subject: RES: [dotNetRDF-Support] Writing RDF
> 
> I'am doing a serialization of a RDF/XML, and I'am losing the Base URI.
> 
> Felipe Guimarães Santos | desenvolvedor
> 
> 
> fel...@in...  |  www.invit.com.br | @sigainvit
> Office: +55 34 3223.4000 - 11 2372.1072 | Mobile: +55 34 9993.5060
> 
> 
> -----Mensagem original-----
> De: Rob Vesse [mailto:rv...@do...]
> Enviada em: segunda-feira, 11 de abril de 2011 05:52
> Para: 'dotNetRDF User Help and Support'
> Cc: Felipe Guimarães Santos
> Assunto: RE: [dotNetRDF-Support] Writing RDF
> 
> Hi Felipe
> 
> Not all RDF serializations support the encoding of a Base URI into the
> serialization.  If you use a format that does not support this then you
> will lose the Base URI information when you parse the generated
> serialization back into a Graph.
> 
> For your reference a quick summary of available standard serializations
> and their Base URI support:
> 
> Serializations that support Base URI encoding:
> -Turtle
> -N3
> -RDF/XML
> 
> Serialization that don't support Base URI encoding:
> -NTriples
> -RDF/JSON
> 
> As always let me know if you have further questions
> 
> Rob Vesse
> 
> > -----Original Message-----
> > From: Felipe Guimarães Santos [mailto:fel...@in...]
> > Sent: 10 April 2011 18:28
> > To: dot...@li...
> > Subject: [dotNetRDF-Support] Writing RDF
> >
> > When I write a RDF from Graph object to a string it losts the baseUri
> > of the Graph, why?
> > I mean, when I parse the string that was generated, the Graph object
> > doesn't has a baseUri.
> >
> >
> > Thanks
> >
> > ---------------------------------------------------------------------
> -
> > -
> > -------
> > Xperia(TM) PLAY
> > It's a major breakthrough. An authentic gaming smartphone on the
> > nation's most reliable network.
> > And it wants your games.
> > http://p.sf.net/sfu/verizon-sfdev
> > _______________________________________________
> > dotNetRDF-Support mailing list
> > dot...@li...
> > https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support
> 
> 
> 

Re: [dotNetRDF-Support] Writing RDF

[Rob V. <rv...@do...>]

Hi Felipe

Not all RDF serializations support the encoding of a Base URI into the
serialization.  If you use a format that does not support this then you will
lose the Base URI information when you parse the generated serialization
back into a Graph.
 
For your reference a quick summary of available standard serializations and
their Base URI support:

Serializations that support Base URI encoding:
-Turtle
-N3
-RDF/XML

Serialization that don't support Base URI encoding:
-NTriples
-RDF/JSON

As always let me know if you have further questions

Rob Vesse

> -----Original Message-----
> From: Felipe Guimarães Santos [mailto:fel...@in...]
> Sent: 10 April 2011 18:28
> To: dot...@li...
> Subject: [dotNetRDF-Support] Writing RDF
> 
> When I write a RDF from Graph object to a string it losts the baseUri
> of the Graph, why?
> I mean, when I parse the string that was generated, the Graph object
> doesn't has a baseUri.
> 
> 
> Thanks
> 
> -----------------------------------------------------------------------
> -------
> Xperia(TM) PLAY
> It's a major breakthrough. An authentic gaming
> smartphone on the nation's most reliable network.
> And it wants your games.
> http://p.sf.net/sfu/verizon-sfdev
> _______________________________________________
> dotNetRDF-Support mailing list
> dot...@li...
> https://lists.sourceforge.net/lists/listinfo/dotnetrdf-support

[dotNetRDF-Support] Writing RDF

[Felipe G. S. <fel...@in...>]

When I write a RDF from Graph object to a string it losts the baseUri of the Graph, why?
I mean, when I parse the string that was generated, the Graph object doesn't has a baseUri.


Thanks

Re: [dotNetRDF-Support] Ontology API example

[Rob V. <rv...@vd...>]

Hi Ian

Have confirmed your issue when the code is used with VB, seems to be 
something to do with the VB compiler not implicitly casting to Object.  
Adding a CObj() call around the t.Subject, t.Object references etc does 
allow you to work around this but it is rather kludgy.

I am investigating whether there is a nicer workaround for VB and will get 
back to you when I know more.

Regards,

Rob Vesse

----------------------------------------
From: "Rob Vesse" <rv...@vd...>
Sent: 10 April 2011 11:53
To: "dotNetRDF User Help and Support" 
<dot...@li...>
Subject: re: [dotNetRDF-Support] Ontology API example 

Hi Ian

Thanks for the feedback, I have updated the example to note that 
Ontology.rdf is an example filename and you should substitute your own 
filename there.

The NullReferenceException on the GetTriplesWithSubjectPredicate() call is 
due to the fact that someclass2 is populated using the GetUriNode() method 
which returns null if there is no such node in the Graph, either check 
someclass2 for null as I have done in the updated example or use 
CreateUriNode() instead.

With regards to the formatter parameter that should be optional, INode's 
have an overload of ToString() which takes the formatter parameter to allow 
you to control exactly how the Node is converted into a String.  But they 
should also have the default ToString() method which all .Net objects have. 
 Not sure if this is some VB compiler specific issue as I do all my coding 
in C# these days and the C# compiler doesn't insist on the formatter 
parameter, will look into this and get back to you.

In the meantime if the compiler insists on the formatter parameter I would 
use an NTriplesFormatter e.g.

Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter
formatter = new VDS.RDF.Writing.Formatting.NTriplesFormatter();

If you have any further questions/issues please let me know

Rob Vesse

----------------------------------------
From: "Ian R Fry" <ia...@fr...>
Sent: 10 April 2011 11:33
To: dot...@li...
Subject: SPAM-LOW:  [dotNetRDF-Support] Ontology API example 

In the second version (showing detail Graphs and Triples) I am getting some 
errors. 
Note I have used VB.Net for a web applicaiton 
  
a)   	Console.WriteLine("Super Class: " + t.Object.ToString());
  	The tostring requires a "formatter" parameter which I have never seen 
before  
  
b) foreach (Triple t in g.GetTriplesWithSubjectPredicate(someClass, 
subClassOf))
 
gives  
Object reference not set to an instance of an object.  


I have imported all the classes.


Here is the code
 

 Dim   g1 =  New   Graph() 
 

FileLoader.Load(g, Server.MapPath( "data/Ontology.rdf"  )) 
 

 Dim   someclass2, subclassof  As   INode 
 

someclass2 = g.GetUriNode( New   Uri( "http://example.org/someClass"  )) 
 

 Dim   t1, t2  As   Triple 
 

 Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter 


subclassof = g.CreateUriNode( New   Uri(NamespaceMapper.RDFS +  
"subClassOf"  )) 
 

 For    Each   t1  In   g.GetTriplesWithSubjectPredicate(someclass2, 
subclassof)  <---- error  
 

Response.Write( "<br>Super Class: "   + t1.Object.ToString(formatter)) 
<---- compiler complains if no formatter  
 

 For    Each   t2  In   g.GetTriplesWithPredicateObject(subclassof, 
someclass) 
 

Response.Write( "<br>Sub Class: "   + t2.Subject.ToString(formatter)) 
 

 Next  
 

 Next  


   


love the product though  


   


Ian Fry  


Fry Systems   

Re: [dotNetRDF-Support] Ontology API example

[Rob V. <rv...@vd...>]

Hi Ian

Thanks for the feedback, I have updated the example to note that 
Ontology.rdf is an example filename and you should substitute your own 
filename there.

The NullReferenceException on the GetTriplesWithSubjectPredicate() call is 
due to the fact that someclass2 is populated using the GetUriNode() method 
which returns null if there is no such node in the Graph, either check 
someclass2 for null as I have done in the updated example or use 
CreateUriNode() instead.

With regards to the formatter parameter that should be optional, INode's 
have an overload of ToString() which takes the formatter parameter to allow 
you to control exactly how the Node is converted into a String.  But they 
should also have the default ToString() method which all .Net objects have. 
 Not sure if this is some VB compiler specific issue as I do all my coding 
in C# these days and the C# compiler doesn't insist on the formatter 
parameter, will look into this and get back to you.

In the meantime if the compiler insists on the formatter parameter I would 
use an NTriplesFormatter e.g.

Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter
formatter = new VDS.RDF.Writing.Formatting.NTriplesFormatter();

If you have any further questions/issues please let me know

Rob Vesse

----------------------------------------
From: "Ian R Fry" <ia...@fr...>
Sent: 10 April 2011 11:33
To: dot...@li...
Subject: SPAM-LOW:  [dotNetRDF-Support] Ontology API example 

In the second version (showing detail Graphs and Triples) I am getting some 
errors. 
Note I have used VB.Net for a web applicaiton 
  
a)   	Console.WriteLine("Super Class: " + t.Object.ToString());
  	The tostring requires a "formatter" parameter which I have never seen 
before  
  
b) foreach (Triple t in g.GetTriplesWithSubjectPredicate(someClass, 
subClassOf))
 
gives  
Object reference not set to an instance of an object.  


I have imported all the classes.


Here is the code
 

 Dim   g1 =  New   Graph() 
 

FileLoader.Load(g, Server.MapPath( "data/Ontology.rdf"  )) 
 

 Dim   someclass2, subclassof  As   INode 
 

someclass2 = g.GetUriNode( New   Uri( "http://example.org/someClass"  )) 
 

 Dim   t1, t2  As   Triple 
 

 Dim   formatter  As   VDS.RDF.Writing.Formatting.INodeFormatter 


subclassof = g.CreateUriNode( New   Uri(NamespaceMapper.RDFS +  
"subClassOf"  )) 
 

 For    Each   t1  In   g.GetTriplesWithSubjectPredicate(someclass2, 
subclassof)  <---- error  
 

Response.Write( "<br>Super Class: "   + t1.Object.ToString(formatter)) 
<---- compiler complains if no formatter  
 

 For    Each   t2  In   g.GetTriplesWithPredicateObject(subclassof, 
someclass) 
 

Response.Write( "<br>Sub Class: "   + t2.Subject.ToString(formatter)) 
 

 Next  
 

 Next  


   


love the product though  


   


Ian Fry  


Fry Systems   
 

[dotNetRDF-Support] Ontology API example

[Ian R F. <ia...@fr...>]

In the second version (showing detail Graphs and Triples) I am getting some errors.
Note I have used VB.Net for a web applicaiton
 
a)    Console.WriteLine("Super Class: " + t.Object.ToString());
   The tostring requires a "formatter" parameter which I have never seen before
 
b) foreach (Triple t in g.GetTriplesWithSubjectPredicate(someClass, subClassOf))

gives 

Object reference not set to an instance of an object. 


I have imported all the classes.

Here is the code

Dim g1 = New Graph()

FileLoader.Load(g, Server.MapPath("data/Ontology.rdf"))

Dim someclass2, subclassof As INode

someclass2 = g.GetUriNode(New Uri("http://example.org/someClass"))

Dim t1, t2 As Triple

Dim formatter As VDS.RDF.Writing.Formatting.INodeFormatter

subclassof = g.CreateUriNode(New Uri(NamespaceMapper.RDFS + "subClassOf"))

For Each t1 In g.GetTriplesWithSubjectPredicate(someclass2, subclassof)  <---- error

Response.Write("<br>Super Class: " + t1.Object.ToString(formatter)) <---- compiler complains if no formatter

For Each t2 In g.GetTriplesWithPredicateObject(subclassof, someclass)

Response.Write("<br>Sub Class: " + t2.Subject.ToString(formatter))

Next

Next

 

love the product though

 

Ian Fry

Fry Systems

[dotNetRDF-Support] Ontology API example

[Ian R F. <ia...@fr...>]

This refers to a pre-existing rdf file called Ontology.rdf
Can't seem to find it anywhere....
 
Ian Fry
Fry Systems Pty lTD

[dotNetRDF-Support] Pending Merge of 0.4.1 Branch to Trunk

[Rob V. <rv...@do...>]

Hi all

It is planned that the 0.4.1 branch - which contains some important 
improvements but also some minor breaking changes - will be merged into the 
Trunk at the end of the week.

Anyone who is currently using 0.4.0 from SVN (i.e. the stable 0.4.0 release 
with some minor bug fixes) should ensure they have obtained a copy of the 
Trunk prior to this time.  On Friday the 0.4.1 branch will be merged and we 
will begin integration and regression testing on the core library with a 
view to preparing for the 0.4.1 release at the end of April.

As always if you have any questions please let me know,

Regards,

Rob Vesse

 

Re: [dotNetRDF-Support] [Dotnetrdf-support] RES: SPARQL query

[Rob V. <rv...@do...>]

Hi Felipe

Tested your queries with the latest version (0.4.0) and all the queries returned 56 results as expected.  The incorrect results you are seeing are due to bugs in the older versions of the library that were fixed in the 0.4.0 release.

Upgrading to the 0.4.0 release should solve your problem which is available from either of the following sources:
- http://www.dotnetrdf.org/content.asp?pageID=Download%20dotNetRDF
- http://sourceforge.net/projects/dotnetrdf/files/Library/0.4.0%20Beta/dotnetrdf_library_040_beta.zip/download

Regards,

Rob Vesse

----------------------------------------
From: "Felipe Guimarães Santos" <fel...@in...>
Sent: 29 March 2011 16:54
To: "rv...@vd..." <rv...@vd...>, "dotNetRDF User Help and Support" <dot...@li...>
Subject: [Dotnetrdf-support] RES:  SPARQL query 

I am using 0.3.9 versionThe ontolgy is attached. Thanks Felipe Guimarães Santos | desenvolvedor

fel...@in...  |  www.invit.com.br | @sigainvit
Office: +55 34 3223.4000 - 11 2372.1072 | Mobile: +55 34 9993.5060   De: Rob Vesse [mailto:rv...@vd...] 
Enviada em: terça-feira, 29 de março de 2011 12:39
Para: dotNetRDF User Help and Support
Assunto: Re: [Dotnetrdf-support] SPARQL query Hi Felipe

They look like they should be equivalent.  This may be a bug in the engine but I can't tell without testing the queries myself for which I need the data to test against, do you have a copy/link to the food ontology as the URI in your queries does not work?

Also what version of dotNetRDF are you using?  There were some bug fixes to joins in the 0.4.0 release so if you are using an earlier version this may be due to bugs in previous releases.  In particular the 3rd of your queries may be affected by that bug and a bug in the optimiser from the older releases.

It looks like all the queries optimise reasonably using the 0.4.0 release so I just need the data to test them against to see whether it is a bug in the joins.

Regards,

Rob Vesse
----------------------------------------
From: "Felipe Guimarães Santos" <fel...@in...>
Sent: 29 March 2011 16:17
To: "dot...@li..." <dot...@li...>
Subject: [Dotnetrdf-support] SPARQL queryHi, I don't know if I missunderstood SPARQL or this is a bug.See the queries below.To me all of this queries should have the same results, but they don't have.Why? prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {{?food fd:matchWithBody ?body1.        ?food fd:matchWithFlavor ?flavor1.        ?food  fd:matchWithSugar ?sugar1.}       {?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}               FILTER(?flavor1 = ?flavor)       FILTER(?sugar1 = ?sugar)       FILTER(?body1 = ?body)       }56 results prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {{?food fd:matchWithBody ?body.        ?food fd:matchWithFlavor ?flavor.        ?food  fd:matchWithSugar ?sugar.}       {?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}}245 results prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3..org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {?food fd:matchWithBody ?body.        ?food fd:matchWithFlavor ?flavor.        ?food  fd:matchWithSugar ?sugar.       ?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}67733 results  Thanks. Felipe Guimarães Santos | desenvolvedor

fel...@in...  |  www.invit.com.br | @sigainvit
Office: +55 34 3223.4000 - 11 2372.1072 | Mobile: +55 34 9993.5060   Confidencialidade: A informação contida nesta mensagem de e-mail, incluindo quaisquer anexos, é confidencial e está reservada apenas à pessoa ou entidade para a qual foi endereçada. Se você não é o destinatário ou a pessoa responsável por encaminhar esta mensagem ao destinatário, você está, por meio desta, notificado que não deverá rever, retransmitir, imprimir, copiar, usar ou distribuir esta mensagem de e-mail ou quaisquer anexos. Caso você tenha recebido esta mensagem por engano, por favor, contate o remetente imediatamente e apague esta mensagem de seu computador ou de qualquer outro banco de dados. Muito obrigado. 
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Re: [Dotnetrdf-support] SPARQL query

[Rob V. <rv...@vd...>]

Hi Felipe

They look like they should be equivalent.  This may be a bug in the engine but I can't tell without testing the queries myself for which I need the data to test against, do you have a copy/link to the food ontology as the URI in your queries does not work?

Also what version of dotNetRDF are you using?  There were some bug fixes to joins in the 0.4.0 release so if you are using an earlier version this may be due to bugs in previous releases.  In particular the 3rd of your queries may be affected by that bug and a bug in the optimiser from the older releases.

It looks like all the queries optimise reasonably using the 0.4.0 release so I just need the data to test them against to see whether it is a bug in the joins.

Regards,

Rob Vesse

----------------------------------------
From: "Felipe Guimarães Santos" <fel...@in...>
Sent: 29 March 2011 16:17
To: "dot...@li..." <dot...@li...>
Subject: [Dotnetrdf-support] SPARQL query 

Hi, I don't know if I missunderstood SPARQL or this is a bug.See the queries below.To me all of this queries should have the same results, but they don't have.Why? prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {{?food fd:matchWithBody ?body1.        ?food fd:matchWithFlavor ?flavor1.        ?food  fd:matchWithSugar ?sugar1.}       {?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}               FILTER(?flavor1 = ?flavor)       FILTER(?sugar1 = ?sugar)       FILTER(?body1 = ?body)       }56 results prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {{?food fd:matchWithBody ?body.        ?food fd:matchWithFlavor ?flavor.        ?food  fd:matchWithSugar ?sugar.}       {?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}}245 results prefix fd: <http://www.agent.com/ontologies/food.owl#>prefix wine: <http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#>select ?wine ?food ?body ?flavor ?sugarwhere {?food fd:matchWithBody ?body.        ?food fd:matchWithFlavor ?flavor.        ?food  fd:matchWithSugar ?sugar.       ?wine wine:hasBody ?body.        ?wine wine:hasFlavor ?flavor.        ?wine wine:hasSugar ?sugar.}67733 results  Thanks. Felipe Guimarães Santos | desenvolvedor

fel...@in...  |  www.invit.com.br | @sigainvit
Office: +55 34 3223.4000 - 11 2372.1072 | Mobile: +55 34 9993.5060   Confidencialidade: A informação contida nesta mensagem de e-mail, incluindo quaisquer anexos, é confidencial e está reservada apenas à pessoa ou entidade para a qual foi endereçada. Se você não é o destinatário ou a pessoa responsável por encaminhar esta mensagem ao destinatário, você está, por meio desta, notificado que não deverá rever, retransmitir, imprimir, copiar, usar ou distribuir esta mensagem de e-mail ou quaisquer anexos. Caso você tenha recebido esta mensagem por engano, por favor, contate o remetente imediatamente e apague esta mensagem de seu computador ou de qualquer outro banco de dados. Muito obrigado. 
Confidentiality Notice: The information contained in this email message, including any attachment, is confidential and is intended only for the person or entity to which it is addressed. If you are neither the intended recipient nor the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that you may not review, retransmit, convert to hard copy, copy, use or distribute this email message or any attachments to it. If you have received this email in error, please contact the sender immediately and delete this message from any computer or other data bank. Thank you.    

Re: [Dotnetrdf-support] Jtrac

[Rob V. <rv...@do...>]

Hi Regionald

I'm not sure I understand your question and email subject here.

dotNetRDF is licensed under a choose your own license model where you can 
select from the GNU GPL v3, LGPL v3 or the MIT license as appropriate for 
your needs:

- GNU GPL - http://www.opensource.org/licenses/gpl-3.0
- LGPL - http://www.opensource.org/licenses/lgpl-3.0
- MIT - http://www.opensource.org/licenses/mit-license

dotNetRDF does not use an Apache license and has absolutely no relation to 
the JTrac project hence why I am confused by your question and email 
subject

If you have further questions please let me know

Rob Vesse

----------------------------------------
From: "Mathebula, Regionald" <Mat...@pb...>
Sent: 28 March 2011 10:33
To: dot...@li...
Subject: [Dotnetrdf-support] Jtrac 

Can you please assist me finding the apache licensing     Kind Regards  
Regionald MathebulaTel : 27-(0)11-514-7240 mat...@pb...  

______________________________________________________________________

NOTICE: This communication and any attachments ("this message") may contain 
confidential information for the sole use of the intended recipient(s). Any 
unauthorized use, disclosure, viewing, copying, alteration, dissemination 
or distribution of, or reliance on this message is strictly prohibited. If 
you have received this message in error, or you are not an authorized 
recipient, please notify the sender immediately by replying to this 
message, delete this message and all copies from your e-mail system and 
destroy any printed copies.

[Dotnetrdf-support] Jtrac

[Mathebula, R. <Mat...@pb...>]

Can you please assist me finding the apache licensing 

 

 

 

 

Kind Regards

 

 

Regionald Mathebula

Tel : 27-(0)11-514-7240 

mat...@pb... <mailto:mat...@pb...> 

 

 


______________________________________________________________________
NOTICE: This communication and any attachments ("this message") may contain confidential information for the sole use of the intended recipient(s). Any unauthorized use, disclosure, viewing, copying, alteration, dissemination or distribution of, or reliance on this message is strictly prohibited. If you have received this message in error, or you are not an authorized recipient, please notify the sender immediately by replying to this message, delete this message and all copies from your e-mail system and destroy any printed copies.

[Dotnetrdf-support] MicrosoftSqlStoreManager

[Felipe G. S. <fel...@in...>]

I saved a graph into the database but the nodes table has more nodes(_nodes) than the graph object(in memory) . Why?


Felipe Santos

[Dotnetrdf-support] dotNetRDF 0.4.0 Beta Released

[Rob V. <rv...@do...>]

Hi all

The new release of dotNetRDF is now available.  The new version is 0.4.0 
and is our first official Beta release.  Below is a quick summary of new 
features, you can read more online at 
http://www.dotnetrdf.org/blogitem.asp?blogID=40 or see the full Change Log 
in the download package.

Key New Features/Improvements
- Much improved SPARQL 1.1 support for both Query and Update
- Graph Difference calculation
- Convert/Cast Graphs and SPARQL Result Sets into DataTables
- Support for simple N3 rules
- Some internal restructuring to improve performance and extensibility
- Various bug fixes for 0.3.1 issues

As a major release this does make some breaking API changes but mostly to 
things that were only used internally.  If you have any issues when 
upgrading please get in touch.

You may experience some minor differences in SPARQL evaluation due to fixes 
to both fixes/improvements in our engine and changes made to make our 
implementation meet the specification better where the official test suites 
indicated our implementation was incorrect.

We strongly recommend you upgrade to the latest version ASAP
- http://www.dotnetrdf.org/content.asp?pageID=Download%20dotNetRDF
- 
http://sourceforge.net/projects/dotnetrdf/files/Library/0.4.0%20Beta/dotnetr
df_library_040_beta.zip/download

Best Regards,

Rob Vesse

 

Re: [Dotnetrdf-support] (no subject)

[Rob V. <rv...@do...>]

Hi Siddu

When creating a UriNode you either must provide it with a Uri instance or a 
String.  If you provide it with a String like you have done it is treated 
as a QName.

You must explicitly use URIs like so:

 UriNode dotNetRDF = g.CreateUriNode(new Uri("http://www.dotnetrdf.org"));
 UriNode says = g.CreateUriNode(new Uri("http://example.org/says"));

If you need any more help please let me know

Rob Vesse

----------------------------------------
From: "Marulasiddappa" <sid...@ut...>
Sent: 28 February 2011 07:48
To: dot...@li...
Subject: [Dotnetrdf-support] (no subject) 

Hi, I am writing a simple code,  //Need a Graph firstGraph g = new Graph(); 
//Create some NodesURINode dotNetRDF = 
g.CreateURINode("http://www.dotnetrdf.org");URINode createdBy = 
g.CreateURINode("http://example.org/createdBy");LiteralNode robVesse = 
g.CreateLiteralNode("Rob Vesse"); //Assert this TripleTriple t = new 
Triple(dotNetRDF, createdBy, robVesse);g.Assert(t);  When I try to execute 
this code,I got following error, maybe it is treating http: also namespace 
prefix. How shall I proceed with this? RDFException: The Namespace URI for 
the given Prefix 'http' is not known by the in-scope 
NamespaceMapperStackTrace: "   at 
VDS.RDF.NamespaceMapper.GetNamespaceUri(String prefix)\r\n   at 
VDS.RDF.Tools.ResolveQName(String qname, NamespaceMapper nsmap, Uri 
baseUri)\r\n   at VDS.RDF.UriNode..ctor(IGraph g, String qname)\r\n   at 
VDS.RDF.BaseGraph.CreateUriNode(String qname)\r\n   at 
RDFParser.ParseToRdfXmlString(List`1 triples) in 
f:\\UserSpiral\\App_Code\\RDFParser.cs:line 35\r\n   at 
Spidral.UserSpiral.DataProviders.UserDataProvider.GetUser(Guid id) in 
f:\\UserSpiral\\App_Code\\DataProvider\\UserDataProvider.cs:line 169\r\n   
at Spidral.UserSpiral.Controllers.UserController.BindUser() in 
f:\\UserSpiral\\Controllers\\UserView.aspx.cs:line 41\r\n   at 
Spidral.UserSpiral.Controllers.UserController.Page_Load(Object sender, 
EventArgs e) in f:\\UserSpiral\\Controllers\\UserView.aspx.cs:line 21\r\n   
at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, 
Object t, EventArgs e)\r\n   at 
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, 
EventArgs e)\r\n   at System.Web.UI.Control.OnLoad(EventArgs e)\r\n   at 
System.Web.UI.Control.LoadRecursive()\r\n   at 
System.Web.UI.Page.ProcessRequestMain(Boolean 
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)"  Can 
you let me know the solution to this please?   Regards,Siddu 

[Dotnetrdf-support] (no subject)

[Marulasiddappa <sid...@ut...>]

Hi,

 

I am writing a simple code,

 

 

//Need a Graph first

Graph g = new Graph();

 

//Create some Nodes

URINode dotNetRDF = g.CreateURINode("http://www.dotnetrdf.org");

URINode createdBy = g.CreateURINode("http://example.org/createdBy");

LiteralNode robVesse = g.CreateLiteralNode("Rob Vesse");

 

//Assert this Triple

Triple t = new Triple(dotNetRDF, createdBy, robVesse);

g.Assert(t);

 

 

When I try to execute this code,

I got following error, maybe it is treating http: also namespace prefix. How
shall I proceed with this?

 

RDFException: The Namespace URI for the given Prefix 'http' is not known by
the in-scope NamespaceMapper

StackTrace: "   at VDS.RDF.NamespaceMapper.GetNamespaceUri(String
prefix)\r\n   at VDS.RDF.Tools.ResolveQName(String qname, NamespaceMapper
nsmap, Uri baseUri)\r\n   at VDS.RDF.UriNode..ctor(IGraph g, String
qname)\r\n   at VDS.RDF.BaseGraph.CreateUriNode(String qname)\r\n   at
RDFParser.ParseToRdfXmlString(List`1 triples) in
f:\\UserSpiral\\App_Code\\RDFParser.cs:line 35\r\n   at
Spidral.UserSpiral.DataProviders.UserDataProvider.GetUser(Guid id) in
f:\\UserSpiral\\App_Code\\DataProvider\\UserDataProvider.cs:line 169\r\n
at Spidral.UserSpiral.Controllers.UserController.BindUser() in
f:\\UserSpiral\\Controllers\\UserView.aspx.cs:line 41\r\n   at
Spidral.UserSpiral.Controllers.UserController.Page_Load(Object sender,
EventArgs e) in f:\\UserSpiral\\Controllers\\UserView.aspx.cs:line 21\r\n
at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o,
Object t, EventArgs e)\r\n   at
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender,
EventArgs e)\r\n   at System.Web.UI.Control.OnLoad(EventArgs e)\r\n   at
System.Web.UI.Control.LoadRecursive()\r\n   at
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint,
Boolean includeStagesAfterAsyncPoint)"

 

 

Can you let me know the solution to this please?

 

 

 

Regards,

Siddu

 

Re: [Dotnetrdf-support] dotNetRdf ontology package

[Rob V. <rv...@do...>]

Hi Daniel

It depends on what information you are after.  If you have an OntologyGraph to start with then you can use CreateOntologyClass() with either a URI/Node to get an OntologyClass which has access to various information about the class.  Even if you aren't using an OntologyGraph you can still just create an OntologyClass by passing in a Node and a Graph to its constructor.

If you just want all Triples mentioning the class then you have the Triples, TripleWithSubject etc. properties which will give you all Triples that have the Class mentioned in them in the specified position.

What I suspect you are asking is about properties which have rdfs:range and rdfs:domain of a Class?  Currently there is no direct way to get this information form an OntologyClass - this can be added for future releases if it would be helpful?

As a workaround for this you could do the following:

            OntologyGraph g = new OntologyGraph();
            //Load your data into the Graph from somewhere...

            //Get the Class of interest
            OntologyClass cls = g.CreateOntologyClass(new Uri("http://example.org/yourClass"));

            //Find Triples where Predicate is rdfs:range or rdfs:domain and the Object is the Class
            UriNode rdfsRange = g.CreateUriNode(new Uri(NamespaceMapper.RDFS + "range"));
            UriNode rdfsDomain = g.CreateUriNode(new Uri(NamespaceMapper.RDFS + "domain"));
            List<OntologyProperty> ranges = new List<OntologyProperty>();
            List<OntologyProperty> domains = new List<OntologyProperty>();
            foreach (Triple t in cls.TriplesWithObject)
            {
                if (t.Predicate.Equals(rdfsRange))
                {
                    ranges.Add(new OntologyProperty(t.Subject, g));
                }
                else if (t.Predicate.Equals(rdfsDomain))
                {
                    domains.Add(new OntologyProperty(t.Subject, g));
                }
            }

            //Do whatever you want with the Ranges and Domains... 

Note that if you have an OntologyProperty you can easily get back to the classes it has as its domain and range as there are two properties - Domains and Ranges - that allow you to do this.

Hope this helps, let me know if you need more help/information

Regards,

Rob Vesse

----------------------------------------
From: "Daniel Bittencourt" <db...@gm...>
Sent: 22 February 2011 21:21
To: rv...@do...
Subject: dotNetRdf ontology package 

Hi there!

I'm studying your library and more specificaly the features of the ontology package. Although I found it very usefull to create or edit an ontology, I didn't have found many methods to get some information about the ontology. For example, given a class, a method that returns all her properties. Is there something that I'm missing or an easy way to retrieve that kind of information?

Thank you for your attention,
-- 
Daniel Bittencourt
Computer Science student, Federal University of Uberlândia
Brazil

Re: [Dotnetrdf-support] OnDemandTripleStore

[Rob V. <rv...@do...>]

Hi Felipe

It depends upon your query. If your query does not explicitly reference any Graphs then it operates only over the Graphs currently in memory.  If the query references Graphs then it will load those as the query requests them.

SPARQL provides two mechanisms to reference Graphs - FROM/FROM NAMED and GRAPH clauses.

FROM and FROM NAMED clauses specify the Graphs that the query operates over.  Graphs mentioned in a FROM clause will be loaded at the start of processing a Query since they are used to form the Default Graph which the Query operates over.  Graphs mentioned in a FROM NAMED clause are loaded only if the Query contains a GRAPH clause which has a variable specifier and that variable is not already bound.

You can also use the GRAPH clause with a URI to specify a fixed Graph to use.

Example 1:

SELECT *
FROM <http://example.org/graph1>
FROM NAMED <http://example.org/graph2>
WHERE { ?s ?p ?o }

In this example graph1 would be loaded from the Store but graph2 would not as there is no relevant GRAPH clause to cause it to be loaded

Example 2:

SELECT *

FROM <http://example.org/graph1>

FROM NAMED <http://example.org/graph2>

WHERE 
{ 
  ?s <http://example.org/hasGraph> ?g .
  GRAPH ?g { ?x ?y ?z }
}

In this example graph1 would be loaded but again graph2 would not as although there is a GRAPH clause the Graph Specifier ?g is already bound at that point in the query.  But in this query for every possible distinct value for ?g the Store will attempt to load that Graph from the Store in order to answer the Graph clause

Example 3:

SELECT *
FROM <http://example.org/graph1>
FROM NAMED <http://example.org/graph2>
WHERE { GRAPH ?g { ?s ?p ?o } }

In this example graph1 gets loaded but then graph2 also gets loaded in order to answer the GRAPH clause as ?g is unbound so it uses all the values specified in FROM NAMED clauses to create a Graph for the GRAPH clause.

Example 4:

SELECT *
WHERE { GRAPH <http://example.org/graph1> { ?x ?y ?z } }

In this example graph1 would be loaded as it explicitly needed to answer the Graph clause

A few points to remember when using the OnDemandTripleStore:
If your query references a Graph that does not exist the query will fail with an exceptionThe Store is a read-only view of your underlying store.  Changing the Graphs of the OnDemandTripleStore instance does not change the underlying store.Once a Graph is loaded in memory it stays there until you dispose of the OnDemandTripleStore (or it goes out of scope and gets GC'd by .Net) - if the Graph changes in the underlying store the OnDemandTripleStore will not reflect this changeHope this helps, as always let me know if you need more help

Regards,

Rob Vesse

----------------------------------------
From: "Felipe Guimarães Santos" <fel...@in...>
Sent: 07 February 2011 22:17
To: "dot...@li..." <dot...@li...>
Subject: [Dotnetrdf-support] OnDemandTripleStore 

If I use OnDemandTripleStore the SPARQL query will load the graphs on demand, or it will do the Query only with the loaded Graphs?  Thanks Felipe Guimarães Santos | desenvolvedor

fel...@in...  |  www.invit.com.br | @sigainvit
Office: +55 34 3223.4000 - 11 5506.8280  | Mobile: +55 34 9993.5060    Confidencialidade: A informação contida nesta mensagem de e-mail, incluindo quaisquer anexos, é confidencial e está reservada apenas à pessoa ou entidade para a qual foi endereçada. Se você não é o destinatário ou a pessoa responsável por encaminhar esta mensagem ao destinatário, você está, por meio desta, notificado que não deverá rever, retransmitir, imprimir, copiar, usar ou distribuir esta mensagem de e-mail ou quaisquer anexos. Caso você tenha recebido esta mensagem por engano, por favor, contate o remetente imediatamente e apague esta mensagem de seu computador ou de qualquer outro banco de dados. Muito obrigado. 
Confidentiality Notice: The information contained in this email message, including any attachment, is confidential and is intended only for the person or entity to which it is addressed. If you are neither the intended recipient nor the employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that you may not review, retransmit, convert to hard copy, copy, use or distribute this email message or any attachments to it. If you have received this email in error, please contact the sender immediately and delete this message from any computer or other data bank. Thank you.    

[Dotnetrdf-support] Proposed Deprecation of SQL Stores in future releases

[Rob V. <rv...@do...>]

Hi All

I wanted to make everyone aware that it is my intention to mark all the SQL 
Stores and their related classes as obsolete in the next release (0.4.0 
Beta) of dotNetRDF.  They will still be usable for the next few versions 
(most likely until the 0.5.x releases which will be late 2011 at the 
earliest) in their current forms. I am not necessarily going to remove SQL 
stores in their entirety but I would like to significantly restructure the 
existing code.  It is likely that I will start from scratch and just 
re-implement support as IGenericIOManager implementations.  It is very 
likely that the existing ISqlIOManager interface will be removed form the 
library completely.

I am not yet sure whether I will modify the actual database structure or 
not though if I do so I will provide upgrade mechanisms for pre-existing 
stores in some form.  One possibility which I am looking into is moving 
some of the hard work off onto the SQL server by making use of stored 
procedures instead of doing most things client side.  Another possible 
improvement is to virtualise the data returned to some degree so that 
actual values aren't retrieved from the database until explicitly needed 
which should give a boost to read speeds in some circumstances.

Despite this I would like to point out that I am introducing a couple of 
useful new features into the API that can benefit users of existing SQL 
Stores:
The ability to explicitly reference the default unnamed graph in SPARQL 
Query and Update using the URI <dotnetrdf:default-graph> (as requested by 
the iRingTools team) - this improvement applies to in-memory stores as 
wellAn SqlDataset - this is an implementation of a new abstraction layer 
which allows for querying out of memory data using the library's existing 
Leviathan SPARQL Engine.  This means that the contents of a SQL store need 
not be loaded into memory prior to querying them.  Query Performance is not 
as good as in-memory querying due to the overheads of going to and from the 
database but this is a trade off against not needing to use large amounts 
of RAM to realise the data in-memory prior to querying.Alongside the 
aforementioned I have been working on adding support for a number of new 
stores (both 3rd party and internally developed) which will provide a 
broader range of alternative stores to SQL stores should you wish to 
migrate from your existing SQL Stores.

If you have any questions/queries about this please let me know

Best Regards,

Rob Vesse
 

[Dotnetrdf-support] Support over the Holiday Period

[Rob V. <rv...@do...>]

Hello All

Happy Holidays to you all!

This is just an informative message to say that from today until the New 
Year I will be travelling visiting family for the holidays and so support 
requests may take longer than usual to resolve.  Also there may be some 
issues that I am unable to resolve as I will only have my laptop and won't 
have access to certain software for testing and debugging - namely most of 
the 3rd party Triple Stores which dotNetRDF supports.

I will try and respond to any support requests but can't guarantee as fast 
a response as I usually try to give

Thanks for your understanding

Rob Vesse

 

Re: [Dotnetrdf-support] Rulebase

[Rob V. <rv...@do...>]

Hi Tomas

There is not really any rules support in the 0.3.1 release that can do what you want but it is very straightforward to do with SPARQL queries e.g.

PREFIX : <http://example.org/czechRoyals#>


SELECT ?grandFather ?grandSon

WHERE 

{

  ?grandFather :fatherOf ?x . ?x :fatherOf ?grandSon

}

If you want to generate actual Triples with this data you can either turn the above into a CONSTRUCT query to generate a Graph with the additional data like so:

PREFIX : <http://example.org/czechRoyals#>


CONSTRUCT 

{

    ?grandFather :grandFatherOf ?grandSon .

}

WHERE 

{

  ?grandFather :fatherOf ?x . ?x :fatherOf ?grandSon

}

Or if you have a Triple Store which supports SPARQL Update (such as the TripleStore class in dotNetRDF) then you can create a SPARQL Update command to add the generated data straight back into the Store e.g.

PREFIX : <http://example.org/czechRoyals#>


INSERT

{

    ?grandFather :grandFatherOf ?grandSon .

}

WHERE 

{

  ?grandFather :fatherOf ?x . ?x :fatherOf ?grandSon

}

Hope this helps you get started, please ask if you have further questions/issues.

Best Regards,

Rob Vesse

----------------------------------------
From: "Tomas Franek" <tom...@se...>
Sent: 15 December 2010 16:25
To: rv...@do...
Subject: Rulebase 

I tried your dotnetRDF in my school project and I need help with using rulebase.

I have triples that describe Czech kings family

sample:

Object "Jan Lucembursky"
Predicate  "FatherOf"
Subject "CharlesIV"

Object "CharlesIV"
Predicate "FatherOf"
Subject "Jan"

Object "CharlesIV"
Predicate "FatherOf"
Subject "Vaclav IV"

Object "VaclavIV"
Predicate "FatherOf"
Subject "Marketa"
.
.
.
.
.

I woud like create rule "GrandFatherOf", and make qeury that show  all couples grandfather and grandson(granddaughter )

can you help me with this?

Tomás Franek

Re: [Dotnetrdf-support] Help retrieving value from RDF file

[Rob V. <rv...@vd...>]

Hi Anton

You can't use a semicolon to reuse a subject inside another Graph Pattern.  
You have to restate the subject inside the OPTIONAL clause.  Therefore your 
query would need to be the following:

"PREFIX dc: 
<http://purl.org/dc/elements/1.1/> PREFIX image: 
<http://www.eea.europa.eu/portal_types/Image#> SELECT ?image ?description 
WHERE { ?image a image:Image . OPTIONAL { ?image dc:description 
?description . } 
}"    ;  

The above should hopefully work fine for you  

Best Regards

Rob Vesse  

----------------------------------------
From: "Anton Hughes" <Ant...@ee...>
Sent: 01 December 2010 14:50
To: "rv...@do..." <rv...@do...>, "dotNetRDF User Help and 
Support" <dot...@li...>
Subject: Re: [Dotnetrdf-support] Help retrieving value from RDF file 






Hi Rob 
  
Thank you very much for your help. 
  
I have one futher question. 
  
I am currently using the following query, which works for many 
cases but not all: 

   

"PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX image: 
<http://www.eea.europa.eu/portal_types/Image#> SELECT ?image ?description 
WHERE { ?image a image:Image ; dc:description ?description 
}"   ;  


If the image does 
not have a discription then it is not included in the result 
set.  
  
I have tried with the following query, however it does not 
work: 

   

"PREFIX dc: 
<http://purl.org/dc/elements/1.1/> PREFIX image: 
<http://www.eea.europa.eu/portal_types/Image#> SELECT ?image ?description 
WHERE { ?image a image:Image ; OPTIONAL { dc:description ?description ; } 
}"    ;  


Could you perhaps 
assist me in writing the query so that the description is 
optional?  


  


Thanks and kind regards, 


Anton  
Hughes 

----------------------------------------

From: Rob Vesse [mailto:rv...@do...] 

Sent: 15. november 2010 18:20
To: dotNetRDF User Help and 
Support
Cc: Anton Hughes
Subject: re: [Dotnetrdf-support] 
Help retrieving value from RDF file


Hi 
Anton

Once you have retrieved the value of the Image URL (I assume you 
are enumerating over ts to get the value) you can use the INode that you 
retrieved to then make another query

e.g.

//Assuming you have the INode representing the image URI in a 
variable called url    
UriNode     description = 
g.CreateUriNode("dc:description");
 ts = 
g.GetTriplesWithSubjectPredicate(url, description);
foreach (Triple t in 
ts)
{
       //Do something with t.Object which will be an INode containing the 
description
        //Probably easiest to cast to literal and 
use the value property e.g.
        //((LiteralNode)t.Object).Value    
}

Generally speaking if you want to retrieve multiple values from a 
Graph like this it'll usually be easier to write an appropriate SPARQL 
query 
e..g.

    PREFIX dc: <http://purl.org/dc/elements/1.1/> 
PREFIX image: <http://www.eea.europa.eu/portal_types/Image#>

SELECT ?image ?description
WHERE 
{ 
  ?image a image:Image ;
            dc:description ?description .
}

You 
can execute this on a Graph by using the ExecuteQuery() extension method.  
You'll get back a SparqlResultSet (typed as Object so you'll need to cast 
it 
explicitly to SparqlResultSet) which you can then enumerate through and get 
the 
URL and Description of each Image in the Graph.

Advantage of the SPARQL 
method is that adding additional values to retrieve is very easy as you 
only 
have to modify your SPARQL query.

Let me know if you need any more help 
on this.

Best Regards,
Rob 
Vesse

----------------------------------------

From: "Anton Hughes" 
<Ant...@ee...>
Sent: 15 November 2010 
16:55
To: "dot...@li..." 
<dot...@li...>
Subject: 
[Dotnetrdf-support] Help retrieving value from RDF file 


 

Hi 
all 
  
Im currently using 
dotnetRDF on a project, and its working well in most cases. 
  
However Im stuck 
with trying to retrieve some values. 
  

the c# code I'm 
using is to get the image url is: 
  
   


//Get all Triples which meet some 
criteria
   //Want to find everything 
that is rdf:type ex:Person
    UriNode    
rdfType = g.CreateUriNode(  "rdf:type"    );
 //UriNode person = 
g.CreateUriNode("image:Image"); 
//folder:Folder
    UriNode    person = g.CreateUriNode("image:Image"  );
 ts = g.GetTriplesWithPredicateObject(rdfType, 
person);

if somone could 
help me I would be very 
appreciative. 
Here is a sample of 
the rdf doc that I am using. I can retrieve the value for the image URL, 
but I 
need to get the value for the 'description'. 
  
<?xml 
version="1.0" encoding="utf-8"?>
<rdf:RDF
  
xmlns:dcterms='http://purl.org/dc/terms/'
  
xmlns:folder='http://www.eea.europa.eu/portal_types/Folder#'
  
xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
  
xmlns:dc='http://purl.org/dc/elements/1.1/'
  
xmlns:image='http://www.eea.europa.eu/portal_types/Image#'
>
  
<image:Image 
rdf:about="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-i
mages/satellite-images/poland-forest">
    
<dc:created xml:lang="en">2010/10/12 15:10:57.842 
GMT+2</dc:created>
    
<dc:creator>deliggia</dc:creator>
    
<dc:effective xml:lang="en">2010/09/29 17:11:35 
GMT+2</dc:effective>
    
<dcterms:isPartOf>
      <folder:Folder 
rdf:about="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-i
mages/satellite-images">
        
<folder:id 
xml:lang="en">satellite-images</folder:id>
        
<dc:created xml:lang="en">2010/09/29 17:03:59.451 
GMT+2</dc:created>
        
<dc:creator>deliggia</dc:creator>
        
<dc:effective xml:lang="en">2010/09/29 17:11:35 
GMT+2</dc:effective>
        
<dcterms:isPartOf 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images"/>
        
<dc:modified xml:lang="en">2010/09/29 17:54:54.189 
GMT+2</dc:modified>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/poland-forest"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/forest-legend"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/bialowieza-primaeval-forest-poland-2"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/satellite-images-1"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/bialowieza-primaeval-forest-poland"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/bialowieza-primaeval-forest-poland-1"/>
        
<dcterms:hasPart 
rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellit
e-images/satellite-images/poland-meris-forest"/>
        
<dc:title xml:lang="en">Satellite 
images</dc:title>
      
</folder:Folder>
    
</dcterms:isPartOf>
    <dc:description 
xml:lang="en">Satellite data are an excellent tool to determine forest 
extent 
and changes in forest cover and density. Nowadays, tropical deforestation 
as 
well as reforestation and deforestation are routinely observed and 
monitored by 
satellites in the frame of the Kyoto protocol.  
 
Copyright: European 
Forest Institute</dc:description>
    <dc:modified 
xml:lang="en">2010/10/12 15:15:59.270 
GMT+2</dc:modified>
    <image:id 
xml:lang="en">poland-forest</image:id>
    
<dc:title xml:lang="en">Poland Forest</dc:title>
  
</image:Image>   
</rdf:RDF> 
  
Kind 
regards, 
Anton 

Re: [Dotnetrdf-support] Help retrieving value from RDF file

[Anton H. <Ant...@ee...>]

Hi Rob

Thank you very much for your help.

I have one futher question.

I am currently using the following query, which works for many cases but not all:

"PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX image: <http://www.eea.europa.eu/portal_types/Image#> SELECT ?image ?description WHERE { ?image a image:Image ; dc:description ?description }";

If the image does not have a discription then it is not included in the result set.


I have tried with the following query, however it does not work:

"PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX image: <http://www.eea.europa.eu/portal_types/Image#> SELECT ?image ?description WHERE { ?image a image:Image ; OPTIONAL { dc:description ?description ; } }";

Could you perhaps assist me in writing the query so that the description is optional?



Thanks and kind regards,

Anton  Hughes

________________________________
From: Rob Vesse [mailto:rv...@do...]
Sent: 15. november 2010 18:20
To: dotNetRDF User Help and Support
Cc: Anton Hughes
Subject: re: [Dotnetrdf-support] Help retrieving value from RDF file

Hi Anton

Once you have retrieved the value of the Image URL (I assume you are enumerating over ts to get the value) you can use the INode that you retrieved to then make another query

e.g.

//Assuming you have the INode representing the image URI in a variable called url
UriNode description = g.CreateUriNode("dc:description");
ts = g.GetTriplesWithSubjectPredicate(url, description);
foreach (Triple t in ts)
{
    //Do something with t.Object which will be an INode containing the description
    //Probably easiest to cast to literal and use the value property e.g.
    //((LiteralNode)t.Object).Value
}

Generally speaking if you want to retrieve multiple values from a Graph like this it'll usually be easier to write an appropriate SPARQL query e..g.

PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX image: <http://www.eea.europa.eu/portal_types/Image#>

SELECT ?image ?description
WHERE
{
  ?image a image:Image ;
            dc:description ?description .
}

You can execute this on a Graph by using the ExecuteQuery() extension method.  You'll get back a SparqlResultSet (typed as Object so you'll need to cast it explicitly to SparqlResultSet) which you can then enumerate through and get the URL and Description of each Image in the Graph.

Advantage of the SPARQL method is that adding additional values to retrieve is very easy as you only have to modify your SPARQL query.

Let me know if you need any more help on this.

Best Regards,
Rob Vesse

________________________________
From: "Anton Hughes" <Ant...@ee...>
Sent: 15 November 2010 16:55
To: "dot...@li..." <dot...@li...>
Subject: [Dotnetrdf-support] Help retrieving value from RDF file


Hi all

Im currently using dotnetRDF on a project, and its working well in most cases.

However Im stuck with trying to retrieve some values.

the c# code I'm using is to get the image url is:


//Get all Triples which meet some criteria
//Want to find everything that is rdf:type ex:Person
UriNode rdfType = g.CreateUriNode("rdf:type");
//UriNode person = g.CreateUriNode("image:Image"); //folder:Folder
UriNode person = g.CreateUriNode("image:Image");
ts = g.GetTriplesWithPredicateObject(rdfType, person);

if somone could help me I would be very appreciative.

Here is a sample of the rdf doc that I am using. I can retrieve the value for the image URL, but I need to get the value for the 'description'.

<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF
  xmlns:dcterms='http://purl.org/dc/terms/'
  xmlns:folder='http://www.eea.europa.eu/portal_types/Folder#'
  xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'
  xmlns:dc='http://purl.org/dc/elements/1.1/'
  xmlns:image='http://www.eea.europa.eu/portal_types/Image#'
>
  <image:Image rdf:about="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/poland-forest">
    <dc:created xml:lang="en">2010/10/12 15:10:57.842 GMT+2</dc:created>
    <dc:creator>deliggia</dc:creator>
    <dc:effective xml:lang="en">2010/09/29 17:11:35 GMT+2</dc:effective>
    <dcterms:isPartOf>
      <folder:Folder rdf:about="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images">
        <folder:id xml:lang="en">satellite-images</folder:id>
        <dc:created xml:lang="en">2010/09/29 17:03:59.451 GMT+2</dc:created>
        <dc:creator>deliggia</dc:creator>
        <dc:effective xml:lang="en">2010/09/29 17:11:35 GMT+2</dc:effective>
        <dcterms:isPartOf rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images%22/>>
        <dc:modified xml:lang="en">2010/09/29 17:54:54.189 GMT+2</dc:modified>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/poland-forest"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/poland-forest%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/forest-legend"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/forest-legend%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland-2"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland-2%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/satellite-images-1"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/satellite-images-1%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland-1"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/bialowieza-primaeval-forest-poland-1%22/>>
        <dcterms:hasPart rdf:resource="http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/poland-meris-forest"/<http://www.eea.europa.eu/atlas/eea/a-day-in-my-forest/satellite-images/satellite-images/poland-meris-forest%22/>>
        <dc:title xml:lang="en">Satellite images</dc:title>
      </folder:Folder>
    </dcterms:isPartOf>
    <dc:description xml:lang="en">Satellite data are an excellent tool to determine forest extent and changes in forest cover and density. Nowadays, tropical deforestation as well as reforestation and deforestation are routinely observed and monitored by satellites in the frame of the Kyoto protocol.

Copyright: European Forest Institute</dc:description>
    <dc:modified xml:lang="en">2010/10/12 15:15:59.270 GMT+2</dc:modified>
    <image:id xml:lang="en">poland-forest</image:id>
    <dc:title xml:lang="en">Poland Forest</dc:title>
  </image:Image>
</rdf:RDF>

Kind regards,
Anton