Re: [d2rq-dev] Custom mappings in D2R Server

Sun, 24 Jul 2011 17:15:30 -0700 

Hello again,
First of all, I would like to say that I truly appreciate your effort and time. 
I'm sure that the problem is that I don't explain it well, and I'm sorry for 
that.
"I'm guessing Juan is asking if there's a way to have the ontology in the same 
dataset as the mapped data so that they can both be queried from the D2R Server 
SPARQL endpoint"
Yes, I think we are talking about the same thing. D2R server creates a simple 
ontology for you with the classes and properties that come from the database. I 
would like to link that mapping from the database to a more complex ontology, 
or in case it isn't possible, I would like to customize the mapping in order to 
create a more complex ontology. I would like for example to create new classes 
with no direct tables in the database (for example, in order to establish a 
class hierarchy).
I'll take up a previous example. Let's think in a database with just two tables 
(Teachers and Students). Now I would like to have a D2R Server with the data 
that comes from these two tables. When I create the mapping, two classes are 
created in the D2R server ontology. I would like to have also a new class 
called People, that is the superclass of both of them. Maybe this is possible 
and I couldn't find the way to get it. The aim is that everything (the more 
complex ontology and the mapped data) can be queried from the D2R Server. It 
means that the user can query D2R server about the Students and get all of 
their details, but also can ask if Teachers is subclass of People and get a 
true answer.
"AFAIK you cannot do any inferencing with D2R"
At first, my aim is to get an ontology with the mapped data exposed via D2R 
Server, not doing inferencing. That is, I'm not pretending that the user can 
query about People and get both Teachers and Students data, because the server 
infers that both of them are subclass of People.
Thank you very much again for your patient and help!jfcg
> From: [email protected]
> To: [email protected]
> Date: Sun, 24 Jul 2011 13:40:28 -0400
> Subject: Re: [d2rq-dev] Custom mappings in D2R Server
> 
> I'm not really sure either but I'm guessing Juan is asking if there's a way 
> to have the ontology in the same dataset as the mapped data so that they can 
> both be queried from the D2R Server SPARQL endpoint. As far as I know there 
> isn't a way to do that but you could set up a joseki endpoint with a d2rq 
> model and configure it to allow the dataset to be defined in the query. Then 
> you can pull in the ontology with a  FROM <http://myontology.rdf> or you can 
> dump the database into a native store and load the ontology as well. I think 
> someone a while ago was asking about setting up d2rq behind joseki and was 
> asked why you'd want to do that and this only one of two reasons I can think 
> of why you might want to do that. You'll might have to get a somewhat older 
> version of joseki since d2rq is built against a now somewhat older revision 
> of jena or you can patch d2r to work against the latest jena release. 
> 
> If that's what you're looking to do I could provide more details.
> 
> --Zach
> 
> > -----Original Message-----
> > From: Bo Ferri [mailto:[email protected]]
> > Sent: Sunday, July 24, 2011 12:46 PM
> > To: [email protected]
> > Subject: Re: [d2rq-dev] Custom mappings in D2R Server
> > 
> > Hi Juan,t
> > 
> > it seems that I probably do not really get what your problem might be
> > (all other reading the mailing, you are invited to help me as well ;)
> > ).
> > 
> > Am 24.07.2011 13:32, schrieb Juan Francisco Contreras Gaitan:
> > > Hello Bob,
> > >
> > > I think I didn't explained well. I didn't mean the ontology file is
> > > totally useless in general, for example it could be very useful when
> > > dumping the data and distribute the full owl with D2RQ.
> > 
> > An ontology in general is a separate construct that can be utilised in
> > a
> > D2RQ mapping. For example, when you dump the triples that you will get
> > via your mapping and load them into a proper triple store á la OpenLink
> > Virtuoso or Ontotext Big OWLIM then you can apply proper inferencing
> > task on these descriptions as well, e.g., deriving sub-class relations.
> > 
> > >
> > > I meant that it is useless within D2R Server, because it ignores it
> > > (AFAIK you can't get it to be an argument).
> > 
> > Well I probably tried to explain you this already in a previous reply.
> > AFAIK you cannot do any inferencing with D2R (Richard or someone else
> > please correct me here if I'm wrong).
> > 
> > > Of course you can do a lot
> > > of things with the the ontology and D2RQ, but you have to code them
> > > manually.
> > 
> > If you wanna apply an existing (or separately created) ontology in your
> > mapping then you have to do this task more or less manually, but this
> > is
> > more or less the main work one has to do when applying D2R.
> > 
> > > Topbraid has coded some things for you, and for example you
> > > can get the ontology and its instances via D2RQ. All you have to do
> > is
> > > defining an ontology and a mapping. I'm asking if something similar
> > is
> > > possible with D2R Server.
> > 
> > Yes, and I think this is more or less the essence I tried to explain
> > you
> > via my previous e-mails ;)
> > 
> > >
> > > So, my question would be if the ontology file is useful with D2R
> > Server
> > > directly (like with Topbraid, for example)? Or you have to use D2RQ
> > > Engine to publish your full ontology info in the web?
> > 
> > Usually you would publish your ontology specification separately (see
> > [1]).
> > 
> > Cheers,
> > 
> > 
> > Bob
> > 
> > 
> > [1] http://www.w3.org/TR/swbp-vocab-pub/
> > 
> > -----------------------------------------------------------------------
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> ------------------------------------------------------------------------------
> Magic Quadrant for Content-Aware Data Loss Prevention
> Research study explores the data loss prevention market. Includes in-depth
> analysis on the changes within the DLP market, and the criteria used to
> evaluate the strengths and weaknesses of these DLP solutions.
> http://www.accelacomm.com/jaw/sfnl/114/51385063/
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