- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Sat, 5 Dec 2009 17:16:02 -0500
- To: public-rdb2rdf-wg@w3.org, Alexandre Bertails <bertails@w3.org>
I'll be working on this more, but here's a start on the slides
introducing algebra for RDB->RDF and (corresponding) SPARQL->SQL
mappings. If folks want to play with this stuff, try downloading
the appropriate SPARQL from
http://sourceforge.net/projects/swobjects/files/
and executing "SPARQL -s http://hr.example/DB/ -e
"PREFIX emplP: <http://hr.example/DB/Employee#>
SELECT ?empName ?managName
WHERE { ?emp emplP:lastName ?empName .
?emp emplP:manager ?manager .
?manager emplP:lastName ?managName }"
You should see:
SELECT emp.lastName AS empName, manager.lastName AS managName
FROM Employee AS emp
INNER JOIN Employee AS manager ON manager.id=emp.manager
which corresponds closely (modulo NULLs) to the results expected in
http://www.w3.org/2008/07/MappingRules/StemMapping#bgp1
The pitch is that this is a doable and useful task and that the world
will buy us many beers for accomplishing this.
--
-ericP
Received on Saturday, 5 December 2009 22:16:47 UTC