- From: Souri Das <Souripriya.Das@oracle.com>
- Date: Mon, 16 Aug 2010 18:04:55 -0400
- To: public-rdb2rdf-wg@w3.org
I have created new versions (Revision 1) of the schema and example based
upon the Richard's comments and last week's meeting:
http://www.w3.org/2001/sw/rdb2rdf/wiki/An_XML_Schema_for_SQL-based_RDB2RDF_Mapping_%28Revision_1%29
http://www.w3.org/2001/sw/rdb2rdf/wiki/Example_of_SQL-based_RDB2RDF_Mapping:_Revision_1
I am still not sure about a few things, most importantly
- Regarding Comment 2.5 (Lookup Table): How can we translate a SPARQL
query with FILTER involving transformed values?
Example: Consider the following SPARQL query involving a property,
:transfProp, whose values are transformed, via a lookup table, into (-1)
times the original value
(e.g., 10 in an INTEGER column, i.e., "10"^^xsd:integer in RDF,
is transformed into "-10"^^xsd:integer):
SELECT ?x ?y WHERE {?x :transfProp ?v1 . ?y :transfProp ?v2
. FILTER (?v1 > ?v2)}
How can SQL know, without having the lookup table somehow
specified (in a CASE statement or something equivalent), how to evaluate
the FILTER clause?
Thanks,
- Souri.
Received on Monday, 16 August 2010 22:06:14 UTC