- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Fri, 26 Aug 2011 00:56:27 +0100
- To: "public-rdb2rdf-wg@w3.org RDB2RDF" <public-rdb2rdf-wg@w3.org>
There's a new section in R2RML that discusses the handling of datatypes: http://www.w3.org/2001/sw/rdb2rdf/r2rml/#datatype-conversions The definitions and tables in that section are referenced from various places throughout the spec, in particular: http://www.w3.org/2001/sw/rdb2rdf/r2rml/#typed-literals http://www.w3.org/2001/sw/rdb2rdf/r2rml/#generated-rdf-term Some noteworthy features: - it is now an error to have a logical column that cannot be CAST to string - unknown/user-defined types are CAST to string and mapped to plain literal - rr:datatype is implicit if unspecified, that is, date column will be xsd:date even without explicit rr:datatype - explicit rr:datatype that doesn't match the implicit type results in typed literal where the lexical form is simply the result of CAST to string - implementations MUST support literal well-formedness checks for the 8 supported XSD types - implementations MAY support literal well-formedness checks for additional types - ill-typed literal is a data error - I ignored INTERVAL because it's so freaking complicated - binary types get mapped to xsd:base64Binary Please review and comment! Process: I've set ISSUE-29, ISSUE-48 and ISSUE-51 to Pending Review and propose: [[ PROPOSAL: Close ISSUE-29; all places that interpret SQL values as string now use "conversion to string" ]] [[ PROPOSAL: Close ISSUE-48 as it is addressed in http://www.w3.org/2001/sw/rdb2rdf/r2rml/#datatype-conversions ]] [[ PROPOSAL: Close ISSUE-51; the spec now demands that “supported RDF types” MUST raise data error, and other types MAY raise data error ]]
Received on Thursday, 25 August 2011 23:56:58 UTC