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Re: add NULL cases to conformance test

From: Ashok Malhotra <ashok.malhotra@oracle.com>
Date: Tue, 17 Sep 2013 16:58:54 -0400
Message-ID: <5238C28E.4020409@oracle.com>
To: vladimir.alexiev@ontotext.com
CC: public-rdb2rdf-comments@w3.org, "'Gregg Garcia'" <GGarcia@getty.edu>
Thanks, Vladimir!
I will file this suggestion and we can look at it if we reopen the WG.
All the best, Ashok
On 9/17/2013 4:03 PM, Vladimir Alexiev wrote:
> Hi everyone!
>
> If a column value (or any of the columns in a rr:template) is null, an r2rml processor should skip the involved triple.
> If the rr:subjectMap column is null, it should skip all triples in that rr:TriplesMap.
> This is especially important since R2RML doesn't offer any conditionals.
>
> This behaviour is stated quite definitely at:
> http://www.w3.org/2001/sw/rdb2rdf/wiki/RDBNullValues#R2RML
>
> 1. But IMHO the R2RML spec is silent on what happens when a subjectMap or objectMap is null. If we read pedantically:
> "A predicate-object map is a function that creates *one* or more predicate-object pairs for each logical table row"
> then it should generate a triple with null.
>
> Please add some langauge to the effect of the above wiki page.
>
> 2. Please also add conformance tests with NULLs.
> E.g. the perl module RDF::RDB2RDF does NOT ignore nulls, even though it's passed the conformance test.
>
> Thanks!
> --
> Vladimir Alexiev, PhD, PMP
> Lead, Data and Ontology Management Group
> Ontotext Corp, www.ontotext.com
> Sirma Group Holding, www.sirma.com
> Email: vladimir.alexiev@ontotext.com, skype:valexiev1
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>
>
>
>
>
Received on Tuesday, 17 September 2013 20:59:58 UTC

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