On Tuesday 02 September 2008 19:12:45 Ivan Mikhailov wrote:
> > Ah, yes, it was just an example. In practise, we have some OPTIONALs and
> > a FILTER bound( thing that takes care of all these things.
>
> OK. Just remember that bif:contains will work only with triple in same
> group at same level such that "subject" of bif:contains is object of
> that triple. So it is impossible to bind a variable in one place and
> make free-text search in other. Say, the following will report an error:
>
> DESCRIBE ?resource WHERE {
> { ?resource dct:title ?free .
> }
> UNION
> { ?resource dct:subject ?var .
> ?var skos:prefLabel ?free .
> }
> ?free bif:contains "Da*" .
> }
>
> That is because free-text index is areal index that should operate on
> real table alias, not on something "derived" like union or subquery.
Oh, OK, but
DESCRIBE ?resource WHERE {
{ ?resource dct:title ?free1 . ?free1 bif:contains "Da*" .
}
UNION
{ ?resource dct:subject ?var .
?var skos:prefLabel ?free2 .
?free2 bif:contains "Da*" .
}
}
will work?
> > I was wondering if I
> > could somehow exclude the sub:literals predicate from the DESCRIBE
> > result?
>
> It's a problem of SPARQL spec. There's no syntax for configuration
> options; I've failed to push that idea into initial version of the W3C
> spec. We shall see if the second attempt will be better. If not, then we
> will violate the spec (and create one more interop issue) -- "the best
> critique is sabotage".
Yeah, I know, but I certainly prefer to keep the conflict level low and to
rough consensus in the standards process.
It seems to me that a solution to this problem would be to allow matching
graphs that are not part of the result set, e.g.
DESCRIBE ?foo FROM </foo> WHERE GRAPH </bar> { ?foo dct:title "Foo" . } or
something like that...
Kind regards
Kjetil Kjernsmo
--
Senior Knowledge Engineer
Direct: +47 6783 1136 | Mobile: +47 986 48 234
Email: kjetil.kjern...@computas.com
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