- From: Howard Katz <howardk@fatdog.com>
- Date: Fri, 16 Apr 2004 13:59:46 -0700
- To: "Seaborne, Andy" <andy.seaborne@hp.com>, "RDF Data Access Working Group" <public-rdf-dawg@w3.org>
Aha. I hadn't bothered trying to reconstruct the bottom of his slide #4, which comes out looking like: declare namespace rdf = "rdf.tagsalad.org"; for $artist in rdf:subject("c:creates", ()), $artifact := rdf:object($artist, "c:creates"), $museum := rdf:subject("c:exhibits", $artifact) return <result> <artist>{ $artist }</artist> <artifact>{ $artifact }</artifact> <museum>{ $museum }</museum> </result> Very cool. Looks a lot like RDFLib a moi. Howard > -----Original Message----- > From: public-rdf-dawg-request@w3.org > [mailto:public-rdf-dawg-request@w3.org]On Behalf Of Seaborne, Andy > Sent: Friday, April 16, 2004 8:16 AM > To: RDF Data Access Working Group > Subject: RE: Supplemental XQuery reading list > > > > See also Jonathan Robie's talk at the tech plenary: > > http://www.w3.org/2004/Talks/tp-robie/ > > He and I talked about this beforehand - the use of XQuery to extract > information from RDF sources and create XHTML/XML looks like a good use of > XQuery. The approach is to provide accessors into the RDF graph (the > abstract syntax, not the concrete RDF/XML syntax). > > Andy > > -------- Original Message -------- > > From: Howard Katz <> > > Date: 16 April 2004 15:53 > > > > > I can't speak to Andy's agenda, but one point that's been kicking > > > around in the XQuery/RDF Query arena for a while is that XQuery can be > > > used to express SQL queries so it must be able to express RDF > > > queries. > > > > It can, if you're able to work out a mapping from the RDF data model > > into > > the XQuery data model, which is basically the XML Infoset + XML Schema > > support + support for multiple documents. > > > > I'm finding myself quite interested in the inverse problem: would it be > > possible and useful to be able to map from the XQuery surface language > > into > > an underlying RDF graph-based data model, so that XQuery syntax can be > > used > > to interrogate an RDF data store more or less directly? In other words, > > can > > we swap out XQuery's underlying XML-based data model and slide in an > > RDF-based one in its place so that we don't have to do the mapping to > > XML? > > I'll be talking about this after Amsterdam. > > > > > I've seen a couple approaches that I believe workable [1] > > > [2], but would like to see how people solve the problem for SQL. > > > > I've given a few pointers in my response to Andy's email re SQL-to-XML > > mappings for XQuery. > > > > > I suspect that in standardizing an RDF query language we are going > > > beyond where existing SQL mappings to XQuery have gone in that we want > > > *one* mapping to XQuery that operates on XQuery+whatever > > > implementations from different vendors. Does such a "standard" mapping > > > to SQL exist? > > > > I'm not sure what you mean by the last, Eric. Can you explain a bit > > more? > > > > Howard > > > > > [1] http://www.w3.org/2001/11/13-RDF-Query-Rules/#XQueryFA > > > [2] http://www.w3.org/2001/11/13-RDF-Query-Rules/#TreeHugger -- > > > -eric > > > > > > office: +81.466.49.1170 W3C, Keio Research Institute at SFC, > > > Shonan Fujisawa Campus, Keio University, > > > 5322 Endo, Fujisawa, Kanagawa 252-8520 > > > JAPAN +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA > > > cell: +1.857.222.5741 (does not work in Asia) > > > > > > (eric@w3.org) > > > Feel free to forward this message to any list for any purpose other > > > than email address distribution. >
Received on Friday, 16 April 2004 16:58:35 UTC