- From: Alberto Reggiori <alberto@asemantics.com>
- Date: Wed, 23 Feb 2005 18:28:01 +0100
- To: "Geoff Chappell" <geoff@sover.net>
- Cc: <andy.seaborne@hp.com>, <public-rdf-dawg-comments@w3.org>
On Feb 23, 2005, at 6:12 PM, Geoff Chappell wrote: > > I'll predict that people are going to get pretty confused about > FROM/WITH if > they remain as they are. indeed - and your worry confirms other feelings around looking at current SPARQL RDF-dataset selection syntax. Lots of people keeps associating SPARQL to RDQL, which used FROM. And they will still do so for another while, till they will get used to a new syntax (and design). > I wonder if a slightly different model would make > more sense to people - e.g. something like this: > > SELECT ?src > FROM <http://example.org/foaf/aliceFoaf> > <http://example.org/foaf/bobFoaf> > AS <http://example.org/foaf/allFoaf> right - or add a NAMED modifier to FROM when is dealing with a named graph instead which would mean a simple change into current spec s/FROM/FROM NAMED/ s/WITH/FROM/ and would avoid lot of confusion > I.e. use AS to rename one or more graphs; if no AS is specified each > graph > is known by its own uri/name. You'd need to come up with a well-known > name > for the default/background/nameless graph - e.g: yes your AS modifier would play a similar trick too > > SELECT ?src > FROM <http://example.org/foaf/aliceFoaf> > <http://example.org/foaf/bobFoaf> > AS <http://example.org/foaf/allFoaf>, > <http://example.org/otherData> > AS <http://www.sparql.org/DefaultGraph> > ... > > would have one named graph (allFoaf - containing bob and alice's foaf > data) > and one background graph (DefaultGraph containing otherData). > > Then: > > WHERE > ( ?x ?y ?z ) > > would match all triples in the default > (<http://www.sparql.org/DefaultGraph>) graph. > > Or Alternatively, have no name for the background graph and say that > if no > AS is specified, the graph(s) are in the background graph - e.g: > > SELECT ?src > FROM <http://example.org/foaf/aliceFoaf> > <http://example.org/foaf/bobFoaf> > AS <http://example.org/foaf/allFoaf>, > <http://example.org/otherData> > ... > > would have one named graph (allFoaf - containing bob and alice's foaf > data) > and one background graph (containing otherData). > > I don't think the slight benefit you get from the FROM/WITH shorthand > outweighs the confusion it will likely cause. we fully support your view and worries here - and it would be good to find more common syntax/terminology to specify the RDF-dataset in the LC document. True, this is purely syntax problem, but very key to the wider adoption of SPARQL to us. thanks for the comments Geoff - and to Andy to follow up the thread Yours Alberto - Alberto Reggiori, @Semantics S.R.L. www.asemantics.com
Received on Wednesday, 23 February 2005 17:28:06 UTC