- From: Bob DuCharme <bob@snee.com>
- Date: Wed, 17 Nov 2010 07:50:02 -0500
- To: Rob Vesse <rav08r@ecs.soton.ac.uk>
- CC: public-sparql-dev@w3.org
That makes sense, but if I can do this SELECT ?classTitle WHERE { GRAPH <http://example.com/classes/new/201106> { ?s <http://example.com/ns/sample#classTitle> ?classTitle } . } does FROM NAMED add anything besides the ability to list a few graphs and then says GRAPH ?varName so that the graph pattern is applied to several graphs? thanks, Bob On 11/17/2010 4:24 AM, Rob Vesse wrote: > FROM NAMED specifies Graphs that are used in GRAPH clauses > > e.g. > > SELECT * FROM NAMED<http://example.org/myGraph> WHERE { ?s ?p ?o . GRAPH > ?g { ?s ?x ?y }} > > Would first find all triples from the default graph (which may in fact be > the union of several graphs) and then the GRAPH part would use Graphs > specified in FROM NAMED clauses to match additional triples. At least > broadly speaking that is how it should work. Actual implementations tend > to vary somewhat. > > The difference should be that a FROM clause specifies a graph that forms > part of the default graph over which the query operates while the FROM > NAMED specifies Graphs used only in Graph clauses > > Rob > > On Tue, 16 Nov 2010 19:29:23 -0500, Bob DuCharme<bob@snee.com> wrote: >> I understand the various examples in the SPARQL spec that use FROM >> NAMED, but I still don't completely understand what the FROM NAMED part >> does, especially compared with FROM<http://some/uri>. >> >> http://www.w3.org/TR/2010/WD-sparql11-query-20101014/#namedGraphs says >> "A query can supply IRIs for the named graphs in the RDF Dataset using >> the FROM NAMED clause." If they're named graphs, don't they already have >> IRIs as names? What is FROM NAMED adding here? >> >> thanks, >> >> Bob
Received on Wednesday, 17 November 2010 12:50:31 UTC