Patrick, I don't think SPARQL can do that, but the iTQL (Mulgara-specific) walk function should help in your case:
http://docs.mulgara.org/itqlcommands/select.html#o1532 For example, if you have a tree where the relations are expressed via fedora-rels-ext:isMemberOf arcs from child to parent, and the tree is structured like this: demo:root demo:child1 demo:grandchild1a demo:child2 demo:grandchild2a demo:grandchild2b ...then the following query would provide the path from a known descendent (grandchild2b) to the root: select $child $parent from <#ri> where walk ( <info:fedora/demo:grandchild2b> <fedora-rels-ext:isMemberOf> $parent and $child <fedora-rels-ext:isMemberOf> $parent ) ...expressed via the following tuples: "child","parent" info:fedora/demo:child2,info:fedora/demo:root info:fedora/demo:grandchild2b,info:fedora/demo:child2 Or, if you want to go from the top down (root and all descendents), the following query: select $parent $child from <#ri> where walk ( $child <fedora-rels-ext:isMemberOf> <info:fedora/demo:root> and $child <fedora-rels-ext:isMemberOf> $parent ) ...would expresss the structure of the entire tree as: "parent","child" info:fedora/demo:root,info:fedora/demo:child1 info:fedora/demo:root,info:fedora/demo:child2 info:fedora/demo:child1,info:fedora/demo:grandchild1a info:fedora/demo:child2,info:fedora/demo:grandchild2a info:fedora/demo:child2,info:fedora/demo:grandchild2b I think the latter query is more like what you want, but may quickly become expensive to run (memory and performance-wise), if the root has a large number of descendents. - Chris On Thu, Dec 16, 2010 at 4:25 PM, Yott, Patrick <p.y...@neu.edu> wrote: > (fearing the brash laughter this might produce) > > Is there a way to perform a RI query that will retrieve all objects within a > hierarchy? > > Consider this case. > > We might have a collection object for the chemistry department, which is in > turn referenced in the RELS-EXT datastreams for 4 collection objects > (Research Papers, Research Data, Theses, and Stuff). Each of these > collection objects may (and will quite likely) be similarly referenced by > additional, ‘deeper down the tree’ collection objects. > > I’d like to be able to generate a list of all the collection objects that > form a tree based on the chemistry object. I can do this relatively easily > if I create a “shadow” graph in SQL, but I’m not confident that its possible > with a SPARQL query. > > As always, my thanks in advance! > p > > > Patrick M. Yott > Digital Library Manager > Northeastern University Libraries > 360 Huntington Avenue, SL270 > Boston, MA 02120 > p 617.373.4194 > f 617.373.5409 > p.y...@neu.edu ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Fedora-commons-users mailing list Fedora-commons-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
