I don't believe that literals are valid as predicates in RDF but also I don't believe TDB enforces any restrictions on what kind of Nodes can be stored.
Strictly speaking those should be invalid triples and in principal a SPARQL Update engine should refuse to insert them but I may be interpreting the spec wrong. Andy can probably answer the question better than I can Rob On 6/18/12 5:12 PM, "Tim Harsch" <[email protected]> wrote: >Not sure what I am seeing here. Is it OK for literal's to be predicates >in this case? > > >1) Start up Fuseki-0.2.1 incubating >2) load books.ttl > >3) run this >PREFIX dc: <http://purl.org/dc/elements/1.1/> >INSERT { > ?s ?c 1 >} >WHERE { > ?s dc:title ?c . >} > >4) run this (notice literal as predicate) >-------------------------------------------------------------------------- >------------------------------------------------------- >| s | p > | o | >========================================================================== >======================================================= >| <http://example.org/book/book5> | "Harry Potter and the Order of the >Phoenix" | 1 | >| <http://example.org/book/book5> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Order of the Phoenix" | >| <http://example.org/book/book5> | ><http://purl.org/dc/elements/1.1/creator> | "J.K. Rowling" > | >| <http://example.org/book/book3> | "Harry Potter and the Prisoner Of >Azkaban" | 1 | >| <http://example.org/book/book3> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Prisoner Of Azkaban" | >| <http://example.org/book/book3> | ><http://purl.org/dc/elements/1.1/creator> | _:b0 > | >| _:b1 | ><http://www.w3.org/2001/vcard-rdf/3.0#Family> | "Rowling" > | >| _:b1 | ><http://www.w3.org/2001/vcard-rdf/3.0#Given> | "Joanna" > | >| <http://example.org/book/book1> | "Harry Potter and the Philosopher's >Stone" | 1 | >| <http://example.org/book/book1> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Philosopher's Stone" | >| <http://example.org/book/book1> | ><http://purl.org/dc/elements/1.1/creator> | "J.K. Rowling" > | >| <http://example.org/book/book6> | "Harry Potter and the Half-Blood >Prince" | 1 | >| <http://example.org/book/book6> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Half-Blood Prince" | >| <http://example.org/book/book6> | ><http://purl.org/dc/elements/1.1/creator> | "J.K. Rowling" > | >| <http://example.org/book/book4> | "Harry Potter and the Goblet of Fire" > | 1 | >| <http://example.org/book/book4> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Goblet of Fire" | >| _:b0 | ><http://www.w3.org/2001/vcard-rdf/3.0#FN> | "J.K. Rowling" > | >| _:b0 | ><http://www.w3.org/2001/vcard-rdf/3.0#N> | _:b1 > | >| <http://example.org/book/book2> | "Harry Potter and the Chamber of >Secrets" | 1 | >| <http://example.org/book/book2> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Chamber of Secrets" | >| <http://example.org/book/book2> | ><http://purl.org/dc/elements/1.1/creator> | _:b0 > | >| <http://example.org/book/book7> | "Harry Potter and the Deathly >Hallows" | 1 | >| <http://example.org/book/book7> | ><http://purl.org/dc/elements/1.1/title> | "Harry Potter and the >Deathly Hallows" | >| <http://example.org/book/book7> | ><http://purl.org/dc/elements/1.1/creator> | "J.K. Rowling" > | >-------------------------------------------------------------------------- >-------------------------------------------------------
