1/ The data is likely wrong.
Get it working with a query string in your program exactly like the
tutorial.
You have a graph name of
<file:src/main/resources/dataset-named-graph-1.ttl>
in the code and
<dataset-named-graph-1.ttl>
in the data. The relative URIs will be resolved to absolute ones.
Try using
<file:///...your filing system
path.../src/main/resources/dataset-named-graph-1.ttl>
in both places or put the files in the currentl directory, not
src/main/resources/
And print the data and the query to check.
2/ The algebra is printable so print out the op you build and print out
the query.
http://www.sparql.org/query-validator.html
The algebra should be:
(project (?date ?title ?g)
(filter (> ?date "2005-08-01T00:00:00Z"^^xsd:dateTime)
(join ## Or (sequence)
(bgp (triple ?g dc:date ?date))
(graph ?g
(bgp (triple ?b dc:title ?title))))))
You can also use the command line "qparse" to get thiswith --print=op.
3/ Start simple and add bits until it stops working:
e.g. Check the graph names with:
(graph ?g
(bgp (triple ?s ?p ?o))
Andy
