Canned Queries

RPT ships with several useful queries on its classpath. Classpath resources can be printed out using cpcat. The following snippet shows examples of invocations and their output:

Overview 

$ rpt cpcat spo.rq
CONSTRUCT WHERE { ?s ?p ?o }

$ rpt cpcat gspo.rq
CONSTRUCT WHERE { GRAPH ?g { ?s ?p ?o } }

Any resource (query or data) on the classpath can be used as an argument to the integrate command:

rpt integrate yourdata.nt spo.rq
# When spo.rq is executed then the data is queried and printed out on STDOUT

Reference

The exact definitions can be viewed with rpt cpcat resource.rq.

  • spo.rq: Output triples from the default graph.
  • gspo.rq: Output quads from the named graphs.
  • spogspo.rq: Output all triples followed by all quads.
  • tree.rq: Deterministically replaces all intermediate nodes with blank nodes. Intermediate nodes are those that appear both as subject and as objects. Useful in conjunction with --out-format turtle/pretty for formatting e.g. RML.
  • gtree.rq: Named graph version of tree.rq.
  • rename.rq: Replaces all occurrences of an IRI in subject and object positions with a different one. Usage (using environment variables): FROM='urn:from' TO='urn:to' rpt integrate data.nt rename.rq
  • count.rq: Return the sum of the counts of triples in the default graph and quads in the named graphs.
  • s.rq: List the distinct subjects in the default graph.