Exploring Graphs with Elixir

Querying the Local RDF Service

We’re going to need some RDF data. To keep it simple, we’ll take the RDF description we generated in the previous chapter for a book resource—the book graph:

iex> graph_context RDFGraph
RDFGraph

iex> graph_create read_graph("book.ttl")
#GraphCommons.Graph<type: rdf, file: "", data: "">

iex> graph_info
%GraphCommons.Service.GraphInfo{
  file: "",
  labels: ["Book", "Organization", "Person"],
  num_edges: 27,
  num_nodes: 8,
  type: :rdf
}

Here we selected the RDFGraph graph service and then created a new graph using the book.ttl stored graph.

Now let’s have a look at the SELECT and CONSTRUCT query forms.

SELECT

Let’s use a simple SELECT query that returns all the RDF terms ...