Add filter, add READMES

backend_go/graph_queries/hierarchy.go

@@ -0,0 +1,24 @@
+package graph_queries
+
+import "fmt"
+
+func hierarchyEdgeQuery(edgeLimit int, includeBNodes bool) string {
+	bnodeFilter := ""
+	if !includeBNodes {
+		bnodeFilter = "FILTER(!isBlank(?s) && !isBlank(?o))"
+	}
+
+	return fmt.Sprintf(`
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+SELECT ?s ?p ?o
+WHERE {
+  VALUES ?p { rdfs:subClassOf }
+  ?s ?p ?o .
+  FILTER(!isLiteral(?o))
+  %s
+}
+LIMIT %d
+`, bnodeFilter, edgeLimit)
+}
+