Getting a union graph using rdflib and anzograph

Question

I have a number of graphs in an anzograph. Using rdflib, I want to access them as a union graph.

Without the store and parsing the graphs into memory, it works fine as a ConjunctiveGraph. However, when attaching to Anzo as a store, I cannot get the union graph.

Here are the snippets:

import rdflib
import rdflib.plugins.stores.sparqlstore as store

store = store.SPARQLUpdateStore("http://192.168.1.104:7070/sparql", "http://192.168.1.104:7070/update")
graph = rdflib.ConjunctiveGraph(store=store)

Then

for c, in graph.query("select (count(*)as ?c) {?s ?p ?o}"):
    print(c)

gives this output

While

for g, c in graph.query("select distinct ?g (count(*)as ?c) {graph ?g{?s ?p ?o}}group by ?g"):
    print(g, c)

gives

urn:2022-11-25.ttl 5760
urn:2022-11-27.ttl 9160
urn:2022-11-24.ttl 5565
urn:2022-11-26.ttl 7645
urn:2022-11-22.ttl 2820
urn:2022-11-23.ttl 7250

The rdflib manual states

A ConjunctiveGraph is an (unnamed) aggregation of all the named graphs in a store. ... All queries are carried out against the union of all graphs.

Is there any setup to achieve a union graph with Anzo as the store?

Getting a union graph using rdflib and anzograph

0 Answers0