SPARQLStore won't work with preparedQuery

[aucampia]

When using a graph with SPARQLStore, Graph.query will call Store.query:

rdflib/rdflib/graph.py

Lines 1381 to 1391 in 0856ac8

	if hasattr(self.store, "query") and use_store_provided:
	try:
	return self.store.query(
	query_object,
	initNs,
	initBindings,
	self.default_union and "__UNION__" or self.identifier,
	**kwargs,
	)
	except NotImplementedError:
	pass # store has no own implementation

And this will then proceed to assert that the query is a str:

rdflib/rdflib/plugins/stores/sparqlstore.py

Lines 183 to 192 in 0856ac8

	def query(
	self,
	query,
	initNs=None, # noqa: N803
	initBindings=None,
	queryGraph=None,
	DEBUG=False,
	):
	self.debug = DEBUG
	assert isinstance(query, str)

And even without this assert, things won't work unless it is a str.

This is not an ideal situation, a better situation would be one of:

1. Either don't support query objects, and only strings
2. Obtain a string for the query object in SPARQLStore
3. Have a different methods for working with prepared query

Either way, the interface of Store ideally should have a good match with all the implementations of it that comes with RDFLib.

[mamiksik]

Hey, I am experiencing the same issue and the documentation does not explain this limitation.