问题
I have a graph of RDF data, that is the result of a SPARQL query in rdflib, but this question is valid just on any endpoint too. The graph looks like the picture below.
I want to find a way to query the nodes that are shared between two clusters. Those are basically the nodes that are:
- Subject to two objects
- Object to two subjects
- Object to a subject, and, then subject to another object
I tried with Graph.subjects() and Graph.objects() on rdflib it seems to me that they are only iterable and I have to iterate the whole graph three times, for each of the above scenarios, and it would result in a lot of double counting.
I was wondering if anyone has an idea on how to do this in a better way, perhaps within SPARQL to begin with.
来源：https://stackoverflow.com/questions/53863374/querying-the-shared-nodes-in-a-rdf-graph