guiveg / rdfsurveyor

Exploration tool for RDF datasets
Apache License 2.0
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rdfsurveyor should explore named graphs #1

Open jmvanel opened 6 years ago

jmvanel commented 6 years ago

On my SPARQL http://semantic-forms.cc:9112/sparql there is almost nothing in the anonymous graph. rdfsurveyor says: No data in the repository!

NOTE: explanation why all is in named graphs in semantic-forms: https://github.com/jmvanel/semantic_forms/wiki/User_manual#the-rdf-cache-and-database

jmvanel commented 6 years ago

I implemented a second SPARQL endpoint: http://semantic-forms.cc:9112/sparql2 that puts all the named graphs' content in the anonymous graph (called union graph in Jena doc.).

Now if works, but there are several issues.

guiveg commented 6 years ago

I'm not sure if there is an issue with named graphs. The user can specify a named graph URI (using the "Named graph URI" field) or just leave it blank. In either case, RDF Surveyor first tests if there is at least one triple before going to the repo page. This is the specific SPARQL query to test this: SELECT * WHERE { ?s ?p ?o . } LIMIT 1

jmvanel commented 6 years ago

As I understand, surveyor gives the ability to specify ONE named graph. The case for my database is more general: there are tens or hundreds of named graphs, and in fact all the triples are in one of the named graphs. Here is a view of the named graphs in a typical semantic_forms instance: http://semantic-forms.cc:9112/showNamedGraphs Each RDF document downloaded from the LOD in in its own named graph, plus user (keyboard) input each in a user:XXX named graph,

Anyway, since this issue, I provided a second second SPARQL endpoint: http://semantic-forms.cc:9112/sparql2 as said before, so you could close the issue, except if you want to connect to other such multi-graph endpoints.

guiveg commented 6 years ago

OK, I see... Well, RDF Surveyor is just prepared to select ONE named graph if specified. Basically, this is the same approach as Virtuoso SPARQL Query Editor.

I'd like to support multiple named graphs, i.e. your case, but I'm a bit unsure about how to do it. If you have any ideas, please send me an e-mail.