It's hard too understand cold but this looks odd to me:
In App.java@
DgraphDB db = new DgraphDB(dsg, new DatasetPrefixesDgraphDB());
Dataset dataset = DatasetFactory.wrap(db);
Model myMod = dataset.getDefaultModel();
...
Dataset ds = DatasetFactory.create(myMod);
ds.asDatasetGraph().setDefaultGraph(infgraph);
---------
If using StorageRDF, then I'd the dataset to be built with
DatasetGraphStorage
(see TDB2)
setDefaultGraph, slightly contrary to name, is a copy. It is a bit of
legacy hangover.
I'd expect:
StorageDgraphDB Dg_dsg =
new StorageDgraphDB(txnSystem, tripleTable, quadTable);
DatasetGragh dsg1 =
new DatasetGraphStorage(Dg_dsg,
new DatasetPrefixesDgraphDB(),
txnSystem);
And inference:
Graph g = dsg1.getDefaultGraph();
InfGraph infgraph = reasoner.bind(g);
infgraph.setDerivationLogging(true);
create a layer:
DatasetGraph dsg2 = DatasetGraphFactory.wrap(g);
FusekiServer server = FusekiServer.create()
.add("/ds", dsg2)
(untested)
Andy
On 12/01/2022 14:39, brain wrote:
Hi Andy and Jena,
So glad to see you here.
I just upload my code to GitHub
https://github.com/analyticservicedev/dgraph-jena
<https://github.com/analyticservicedev/dgraph-jena>
It’s short and a little dirty .
I have `class DgraphTripleTable implements TripleStore`.
And do CRUD with add() delete() find() or findXxxMethods()
Then I have DgraphTripleTable in `class StorageDgraphDB implements
StorageRDF`
And then wrap the StorageDgraphDB with ds= DatasetFactory.wrap(db);
Finally, I have FusekiServer.create().add("/ds",
ds).port(6384).build().start()
I have a test file in src/test/java/com/jena/app/Inf.java
There are three methods named main tdbmain memoryMain
for different storage backend: Dgraph 、 TDB、 Memory
Could you check my code and give me some advice to help me make it run?
Thank you very much.
On Jan 12, 2022, at 9:45 PM, Andy Seaborne <a...@apache.org> wrote:
On 12/01/2022 09:10, brain wrote:
Hello,
I need some help.
With this guide,
https://jena.apache.org/documentation/fuseki2/fuseki-embedded.html,
<https://jena.apache.org/documentation/fuseki2/fuseki-embedded.html,>
I created an embeded-fuseki server to provide a SPARQL service .
I make an implemention of `org.apache.jena.dboe.storage.StorageRDF`
interface in Java, so I can store rdf triples with my own storage engine(a
distributed database). And it works. I can query the rdfs with SPARQL.
However, I have some problems.
When I try to change my model to a `InfGraph` , the reasoner can't
works. It must be some bugs in my code. but I can't find it .
Is there any guide or something else to help me fix the bug .
Our data stored in a distributed database. We want to do SPARQL Query and
Inference.
Thanks
Hi there,
Could you give some details of your setup?
+ How do you query with RDFS?
+ What level of inferencing are you setting for the InfGraph?
+ Are you using an assembler or setting up the InGraph with code?
If it is RDFS you are wanting, there's a different approach that might work
better for you:
https://jena.apache.org/documentation/rdfs/
This is fixed schema, data-centric (so it is not full RDFS reasoning - there
are no axiomatic triples, and iyt assumes that vocabulary like subproperty or
subclass isn't being subproperty'ed.)
But keeps no in-memory state from the data itself so it scales and you can
directly update the data and see new inferred triples.
Andy
