Do you have TDB defaultUnionGraph turned on?
On 22 May 2014 16:51, Hubert Le Van Gong <[email protected]> wrote: > Cool, it worked fine. > > Just curious, I noticed that the named graphs end up embedded in the > required default (nameless) graph (see below). > Any particular reason to do this and not have the default graph empty, > followed by the named graphs? > > Cheers, > Hubert > > { > "@graph" : > [ > { > "@graph" : > [...], > "@id" : "http://example.org/graph1"; > }, > { > "@graph" : > [...], > "@id" : "http://example.org/graph2"; > }, > ] > } > > > On Thu, May 22, 2014 at 4:16 AM, Andy Seaborne <[email protected]> wrote: > >> On 22/05/14 03:03, Hubert Le Van Gong wrote: >> >>> Greetings, >>> >>> I have a set of N-Quad statements that relate to different graphs. How do >>> I >>> go about exporting all those statements into a single JSON-LD object? >>> >>> For instance, I would expect that something like: >>> <http://one.example/subject3> <http://one.example/predicate3> < >>> http://one.example/object3> <http://example.org/graph3> . >>> _:subject1 <http://an.example/predicate1> "object1" < >>> http://example.org/graph1> . >>> _:subject2 <http://an.example/predicate2> "object2" < >>> http://example.org/graph2> . >>> >>> would end up as the following JSON-LD (disclaimer: I'm not 100% sure this >>> is correct, JSON-LD wise): >>> >>> [ >>> { >>> "@context": { >>> "predicate3": "http://one.example/predicate3"; >>> }, >>> "@id": "http://example.org/graph3";, >>> "@graph": >>> [ >>> { >>> "@id": "http://one.example/subject3";, >>> "predicate3": "http://one.example/object3"; >>> } >>> ] >>> }, >>> { >>> "@context": { >>> "predicate1": "http://an.example/predicate1"; >>> }, >>> "@id": "http://example.org/graph1";, >>> "@graph": >>> [ >>> { >>> "@id": "_:b0", >>> "predicate1": "object1" >>> } >>> ] >>> }, >>> { >>> "@context": { >>> "predicate2": "http://an.example/predicate2"; >>> }, >>> "@id": "http://example.org/graph2";, >>> "@graph": >>> [ >>> { >>> "@id": "_:b0", >>> "predicate2": "object2" >>> } >>> ] >>> } >>> ] >>> >>> >>> So far, the approach I took was to load the n-quads using: >>> RDFDataMgr.read(dataset, in, RDFLanguages.NQUADS); >>> >> >> >> >>> and then iterate through the graph names, to get each model with: >>> Model model = dataset.getNamedModel(name); >>> >>> Something like model.write(out, RDFLanguages.strLangJSONLD); works well to >>> convert the data to JSON-LD, however it does not add any graph info >>> (@graph). >>> While I could probably stitch those parts together, I was hoping for a >>> cleaner way to do this. >>> >> >> If you write the whole dataset: >> >> RDFDataMgr.write(System.out, dataset, Lang.JSONLD) ; >> >> all the graphs will come out, named. >> >> If you want to print one graph, with it's name, create a separate dataset, >> put just that graph in it, as a named graph, and print that. >> >> Models don't have names - it's the container (dataset) that gives it it's >> name. It can have several names (be included several times, or in several >> places). >> >> Andy >> >> >> >>> In particular, I tried to create a new model by uniting 2 models at a time >>> but it did not quite work (although I do see @graph added)... >>> >>> Can anyone shed some light on the best approach for this? >>> >>> Cheers, >>> Hubert >>> >>> PS: my apologies if it's already been discussed before but I did not find >>> anything on this particular topic in the list archive. >>> >>> >>
