This is fine , I can get all the TDB prefix mappings with: dataset.getDefaultModel().getNsPrefixMap() , but I don't see how I can add them to a graph resulting from a SPARQL query, in order to write it. I see nothing for this in RDFDataMgr . And then, if I can add them while printing a graph, will the big list of prefixes be added, or only the prefixes actually used will be printed ?
Jean-Marc Vanel <http://semantic-forms.cc:9112/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me> +33 (0)6 89 16 29 52 Le mar. 1 déc. 2020 à 21:34, Andy Seaborne <a...@apache.org> a écrit : > > > On 01/12/2020 19:02, Jean-Marc Vanel wrote: > > Empty maps are obtained by calling getPrefixMapping() , > > either with a graph from a SPARQL query, or from the Union Graph. > > Perfect timing! > > JENA-2006 (in-progress as of 2020-12-01 - PR went in today. > adds Dataset.getPrefixMapping() and DatsetGraph.prefixes() > > For a TDB database, all graphs will have the same prefix map, including > the union graph. > > Currently - 3.17.0 - the dataset prefixes (i.e. as used for output) are > held with the default graph. While the code supports additonal prefix > sets, they are accssible without going into the implementation. > > JENA-2006 changes all that. > > > From a SPARQL query, only possible prefix mappings are from the query, > not > > the database. > > They are on the default graph, if there are any from TriG. > > > Same thing with > > PrefixMappingUtils.calcInUsePrefixMapping(graph) > > There is a class called DatasetPrefixesTDB , but it seems a low level > > implementation class. > > Some code comments imply that a prefixes map is not maintained > > permanently ... > > > > Not yet tested with 3.17.0 . > > No change. > > Andy > > > > > Jean-Marc Vanel > > < > http://semantic-forms.cc:1952/display?displayuri=http://jmvanel.free.fr/jmv.rdf%23me > > > > +33 (0)6 89 16 29 52 > > Twitter: @jmvanel , @jmvanel_fr ; chat: irc://irc.freenode.net#eulergui > > Chroniques jardin > > < > http://semantic-forms.cc:1952/history?uri=http%3A%2F%2Fdbpedia.org%2Fresource%2FChronicle > > > > >
