I see you point Merlin. I am new to federated query as you guessed :) I do have two different datasets with unnamed graphs (default graphs). I use one of the dataset endpoints and link in the other with SERVICE. The query below give my a intersect instead of the union. How to I perform a union between the to different dataset with unnamed graphs?
PREFIX ex: <http://clearbyte.org/> SELECT ?s ?p ?o WHERE { ?s ?p ?o SERVICE <http://localhost:8080/fuseki/model2> { ?s ?p ?o } } Result: 1 ex:Guernica<http://clearbyte.org/Guernica> <http://www.w3.org/2000/01/rdf-schema#label><http://www.w3.org/2000/01/rdf-schema#label> "Guernica" 2 ex:Picasso<http://clearbyte.org/Picasso> ex:homeAddress<http://clearbyte.org/homeAddress> _:b0 3 ex:Picasso<http://clearbyte.org/Picasso> <http://xmlns.com/foaf/0.1/surname><http://xmlns.com/foaf/0.1/surname> "Picasso" 4 ex:Picasso<http://clearbyte.org/Picasso> ex:creatorOf<http://clearbyte.org/creatorOf> ex:guernica<http://clearbyte.org/guernica> 5 ex:Picasso<http://clearbyte.org/Picasso> <http://xmlns.com/foaf/0.1/firstName><http://xmlns.com/foaf/0.1/firstName> "Pablo" //Cheers ________________________________ Från: Bögershausen, Merlin <merlin.boegershau...@rwth-aachen.de> Skickat: den 23 april 2020 14:35 Till: users@jena.apache.org <users@jena.apache.org> Ämne: AW: Union different dataset in Fuseki Hi, Very interesting part seems still not clear. Do you have two graphs in the SAME dataset which need to be merged or do you have two datasets with graphs that need to be merged. Two datasets (datasets are a set of graphs) mean that you have two SPARQL endpoints in fuseki. A Query is send to exactly one endpoint. If a query needs information from a second dataset the second endpoint need to be queried. This is done with the SERVICE pattern, see example in [1]. (union with federated query) If the data is in two graph in the SAME dataset the FROM keyword does the trick. In this ´scenario you must have at least one named graph. Example see [2], this is the SPARQL language recommendation with good examples to start from. (union with graph pattern) Best Merlin [1] https://www.w3.org/TR/sparql11-query/#specifyingDataset [2] https://jena.apache.org/tutorials/sparql_datasets.html -----Ursprüngliche Nachricht----- Von: Glenn TheMan <anykeystu...@hotmail.com> Gesendet: Donnerstag, 23. April 2020 13:49 An: users@jena.apache.org Betreff: Sv: Union different dataset in Fuseki Sorry if my question was imprecise and to upset people. Even the W3C guide for federated states "... opportunity to merge data distributed across the Web" But union of the two dataset is what I want. I was unclear about the syntax and how to use prefix for the two local dataset in the query. My dataset's are local so I don't need use the SERVICE keyword i guess, please provide an example bases on the initial question? Cheers ________________________________ Från: Bögershausen, Merlin <merlin.boegershau...@rwth-aachen.de> Skickat: den 23 april 2020 12:24 Till: users@jena.apache.org <users@jena.apache.org> Ämne: AW: Union different dataset in Fuseki Hi Glenn, "merge" and "redundant" are a very overloaded term, please be as specific as possible ;-) And even equality is not that clear [1]. If the data is located in different datasets you should use federated queries [2]. If they are in the same dataset but in different graphs the graph pattern should be enough. I suggest reading the SPARQL tutorial [3] to understand the basics of SPARQL. Please understand the sources and repost the question afterwards, if still relevant. Best Merlin [1] https://www.w3.org/TR/sparql11-query/#OperatorMapping [2] https://jena.apache.org/documentation/query/service.html [3] https://jena.apache.org/tutorials/sparql.html -----Ursprüngliche Nachricht----- Von: Lorenz Buehmann <buehm...@informatik.uni-leipzig.de> Gesendet: Donnerstag, 23. April 2020 12:09 An: users@jena.apache.org Betreff: Re: Union different dataset in Fuseki what do you mean by "merge"? What is the result? A proper RDF dataset? Then indeed CONSTRUCT. "optional" is **not** a query type, so I don't understand what you mean by this. Please provide some more details, also what "redundant" means. Also, if you have multiple models, Fuseki setup allows for configuring to query the UNION of both On 23.04.20 12:05, Glenn TheMan wrote: > Hi, I am trying to merge two models (with some redundant info) that are > persist in two different dataset's in Fuseki (3.14). I am using the included > SPARQL query console and set the endpoint for the query to > http://localhost:8080/fuseki/. > How would the SPARQL syntax look like to merge the similar datasets (using > select, construct or optional)? > > Greetings. > > This is my attempt; > PREFIX a: <http://localhost:8080/fuseki/model1/> > PREFIX b: <http://localhost:8080/fuseki/model2/> > SELECT ?s ?p ?o > WHERE > { > { > ?s ?p ?o > } > UNION > { > ?s ?p ?p > } > } >
