Hi,
If you search for "UNION" in the SPARQL Recommendation 1.1 [1] there
are multiple examples usages of UNION.
UNION Syntax: { TriplePattern1 } UNION { TriplePattern2 }
My Suggestions:
Curly braces around the first ?s ?p ?oCheck the Service URL, usualy the
default endpoint URL end with "query" or "sparql", see section of the
Fuseki Server Doku [2]
Best Merlin
[1] <https://www.w3.org/TR/sparql11-query/>
[2] <https://jena.apache.org/documentation/fuseki2/fuseki-main.html>
Am Do, 23. Apr, 2020 um 4:55 P. M. schrieb Glenn TheMan
<[email protected]>:
Well I maybe be a newbie on SPARQL but I've bean using Jena and RDF4J
crunching data programmatically and avoid SPARQL as much as I can. So
yes I've done UNION/Intersect etc in code even in SPARQL but not
federated. I've read the W3C federated manual, copying the OPTIONAL
syntax since there are no UNION example, but no luck. Some syntax
help would be appreciated?
SELECT ?s ?p ?o
WHERE
{
?s ?p ?o
UNION {
SERVICE <<http://localhost:8080/fuseki/model2>> {
?s ?p ?o
}
}
}
//Cheers
________________________________
Från: Bögershausen, Merlin <[email protected]
<mailto:[email protected]>>
Skickat: den 23 april 2020 16:43
Till: [email protected] <mailto:[email protected]>
<[email protected] <mailto:[email protected]>>
Ämne: AW: Union different dataset in Fuseki
You are half way done ;)
Now use the UNION Key word [1].
UNION produces the UNION of two Collections of triples.
In your case the triple pattern ?s ?p ?o produces the first and the
service produces the second collection.
Best Merlin
[1] <https://en.wikibooks.org/wiki/SPARQL/UNION>
-----Ursprüngliche Nachricht-----
Von: Glenn TheMan <[email protected]
<mailto:[email protected]>>
Gesendet: Donnerstag, 23. April 2020 15:27
An: [email protected] <mailto:[email protected]>
Betreff: Sv: Union different dataset in Fuseki
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 <[email protected]
<mailto:[email protected]>>
Skickat: den 23 april 2020 14:35
Till: [email protected] <mailto:[email protected]>
<[email protected] <mailto:[email protected]>>
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 <[email protected]
<mailto:[email protected]>>
Gesendet: Donnerstag, 23. April 2020 13:49
An: [email protected] <mailto:[email protected]>
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 <[email protected]
<mailto:[email protected]>>
Skickat: den 23 april 2020 12:24
Till: [email protected] <mailto:[email protected]>
<[email protected] <mailto:[email protected]>>
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 <[email protected]
<mailto:[email protected]>>
Gesendet: Donnerstag, 23. April 2020 12:09
An: [email protected] <mailto:[email protected]>
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
}
}
