galgonek opened a new issue, #2992: URL: https://github.com/apache/jena/issues/2992
### Version 5.3.0 ### What happened? I used the service enhancer plugin and executed the following query: ```sparql PREFIX sachem: <http://bioinfo.uochb.cas.cz/rdf/v1.0/sachem#> SELECT * WHERE { VALUES ?STRUCTURE { "[He]" "[Ar]" } SERVICE <loop:bulk+5:https://idsm.elixir-czech.cz/sparql/endpoint/chebi> { ?COMPOUND sachem:substructureSearch [ sachem:query ?STRUCTURE ] } } ``` After running this query, the following query is sent to the specified endpoint: ``` SELECT * WHERE { { ?COMPOUND <http://bioinfo.uochb.cas.cz/rdf/v1.0/sachem#substructureSearch> _:b0 . _:b0 <http://bioinfo.uochb.cas.cz/rdf/v1.0/sachem#query> "[He]" BIND(0 AS ?__idx__) } UNION { { ?COMPOUND <http://bioinfo.uochb.cas.cz/rdf/v1.0/sachem#substructureSearch> _:b0 . _:b0 <http://bioinfo.uochb.cas.cz/rdf/v1.0/sachem#query> "[Ar]" BIND(1 AS ?__idx__) } UNION { BIND(1000000000 AS ?__idx__) } } } ORDER BY ASC(?__idx__) ``` I believe that this generated query violates the SPARQL specification. According to the [specification](https://www.w3.org/TR/sparql11-query/#bgpBNodeLabels), _when using blank nodes of the form \_:abc, labels for blank nodes are scoped to the basic graph pattern. A label can be used in only a single basic graph pattern in any query._ However, the generated query uses the label `_:b0` in two separate basic graph patterns, which, in my opinion, contradicts this rule. ### Relevant output and stacktrace ```shell ``` ### Are you interested in making a pull request? None -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
