Label service variables don’t get added to SELECT *
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Description

SELECT * WHERE {
  BIND(wd:Q42 AS ?item)
  SERVICE wikibase:label {
    bd:serviceParam wikibase:language "en".
    ?item rdfs:label ?itemLabel.
  }
}

This query (link) should return both ?item and ?itemLabel, since the label is explicitly selected in the service. But the result only has ?item.

Details

	Subject	Repo	Branch	Lines +/-
	Fix projection for label service.	wikidata/query/rdf	master	+115 -48

Customize query in gerrit

Related Objects

Mentioned In: rWDQGe6c5762002a0: Convert wildcard query to use variables
rWDQGca9c661d04b5: Convert wildcard query to use variables
rWDQGd7dd3f32a3dc: Convert wildcard query to use variables

Event Timeline

Lucas_Werkmeister_WMDE created this task.Jul 20 2017, 4:53 PM

Restricted Application added a project: Discovery-ARCHIVED. · View Herald TranscriptJul 20 2017, 4:53 PM

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Smalyshev moved this task from Incoming to Current work on the Wikidata-Query-Service board.Jul 26 2017, 8:19 AM

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Lucas_Werkmeister_WMDE added a subscriber: • Jonas.Aug 1 2017, 3:51 PM

@Smalyshev is it possible to fix this before Wikimania? @Jonas needs this for improving the query helper’s behavior for creating a query from scratch: the query helper starts with SELECT * WHERE {}, and adding variables to the label service is easy, but expanding the * is hard unless we do it in some hacky way.

I'll take a look. If it's a bug in the service, yes, if it's upstream issue, may take longer.

But expanding * should not be too hard I think - just scanning query text for \b\?\w+\b should extract vars (it's not bulletproof as it might also capture inside strings but I haven't seen many strings with such pattern inside)?

In any case, I'll take a look.

Smalyshev added a project: Discovery-Wikidata-Query-Service-Sprint.Aug 1 2017, 4:56 PM

• Jonas mentioned this in rWDQGd7dd3f32a3dc: Convert wildcard query to use variables.Aug 2 2017, 9:50 AM

• Jonas mentioned this in rWDQGca9c661d04b5: Convert wildcard query to use variables.Aug 2 2017, 1:39 PM

• Jonas mentioned this in rWDQGe6c5762002a0: Convert wildcard query to use variables.Aug 2 2017, 2:45 PM

Smalyshev claimed this task.Aug 3 2017, 6:37 PM

Smalyshev moved this task from Backlog to In progress on the Discovery-Wikidata-Query-Service-Sprint board.

Change 370099 had a related patch set uploaded (by Smalyshev; owner: Smalyshev):
[wikidata/query/rdf@master] Fix projection for label service.

https://gerrit.wikimedia.org/r/370099

gerritbot added a project: Patch-For-Review.Aug 3 2017, 9:48 PM

Smalyshev moved this task from In progress to Needs review on the Discovery-Wikidata-Query-Service-Sprint board.Aug 3 2017, 11:35 PM

Change 370099 merged by jenkins-bot:
[wikidata/query/rdf@master] Fix projection for label service.