Add support for URI and CONCAT

[dpriskorn]

PREFIX wdt: 
PREFIX wd: 
PREFIX wikibase: 
#defaultView:Map
#title:Map of all humans with Libris-URI according to birthplace in Wikidata
#note: Times out on BlazeGraph
SELECT ?item ?librisuri ?coord (sample(?img) AS ?image) (sample(?map) AS ?map) WHERE {
  #?item wdt:P625 ?coord.
  ?item wdt:P5587 ?librisid;
        wdt:P31 wd:Q5;
        wdt:P19 ?birthplace. 
  ?birthplace wdt:P625 ?coord.
  OPTIONAL {?item wdt:P18 ?img}.
  OPTIONAL {?item wdt:P242 ?map}.
  BIND(URI(CONCAT("https://libris.kb.se/katalogisering/",?librisid)) AS ?librisuri)
#SERVICE wikibase:label { bd:serviceParam wikibase:language "sv,en". }
} 
group by ?item ?librisuri ?coord 

Exception: ParseException, cause: Unexpected input: URI(CONCAT("https://libris.kb.se/katalogisering/",?librisid)) AS ?librisuri) #SERVICE wikibase:label { bd:serviceParam wikibase:language "sv,en". } } group by ?item ?librisuri ?coord 

This works:

PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wikibase: <http://wikiba.se/ontology#>
#defaultView:Map
#title:Map of all humans with Libris-URI according to birthplace in Wikidata
#note: Times out on BlazeGraph
SELECT ?item #?librisuri 
?coord (sample(?img) AS ?image) (sample(?map) AS ?map) WHERE {
  #?item wdt:P625 ?coord.
  ?item wdt:P5587 ?librisid;
        wdt:P31 wd:Q5;
        wdt:P19 ?birthplace. 
  ?birthplace wdt:P625 ?coord.
  OPTIONAL {?item wdt:P18 ?img}.
  OPTIONAL {?item wdt:P242 ?map}.
  # BIND(URI(CONCAT("https://libris.kb.se/katalogisering/",?librisid)) AS ?librisuri)
#SERVICE wikibase:label { bd:serviceParam wikibase:language "sv,en". }
} 
group by ?item 
#?librisuri 
?coord 

[hannahbast]

@dpriskorn Thanks, Dennis. It has nothing to do with the BIND. The issue here is that most functions (like URI or CONCAT) are not yet supported, but will be very soon. As you can see in the last commits, we are currently working on an efficient implementation for general SPARQL expressions. Once that groundwork is laid (the code is already all there, just not yet fully reviewed), it will be very easy to add arbitrary functions.

Without the URI and CONCAT, the query works fine and is also fast (300ms on QLever vs. 5s on Blazegraph vs. 1.6s on Virtuoso, if not cached = wait some time before you ask the query again).

PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wikibase: <http://wikiba.se/ontology#>
SELECT ?item ?librisuri ?coord (SAMPLE(?img) AS ?image) (SAMPLE(?map) AS ?map) WHERE {
  ?item wdt:P5587 ?librisid ;
        wdt:P31 wd:Q5 ;
        wdt:P19 ?birthplace . 
  ?birthplace wdt:P625 ?coord .
  OPTIONAL { ?item wdt:P18 ?img } .
  OPTIONAL { ?item wdt:P242 ?map } .
  BIND(?librisid AS ?librisuri)
} 
GROUP BY ?item ?librisuri ?coord

[hannahbast]

Moved to #615