Clever Geek Handbook

Handling Special Characters in SPARQL-Filter Expressions

I am accessing SPARQL-Endpoint dbpedia [1] to get the URI for a given city. To do this, I use the following query:

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX dbpedia: <http://dbpedia.org/ontology/> 
select distinct * where 
  {?uri rdfs:label ?label. 
  FILTER (REGEX(STR(?label), "^Köln$", "i")). 
  ?uri a dbpedia:PopulatedPlace.
}

If I ask for a city without a German umlaut, everything works fine, but if there is an umlaut, I get nothing. When executing this request with code, I even get a 406 error (Invalid)

Any idea how to deal with umlauts in a SPARQL query against dbpedia?

Thanks in advance,
Frank

[1] http://dbpedia.org/sparql

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There seems to be a mistake in handling your character, maybe in transport or otherwise. It works when you just write it in unicode hex for ö , for example:

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX dbpedia: <http://dbpedia.org/ontology/> 
select distinct * where 
  {?uri rdfs:label ?label. 
  FILTER (REGEX(STR(?label), "^K\u00F6ln$")). 
  ?uri a dbpedia:PopulatedPlace.
}


Edit: I can see now that this doesn't work with the 'i' flag. The documentation assumes the "u" flag is applicable here.

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