SPARQL select optional with language

Question

I have some triples that look like this:

test:thing rdfs:label \"Non-Language Label\"
test:thing rdfs:label \"English Label\"@en
test:thing rdfs:label \"French L         


        

Answer 1

PREFIX rdfs:  
SELECT ?uri ?label ?preferredLabel
WHERE 
{
  {
   ?uri rdfs:label ?label . FILTER(LANG(?label) = "" && regex(str(?label), '(^|\\\\W)fr', 'i'))
  }
  UNION
  {
   ?uri rdfs:label ?preferredLabel . FILTER(LANG(?preferredLabel) = "fr" && regex(str(?preferredLabel), '(^|\\\\W)fr', 'i'))
  }
}