SPARQL query language tag weirdness

This works:

SELECT * WHERE{
?x rdfs:la开发者_开发问答bel "Chalti Ka Naam Gaadi"@en .
?x foaf:name ?z .    
}

(Results on DBpedia SPARQL Explorer)

This doesn't:

SELECT * WHERE{
?x foaf:name "Chalti Ka Naam Gaadi" .
?x rdfs:label ?z .    
}

(Results on DBpedia SPARQL Explorer)

Why?

Your issue is that plain literals with language tags: "Chalti Ka Naam Gaadi"@en

are not the same as plain literals without language tags: "Chalti Ka Naam Gaadi"

Literals are structured things made of a lexical part, language (maybe), or datatype (maybe).

You could filter: FILTER ( str( ?name ) = "Chalti Ka Naam Gaadi")

(str() returns the lexical part of the literal)

but, depending on the query engine, that will be much slower.