Sparql queries with two variables - sparql

Question

How can I make a sparql query with 2 variables?
And let me explain:
I have an ontology for historical maps. My entities are:HistoricalMap , Language , Color
and the object properties that connect them are:hasLanguage , hasColor (the hist.map has language and has color).
If I make the query:
SELECT ?HistoricalMap ?Language ?Color
WHERE { ?HistoricalMap p1:hasLanguage ?Language.
?HistoricalMap p1:hasColor ?Color.
}
I get all the maps that have color and language.
How can i ask for the map that hasColor "Red" AND hasLanguage French?

Answer 1

Because you want "AND", you can just use constants in the pattern.
SELECT ?HistoricalMap
WHERE { ?HistoricalMap p1:hasLanguage "French".
?HistoricalMap p1:hasColor "Red" .
}
If you also want to return the variables still, use FILTER:
SELECT ?HistoricalMap ?Language ?Color
WHERE { ?HistoricalMap p1:hasLanguage ?Language.
?HistoricalMap p1:hasColor ?Color.
FILTER(?Language = "French" && ?Color = "Red")
}

Answer 2

you need to understand how the french language and the colour red are represented in your data.
it should be enough to see how they are returned when doing the query you have mentioned.
querying dbpedia, that would be, for instance:
SELECT ?entity
WHERE {
?entity dbpedia-owl:colour <http://dbpedia.org/resource/Red> .
?entity dbpedia-owl:language <http://dbpedia.org/resource/French_language> .
}