How many {brand} are to/by {iPhone} ?
How many types of iPhone exist?
SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1716 wd:Q2766 }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1716> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q2766 .
} 

How many different kinds of iPhones are there?