How many {spouse} are for {Kangxi Emperor} ?
Which is the number of wives that Kangxi Emperor has?
How many spouses does the Kangxi Emperor have?
SELECT ( COUNT ( ?c ) AS ?u ) { resource:Kangxi_Emperor property:spouse ?c }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q17790> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P26> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q17790 wdt:P26 ?obj }
18