How many {field of work} are to/by {Middle Ages} ?
What is the number of professions in the middle ages?
How many fields of work were there in the middle ages?
SELECT ( COUNT ( ?i ) AS ?h ) { ?i property:field_of_work resource:Middle_Ages }
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/P101> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q12554 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P101 wd:Q12554 }
94