Database: store_product
Question: What city is the headquarter of the store Blackville?
SQL:
SELECT t3.headquartered_city FROM store AS t1 JOIN store_district AS t2 ON t1.store_id  =  t2.store_id JOIN district AS t3 ON t2.district_id  =  t3.district_id WHERE t1.store_name  =  "Blackville"