Database: store_product
Question: What is the city with the most number of flagship stores?
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 GROUP BY t3.headquartered_city ORDER BY count(*) DESC LIMIT 1