Table schema:
CREATE TABLE store_district (store_id VARCHAR); CREATE TABLE district (district_id VARCHAR, city_population VARCHAR); CREATE TABLE store (store_name VARCHAR, store_id VARCHAR)

Question: Find all the stores in the district with the most population.
SQL: SELECT t1.store_name FROM store AS t1 JOIN store_district AS t2 ON t1.store_id = t2.store_id WHERE district_id = (SELECT district_id FROM district ORDER BY city_population DESC LIMIT 1)