ค้นหาเมืองที่ลูกค้าอาศัยอยู่มากที่สุด ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
Find the city where the most customers live.It is not neccessary to use all the tables.
 addresses:  address_id [ number]  address_content [ text]  city [ text]  zip_postcode [ text]  state_province_county [ text]  country [ text]  other_address_details [ text] 
SELECT t3.city FROM customers AS t1 JOIN customer_addresses AS t2 ON t1.customer_id = t2.customer_id JOIN addresses AS t3 ON t2.address_id = t3.address_id GROUP BY t3.city ORDER BY COUNT(*) DESC LIMIT 1