How i can improve this sql query ? Question in describtion

There is 3 table 1- country —- id,country_name 2- city ——- id,city_name,country_id 3- customer — customer_name, city_id and the question is “Write the query that finds the country name, city name, and the number of customers of cities with more customers than the average number of customers in the cities.” and my solution is SELECT … Read more