如何在sql中为每个column_name选择avg（value）

Question

I have a table named studios with the columns "earnings" and "country". Each item of that table describes a studio in a country and its earnings.
How can I select the average earnings of the studios for each country?

SELECT AVG(earnings) --I want per country
FROM studios

Answer 1

SELECT country,AVG(earnings) FROM studios GROUP BY country;

Answer 2

You can do that: "SELECT AVG(earnings) FROM studios GROUP BY country" If you have column country_id is for prefer.

You can use and this query "SELECT AVG(earnings),country FROM studios GROUP BY country"

Answer 3

你可以用这个：

SELECT AVG(earnings) , country from studios group by country