从列中选择最高值

Question

How can I find top 5 countries with highest population per continent. I just want to use below 1 table:

URL: http://dev.mysql.com/doc/index-other.html

Database: world database (MyISAM version, used in MySQL certifications and training)

Below is what I came up with:

select Continent,
substring_index(
GROUP_CONCAT(distinct cast(Name as char)), ',', 5)
From
country
group by
Continent,Name;

Thanks, Rio

Answer 1

This one is with correlated sub-query :

SELECT c.name, c.continent 
WHERE population IN (SELECT population 
                    FROM country c1
                    WHERE c.continent = c1.continent
                    ORDER by population
                    LIMIT 5)
FROM country c

Not having database schema I made some assumptions about its fields.