环路多个和mysql的

Question

对于报告工具IM建设我想是可以把很多的“事件”是如何发生在已记录每一个国家到目前为止，我有这个疑问：

SELECT 'country', 
     COUNT(*) AS total, 
     SUM(CASE WHEN `country` = 'USA' THEN 1 ELSE 0 END) AS USCount, 
     SUM(CASE WHEN `country` = 'Canada' THEN 1 ELSE 0 END) AS CanadaCount 
    FROM events WHERE `date` > '2015-06-01' AND `date` < '2015-08-01' 

唯一问题在于，当我开始将其他国家添加到组合中时，情况将会变得很大。有没有办法可以循环遍历各个国家以检索每个国家的所有不同计数？谢谢。

Answer 1

集团是由国名，以获得数国明智

SELECT country, 
    COUNT(*) AS total 
FROM events WHERE `date` > '2015-06-01' AND `date` < '2015-08-01' group by country; 

Answer 2

试试下面的SQL语句：

Select country, count (*) 
From events 
Group by country