mysql - mysql中的平均百分比值

Question

我试图将计数值除以子查询的值并乘以 100 以获得它的百分比。下面的代码有效......

SELECT data, rota as rt, COUNT(cliente_id) / 
(
 SELECT COUNT(DISTINCT cliente_id)
 FROM vw_grafico
 WHERE rota = rt  
) * 100 ) AS porcentagem

FROM vw_grafico
WHERE WEEKDAY(data)+1  = rota 
AND YEAR(data) = 2013
GROUP BY month(data)
ORDER BY data ASC

...但是，除此之外，我需要按月计算该值的平均值，这就是我的问题...当我尝试执行此操作时出现错误“无效使用组函数”：

SELECT data, rota as rt, AVG(COUNT(cliente_id) / 
(
 SELECT COUNT(DISTINCT cliente_id)
 FROM vw_grafico
 WHERE rota = rt  
) * 100 ) AS porcentagem

FROM vw_grafico
WHERE WEEKDAY(data)+1 = rota 
AND YEAR(data) = 2013
GROUP BY month(data)
ORDER BY data ASC

我应该怎么做才能解决这个错误？

Answer 1

Select list fields( not aggregates) must be Subset of Group by List that in your query this is not true and your error is for that.

在您的查询中：

SELECT data, rota as rt, AVG(COUNT(cliente_id) / 
(
 SELECT COUNT(DISTINCT cliente_id)
 FROM vw_grafico
 WHERE rota = rt  
) * 100 ) AS porcentagem

FROM vw_grafico
WHERE WEEKDAY(data)+1 = rota 
AND YEAR(data) = 2013
GROUP BY month(data)
ORDER BY data ASC

选择列表是：

data, rota as rt

和组列表是：

month(data)

选择列表字段不是组列表的子集。所有选择列表字段必须在组列表中，例如：

SELECT month(data), rota as rt, AVG(COUNT(cliente_id) / 
(
 SELECT COUNT(DISTINCT cliente_id)
 FROM vw_grafico
 WHERE rota = rt  
) * 100 ) AS porcentagem

FROM vw_grafico
WHERE WEEKDAY(data)+1 = rota 
AND YEAR(data) = 2013
GROUP BY month(data), rota
ORDER BY data ASC