在 MYSQL 查询中求和后求和答案

【问题标题】：Sum after Averaging in MYSQL Query在 MYSQL 查询中求和后求和
【发布时间】：2012-07-25 07:21:17
【问题描述】：

当我尝试对列进行平均处理然后我想对结果求和时遇到了麻烦，我正在使用 MYSQL 来执行此操作。谁能帮我？这是无效的查询：

SUM(IF(AVG(Value)=3,1,0)) AS green

完整查询：

SELECT
  cluster,
  SUM(IF(AVG(Value) AS Value = 3,1,0)) AS green
FROM network
WHERE date>= '2012-07-01'
    AND date<= '2012-07-02'
    AND Region = 'SOMEREG'
    AND cluster IS NOT NULL
GROUP BY cluster

【问题讨论】：

你能把表结构连同完整的查询和group by子句的详细信息一起发布吗？
我已经更新了查询，我会等待答案；）
如果 avg(value) = 3，您似乎想显示值的计数或总和。我说的对吗？

标签： mysql sum average

【解决方案1】：

That should not be an if, but a where in the select statement.

SELECT cluster,
SUM(Value) AS sumValue AVG(Value) AS avgValue
FROM network
WHERE date>= '2012-07-01'
AND date<= '2012-07-02'
AND Region = 'SOMEREG'
AND ((AVG(Value) = 3) OR (AVG(Value) = 1) OR (AVG(Value) = 0))
AND cluster IS NOT NULL
GROUP BY cluster

【讨论】：

@George Aguirre：您自己先尝试查询了吗？？
真相查询是：SELECT cluster, SUM(IF(AVG(Value)=3,1,0)) AS green, SUM(IF(AVG(Value)=2,1,0) ) 为黄色，SUM(IF(AVG(Value)=1,1,0)) 为红色，来自表 WHERE date>= '2012-07-01' AND date

【解决方案2】：

只需这样做

SELECT
  IFNULL(cluster,'Total'),
  SUM(IF(AVG(Value) AS Value = 3,1,0)) AS green
FROM network
WHERE date>= '2012-07-01'
    AND date<= '2012-07-02'
    AND Region = 'SOMEREG'
    AND cluster IS NOT NULL
GROUP BY cluster with roll up

添加汇总将添加所有平均值

【讨论】：

【解决方案3】：

您一次只能应用一个聚合函数。

同一个 group by 子句的多个聚合函数没有意义。您需要创建派生表来查找平均值的总和。试试：

SELECT SUM(green) AS green
FROM (
      SELECT cluster,
             IF(AVG(Value) = 3, 1, 0) AS green
      FROM network
      WHERE date BETWEEN '2012-07-01' AND '2012-07-02'
            AND Region = 'SOMEREG'
            AND cluster IS NOT NULL
      GROUP BY cluster
     ) a;

【讨论】：

那么，如何求和平均结果？有什么想法吗？