Question

您好我正在尝试计算结果集的平均值，但我无法这样做，选择count（*）的查询会返回1月1日到31日之间每天的通话计数，因此返回了近20行。如何计算结果的平均值，然后将值分配给变量，如SET @abc =（下面的查询）。我正在使用sql server 2005。

SELECT avg(Calls) AS average 
FROM
(
     SELECT COUNT(*) Calls      
     FROM abc 
     WHERE CallDate  BETWEEN '20120101'  AND '20120131' 
     AND datepart(Hh,TranscribeDateTime) = '07' 
     AND datepart(Mi,TranscribeDateTime) BETWEEN '00' AND '59'  
     AND AppID = 123 AND Status ='T' 
     GROUP BY calldate
)

如果我的方法有误，请提出一个。谢谢

Answer 1

看起来你只是缺少派生表的表别名（在SQL Server中需要）和赋值语句（如果要将列AS average分配给变量，也不能为列DECLARE @ABC INT; SELECT @ABC = AVG(Calls) FROM ( SELECT COUNT(*) Calls FROM abc WHERE CallDate BETWEEN '20120101' AND '20120131' AND datepart(Hh,TranscribeDateTime) = '07' AND datepart(Mi,TranscribeDateTime) BETWEEN '00' AND '59' AND AppID = 123 AND Status ='T' GROUP BY calldate ) T /* <-- Alias here */添加别名）< / p>

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查找返回多行的count（*）的平均值

1 个答案: