Question

我有一张包含日期列的5000条记录的表格。

如何找到这些日期的平均值。我试过了AVG(datefield)，但它说Operand data type datetime is invalid for avg operator

Answer 1

如果您只想平均日期：

SELECT CAST(AVG(CAST(datefield AS INT)) AS DATETIME) FROM dates;

如果你想考虑时间：

SELECT CAST(AVG(CAST(datefield AS FLOAT)) AS DATETIME) FROM dates;

请参阅fiddle进行测试。

Answer 2

CONVERT(DATETIME, AVG(CONVERT(FLOAT, datefield))) as [AverageDate]

Answer 3

对于那些遇到转换错误（无法将日期转换为int或float的人）... 这是使用datediff和dateadd

的简单解决方案

SELECT 
DATEADD(DAY, AVG(DATEDIFF(DAY, '1900-01-01', datefield)), '1900-01-01') AS [AverageDate]
FROM dates;

请注意，1900年1月1日是任意日期，两个地方都必须相同。

Answer 4

我做了这个，希望以后能帮到其他人！ SQL 很糟糕，因为它没有让这变得更容易。

Declare @Day as int;
Declare @Month as int;
Declare @Year as int;
Declare @Date as varchar(50);
SET @Day = (SELECT AVG(DAY(Column_name)) FROM Table_Name)
SET @Month = (SELECT AVG(MONTH(Column_name)) FROM Table_Name)
SET @Year = (SELECT AVG(YEAR(Column_name)) FROM Table_Name)
SET @Date =  CAST(@Day as varchar) +'-' + CAST(@Month as varchar) + '-' + CAST(@Year as varchar);
SELECT CONVERT(datetime2,@Date,103)

如何在SQL Server中的日期列中查找平均值

4 个答案: