获取select语句的AVERAGE（）

Question

如何获得select查询结果的平均值

示例：

select x from dbo.table1 as a
where MONTH(a.mymonth) = 1 AND YEAR(a.myyear) = 2013

是否可以使用AVG()功能？

Answer 1

这就是你要找的全部吗？

select AVG(x)
from dbo.table1
where MONTH(mymonth) = 1 AND YEAR(myyear) = 2013

Sample Fiddle Demo

根据您的x数据类型，您可能希望将其强制转换为小数：

SELECT AVG(CAST(x as decimal))

Answer 2

是否可以使用AVG（）函数？

是的，将它包裹在x周围，所以：

    select AVG(x) from dbo.table1 as a
    where MONTH(a.mymonth) = 1 AND YEAR(a.myyear) = 2013

此处了解更多信息。

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_avg

Answer 3

如果您希望平均x您的select查询应如下所示：

Select AVG(x)
from dbo.table1 as a
where MONTH(a.mymonth) = 1 AND YEAR(a.myyear) = 2013