1
我想計算沒有異常值的平均值(帶有2個標準偏差)。我不斷收到錯誤消息「聚合不應出現在WHERE子句中,除非它是在含有HAVING子句或選擇列表在子查詢中,並且被聚合的列是外部引用。如何計算沒有異常值的平均值
select
b.[Location],
b.[txtOrderSubType],
avg (DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate])) as
[Avg Duration in min],
from dbo.tbl1
Where
DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate])< (
AVG(DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate]))+
2*STDEVP(DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate])))
and DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate])> (
AVG(DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate]))-
2*STDEVP(DATEDIFF(MINUTE, b.[dteActualStartDate], b.[dteActualEndDate])))
group by b.[Location], b.[txtOrderSubType]