SQL – STDEVP或STDEV以及如何使用?

前端之家收集整理的这篇文章主要介绍了SQL – STDEVP或STDEV以及如何使用?前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
我有一张桌子:
LocationId OriginalValue Mean
1          0.45         3.99  
2          0.33         3.99
3          16.74        3.99
4          3.31         3.99

等等…

我将如何使用此表格制定标准偏差,以及您将推荐什么 – STDEVP或STDEV?

解决方法

要使用它,只需:
SELECT STDEVP(OriginalValue)
FROM yourTable

从下面你可能想要STDEVP.

here

STDEV is used when the group of numbers being evaluated are only a partial sampling of the whole population. The denominator for dividing the sum of squared deviations is N-1,where N is the number of observations ( a count of items in the data set ). Technically,subtracting the 1 is referred to as “non-biased.”

STDEVP is used when the group of numbers being evaluated is complete – it’s the entire population of values. In this case,the 1 is NOT subtracted and the denominator for dividing the sum of squared deviations is simply N itself,the number of observations ( a count of items in the data set ). Technically,this is referred to as “biased.” Remembering that the P in STDEVP stands for “population” may be helpful. Since the data set is not a mere sample,but constituted of ALL the actual values,this standard deviation function can return a more precise result.

原文链接:https://www.f2er.com/mssql/83082.html

猜你在找的MsSQL相关文章