====== Standard Deviation Formula in Hibernate ======

There isn't any standard deviation formula in hibernate: 

http://stackoverflow.com/questions/740293/is-it-possible-to-do-standard-deviation-in-nhibernate/17786363

However, I think that the better approximation is to calculate it using the following formula:

<code>
sqrt((sum(value*value)/count(value)) - (avg(value) * avg(value)))
</code>