Re: Fwd: Ask for a question - Mailing list pgsql-general

On 21/01/2015 17:32, Pierre Hsieh wrote:
> Hi guys,
>
> Thanks for your replies.
>
>  I certainly can use VBA and ADODB object in Excel to do it. Due to
> performance, I wanna try to do it by SQL command in PG. However, I am
> not expert in PG, so I need few help from your guys. Let me to describe
> my question clearly as following.
>
> The final results which I wanna get
> are STDDEV(a1,a2,a3,...), STDDEV(b1,b2,b3,...), ..etc. I definitely know
> how to use standard deviation function in PG, but the critical problem
> for me is how to calculate a1, a2, a3, b1, b2, b3...etc. The rule to
> calculate them is a little complicated because it needs not only moving
> window function but also few logical rules. Please see details as
> following or attachment. I put some colors in rules. Hopefully, it's
> easier for you guys to read them. Thanks

Sorry, either I'm being stupid or your description isn't clear. Can you
show your table structure, ideally with some sample data, and what you
hope to get from the query?

Ray.


--
Raymond O'Donnell :: Galway :: Ireland
rod@iol.ie