Re: histogram

David Johnston wrote:
> Given that you are actively implementing the code that uses the 1 and 2 I
> don't see how it is that egregious. When generating calculated fields it is
> cleaner than the alternative:
>
> Select trunc(distance * 10.)/10., count(*)
> From doc_ads
> Group by (trunc(distance * 10.))
> Order by (trunc(distance * 10.))
>
> It would be nice if you could do:
>
> Select trunc(distance * 10.)/10. AS bin, count(*) AS frequency
> From doc_ads
> Group by bin
> Order by bin
>
> But I do not believe that is allowed (though I may have my syntax wrong...)
>
> David J.
>
>
>>> re: 1 and 2. They're horrible (imho) reference to the attributes of the
>>>
> returned tuple. Or at best an exposure of the implementation. :)
>
>
>>> Joel Reymont wrote:
>>>
>>>> I think this should do what I want
>>>>
>>>> select trunc(distance * 10.)/10., count(*)
>>>> from doc_ads
>>>> group by 1 order by 1
>>>>
>>>> Thanks, Joel
>>>>
>
>
I think we're supposed to bottom-post here.

I agree in the case of generated columns and old servers but you see the
practice more commonly than really necessary. But in 8.4 at least

select trunc(distance * 10.0 )/10.0 as histo, count(*) as tally
from d group by histo order by tally;

works just fine for me