Re: [Haskelldb-users] GROUP BY and unique

[Justin B. <jgb...@gm...>]

On Thu, Jul 10, 2008 at 12:04 AM, Henning Thielemann
<has...@he...> wrote:
>
> I found the idea of implementing grouping by the 'unique' statement rather
> elegant, but its translation is not conform to SQL, isn't it?

Thank you - I contributed that code.

>
>
>     do p <- table Points.points
>        r <- project (Points.c << p!Points.c)
>        unique
>        return r
>
> Is translated to
>
> SELECT C2 C
> FROM (SELECT C C2
>       FROM POINTS T1
>       GROUP BY C2) T1
>
>
> But the C2 after GROUP BY does not denote a column of a table. It may be
> replaced by C or the GROUP BY may be moved to the outer SELECT statement.
>

Looks like a bug. I have been able to reproduce and will try to submit
a patch ASAP. Thanks.

Justin