Select groupping by one column

[Josué Maldonado]

Hello list,

I have a table called pedh that looks like this:

REFNO FECHA OCNUM PVD
0199 10/12/2003 5224 632
0199 10/12/2003 5224 632
1264 10/18/2003 8991 210
1264 10/18/2003 8991 210
1264 10/18/2003 8991 210
9093 10/20/2003 6895 520
9093 10/20/2003 6895 520

I need to select one record groupped by column refno, I tried using this
code:

select refno, max(fecha), max(ocnum), max(pvd) from pedh

It seems to work fine, but is there another way to get the same result
avoing use of aggregate functions?


Thanks in advance




--
Josué Maldonado



---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org

[Bruno Wolff III]

Re: Select groupping by one column

On Thu, Dec 18, 2003 at 15:09:52 -0800,
Josué Maldonado <josue@lamundia l.hn> wrote:[color=blue]
> Hello list,
>
> I have a table called pedh that looks like this:
>
> REFNO FECHA OCNUM PVD
> 0199 10/12/2003 5224 632
> 0199 10/12/2003 5224 632
> 1264 10/18/2003 8991 210
> 1264 10/18/2003 8991 210
> 1264 10/18/2003 8991 210
> 9093 10/20/2003 6895 520
> 9093 10/20/2003 6895 520
>
> I need to select one record groupped by column refno, I tried using this
> code:
>
> select refno, max(fecha), max(ocnum), max(pvd) from pedh[/color]

I don't see how that could work. Maybe you left off group by. But if you
did the aggreates could come from different rows, which might not be what
you want.
[color=blue]
>
> It seems to work fine, but is there another way to get the same result
> avoing use of aggregate functions?[/color]

You might be able to use distinct on instead of aggregates.

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org

[Josué Maldonado]

Re: Select groupping by one column

Hello Bruno,

Bruno Wolff III wrote:[color=blue][color=green]
>>
>>select refno, max(fecha), max(ocnum), max(pvd) from pedh[/color]
>
>
> I don't see how that could work. Maybe you left off group by. But if you
> did the aggreates could come from different rows, which might not be what
> you want.[/color]

I missed the group by 1, I'm sorry.
[color=blue]
>
>[color=green]
>>It seems to work fine, but is there another way to get the same result
>>avoing use of aggregate functions?[/color]
>
>
> You might be able to use distinct on instead of aggregates.[/color]

Thanks



---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster