Re: Restriction by grouping problem.

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От Jeff Barrett
Тема Re: Restriction by grouping problem.
Дата
Msg-id 9jq4a9$gfr$1@news.tht.net
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Ответ на Re: Restriction by grouping problem.  ("Josh Berkus" <josh@agliodbs.com>)
Ответы Re: Re: Restriction by grouping problem.  (Philip Warner <pjw@rhyme.com.au>)
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Yeah I have been having a bit of a problem expressing myself in terms of
this query, sorry about that.

What I need is:

SELECT getfile FROM logs (and a restriction that results in finding the rows
with the lowest datetime for each unique sid)

To define this table a bit more:

Logs table has a primary key of logid (int4) and serveral columns, of which
I am deling with sid (text), getfile (text), and datetime (int4). Now a
select getfile, datetime, logid from logs where sid = onevalue; would return
a set of rows for that sid, the row I want is for the one with the smallest
aka min(datetime) and I want this for every row in the table.

Thanks for the quick response Josh, hopefully above will help out some.

--Jeff

""Josh Berkus"" <josh@agliodbs.com> wrote in message
news:web-92249@davinci.ethosmedia.com...
> Jeff,
>
> > The query I have now:
>
> >
>
> > SELECT min(datettime), sid FROM logs GROUP by sid;
>
> >
>
> > This returns the first instance of an sid in the logs table, there
>
> > can be
>
> > many rows in the table for each sid. The problem I have is that I do
>
> > not
>
> > need the SID I just need to group the min(datetime) by it.
>
> The answer to this question is simple:
>
> SELECT min(datetime) as mintime FROM logs GROUP BY sid;
>
> However, I get the impression that your intended problem was more
> complicated.  Can you re-explain it?
>
> -Josh
>
>
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