From: | Arturo Perez <aperez(at)hayesinc(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: xpath_string and group by |
Date: | 2006-08-29 11:05:44 |
Message-ID: | aperez-8D5C3B.07054029082006@news.hub.org |
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Lists: | pgsql-general |
In article <20060829105458(dot)GB22806(at)svana(dot)org>,
kleptog(at)svana(dot)org (Martijn van Oosterhout) wrote:
> On Sat, Aug 26, 2006 at 03:51:06PM -0400, Perez wrote:
> > Hi all,
> >
> > Using 8.1.4 and contrib/xml2. When I do a
> >
> > select xpath_string(note, '//Thing') as note,
> > count(aDate) from theTable
> > group by lower(xpath_string(note, '//Thing'))
> > order by 2 desc;
> >
> > I get an error:
> > GROUP BY must contain note.
> > But I can do that for a plain text/varchar field. Adding the non-xpath
> > note field messes up the grouping.
>
> I wonder if it's getting confused about which "note" you're referring
> to in the GROUP BY clause.
>
> > select note, count(aDate) from
> > (select lower(xpath_string(note, '//Thing')) as note, aDate from
> > theTable) as foo
> > group by note
>
> This is about the same thing, so why not use that?
>
> Have a nice day,
You're right, it is almost the same thing. But the second form loses
the case of the original - everything is returned lower case. If I must
I must but I'ld like to preserve the case is possible.
-arturo
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