Re: join problem or maybe group :(

found a way, but im not sure its the optimum way

SELECT * from sections left join articles using (sec_id) where art_id =
(SELECT art_id from articles where sec_id = sections.sec_id order by
art_date DESC limit 1,0) order by sec_order;

Just wonder, how can i do:

select max(column1), column2 from table;

its saying:
ERROR:  Attribute table.column2 must be GROUPed or used in an aggregate
function

and all i want is that column2 value will be the mate fo column1 max?

like if
clumn1     column2
1                 a
2                 b
3                 c

it will return 3,c
>
> On Thu, 29 Aug 2002, Ben-Nes Michael wrote:
>
> > hmmm, me again.
> >
> > Ill attack the subject from another way.
> >
> > Can i limit the left joined table to one result ?
> >
> > like:
> >
> > select * from table1 left join table2 using (column) limit table2 1,0; ?
>
> I don't think so, however, it's possible that maybe a distinct on in
> a subselect may help if you don't mind using postgresql extensions.
>
> Maybe something like (complete untested):
>
> select * from sections left join
>  (select distinct on (sec_id) * from articles order by art_date desc)
>  as articles
>  using (sec_id);
>
> > > I want to select sections using left join on articles, but i want to
> > retrive
> > > only one row from articles per section and the one should be the
latest
> > > art_date.
> > >
> > > Can it be done ?
> > >
> > > CREATE TABLE sections (
> > > sec_id SERIAL PRIMARY KEY,
> > > sec_name VARCHAR (30),
> > > sec_order INT2
> > > );
> > >
> > >
> > > CREATE TABLE articles (
> > > art_id SERIAL PRIMARY KEY,
> > > sec_id INT4 REFERENCES sections ON UPDATE CASCADE ON DELETE CASCADE,
> > > art_name VARCHAR (30),
> > > art_date DATE
> > > );
> > >
> > > Cheer
> > >
> > >
> > >
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