select inner join problem

[Irlan agous]

Hello
i have t tables reactie and form and this query

$sql = "select reactie.persid, form.oproep,for m.foto,form.id from
reactie,form
INNER JOIN reactie ON (reactie.persid = form.id) group by reactie.persid
order by reactie.persid DESC LIMIT 0,5";

$result = mysql_query($sq l);

Why i always get the error message invalid result resource? I want to group
the persid and order them DESC. But i cant get it to work can someone please
help?

reactie

logid persid
1 2
3 2
4 3

form

id oproep foto
2 bla blabla
3 frt hadiha

[Ewoud Dronkert]

Re: select inner join problem

On Sun, 1 May 2005 20:44:42 +0200, Irlan agous wrote:[color=blue]
> $sql = "select reactie.persid, form.oproep,for m.foto,form.id from
> reactie,form INNER JOIN reactie ON (reactie.persid = form.id)
>
> Why i always get the error message[/color]

Remove first 'reactie', or replace 'inner join reactie on r.id=f.id' by
'where r.id=f.id'. See http://dev.mysql.com/doc/mysql/en/join.html


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[Tim Roberts]

Re: select inner join problem

"Irlan agous" <irlan345@msn.c om> wrote:
[color=blue]
>Hello
>i have t tables reactie and form and this query
>
>$sql = "select reactie.persid, form.oproep,for m.foto,form.id from
>reactie,form
> INNER JOIN reactie ON (reactie.persid = form.id) group by reactie.persid
>order by reactie.persid DESC LIMIT 0,5";
>
> $result = mysql_query($sq l);
>
>Why i always get the error message invalid result resource? I want to group
>the persid and order them DESC. But i cant get it to work can someone please
>help?
>
>reactie
>
>logid persid
>1 2
>3 2
>4 3
>
>form
>
>id oproep foto
>2 bla blabla
>3 frt hadiha[/color]

In addition to the other advice about removing the first "reactie", which
was correct, you also have some confusion about the purpoose of GROUP BY.
GROUP BY is used when you want to use the so-called "aggregate" functions,
like SUM or COUNT. If you aren't using SUM or COUNT (or another aggregate
function), then you don't need GROUP BY (and, in fact, CANNOT use GROUP
BY):

SELECT reactie.persid, form.oproep,for m.foto
FROM reactie INNER JOIN form ON (reactie.persid = form.id)
ORDER BY reactie.persid DESC
LIMIT 0,5;

Note that, since reactie.persid == form.id, there is no point in including
both fields in the SELECT.
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.