Re: [SQL] subquery, except and view

> 
> I don't understand why the two queries below
> are not correct with Postgresql though it be correct with Oracle
> (I want to know the clients which have not 
> made more than 2 commands) :
> 
> ------- 
> QUERY 1
> -------
> 
> select clt.num_clt 
> from client clt
> where clt.num_clt not in
>    (select cd.num_clt 
>     from commande cd
>     group by cd.num_clt
>     having count(*) > 2);
> 
> The PostgreSQL Error is : rewrite: aggregate column
>   view must be at rigth side in qual
> 
> I test the subquery and it is ok.
> 
More or less this question is asked again and again - I've asked
this before - perhaps 3-4 weeks ago - it should be put into a faq.
It's a restriction of PostgreSQL and it's SQL parser. The
aggregate column is count(*) and it "could" work perhaps if
you rewrite it as  ".... 2 <= count(*)".
It was said on this list, that the rewriter might interpret the 
statement not correctly and return wrong results.
You should have a closer look at the archive with subjects like
having, group ... (last 8 weeks).
Marten