Date: Thu, 13 Nov 2003 23:11:53 -0600
From: Bruno Wolff III <bruno@wolff.to>
To: Abdul Wahab Dahalan <wahab@mimos.my>
Cc: pgsql-sql@postgresql.org
Subject: Re: Need Help
Message-ID: <20031114051153.GB29956@wolff.to>
Mail-Followup-To: Abdul Wahab Dahalan <wahab@mimos.my>,
	pgsql-sql@postgresql.org
References: <3FB42A2F.20801@mimos.my>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3FB42A2F.20801@mimos.my>
User-Agent: Mutt/1.5.4i

On Fri, Nov 14, 2003 at 09:04:47 +0800,
  Abdul Wahab Dahalan <wahab@mimos.my> wrote:
> Hi!
> 
> If I've a table like this
> 
> kk     kj      pngk      vote      
> 01     02      a         12        
> 01     02      b         10        
> 01     03      c          5
> 
> and I want to have a query so that it give me a result as below. 
> 
> The condition is for each record with the same kk and kj
> but difference pngk will be give a mark *;
> [In this example for record 1 and record 2 we have same kk=01 and kj=02
> but difference pngk a and b so we give * for the mark]
> 
> 
> kk     kj      pngk      vote     mark 
> 01     02       a        12       * 
> 01     02       b        10       * 
> 01     03       c         5
> 
> How should I write the query?

You could do something like:
select a.kk, a.kj, a.pngk, a.vote, b.star
  from table a left join
    (select '*' star, kk, kj from table group by kk, kj having count(*) > 1) b
    on (a.kk = b.kk and a.kj = b.kj);

I didn't test this so there might be a syntax problem, but it should make it
clear how to do what you want.