Date: Wed, 14 Aug 2002 21:57:02 +0900
From: Masaru Sugawara <rk73@sea.plala.or.jp>
To: Andre Schubert <andre@km3.de>
Subject: Re: Need Help for select
Cc: pgsql-sql@postgresql.org
In-Reply-To: <20020814091053.1d3138db.andre@km3.de>
References: <20020812151148.26186.qmail@web40013.mail.yahoo.com>
	<20020814091053.1d3138db.andre@km3.de>
Errors-To: rk73@sea.plala.or.jp
Message-Id: <20020814201310.C84C.RK73@sea.plala.or.jp>
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On Wed, 14 Aug 2002 09:10:53 +0200
Andre Schubert <andre@km3.de> wrote:

> The ride side as follows.
> Table d contains information about subitems.
> Table c holds information about subitems and items of type bar.
> Each subitem can have 0..n items bar selected.
> 
> What i want is that a subitem is only activated for a foo item if
> the foo-item has exactly selected the same bar items selected as
> as the relation between table c and d.
> 
> Example 1:
> The foo-item A_Name1 has selected the bar-items 1 and 2.
> The subitem D_Name1 is only activated for a foo-item if that foo-item
> has selected the bar-items 1 and 2, this happens for A_Name1.
> 


If this mention implies that the tuple of (1, 1) in the c is supposed
to take precedence over that of (2, 1),


SELECT a.name, d.name
FROM (SELECT DISTINCT min(b.a_id) AS a_id, c.d_id
        FROM b, c
       WHERE b.c_id = c.b_id
      GROUP BY b.c_id, c.d_id
      ) AS t, 
      a, 
      d
WHERE a.id = t.a_id
  AND d.id = t.d_id


Regards,
Masaru Sugawara