Re: Need Help for select

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