Re: Need Help for select - Mailing list pgsql-sql

From Andre Schubert
Subject Re: Need Help for select
Date
Msg-id 20020814160421.2c75727e.andre@km3.de
Whole thread Raw
In response to Re: Need Help for select  (Masaru Sugawara <rk73@sea.plala.or.jp>)
Responses Re: Need Help for select
Re: Need Help for select
List pgsql-sql
On Wed, 14 Aug 2002 21:57:02 +0900
"Masaru Sugawara" <rk73@sea.plala.or.jp> wrote:

> 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),

I want to compare if a tuple in c exist in b for each c.d_id and b.a_id.
In c exists 3 tuples: (1,2), (3,4), (5)
and want to find these tuples in b.

select a.name,d.name from a,b,c,d where "tuple found in b" = "tuple found in c" and b.a_id = a.id and c.d_id = d.id

My english is not so good, but i hope you understand what i want to do.

Thanks in advance

> 
> 
> 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
> 
> 
> 
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