Re: Need Help for select

On Wed, 14 Aug 2002 16:04:21 +0200
Andre Schubert <andre@km3.de> wrote:


> > 
> > 
> > If this mention implies that the tuple of (1, 1) in the c is supposed
           ^^                                                           b  
 
> > 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.


I were able to catch what conditions join b to c. I try to think again.



> 
> 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