From: Richard Broersma Jr <rabroersma@yahoo.com>
To: Ehab Galal <ehabgalal123@hotmail.com>
To: pgsql-sql@postgresql.org
Subject: Re: SQL command join question
Date: Wed, 29 Nov 2006 16:57:18 -0800 (PST)
Message-ID: <458025.22989.qm@web31815.mail.mud.yahoo.com> (raw)
In-Reply-To: <BAY24-F23D89B0EEF2CFB0C611FFA96DB0@phx.gbl>
> SELECT t1.*
> FROM (t1 outer join t2 on (t1.a=t2.a and t1.b=t2.b)) t outer join t3 on
^^
> (t1.c=t3.c);
^^ -- which one t or t1?
> I'm getting the following error message:
> ERROR: invalid reference to FROM-clause entry for table "t1"
> HINT: There is an entry for table "t1", but it cannot be referenced from
> this part of the query.
I am not use if I am about to give to the correct advice, but here is what stands out at me:
when you specify an outer join, I believe that you have to specify whether it is a
(left|right|full).
Also you are using a "t" to alias the (t1 .. t2 on (...)). First of all, I am not sure this is
good syntax, but if I am wrong I will have learned something new. That aside, if it is legal
syntax, I don't believe that you can refer to any of it's enternal tables any more. So (t1.c=...)
should really be (t.c=...).
this is what I expect would work:
select
*
from
t1
left outer join
t2
on
((t1.a,t1.b) = (t2.a,t2.b))
left outer join
t3
on
(t1.c = t3.c)
;
Regards,
Richard Broersma Jr.
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To: pgsql-sql@postgresql.org
Cc: rabroersma@yahoo.com, ehabgalal123@hotmail.com
Subject: Re: SQL command join question
In-Reply-To: <458025.22989.qm@web31815.mail.mud.yahoo.com>
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