From: Tom Lane <tgl@sss.pgh.pa.us>
To: otter117@yahoo.de
Cc: pgsql-docs@postgresql.org
Subject: Re: undocumented feature or bug in subquery : psql (PostgreSQL) 9.4.6 on SLES12 SP1
Date: Fri, 26 Aug 2016 09:07:14 -0400
Message-ID: <26546.1472216834@sss.pgh.pa.us> (raw)
In-Reply-To: <20160825162900.15675.78433@wrigleys.postgresql.org>
References: <20160825162900.15675.78433@wrigleys.postgresql.org>
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otter117@yahoo.de writes:
> 2 tables a and b
> Table "public.a"
> Column | Type | Modifiers
> -----------------+--------------------------+---------------
> foo | integer | not null
> bar | integer | not null
> Table "public.b"
> Column | Type | Modifiers
> -----------------+--------------------------+---------------
> bar | integer | not null
> No error when executing this statement even though table b does not contain
> column foo
> SELECT foo,bar FROM a WHERE foo=1 AND bar NOT IN (SELECT bar FROM b WHERE
> bar > 2 AND foo=2)
No, but table a does, and that's a legal outer reference per the SQL
standard. This is neither a bug nor undocumented.
> Do I need to qualify all columns in the subquery or is this a bug is psql
> 9.4.6?
It's often wise to qualify column references in multi-table queries
(subqueries or not) to ensure they are referencing what you think
they're referencing.
regards, tom lane
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To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, otter117@yahoo.de
Subject: Re: undocumented feature or bug in subquery : psql (PostgreSQL) 9.4.6 on SLES12 SP1
In-Reply-To: <26546.1472216834@sss.pgh.pa.us>
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