From: T E Schmitz <mailreg@numerixtechnology.de>
Cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: CHECK col A not NULL if col B='x'
Date: Tue, 28 Sep 2004 16:01:38 +0100
Message-ID: <41597CD2.1030602@numerixtechnology.de> (raw)
In-Reply-To: <200409281112.02986.martin@bugs.unl.edu.ar>
References: <41596EDA.4030909@numerixtechnology.de>
<200409281112.02986.martin@bugs.unl.edu.ar>
Hello again,
Martin Marques wrote:
> El Mar 28 Sep 2004 11:02, T E Schmitz escribió:
>
>>Is it possible to set up a table CHECK, which ensures that column A is
>>NOT NULL if column B = 'x' ?
>
>
> CONSTRAINT somename CHECK (B <> 'x' OR A IS NOT NULL)
I noticed a table constraint can be added via ALTER TABLE. Is it correct
that a column constraint cannot be added via the ALTER TABLE other than
by dropping and adding the column? (I am using psql 7.4.2.)
--
Regards/Gruß,
Tarlika Elisabeth Schmitz
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To: pgsql-sql@postgresql.org
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Subject: Re: CHECK col A not NULL if col B='x'
In-Reply-To: <41597CD2.1030602@numerixtechnology.de>
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