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From: Andreas Joseph Krogh <andreak@officenet.no>
To: pgsql-sql@postgresql.org
Subject: Conditional NOT NULL constraint
Date: Wed, 28 Feb 2007 11:30:47 +0100
Message-ID: <200702281130.47396.andreak@officenet.no> (raw)

Hi all!
Is there a simple way to add a "NOT NULL constraint" to a column without using 
a trigger if another column is not null?
Something like this:

CREATE TABLE activity(
id SERIAL primary key,
name varchar not null,
created timestamp not null default now(),
modified timestamp,
created_by integer not null,
modified_by integer
);

alter table activity alter column modified_by set not null where modified is 
not null;

I want a constraint which says: "modified_by not null if modified is not 
null".

I know I could use a trigger for this, but I'm curious if there is a way to do 
this with an index.

-- 
Andreas Joseph Krogh <andreak@officenet.no>
Senior Software Developer / Manager
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