From: Andreas Joseph Krogh <andreak@officenet.no>
Organization: OfficeNet AS
To: pgsql-sql@postgresql.org
Subject: Conditional NOT NULL constraint
Date: Wed, 28 Feb 2007 11:30:47 +0100
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Hi all!
Is there a simple way to add a "NOT NULL constraint" to a column without us=
ing=20
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 i=
s=20
not null;

I want a constraint which says: "modified_by not null if modified is not=20
null".

I know I could use a trigger for this, but I'm curious if there is a way to=
 do=20
this with an index.

=2D-=20
Andreas Joseph Krogh <andreak@officenet.no>
Senior Software Developer / Manager
gpg public_key: http://dev.officenet.no/~andreak/public_key.asc
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