Re: updating table field whenever other table field changes

From: Jan Wieck <JanWieck(at)Yahoo(dot)com>
To: Andrew <tech7890(at)Yahoo(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: updating table field whenever other table field changes
Date: 2003-04-04 01:29:03
Message-ID: 3E8CDFDF.2486DCDF@Yahoo.com
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Andrew wrote:
>
> Hello postgresql.questions group!
>
> What do you think the best way to attack the following is:
> parent table a - [status_field]
>
> child table b - [status_field]
>
> I need trigger or similar to achieve the following:
> if a.status_field changes than all children of table a have their
> b.status_field change to the same value as a.

If b.status_field allways has to have a value that exists in
a.status_field (or maybe NULL if you allow it to), you want to define a
FOREIGN KEY constraint with the referential action ON UPDATE CASCADE.

Jan

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