Re: Can I wrtie a function that has a BEFORE trigger that is not column name dpendent?

From: Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
To: stan <stanb(at)panix(dot)com>, pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Can I wrtie a function that has a BEFORE trigger that is not column name dpendent?
Date: 2019-09-14 18:50:08
Message-ID: 076f1857-e2d2-0d91-7520-cd2f2b57a2df@aklaver.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

On 9/14/19 11:33 AM, stan wrote:
> I would like to write a generic function that I can place as a BEFORE trigger
> on several tables. It would do a max() on the column it was triggered for, and
> return(max + 1) unless max returns a NULL, in which case it would return one.
>
> Yes, I know this looks a lot like a sequence, but normally this value would
> be provided manually at row input time, I just want to allow for some
> automated updates.
>
> The trick is hat the function needs to work for any numeric column I place it n
> as a trigger.
>

What procedural language?

Triggers are placed on tables not columns so you will need some way of
identifying the column(s) in the table. Trigger functions can take
arguments even though they are not declared in the function creation. So
that is one way of defining the column.

>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Adrian Klaver 2019-09-14 19:51:29 Re: Can I wrtie a function that has a BEFORE trigger that is not column name dpendent?
Previous Message stan 2019-09-14 18:33:50 Can I wrtie a function that has a BEFORE trigger that is not column name dpendent?