Re: Custom Contraint Violation Errors

On Thu, Nov 3, 2011 at 11:56 PM, Michael Musenbrock <redeamer@gmx.net> wrote:

> But I have not
> found any information if this is possible to create a trigger on a
> constraint violation, and if yes, how could that be done?

You want to use the special type of "CONSTRAINT" trigger.

http://www.postgresql.org/docs/9.1/interactive/sql-createtrigger.html

Notice that constraint triggers require the developer of the trigger
to RAISE EXCEPTION when the constraint is violated.

http://www.postgresql.org/docs/9.1/interactive/plpgsql-errors-and-messages.html

The syntax for RAISE EXCEPTION allow the developer to specify any
desired message.

--
Regards,
Richard Broersma Jr.