[postgis-users] Trigger question

[Michael Fuhr]

On Wed, Mar 28, 2007 at 03:25:15PM +0930, Stephen Davies wrote:
> I am trying to write a plpgsql trigger to calculate and store the area 
> of a polygon but am getting no result.
[...]
> create trigger setarea after insert or update on unit for each row 
> execute procedure setarea();
>
> This generates no error at creation or update time but does not give me 
> an area either.

AFTER triggers can't modify the row; use a BEFORE trigger.

-- 
Michael Fuhr