Re: BEFORE ... Statement-level trigger

On 2/18/19 8:20 AM, Jitendra Loyal wrote:
> Thanks Adrian
>
> I am trying to understand as to how a BEFORE statement-level trigger can
> be used. Since it is a trigger, one needs to know which rows are being
> affected.

But you can't:

https://www.postgresql.org/docs/10/plpgsql-trigger.html

"NEW

Data type RECORD; variable holding the new database row for
INSERT/UPDATE operations in row-level triggers. This variable is
unassigned in statement-level triggers and for DELETE operations.
OLD

Data type RECORD; variable holding the old database row for
UPDATE/DELETE operations in row-level triggers. This variable is
unassigned in statement-level triggers and for INSERT operations.
"

>
> Regards,
> Jiten
>
> On Mon 18 Feb, 2019, 9:42 PM Adrian Klaver, <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>> wrote:
>
> On 2/18/19 4:06 AM, Jitendra Loyal wrote:
> > The behaviour is not clear for BEFORE Statement-level Trigger.
> This is
> > because transition tables cannot be used. So how does one get
> access to
> > the rows being affected? It is not documented either.
>
> If you need the row values then use a FOR ROW trigger.
>
> >
> > Thanks
> > Jiten
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>

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