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.klaver@aklaver.com 
> <mailto:adrian.klaver@aklaver.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.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com