restrict update trigger to updated rows

How do I restrict an update trigger to just the rows updated?
Would like to have two audit fields with user and time of modification for
updates.
The following trigger would attempt to update all rows in the table:
ALTER trigger tm_stmp_admit_proc
on dbo.tblAdmissions_procedures
for update
as
begin
update tblAdmissions_procedures
set time_stamp = current_timestamp,user_modify = system_user
end
Couldn't find any description in BOL analogous to the FOR EACH ROW parameter
in
PostgreSQL:
CREATE OR REPLACE FUNCTION public.timestamper()
RETURNS trigger AS
'
BEGIN
NEW.time_stamp := \'now\';
NEW.user_modify := current_user;
RETURN NEW;
END;
'
LANGUAGE 'plpgsql' VOLATILE;
CREATE TRIGGER timestamper
BEFORE INSERT OR UPDATE
ON public.admit_procedures
FOR EACH ROW
EXECUTE PROCEDURE public.timestamper();
Thanks,
David P. Lurie
If you have a primary key column in the table
use INSERTED table in the trigger.
like
update tblAdmissions_procedures
set time_stamp = current_timestamp,user_modify = system_user
where exists ( select keycolumn from inserted
where tblAdmissions_procedures.keycolumn = inserted.keycolumn )
but, then u may also have to set this parameter
SET RECURSIVE_TRIGGERS OFF
HTH
Faris
"David P. Lurie" <abc@.def.net> schrieb im Newsbeitrag
news:%23Di0ArVbEHA.2944@.TK2MSFTNGP11.phx.gbl...
> How do I restrict an update trigger to just the rows updated?
> Would like to have two audit fields with user and time of modification for
> updates.
> The following trigger would attempt to update all rows in the table:
> ALTER trigger tm_stmp_admit_proc
> on dbo.tblAdmissions_procedures
> for update
> as
> begin
> update tblAdmissions_procedures
> set time_stamp = current_timestamp,user_modify = system_user
> end
> Couldn't find any description in BOL analogous to the FOR EACH ROW
parameter
> in
> PostgreSQL:
> CREATE OR REPLACE FUNCTION public.timestamper()
> RETURNS trigger AS
> '
> BEGIN
> NEW.time_stamp := \'now\';
> NEW.user_modify := current_user;
> RETURN NEW;
> END;
> '
> LANGUAGE 'plpgsql' VOLATILE;
> CREATE TRIGGER timestamper
> BEFORE INSERT OR UPDATE
> ON public.admit_procedures
> FOR EACH ROW
> EXECUTE PROCEDURE public.timestamper();
> Thanks,
> David P. Lurie
>
|||Thanks a lot -
I tested this on two of the tables, and seems to work. Didn't turn off
recursive triggers to see whether it was necessary, and no problems thus far
with a few updates on each table. Assume that infinite loop would have
occurred if that setting was needed.
David P. Lurie
"Faris" <faris@.bss-india.com> wrote in message
news:eTBHKhWbEHA.3944@.tk2msftngp13.phx.gbl...
> If you have a primary key column in the table
> use INSERTED table in the trigger.
> like
> update tblAdmissions_procedures
> set time_stamp = current_timestamp,user_modify = system_user
> where exists ( select keycolumn from inserted
> where tblAdmissions_procedures.keycolumn = inserted.keycolumn )
> but, then u may also have to set this parameter
> SET RECURSIVE_TRIGGERS OFF
> HTH
> Faris