Re: regarding triggers

On 1/10/06, surabhi.ahuja <surabhi(dot)ahuja(at)iiitb(dot)ac(dot)in> wrote:
>
>
> is there an advantage of using a trigger? when the same job can be performed
> by a stored procedure?
>

a trigger is actually a stored procedure... the advantage is that it's
called automagically when an event happens...

> one more question is as follows:
> suppose i have a table x, with a primary attribute 'a'
>
> and i have a table y, with the primary attribute 'b', and a foreign key 'a'.
>
> suppose i say delete from x where a = '1',
>
> it means that not only the rows from x get deleted but also rows from y get
> deleted.
>

only if you specified ON DELETE CASCADE at FOREIGN KEY creation

> now i have a trigger which is written for deletes taking place from the
> table y.
>
> however if i say delete from x where a = '1',
>
> will the trigger (mentioned above) still be called? (because delete are also
> taking place from the table y)
>

if the DELETE will CASCADE, yes

> thanks,
> regards
> Surabhi

--
regards,
Jaime Casanova
(DBA: DataBase Aniquilator ;)