Re: statement level trigger vs. row trigger

Katherine wrote:

> actually, your question is quite appropriate since you have to hunt for the
> answer. check out this link:
> http://technet.oracle.com/doc/server.815/a68003/01_13dbt.htm#7445
>
> The difference between a rowlevel and a statement trigger is that the
> statement trigger allows one event to take place, such as writing to a log
> table with just one entry for the trigger event. The statement level
> triggers are useful for performing validation-type actions where you want to
> track that some event took place. in the example on the link, the salary
> of 5 employees in dept 20 was increased with a row level trigger. also, a
> validation record was inserted into a log table of when this trigger was
> fired and the data changed.
>
> The row level triggers fire for each row effected by the trigger. For
> example, if there are five rows are affected by the trigger DML, then the
> trigger fires five times when an UPDATE (for example) is entered.
>
> The "FOR EACH ROW" option determines whether the trigger is a row trigger or
> a statement trigger.
>
> i think you'll find an adequate explanation of mutating tables on the link
> above.
>
> hope this helps
>
> "tshen" <tshen01_at_hotmail.com> wrote in message
> news:gplx8.47730$7e5.14622489_at_news02.optonline.net...
> > hi, guys:
> >
> > Can anybody tell me the diff between statement level trigger and row
> > trigger? and
> > why cann't do the "select" on mutating tables, thanks.
> >
> > tshen
> >
> >
> >
> >

I would disagree with your explanation of statement versus row level triggers. A statement level trigger fires one per transaction. You can do 1,000 inserts and the trigger will fire once for all 1,000 records. The row level trigger will fire 1,000 times.

Daniel Morgan Received on Wed Apr 24 2002 - 10:05:29 CDT