Re: trigger question

At 11:27 AM 6/27/00 -0400, Tom Lane wrote:
>mikeo <mikeo@spectrumtelecorp.com> writes:
>> in oracle, the triggers were smart enough to know not to reference
>> an old value on insert in an "insert or update" trigger procedure,
>> apparently.
>
>> this is the original oracle trigger that works fine
>> with the same insert statement:
>
>> CREATE OR REPLACE TRIGGER rates_hist_trigger
>>         before insert or update on rates
>>         for each row
>>              WHEN (old.rt_valid <> 'P' or new.rt_valid not in ('Y','N'))
>
>Hmm.  It sounds to me like Oracle treats the OLD fields as being NULL
>if the context is INSERT, which is something we could certainly do at
>the price of losing some error detection capability --- ie, if that
>really had been a typo as I first thought, the system wouldn't flag it
>for you.
>
>Not sure which way is better.  Comments anyone?
>
>            regards, tom lane
>

it would make the insert or update trigger more flexible, and ,
truly by an insert or update procedure, IMHO :), but is definitely not
a priority.  creating a rule for each is just as quick as writing a
function with a trigger to call it.

mikeo