Re: INSERT a number in a column based on other columns OLD INSERTs

Just a final note. If your trigger needs to handle updates or deletes,
then you may need to use OLD or both (OLD and NEW) and return OLD
instead of NEW, depending on what you want to achieve. You also may
return null to avoid the action to be performed, but this only works
with "before" triggers. I would recommend you to read the documentation
on trigger functions. It is excellent and clarifies quite a lot how
things work.

Bye
Charles

On 6/21/2015 16:49, Charles Clavadetscher wrote:
> Hi
>
> The two things have nothing in common. With NEW.time_index = t_ix you
> set the field with a value and with return you return the record (with
> the modified field) to make the insert.
> You have to return NEW, because you have a trigger function. The
> function must return a record of the same type as the table the
> trigger has been created for. You can see it as this:
>
> You make an insert into a table that has a trigger implemented in a
> trigger function.
> BEFORE it is inserted, the record is passed as NEW to the trigger
> function.
> In the function, in this case, you modify a field of NEW and return
> the modified record.
> Now the insert is done as usual using the NEW record returned by the
> trigger function.
>
> Bye
> Charles
>
> On 6/21/2015 03:07, litu16 wrote:
>> Hi, thanks
>> yes I was using AFTER, but it only works with BEFORE
>> so finally I got it to work.
>> thanks to all
>>
>> Im just still wondering
>> why here...
>>
>> *BEGIN
>> IF NEW.time_type = 'Start' THEN
>> SELECT t.time_index FROM table_ebscb_spa_log02 t WHERE t.fn_name =
>> NEW.fn_name AND t.time_type = 'Start' ORDER BY t.timestamp02 DESC
>> LIMIT 1
>> INTO t_ix;
>> GET DIAGNOSTICS n = ROW_COUNT;
>> IF (n = 0) THEN
>> t_ix = 1;
>> ELSE
>> t_ix = t_ix + 1;
>> END IF;
>> END IF;
>> NEW.time_index = t_ix;
>> return NEW;
>> END
>> $$
>> LANGUAGE plpgsql;*
>>
>> I have to put return NEW, instead of NEW.time_index = t_ix????
>>
>> Thanks to all again.
>>
>>
>>
>> --
>> View this message in context:
>> http://postgresql.nabble.com/INSERT-a-number-in-a-column-based-on-other-columns-OLD-INSERTs-tp5854577p5854602.html
>> Sent from the PostgreSQL - general mailing list archive at Nabble.com.
>>
>>
>
>
>