Обсуждение: How to tell which event was fired in Trigger function

Hi,

I am writing a trigger function that is used after DELETE, INSERT, and UPDATE, like so:

    CREATE TRIGGER tr_name AFTER DELETE OR INSERT OR UPDATE ...

How can I tell inside the trigger function if the event was DELETE or INSERT/UPDATE? 

The table has a `NOT NULL id` column, so I am thinking that maybe a DELETE will have a NULL value in NEW.id?  Will that work?  Is there a better way?

Thanks,

On 07/11/2018 10:36 AM, Igal @ Lucee.org wrote:
> Hi,
> 
> I am writing a trigger function that is used after DELETE, INSERT, and 
> UPDATE, like so:
> 
>      CREATE TRIGGER tr_name AFTER DELETE OR INSERT OR UPDATE ...
> 
> How can I tell inside the trigger function if the event was DELETE or 
> INSERT/UPDATE?
> 
> The table has a `NOT NULL id` column, so I am thinking that maybe a 
> DELETE will have a NULL value in NEW.id?  Will that work?  Is there a 
> better way?

https://www.postgresql.org/docs/10/static/plpgsql-trigger.html

> 
> Thanks,
> 
> Igal Sapir
> Lucee Core Developer
> Lucee.org <http://lucee.org/>
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com

On 7/11/2018 10:38 AM, Adrian Klaver wrote:
> On 07/11/2018 10:36 AM, Igal @ Lucee.org wrote:
>> How can I tell inside the trigger function if the event was DELETE or 
>> INSERT/UPDATE?
>
> https://www.postgresql.org/docs/10/static/plpgsql-trigger.html

This looks like it have all of the information that I need.  For some 
reason search engines bring up many other pages but not that one.

Thanks Adrian!

Igal

On Wed, Jul 11, 2018 at 10:54 AM, Igal @ Lucee.org <igal@lucee.org> wrote:

On 7/11/2018 10:38 AM, Adrian Klaver wrote:

On 07/11/2018 10:36 AM, Igal @ Lucee.org wrote:

How can I tell inside the trigger function if the event was DELETE or INSERT/UPDATE?

https://www.postgresql.org/docs/10/static/plpgsql-trigger.html

This looks like it have all of the information that I need.  For some reason search engines bring up many other pages but not that one.

​For these situations I recommend bookmarking and navigating to the Table of Contents [1] for the documentation and looking for relevant chapter titles - in this case the "V. 38 - Triggers" one is right there on the main page.

https://www.postgresql.org/docs/10/static/index.html

On a related note, maybe the pl/pgsql link from the Triggers chapter should link directly to the Triggers section under pl/pgsql instead of the top of the chapter...