Re: recursive inner trigger call

[Red Light <skydelta98@xxxxxxxxx>]

Hi David,

Thanks a lot.

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From: David Johnston <polobo@xxxxxxxxx>
To: 'Red Light' <skydelta98@xxxxxxxxx>; "'Gauthier, Dave'" <dave.gauthier@xxxxxxxxx>
Cc: pgsql-general@xxxxxxxxxxxxxx
Sent: Thursday, December 1, 2011 8:31 PM
Subject: RE: recursive inner trigger call

CREATE OR REPLACE FUNCTION public.store_bv() RETURNS TRIGGER AS $store_bv$
    DECLARE
        v_vmax_actuel          numeric(15,2);
    BEGIN      
    IF (TG_OP = 'UPDATE') OR (TG_OP = 'INSERT')   THEN

        update ed_explore."bv"  set
        c_vmax_actuel = ((d_capacite_barrages_new) / (30*86400)) ;             

 

    END IF;
    RETURN NEW;


    END;
$store_bv$ LANGUAGE plpgsql;

 

In the BEFORE trigger you cannot use an explicit “UPDATE …” statement.  You want to do:

 

NEW.c_vmax_actuel = ((NEW.d_capacite_barrages_new) / (30*86400));

 

To update the value of the in-context record directly within the trigger itself.

 

If the table is at all large this is better anyway since you are not continually updating EVERY SINGLE RECORD regardless of whether it was recently changed.

 

The IF statement, checking for INSERT or UPDATE, is redundant since you should only attach this function to triggers that only fire on insert or update.

 

David J.

 

 

 

From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Red Light
Sent: Thursday, December 01, 2011 2:18 PM
To: Gauthier, Dave
Cc: pgsql-general@xxxxxxxxxxxxxx
Subject: Re: recursive inner trigger call

 

 

Hi Dave,

 

when i use before trigger , nothing happen; i mean no cumputation is done  (and when i start tu duplicate the same data just by mistake ...)

i got the same error.

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From: "Gauthier, Dave" <dave.gauthier@xxxxxxxxx>
To: Red Light <skydelta98@xxxxxxxxx>; "pgsql-general@xxxxxxxxxxxxxx" <pgsql-general@xxxxxxxxxxxxxx>
Sent: Thursday, December 1, 2011 8:09 PM
Subject: RE: recursive inner trigger call

You set the trigger to fire off whenever ed_expore.bv is inserted or updated.  Then the trigger updates ed_explore.bv, which fires the update trigger again, etc... .  Infinite loop.  No?

 

Maybe you just want to use a before trigger to set that value before the insert, then you wouldn't need the recursive after trigger?

 

 

 

 

From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Red Light
Sent: Thursday, December 01, 2011 1:58 PM
To: pgsql-general@xxxxxxxxxxxxxx
Subject: recursive inner trigger call

 

Hi guys,

 

i got the following problematic : i got a table called bv that have some 'entry data' and i have another column that need to be calculated and put back in the table:

 

 

here is my table:

 

 

CREATE TABLE public.bv
(
  id_bv integer NOT NULL,
  c_vmax_actuel real,
  d_capacite_barrages_new real,
  CONSTRAINT "BV_pkey" PRIMARY KEY (id_bv) 
)
WITH (
  OIDS=FALSE
);
ALTER TABLE public.bv OWNER TO postgres;

 

 

i created a trigger that do the necessary computation:

 

CREATE OR REPLACE FUNCTION public.store_bv() RETURNS TRIGGER AS $store_bv$
    DECLARE
        v_vmax_actuel          numeric(15,2);
    BEGIN      
    IF (TG_OP = 'UPDATE') OR (TG_OP = 'INSERT')   THEN
       
        update ed_explore."bv"  set
        c_vmax_actuel = ((d_capacite_barrages_new) / (30*86400)) ;             
    END IF;
    RETURN NEW;


    END;
$store_bv$ LANGUAGE plpgsql;

 

 

the declaration of my trigger :

 

CREATE   TRIGGER store_bv_trigger
after INSERT OR UPDATE  ON ed_explore.bv
    FOR EACH ROW EXECUTE PROCEDURE public.store_bv();

 

 

and now i start to insert my data:

 

insert into public.bv (id_bv,d_capacite_barrages_new) values (1,7324591);commit;

 

 

 

then the trigger got executed and goes in an infinite loop,here is the error that i got :

 

ERREUR:  dépassement de limite (en profondeur) de la pile
HINT:  Augmenter le paramètre « max_stack_depth » après vous être assuré que la
limite de profondeur de la pile de la plateforme est adéquate.
CONTEXT:  instruction SQL « update ed_explore."bv" set c_vmax_actuel = ((d_capacite_barrages_new) / (30*86400)) »

 

 

 

And thanks for you help