Triggers not working

Started by Dale Harrisover 17 years ago5 messagesgeneral
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#1Dale Harris
itsupport@jonkers.com.au

Hi,

I'm running PostgreSQL 8.3.3 and I'm having trouble with triggers not always
working. I have the following tables and functions as documented below. My
problem is that if I perform an update on the Entity table and modify the
Code field, why doesn't the trigger for the Entity table execute? (Row was
initially added via the Account table.)

Dale.

CREATE TABLE "Entity"

(

"ID" bigserial NOT NULL,

"Code" character varying(20) NOT NULL,

"Name" character varying(50) NOT NULL,

"Modified" timestamp(1) with time zone NOT NULL DEFAULT
session_timestamp(),

"ModifiedBy" bigint DEFAULT userid(),

CONSTRAINT "pkEntity" PRIMARY KEY ("ID")

);

CREATE TABLE "Account"

(

"Balance" money NOT NULL DEFAULT '$0.00'::money,

CONSTRAINT "pkAccount" PRIMARY KEY ("ID"),

CONSTRAINT "uniqAccountCode" UNIQUE ("Code")

)

INHERITS ("Entity");

CREATE OR REPLACE FUNCTION entitytrigger() RETURNS trigger AS

$BODY$BEGIN

--Update modified details

raise notice '% being called for % of %.', TG_NAME, TG_OP, TG_TABLE_NAME;

new."Modified" := Session_TimeStamp();

new."ModifiedBy" := UserID();

return new;

END;$BODY$

LANGUAGE 'plpgsql' VOLATILE;

CREATE TRIGGER "trEntityUpdate"

BEFORE UPDATE

ON "Entity"

FOR EACH ROW

EXECUTE PROCEDURE entitytrigger();

CREATE TRIGGER "trAccountUpdate"

BEFORE UPDATE

ON "Account"

FOR EACH ROW

EXECUTE PROCEDURE entitytrigger();

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: Dale Harris (#1)
Re: Triggers not working

"Dale Harris" <itsupport@jonkers.com.au> writes:

I'm running PostgreSQL 8.3.3 and I'm having trouble with triggers not always
working. I have the following tables and functions as documented below. My
problem is that if I perform an update on the Entity table and modify the
Code field, why doesn't the trigger for the Entity table execute? (Row was
initially added via the Account table.)

Worksforme ...

regression=# insert into "Account" values(1,'code','name');
INSERT 0 1
regression=# select * from "Entity";
ID | Code | Name | Modified | ModifiedBy
----+------+------+---------------------------+------------
1 | code | name | 2008-09-22 08:19:51.70-04 | postgres
(1 row)

regression=# update "Entity" set "Code" = 'foo' where "ID" = 1;
NOTICE: trAccountUpdate being called for UPDATE of Account.
UPDATE 1
regression=# select * from "Entity";
ID | Code | Name | Modified | ModifiedBy
----+------+------+---------------------------+------------
1 | foo | name | 2008-09-22 08:20:18.10-04 | postgres
(1 row)

regards, tom lane

#3Dale Harris
itsupport@jonkers.com.au
In reply to: Tom Lane (#2)
Re: Triggers not working

Hi Tom,

The trigger trAccountUpdate got called, but why didn't the trigger
trEntityUpdate get called?

Regards,

Dale Harris.

-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Monday, 22 September 2008 22:22
To: Dale Harris
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Triggers not working

"Dale Harris" <itsupport@jonkers.com.au> writes:

I'm running PostgreSQL 8.3.3 and I'm having trouble with triggers not

always

working. I have the following tables and functions as documented below.

My

problem is that if I perform an update on the Entity table and modify the
Code field, why doesn't the trigger for the Entity table execute? (Row

was

initially added via the Account table.)

Worksforme ...

regression=# insert into "Account" values(1,'code','name');
INSERT 0 1
regression=# select * from "Entity";
ID | Code | Name | Modified | ModifiedBy
----+------+------+---------------------------+------------
1 | code | name | 2008-09-22 08:19:51.70-04 | postgres
(1 row)

regression=# update "Entity" set "Code" = 'foo' where "ID" = 1;
NOTICE: trAccountUpdate being called for UPDATE of Account.
UPDATE 1
regression=# select * from "Entity";
ID | Code | Name | Modified | ModifiedBy
----+------+------+---------------------------+------------
1 | foo | name | 2008-09-22 08:20:18.10-04 | postgres
(1 row)

regards, tom lane

#4Tom Lane
tgl@sss.pgh.pa.us
In reply to: Dale Harris (#3)
Re: Triggers not working

"Dale Harris" <itsupport@jonkers.com.au> writes:

The trigger trAccountUpdate got called, but why didn't the trigger
trEntityUpdate get called?

Triggers only apply to the exact table they're declared on, not
to child tables.

It does seem like there might be some use-case for applying a trigger to
child tables too, but that's not how it works now.

regards, tom lane

#5Dale Harris
itsupport@jonkers.com.au
In reply to: Tom Lane (#4)
Re: Triggers not working

I would have called the Entity table the parent table and not the child
table as the Account table inherits from Entity. Therefore it appears that
the trigger only works on the table where the actual row was added/belongs
to.

It would be great if triggers on the parent table would work for any row
that appears there, even rows added via a child table. It would mean that
any new table that inherits the parent table, in my case Entity, would
automatically have the global trigger I want enforced. Nice enhancement :)

Regards,

Dale Harris.

-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Tuesday, 23 September 2008 13:43
To: Dale Harris
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Triggers not working

"Dale Harris" <itsupport@jonkers.com.au> writes:

The trigger trAccountUpdate got called, but why didn't the trigger
trEntityUpdate get called?

Triggers only apply to the exact table they're declared on, not
to child tables.

It does seem like there might be some use-case for applying a trigger to
child tables too, but that's not how it works now.

regards, tom lane