listing triggers

Started by Erwin Mollerover 21 years ago6 messages
#1Erwin Moller
since_humans_read_this_I_am_spammed_too_much@spamyourself.com

Hi,

When using psql I can list the tables and sequences by typing:
\d

futhermore:
\dt lists tables
\ds lists sequences
\d tablename lists that table.

etc. etc.

But how can I get a listing of all used triggers on a certain table?

Thanks for your time

Regards,
Erwin Moller

#2Christopher Kings-Lynne
chriskl@familyhealth.com.au
In reply to: Erwin Moller (#1)
Re: listing triggers

futhermore:
\dt lists tables
\ds lists sequences
\d tablename lists that table.

etc. etc.

But how can I get a listing of all used triggers on a certain table?

\d <tablename>

Chris

#3Erwin Moller
since_humans_read_this_I_am_spammed_too_much@spamyourself.com
In reply to: Erwin Moller (#1)
Re: listing triggers

Christopher Kings-Lynne wrote:

futhermore:
\dt lists tables
\ds lists sequences
\d tablename lists that table.

etc. etc.

But how can I get a listing of all used triggers on a certain table?

\d <tablename>

Chris

Hi Chris,

Thanks for your response, but this is what I get:

column, Type, and Modifiers
+
Indexes and foreign key contraints.
No triggers.

The triggers are responsible for checking FK-contraints in other tables,
that use the table I want to list as refering key.

This is what the help says:

\d [NAME] describe table, index, sequence, or view
\d{t|i|s|v|S} [PATTERN] (add "+" for more detail)
list tables/indexes/sequences/views/system tables

No triggers....

So, I am still in the dark.

Regards,
Erwin Moller

#4Christopher Kings-Lynne
chriskl@familyhealth.com.au
In reply to: Erwin Moller (#3)
Re: listing triggers

Thanks for your response, but this is what I get:

column, Type, and Modifiers
+
Indexes and foreign key contraints.
No triggers.

It lists triggers. Trust me, I wrote it.

The triggers are responsible for checking FK-contraints in other tables,
that use the table I want to list as refering key.

OK, there you go. Foreign key triggers are hidden from you
automatically. They're considered implementation specific information.

Chris

#5Robert Treat
xzilla@users.sourceforge.net
In reply to: Erwin Moller (#3)
Re: listing triggers

On Sunday 08 August 2004 05:05, Erwin Moller wrote:

But how can I get a listing of all used triggers on a certain table?

\d <tablename>

Thanks for your response, but this is what I get:

column, Type, and Modifiers
+
Indexes and foreign key contraints.
No triggers.

The triggers are responsible for checking FK-contraints in other tables,
that use the table I want to list as refering key.

It depends on how you've implmented your FK's... for example

live=# \d ns_category
Table "public.ns_category"
Column | Type | Modifiers
--------------------+--------------------------+------------------------
ns_category_id | integer | not null
name | character varying(250) | not null
ns_product_type_id | integer | not null
display | boolean | not null default false
date_added | timestamp with time zone | not null
last_update | timestamp with time zone | not null
active | boolean | not null default false
Indexes:
"ns_category_id_pkey" primary key, btree (ns_category_id)
Triggers:
"RI_ConstraintTrigger_18883782" AFTER INSERT OR UPDATE ON ns_category FROM
ns_product_type NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH ROW EXECUTE
PROCEDURE "RI_FKey_check_ins"('ns_product_type_id_fk', 'ns_category',
'ns_product_type', 'UNSPECIFIED', 'ns_product_type_id', 'ns_product_type_id')
"RI_ConstraintTrigger_18883789" AFTER DELETE ON ns_category FROM
ns_product NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH ROW EXECUTE PROCEDURE
"RI_FKey_noaction_del"('ns_category_id_fk', 'ns_product', 'ns_category',
'UNSPECIFIED', 'ns_category_id', 'ns_category_id')
"RI_ConstraintTrigger_18883790" AFTER UPDATE ON ns_category FROM
ns_product NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH ROW EXECUTE PROCEDURE
"RI_FKey_noaction_upd"('ns_category_id_fk', 'ns_product', 'ns_category',
'UNSPECIFIED', 'ns_category_id', 'ns_category_id')

If you are using explicit triggers for FK they will show up under psql \d
output, however if you use implicit triggers (dervied from references syntax
in create table, or alter table add foriegn key syntax) then you wont see the
"triggers", but the constraints will "do the right thing".

db_customer=# create table test (alunos_id integer references alunos (id) on
delete cascade);
CREATE TABLE
db_customer=# \d test
Table "public.test"
Column | Type | Modifiers
-----------+---------+-----------
alunos_id | integer |
Foreign-key constraints:
"$1" FOREIGN KEY (alunos_id) REFERENCES alunos(id) ON DELETE CASCADE

--
Robert Treat
Build A Better Lamp :: Linux Apache {middleware} PostgreSQL

#6Erwin Moller
since_humans_read_this_I_am_spammed_too_much@spamyourself.com
In reply to: Erwin Moller (#1)
Re: listing triggers

Christopher Kings-Lynne wrote:

Thanks for your response, but this is what I get:

column, Type, and Modifiers
+
Indexes and foreign key contraints.
No triggers.

It lists triggers. Trust me, I wrote it.

(Sorry for late response)
Hi Chris,

You wrote it?!?
Ok, in that case I'll better take your word for it. :-)

This is a perfect chance to compliment you for your contributions to that
great database, so.. Thanks! I love it. It actually always works.

I never realized that there is a difference between triggers created
implicitly and explicitly.

Robert Treat explained also that the reason that I don't see them has to do
with the fact that the triggers were created implicitly (dervied from
references syntax in create table, or alter table add foreign key syntax).

Thanks for your help/explanation. (Robert too!)

Regards,
Erwin Moller (a happy PostgreSQL end-user)