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|
--
-- TRIGGERS
--
create table pkeys (pkey1 int4 not null, pkey2 text not null);
create table fkeys (fkey1 int4, fkey2 text, fkey3 int);
create table fkeys2 (fkey21 int4, fkey22 text, pkey23 int not null);
create index fkeys_i on fkeys (fkey1, fkey2);
create index fkeys2_i on fkeys2 (fkey21, fkey22);
create index fkeys2p_i on fkeys2 (pkey23);
insert into pkeys values (10, '1');
insert into pkeys values (20, '2');
insert into pkeys values (30, '3');
insert into pkeys values (40, '4');
insert into pkeys values (50, '5');
insert into pkeys values (60, '6');
create unique index pkeys_i on pkeys (pkey1, pkey2);
--
-- For fkeys:
-- (fkey1, fkey2) --> pkeys (pkey1, pkey2)
-- (fkey3) --> fkeys2 (pkey23)
--
create trigger check_fkeys_pkey_exist
before insert or update on fkeys
for each row
execute procedure
check_primary_key ('fkey1', 'fkey2', 'pkeys', 'pkey1', 'pkey2');
create trigger check_fkeys_pkey2_exist
before insert or update on fkeys
for each row
execute procedure check_primary_key ('fkey3', 'fkeys2', 'pkey23');
--
-- For fkeys2:
-- (fkey21, fkey22) --> pkeys (pkey1, pkey2)
--
create trigger check_fkeys2_pkey_exist
before insert or update on fkeys2
for each row
execute procedure
check_primary_key ('fkey21', 'fkey22', 'pkeys', 'pkey1', 'pkey2');
-- Test comments
COMMENT ON TRIGGER check_fkeys2_pkey_bad ON fkeys2 IS 'wrong';
ERROR: trigger "check_fkeys2_pkey_bad" for table "fkeys2" does not exist
COMMENT ON TRIGGER check_fkeys2_pkey_exist ON fkeys2 IS 'right';
COMMENT ON TRIGGER check_fkeys2_pkey_exist ON fkeys2 IS NULL;
--
-- For pkeys:
-- ON DELETE/UPDATE (pkey1, pkey2) CASCADE:
-- fkeys (fkey1, fkey2) and fkeys2 (fkey21, fkey22)
--
create trigger check_pkeys_fkey_cascade
before delete or update on pkeys
for each row
execute procedure
check_foreign_key (2, 'cascade', 'pkey1', 'pkey2',
'fkeys', 'fkey1', 'fkey2', 'fkeys2', 'fkey21', 'fkey22');
--
-- For fkeys2:
-- ON DELETE/UPDATE (pkey23) RESTRICT:
-- fkeys (fkey3)
--
create trigger check_fkeys2_fkey_restrict
before delete or update on fkeys2
for each row
execute procedure check_foreign_key (1, 'restrict', 'pkey23', 'fkeys', 'fkey3');
insert into fkeys2 values (10, '1', 1);
insert into fkeys2 values (30, '3', 2);
insert into fkeys2 values (40, '4', 5);
insert into fkeys2 values (50, '5', 3);
-- no key in pkeys
insert into fkeys2 values (70, '5', 3);
ERROR: tuple references non-existent key
DETAIL: Trigger "check_fkeys2_pkey_exist" found tuple referencing non-existent key in "pkeys".
insert into fkeys values (10, '1', 2);
insert into fkeys values (30, '3', 3);
insert into fkeys values (40, '4', 2);
insert into fkeys values (50, '5', 2);
-- no key in pkeys
insert into fkeys values (70, '5', 1);
ERROR: tuple references non-existent key
DETAIL: Trigger "check_fkeys_pkey_exist" found tuple referencing non-existent key in "pkeys".
-- no key in fkeys2
insert into fkeys values (60, '6', 4);
ERROR: tuple references non-existent key
DETAIL: Trigger "check_fkeys_pkey2_exist" found tuple referencing non-existent key in "fkeys2".
delete from pkeys where pkey1 = 30 and pkey2 = '3';
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted
ERROR: "check_fkeys2_fkey_restrict": tuple is referenced in "fkeys"
CONTEXT: SQL statement "delete from fkeys2 where fkey21 = $1 and fkey22 = $2 "
delete from pkeys where pkey1 = 40 and pkey2 = '4';
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys2 are deleted
update pkeys set pkey1 = 7, pkey2 = '70' where pkey1 = 50 and pkey2 = '5';
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted
ERROR: "check_fkeys2_fkey_restrict": tuple is referenced in "fkeys"
CONTEXT: SQL statement "delete from fkeys2 where fkey21 = $1 and fkey22 = $2 "
update pkeys set pkey1 = 7, pkey2 = '70' where pkey1 = 10 and pkey2 = '1';
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys are deleted
NOTICE: check_pkeys_fkey_cascade: 1 tuple(s) of fkeys2 are deleted
DROP TABLE pkeys;
DROP TABLE fkeys;
DROP TABLE fkeys2;
-- -- I've disabled the funny_dup17 test because the new semantics
-- -- of AFTER ROW triggers, which get now fired at the end of a
-- -- query always, cause funny_dup17 to enter an endless loop.
-- --
-- -- Jan
--
-- create table dup17 (x int4);
--
-- create trigger dup17_before
-- before insert on dup17
-- for each row
-- execute procedure
-- funny_dup17 ()
-- ;
--
-- insert into dup17 values (17);
-- select count(*) from dup17;
-- insert into dup17 values (17);
-- select count(*) from dup17;
--
-- drop trigger dup17_before on dup17;
--
-- create trigger dup17_after
-- after insert on dup17
-- for each row
-- execute procedure
-- funny_dup17 ()
-- ;
-- insert into dup17 values (13);
-- select count(*) from dup17 where x = 13;
-- insert into dup17 values (13);
-- select count(*) from dup17 where x = 13;
--
-- DROP TABLE dup17;
create sequence ttdummy_seq increment 10 start 0 minvalue 0;
create table tttest (
price_id int4,
price_val int4,
price_on int4,
price_off int4 default 999999
);
create trigger ttdummy
before delete or update on tttest
for each row
execute procedure
ttdummy (price_on, price_off);
create trigger ttserial
before insert or update on tttest
for each row
execute procedure
autoinc (price_on, ttdummy_seq);
insert into tttest values (1, 1, null);
insert into tttest values (2, 2, null);
insert into tttest values (3, 3, 0);
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
2 | 2 | 20 | 999999
3 | 3 | 30 | 999999
(3 rows)
delete from tttest where price_id = 2;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
3 | 3 | 30 | 999999
2 | 2 | 20 | 40
(3 rows)
-- what do we see ?
-- get current prices
select * from tttest where price_off = 999999;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
3 | 3 | 30 | 999999
(2 rows)
-- change price for price_id == 3
update tttest set price_val = 30 where price_id = 3;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
2 | 2 | 20 | 40
3 | 30 | 50 | 999999
3 | 3 | 30 | 50
(4 rows)
-- now we want to change pric_id in ALL tuples
-- this gets us not what we need
update tttest set price_id = 5 where price_id = 3;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
2 | 2 | 20 | 40
3 | 3 | 30 | 50
5 | 30 | 60 | 999999
3 | 30 | 50 | 60
(5 rows)
-- restore data as before last update:
select set_ttdummy(0);
set_ttdummy
-------------
1
(1 row)
delete from tttest where price_id = 5;
update tttest set price_off = 999999 where price_val = 30;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
2 | 2 | 20 | 40
3 | 3 | 30 | 50
3 | 30 | 50 | 999999
(4 rows)
-- and try change price_id now!
update tttest set price_id = 5 where price_id = 3;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
1 | 1 | 10 | 999999
2 | 2 | 20 | 40
5 | 3 | 30 | 50
5 | 30 | 50 | 999999
(4 rows)
-- isn't it what we need ?
select set_ttdummy(1);
set_ttdummy
-------------
0
(1 row)
-- we want to correct some "date"
update tttest set price_on = -1 where price_id = 1;
ERROR: ttdummy (tttest): you cannot change price_on and/or price_off columns (use set_ttdummy)
-- but this doesn't work
-- try in this way
select set_ttdummy(0);
set_ttdummy
-------------
1
(1 row)
update tttest set price_on = -1 where price_id = 1;
select * from tttest;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
2 | 2 | 20 | 40
5 | 3 | 30 | 50
5 | 30 | 50 | 999999
1 | 1 | -1 | 999999
(4 rows)
-- isn't it what we need ?
-- get price for price_id == 5 as it was @ "date" 35
select * from tttest where price_on <= 35 and price_off > 35 and price_id = 5;
price_id | price_val | price_on | price_off
----------+-----------+----------+-----------
5 | 3 | 30 | 50
(1 row)
drop table tttest;
drop sequence ttdummy_seq;
--
-- tests for per-statement triggers
--
CREATE TABLE log_table (tstamp timestamp default timeofday()::timestamp);
CREATE TABLE main_table (a int, b int);
COPY main_table (a,b) FROM stdin;
CREATE FUNCTION trigger_func() RETURNS trigger LANGUAGE plpgsql AS '
BEGIN
RAISE NOTICE ''trigger_func(%) called: action = %, when = %, level = %'', TG_ARGV[0], TG_OP, TG_WHEN, TG_LEVEL;
RETURN NULL;
END;';
CREATE TRIGGER before_ins_stmt_trig BEFORE INSERT ON main_table
FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func('before_ins_stmt');
CREATE TRIGGER after_ins_stmt_trig AFTER INSERT ON main_table
FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func('after_ins_stmt');
--
-- if neither 'FOR EACH ROW' nor 'FOR EACH STATEMENT' was specified,
-- CREATE TRIGGER should default to 'FOR EACH STATEMENT'
--
CREATE TRIGGER after_upd_stmt_trig AFTER UPDATE ON main_table
EXECUTE PROCEDURE trigger_func('after_upd_stmt');
CREATE TRIGGER after_upd_row_trig AFTER UPDATE ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('after_upd_row');
INSERT INTO main_table DEFAULT VALUES;
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
UPDATE main_table SET a = a + 1 WHERE b < 30;
NOTICE: trigger_func(after_upd_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
-- UPDATE that effects zero rows should still call per-statement trigger
UPDATE main_table SET a = a + 2 WHERE b > 100;
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
-- COPY should fire per-row and per-statement INSERT triggers
COPY main_table (a, b) FROM stdin;
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
SELECT * FROM main_table ORDER BY a, b;
a | b
----+----
6 | 10
21 | 20
30 | 40
31 | 10
50 | 35
50 | 60
81 | 15
|
(8 rows)
--
-- test triggers with WHEN clause
--
CREATE TRIGGER modified_a BEFORE UPDATE OF a ON main_table
FOR EACH ROW WHEN (OLD.a <> NEW.a) EXECUTE PROCEDURE trigger_func('modified_a');
CREATE TRIGGER modified_any BEFORE UPDATE OF a ON main_table
FOR EACH ROW WHEN (OLD.* IS DISTINCT FROM NEW.*) EXECUTE PROCEDURE trigger_func('modified_any');
CREATE TRIGGER insert_a AFTER INSERT ON main_table
FOR EACH ROW WHEN (NEW.a = 123) EXECUTE PROCEDURE trigger_func('insert_a');
CREATE TRIGGER delete_a AFTER DELETE ON main_table
FOR EACH ROW WHEN (OLD.a = 123) EXECUTE PROCEDURE trigger_func('delete_a');
CREATE TRIGGER insert_when BEFORE INSERT ON main_table
FOR EACH STATEMENT WHEN (true) EXECUTE PROCEDURE trigger_func('insert_when');
CREATE TRIGGER delete_when AFTER DELETE ON main_table
FOR EACH STATEMENT WHEN (true) EXECUTE PROCEDURE trigger_func('delete_when');
INSERT INTO main_table (a) VALUES (123), (456);
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(insert_when) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(insert_a) called: action = INSERT, when = AFTER, level = ROW
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
COPY main_table FROM stdin;
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(insert_when) called: action = INSERT, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(insert_a) called: action = INSERT, when = AFTER, level = ROW
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
DELETE FROM main_table WHERE a IN (123, 456);
NOTICE: trigger_func(delete_a) called: action = DELETE, when = AFTER, level = ROW
NOTICE: trigger_func(delete_a) called: action = DELETE, when = AFTER, level = ROW
NOTICE: trigger_func(delete_when) called: action = DELETE, when = AFTER, level = STATEMENT
UPDATE main_table SET a = 50, b = 60;
NOTICE: trigger_func(modified_any) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_any) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_a) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_a) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_a) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_a) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(modified_a) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(after_upd_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
SELECT * FROM main_table ORDER BY a, b;
a | b
----+----
6 | 10
21 | 20
30 | 40
31 | 10
50 | 35
50 | 60
81 | 15
|
(8 rows)
SELECT pg_get_triggerdef(oid, true) FROM pg_trigger WHERE tgrelid = 'main_table'::regclass AND tgname = 'modified_a';
pg_get_triggerdef
--------------------------------------------------------------------------------------------------------------------------------------------
CREATE TRIGGER modified_a BEFORE UPDATE OF a ON main_table FOR EACH ROW WHEN (old.a <> new.a) EXECUTE PROCEDURE trigger_func('modified_a')
(1 row)
SELECT pg_get_triggerdef(oid, false) FROM pg_trigger WHERE tgrelid = 'main_table'::regclass AND tgname = 'modified_a';
pg_get_triggerdef
----------------------------------------------------------------------------------------------------------------------------------------------
CREATE TRIGGER modified_a BEFORE UPDATE OF a ON main_table FOR EACH ROW WHEN ((old.a <> new.a)) EXECUTE PROCEDURE trigger_func('modified_a')
(1 row)
SELECT pg_get_triggerdef(oid, true) FROM pg_trigger WHERE tgrelid = 'main_table'::regclass AND tgname = 'modified_any';
pg_get_triggerdef
--------------------------------------------------------------------------------------------------------------------------------------------------------------
CREATE TRIGGER modified_any BEFORE UPDATE OF a ON main_table FOR EACH ROW WHEN (old.* IS DISTINCT FROM new.*) EXECUTE PROCEDURE trigger_func('modified_any')
(1 row)
DROP TRIGGER modified_a ON main_table;
DROP TRIGGER modified_any ON main_table;
DROP TRIGGER insert_a ON main_table;
DROP TRIGGER delete_a ON main_table;
DROP TRIGGER insert_when ON main_table;
DROP TRIGGER delete_when ON main_table;
-- Test column-level triggers
DROP TRIGGER after_upd_row_trig ON main_table;
CREATE TRIGGER before_upd_a_row_trig BEFORE UPDATE OF a ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_upd_a_row');
CREATE TRIGGER after_upd_b_row_trig AFTER UPDATE OF b ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('after_upd_b_row');
CREATE TRIGGER after_upd_a_b_row_trig AFTER UPDATE OF a, b ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('after_upd_a_b_row');
CREATE TRIGGER before_upd_a_stmt_trig BEFORE UPDATE OF a ON main_table
FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func('before_upd_a_stmt');
CREATE TRIGGER after_upd_b_stmt_trig AFTER UPDATE OF b ON main_table
FOR EACH STATEMENT EXECUTE PROCEDURE trigger_func('after_upd_b_stmt');
SELECT pg_get_triggerdef(oid) FROM pg_trigger WHERE tgrelid = 'main_table'::regclass AND tgname = 'after_upd_a_b_row_trig';
pg_get_triggerdef
-------------------------------------------------------------------------------------------------------------------------------------------
CREATE TRIGGER after_upd_a_b_row_trig AFTER UPDATE OF a, b ON main_table FOR EACH ROW EXECUTE PROCEDURE trigger_func('after_upd_a_b_row')
(1 row)
UPDATE main_table SET a = 50;
NOTICE: trigger_func(before_upd_a_stmt) called: action = UPDATE, when = BEFORE, level = STATEMENT
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
UPDATE main_table SET b = 10;
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
NOTICE: trigger_func(after_upd_b_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
--
-- Test case for bug with BEFORE trigger followed by AFTER trigger with WHEN
--
CREATE TABLE some_t (some_col boolean NOT NULL);
CREATE FUNCTION dummy_update_func() RETURNS trigger AS $$
BEGIN
RAISE NOTICE 'dummy_update_func(%) called: action = %, old = %, new = %',
TG_ARGV[0], TG_OP, OLD, NEW;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER some_trig_before BEFORE UPDATE ON some_t FOR EACH ROW
EXECUTE PROCEDURE dummy_update_func('before');
CREATE TRIGGER some_trig_aftera AFTER UPDATE ON some_t FOR EACH ROW
WHEN (NOT OLD.some_col AND NEW.some_col)
EXECUTE PROCEDURE dummy_update_func('aftera');
CREATE TRIGGER some_trig_afterb AFTER UPDATE ON some_t FOR EACH ROW
WHEN (NOT NEW.some_col)
EXECUTE PROCEDURE dummy_update_func('afterb');
INSERT INTO some_t VALUES (TRUE);
UPDATE some_t SET some_col = TRUE;
NOTICE: dummy_update_func(before) called: action = UPDATE, old = (t), new = (t)
UPDATE some_t SET some_col = FALSE;
NOTICE: dummy_update_func(before) called: action = UPDATE, old = (t), new = (f)
NOTICE: dummy_update_func(afterb) called: action = UPDATE, old = (t), new = (f)
UPDATE some_t SET some_col = TRUE;
NOTICE: dummy_update_func(before) called: action = UPDATE, old = (f), new = (t)
NOTICE: dummy_update_func(aftera) called: action = UPDATE, old = (f), new = (t)
DROP TABLE some_t;
-- bogus cases
CREATE TRIGGER error_upd_and_col BEFORE UPDATE OR UPDATE OF a ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('error_upd_and_col');
ERROR: duplicate trigger events specified at or near "ON"
LINE 1: ...ER error_upd_and_col BEFORE UPDATE OR UPDATE OF a ON main_ta...
^
CREATE TRIGGER error_upd_a_a BEFORE UPDATE OF a, a ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('error_upd_a_a');
ERROR: column "a" specified more than once
CREATE TRIGGER error_ins_a BEFORE INSERT OF a ON main_table
FOR EACH ROW EXECUTE PROCEDURE trigger_func('error_ins_a');
ERROR: syntax error at or near "OF"
LINE 1: CREATE TRIGGER error_ins_a BEFORE INSERT OF a ON main_table
^
CREATE TRIGGER error_ins_when BEFORE INSERT OR UPDATE ON main_table
FOR EACH ROW WHEN (OLD.a <> NEW.a)
EXECUTE PROCEDURE trigger_func('error_ins_old');
ERROR: INSERT trigger's WHEN condition cannot reference OLD values
LINE 2: FOR EACH ROW WHEN (OLD.a <> NEW.a)
^
CREATE TRIGGER error_del_when BEFORE DELETE OR UPDATE ON main_table
FOR EACH ROW WHEN (OLD.a <> NEW.a)
EXECUTE PROCEDURE trigger_func('error_del_new');
ERROR: DELETE trigger's WHEN condition cannot reference NEW values
LINE 2: FOR EACH ROW WHEN (OLD.a <> NEW.a)
^
CREATE TRIGGER error_del_when BEFORE INSERT OR UPDATE ON main_table
FOR EACH ROW WHEN (NEW.tableoid <> 0)
EXECUTE PROCEDURE trigger_func('error_when_sys_column');
ERROR: BEFORE trigger's WHEN condition cannot reference NEW system columns
LINE 2: FOR EACH ROW WHEN (NEW.tableoid <> 0)
^
CREATE TRIGGER error_stmt_when BEFORE UPDATE OF a ON main_table
FOR EACH STATEMENT WHEN (OLD.* IS DISTINCT FROM NEW.*)
EXECUTE PROCEDURE trigger_func('error_stmt_when');
ERROR: statement trigger's WHEN condition cannot reference column values
LINE 2: FOR EACH STATEMENT WHEN (OLD.* IS DISTINCT FROM NEW.*)
^
-- check dependency restrictions
ALTER TABLE main_table DROP COLUMN b;
ERROR: cannot drop table main_table column b because other objects depend on it
DETAIL: trigger after_upd_b_row_trig on table main_table depends on table main_table column b
trigger after_upd_a_b_row_trig on table main_table depends on table main_table column b
trigger after_upd_b_stmt_trig on table main_table depends on table main_table column b
HINT: Use DROP ... CASCADE to drop the dependent objects too.
-- this should succeed, but we'll roll it back to keep the triggers around
begin;
DROP TRIGGER after_upd_a_b_row_trig ON main_table;
DROP TRIGGER after_upd_b_row_trig ON main_table;
DROP TRIGGER after_upd_b_stmt_trig ON main_table;
ALTER TABLE main_table DROP COLUMN b;
rollback;
-- Test enable/disable triggers
create table trigtest (i serial primary key);
-- test that disabling RI triggers works
create table trigtest2 (i int references trigtest(i) on delete cascade);
create function trigtest() returns trigger as $$
begin
raise notice '% % % %', TG_RELNAME, TG_OP, TG_WHEN, TG_LEVEL;
return new;
end;$$ language plpgsql;
create trigger trigtest_b_row_tg before insert or update or delete on trigtest
for each row execute procedure trigtest();
create trigger trigtest_a_row_tg after insert or update or delete on trigtest
for each row execute procedure trigtest();
create trigger trigtest_b_stmt_tg before insert or update or delete on trigtest
for each statement execute procedure trigtest();
create trigger trigtest_a_stmt_tg after insert or update or delete on trigtest
for each statement execute procedure trigtest();
insert into trigtest default values;
NOTICE: trigtest INSERT BEFORE STATEMENT
NOTICE: trigtest INSERT BEFORE ROW
NOTICE: trigtest INSERT AFTER ROW
NOTICE: trigtest INSERT AFTER STATEMENT
alter table trigtest disable trigger trigtest_b_row_tg;
insert into trigtest default values;
NOTICE: trigtest INSERT BEFORE STATEMENT
NOTICE: trigtest INSERT AFTER ROW
NOTICE: trigtest INSERT AFTER STATEMENT
alter table trigtest disable trigger user;
insert into trigtest default values;
alter table trigtest enable trigger trigtest_a_stmt_tg;
insert into trigtest default values;
NOTICE: trigtest INSERT AFTER STATEMENT
insert into trigtest2 values(1);
insert into trigtest2 values(2);
delete from trigtest where i=2;
NOTICE: trigtest DELETE AFTER STATEMENT
select * from trigtest2;
i
---
1
(1 row)
alter table trigtest disable trigger all;
delete from trigtest where i=1;
select * from trigtest2;
i
---
1
(1 row)
-- ensure we still insert, even when all triggers are disabled
insert into trigtest default values;
select * from trigtest;
i
---
3
4
5
(3 rows)
drop table trigtest2;
drop table trigtest;
-- dump trigger data
CREATE TABLE trigger_test (
i int,
v varchar
);
CREATE OR REPLACE FUNCTION trigger_data() RETURNS trigger
LANGUAGE plpgsql AS $$
declare
argstr text;
relid text;
begin
relid := TG_relid::regclass;
-- plpgsql can't discover its trigger data in a hash like perl and python
-- can, or by a sort of reflection like tcl can,
-- so we have to hard code the names.
raise NOTICE 'TG_NAME: %', TG_name;
raise NOTICE 'TG_WHEN: %', TG_when;
raise NOTICE 'TG_LEVEL: %', TG_level;
raise NOTICE 'TG_OP: %', TG_op;
raise NOTICE 'TG_RELID::regclass: %', relid;
raise NOTICE 'TG_RELNAME: %', TG_relname;
raise NOTICE 'TG_TABLE_NAME: %', TG_table_name;
raise NOTICE 'TG_TABLE_SCHEMA: %', TG_table_schema;
raise NOTICE 'TG_NARGS: %', TG_nargs;
argstr := '[';
for i in 0 .. TG_nargs - 1 loop
if i > 0 then
argstr := argstr || ', ';
end if;
argstr := argstr || TG_argv[i];
end loop;
argstr := argstr || ']';
raise NOTICE 'TG_ARGV: %', argstr;
if TG_OP != 'INSERT' then
raise NOTICE 'OLD: %', OLD;
end if;
if TG_OP != 'DELETE' then
raise NOTICE 'NEW: %', NEW;
end if;
if TG_OP = 'DELETE' then
return OLD;
else
return NEW;
end if;
end;
$$;
CREATE TRIGGER show_trigger_data_trig
BEFORE INSERT OR UPDATE OR DELETE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo');
insert into trigger_test values(1,'insert');
NOTICE: TG_NAME: show_trigger_data_trig
NOTICE: TG_WHEN: BEFORE
NOTICE: TG_LEVEL: ROW
NOTICE: TG_OP: INSERT
NOTICE: TG_RELID::regclass: trigger_test
NOTICE: TG_RELNAME: trigger_test
NOTICE: TG_TABLE_NAME: trigger_test
NOTICE: TG_TABLE_SCHEMA: public
NOTICE: TG_NARGS: 2
NOTICE: TG_ARGV: [23, skidoo]
NOTICE: NEW: (1,insert)
update trigger_test set v = 'update' where i = 1;
NOTICE: TG_NAME: show_trigger_data_trig
NOTICE: TG_WHEN: BEFORE
NOTICE: TG_LEVEL: ROW
NOTICE: TG_OP: UPDATE
NOTICE: TG_RELID::regclass: trigger_test
NOTICE: TG_RELNAME: trigger_test
NOTICE: TG_TABLE_NAME: trigger_test
NOTICE: TG_TABLE_SCHEMA: public
NOTICE: TG_NARGS: 2
NOTICE: TG_ARGV: [23, skidoo]
NOTICE: OLD: (1,insert)
NOTICE: NEW: (1,update)
delete from trigger_test;
NOTICE: TG_NAME: show_trigger_data_trig
NOTICE: TG_WHEN: BEFORE
NOTICE: TG_LEVEL: ROW
NOTICE: TG_OP: DELETE
NOTICE: TG_RELID::regclass: trigger_test
NOTICE: TG_RELNAME: trigger_test
NOTICE: TG_TABLE_NAME: trigger_test
NOTICE: TG_TABLE_SCHEMA: public
NOTICE: TG_NARGS: 2
NOTICE: TG_ARGV: [23, skidoo]
NOTICE: OLD: (1,update)
DROP TRIGGER show_trigger_data_trig on trigger_test;
DROP FUNCTION trigger_data();
DROP TABLE trigger_test;
--
-- Test use of row comparisons on OLD/NEW
--
CREATE TABLE trigger_test (f1 int, f2 text, f3 text);
-- this is the obvious (and wrong...) way to compare rows
CREATE FUNCTION mytrigger() RETURNS trigger LANGUAGE plpgsql as $$
begin
if row(old.*) = row(new.*) then
raise notice 'row % not changed', new.f1;
else
raise notice 'row % changed', new.f1;
end if;
return new;
end$$;
CREATE TRIGGER t
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE mytrigger();
INSERT INTO trigger_test VALUES(1, 'foo', 'bar');
INSERT INTO trigger_test VALUES(2, 'baz', 'quux');
UPDATE trigger_test SET f3 = 'bar';
NOTICE: row 1 not changed
NOTICE: row 2 changed
UPDATE trigger_test SET f3 = NULL;
NOTICE: row 1 changed
NOTICE: row 2 changed
-- this demonstrates that the above isn't really working as desired:
UPDATE trigger_test SET f3 = NULL;
NOTICE: row 1 changed
NOTICE: row 2 changed
-- the right way when considering nulls is
CREATE OR REPLACE FUNCTION mytrigger() RETURNS trigger LANGUAGE plpgsql as $$
begin
if row(old.*) is distinct from row(new.*) then
raise notice 'row % changed', new.f1;
else
raise notice 'row % not changed', new.f1;
end if;
return new;
end$$;
UPDATE trigger_test SET f3 = 'bar';
NOTICE: row 1 changed
NOTICE: row 2 changed
UPDATE trigger_test SET f3 = NULL;
NOTICE: row 1 changed
NOTICE: row 2 changed
UPDATE trigger_test SET f3 = NULL;
NOTICE: row 1 not changed
NOTICE: row 2 not changed
DROP TABLE trigger_test;
DROP FUNCTION mytrigger();
-- Test snapshot management in serializable transactions involving triggers
-- per bug report in [email protected]
CREATE FUNCTION serializable_update_trig() RETURNS trigger LANGUAGE plpgsql AS
$$
declare
rec record;
begin
new.description = 'updated in trigger';
return new;
end;
$$;
CREATE TABLE serializable_update_tab (
id int,
filler text,
description text
);
CREATE TRIGGER serializable_update_trig BEFORE UPDATE ON serializable_update_tab
FOR EACH ROW EXECUTE PROCEDURE serializable_update_trig();
INSERT INTO serializable_update_tab SELECT a, repeat('xyzxz', 100), 'new'
FROM generate_series(1, 50) a;
BEGIN;
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
UPDATE serializable_update_tab SET description = 'no no', id = 1 WHERE id = 1;
COMMIT;
SELECT description FROM serializable_update_tab WHERE id = 1;
description
--------------------
updated in trigger
(1 row)
DROP TABLE serializable_update_tab;
-- minimal update trigger
CREATE TABLE min_updates_test (
f1 text,
f2 int,
f3 int);
CREATE TABLE min_updates_test_oids (
f1 text,
f2 int,
f3 int) WITH OIDS;
INSERT INTO min_updates_test VALUES ('a',1,2),('b','2',null);
INSERT INTO min_updates_test_oids VALUES ('a',1,2),('b','2',null);
CREATE TRIGGER z_min_update
BEFORE UPDATE ON min_updates_test
FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
CREATE TRIGGER z_min_update
BEFORE UPDATE ON min_updates_test_oids
FOR EACH ROW EXECUTE PROCEDURE suppress_redundant_updates_trigger();
\set QUIET false
UPDATE min_updates_test SET f1 = f1;
UPDATE 0
UPDATE min_updates_test SET f2 = f2 + 1;
UPDATE 2
UPDATE min_updates_test SET f3 = 2 WHERE f3 is null;
UPDATE 1
UPDATE min_updates_test_oids SET f1 = f1;
UPDATE 0
UPDATE min_updates_test_oids SET f2 = f2 + 1;
UPDATE 2
UPDATE min_updates_test_oids SET f3 = 2 WHERE f3 is null;
UPDATE 1
\set QUIET true
SELECT * FROM min_updates_test;
f1 | f2 | f3
----+----+----
a | 2 | 2
b | 3 | 2
(2 rows)
SELECT * FROM min_updates_test_oids;
f1 | f2 | f3
----+----+----
a | 2 | 2
b | 3 | 2
(2 rows)
DROP TABLE min_updates_test;
DROP TABLE min_updates_test_oids;
--
-- Test triggers on views
--
CREATE VIEW main_view AS SELECT a, b FROM main_table;
-- VIEW trigger function
CREATE OR REPLACE FUNCTION view_trigger() RETURNS trigger
LANGUAGE plpgsql AS $$
declare
argstr text := '';
begin
for i in 0 .. TG_nargs - 1 loop
if i > 0 then
argstr := argstr || ', ';
end if;
argstr := argstr || TG_argv[i];
end loop;
raise notice '% % % % (%)', TG_RELNAME, TG_WHEN, TG_OP, TG_LEVEL, argstr;
if TG_LEVEL = 'ROW' then
if TG_OP = 'INSERT' then
raise NOTICE 'NEW: %', NEW;
INSERT INTO main_table VALUES (NEW.a, NEW.b);
RETURN NEW;
end if;
if TG_OP = 'UPDATE' then
raise NOTICE 'OLD: %, NEW: %', OLD, NEW;
UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b;
if NOT FOUND then RETURN NULL; end if;
RETURN NEW;
end if;
if TG_OP = 'DELETE' then
raise NOTICE 'OLD: %', OLD;
DELETE FROM main_table WHERE a = OLD.a AND b = OLD.b;
if NOT FOUND then RETURN NULL; end if;
RETURN OLD;
end if;
end if;
RETURN NULL;
end;
$$;
-- Before row triggers aren't allowed on views
CREATE TRIGGER invalid_trig BEFORE INSERT ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_ins_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
CREATE TRIGGER invalid_trig BEFORE UPDATE ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_upd_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
CREATE TRIGGER invalid_trig BEFORE DELETE ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_del_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
-- After row triggers aren't allowed on views
CREATE TRIGGER invalid_trig AFTER INSERT ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_ins_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
CREATE TRIGGER invalid_trig AFTER UPDATE ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_upd_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
CREATE TRIGGER invalid_trig AFTER DELETE ON main_view
FOR EACH ROW EXECUTE PROCEDURE trigger_func('before_del_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have row-level BEFORE or AFTER triggers.
-- Truncate triggers aren't allowed on views
CREATE TRIGGER invalid_trig BEFORE TRUNCATE ON main_view
EXECUTE PROCEDURE trigger_func('before_tru_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have TRUNCATE triggers.
CREATE TRIGGER invalid_trig AFTER TRUNCATE ON main_view
EXECUTE PROCEDURE trigger_func('before_tru_row');
ERROR: "main_view" is a view
DETAIL: Views cannot have TRUNCATE triggers.
-- INSTEAD OF triggers aren't allowed on tables
CREATE TRIGGER invalid_trig INSTEAD OF INSERT ON main_table
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_ins');
ERROR: "main_table" is a table
DETAIL: Tables cannot have INSTEAD OF triggers.
CREATE TRIGGER invalid_trig INSTEAD OF UPDATE ON main_table
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_upd');
ERROR: "main_table" is a table
DETAIL: Tables cannot have INSTEAD OF triggers.
CREATE TRIGGER invalid_trig INSTEAD OF DELETE ON main_table
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_del');
ERROR: "main_table" is a table
DETAIL: Tables cannot have INSTEAD OF triggers.
-- Don't support WHEN clauses with INSTEAD OF triggers
CREATE TRIGGER invalid_trig INSTEAD OF UPDATE ON main_view
FOR EACH ROW WHEN (OLD.a <> NEW.a) EXECUTE PROCEDURE view_trigger('instead_of_upd');
ERROR: INSTEAD OF triggers cannot have WHEN conditions
-- Don't support column-level INSTEAD OF triggers
CREATE TRIGGER invalid_trig INSTEAD OF UPDATE OF a ON main_view
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_upd');
ERROR: INSTEAD OF triggers cannot have column lists
-- Don't support statement-level INSTEAD OF triggers
CREATE TRIGGER invalid_trig INSTEAD OF UPDATE ON main_view
EXECUTE PROCEDURE view_trigger('instead_of_upd');
ERROR: INSTEAD OF triggers must be FOR EACH ROW
-- Valid INSTEAD OF triggers
CREATE TRIGGER instead_of_insert_trig INSTEAD OF INSERT ON main_view
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_ins');
CREATE TRIGGER instead_of_update_trig INSTEAD OF UPDATE ON main_view
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_upd');
CREATE TRIGGER instead_of_delete_trig INSTEAD OF DELETE ON main_view
FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_del');
-- Valid BEFORE statement VIEW triggers
CREATE TRIGGER before_ins_stmt_trig BEFORE INSERT ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_ins_stmt');
CREATE TRIGGER before_upd_stmt_trig BEFORE UPDATE ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_upd_stmt');
CREATE TRIGGER before_del_stmt_trig BEFORE DELETE ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_del_stmt');
-- Valid AFTER statement VIEW triggers
CREATE TRIGGER after_ins_stmt_trig AFTER INSERT ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_ins_stmt');
CREATE TRIGGER after_upd_stmt_trig AFTER UPDATE ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_upd_stmt');
CREATE TRIGGER after_del_stmt_trig AFTER DELETE ON main_view
FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_del_stmt');
\set QUIET false
-- Insert into view using trigger
INSERT INTO main_view VALUES (20, 30);
NOTICE: main_view BEFORE INSERT STATEMENT (before_view_ins_stmt)
NOTICE: main_view INSTEAD OF INSERT ROW (instead_of_ins)
NOTICE: NEW: (20,30)
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "INSERT INTO main_table VALUES (NEW.a, NEW.b)"
PL/pgSQL function view_trigger() line 17 at SQL statement
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "INSERT INTO main_table VALUES (NEW.a, NEW.b)"
PL/pgSQL function view_trigger() line 17 at SQL statement
NOTICE: main_view AFTER INSERT STATEMENT (after_view_ins_stmt)
INSERT 0 1
INSERT INTO main_view VALUES (21, 31) RETURNING a, b;
NOTICE: main_view BEFORE INSERT STATEMENT (before_view_ins_stmt)
NOTICE: main_view INSTEAD OF INSERT ROW (instead_of_ins)
NOTICE: NEW: (21,31)
NOTICE: trigger_func(before_ins_stmt) called: action = INSERT, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "INSERT INTO main_table VALUES (NEW.a, NEW.b)"
PL/pgSQL function view_trigger() line 17 at SQL statement
NOTICE: trigger_func(after_ins_stmt) called: action = INSERT, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "INSERT INTO main_table VALUES (NEW.a, NEW.b)"
PL/pgSQL function view_trigger() line 17 at SQL statement
NOTICE: main_view AFTER INSERT STATEMENT (after_view_ins_stmt)
a | b
----+----
21 | 31
(1 row)
INSERT 0 1
-- Table trigger will prevent updates
UPDATE main_view SET b = 31 WHERE a = 20;
NOTICE: main_view BEFORE UPDATE STATEMENT (before_view_upd_stmt)
NOTICE: main_view INSTEAD OF UPDATE ROW (instead_of_upd)
NOTICE: OLD: (20,30), NEW: (20,31)
NOTICE: trigger_func(before_upd_a_stmt) called: action = UPDATE, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: main_view AFTER UPDATE STATEMENT (after_view_upd_stmt)
UPDATE 0
UPDATE main_view SET b = 32 WHERE a = 21 AND b = 31 RETURNING a, b;
NOTICE: main_view BEFORE UPDATE STATEMENT (before_view_upd_stmt)
NOTICE: main_view INSTEAD OF UPDATE ROW (instead_of_upd)
NOTICE: OLD: (21,31), NEW: (21,32)
NOTICE: trigger_func(before_upd_a_stmt) called: action = UPDATE, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(before_upd_a_row) called: action = UPDATE, when = BEFORE, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: main_view AFTER UPDATE STATEMENT (after_view_upd_stmt)
a | b
---+---
(0 rows)
UPDATE 0
-- Remove table trigger to allow updates
DROP TRIGGER before_upd_a_row_trig ON main_table;
DROP TRIGGER
UPDATE main_view SET b = 31 WHERE a = 20;
NOTICE: main_view BEFORE UPDATE STATEMENT (before_view_upd_stmt)
NOTICE: main_view INSTEAD OF UPDATE ROW (instead_of_upd)
NOTICE: OLD: (20,30), NEW: (20,31)
NOTICE: trigger_func(before_upd_a_stmt) called: action = UPDATE, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: main_view AFTER UPDATE STATEMENT (after_view_upd_stmt)
UPDATE 1
UPDATE main_view SET b = 32 WHERE a = 21 AND b = 31 RETURNING a, b;
NOTICE: main_view BEFORE UPDATE STATEMENT (before_view_upd_stmt)
NOTICE: main_view INSTEAD OF UPDATE ROW (instead_of_upd)
NOTICE: OLD: (21,31), NEW: (21,32)
NOTICE: trigger_func(before_upd_a_stmt) called: action = UPDATE, when = BEFORE, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_a_b_row) called: action = UPDATE, when = AFTER, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_row) called: action = UPDATE, when = AFTER, level = ROW
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_b_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: trigger_func(after_upd_stmt) called: action = UPDATE, when = AFTER, level = STATEMENT
CONTEXT: SQL statement "UPDATE main_table SET a = NEW.a, b = NEW.b WHERE a = OLD.a AND b = OLD.b"
PL/pgSQL function view_trigger() line 23 at SQL statement
NOTICE: main_view AFTER UPDATE STATEMENT (after_view_upd_stmt)
a | b
----+----
21 | 32
(1 row)
UPDATE 1
-- Before and after stmt triggers should fire even when no rows are affected
UPDATE main_view SET b = 0 WHERE false;
NOTICE: main_view BEFORE UPDATE STATEMENT (before_view_upd_stmt)
NOTICE: main_view AFTER UPDATE STATEMENT (after_view_upd_stmt)
UPDATE 0
-- Delete from view using trigger
DELETE FROM main_view WHERE a IN (20,21);
NOTICE: main_view BEFORE DELETE STATEMENT (before_view_del_stmt)
NOTICE: main_view INSTEAD OF DELETE ROW (instead_of_del)
NOTICE: OLD: (21,10)
NOTICE: main_view INSTEAD OF DELETE ROW (instead_of_del)
NOTICE: OLD: (20,31)
NOTICE: main_view INSTEAD OF DELETE ROW (instead_of_del)
NOTICE: OLD: (21,32)
NOTICE: main_view AFTER DELETE STATEMENT (after_view_del_stmt)
DELETE 3
DELETE FROM main_view WHERE a = 31 RETURNING a, b;
NOTICE: main_view BEFORE DELETE STATEMENT (before_view_del_stmt)
NOTICE: main_view INSTEAD OF DELETE ROW (instead_of_del)
NOTICE: OLD: (31,10)
NOTICE: main_view AFTER DELETE STATEMENT (after_view_del_stmt)
a | b
----+----
31 | 10
(1 row)
DELETE 1
\set QUIET true
-- Describe view should list triggers
\d main_view
View "public.main_view"
Column | Type | Modifiers
--------+---------+-----------
a | integer |
b | integer |
Triggers:
after_del_stmt_trig AFTER DELETE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_del_stmt')
after_ins_stmt_trig AFTER INSERT ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_ins_stmt')
after_upd_stmt_trig AFTER UPDATE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_upd_stmt')
before_del_stmt_trig BEFORE DELETE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_del_stmt')
before_ins_stmt_trig BEFORE INSERT ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_ins_stmt')
before_upd_stmt_trig BEFORE UPDATE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_upd_stmt')
instead_of_delete_trig INSTEAD OF DELETE ON main_view FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_del')
instead_of_insert_trig INSTEAD OF INSERT ON main_view FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_ins')
instead_of_update_trig INSTEAD OF UPDATE ON main_view FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_upd')
-- Test dropping view triggers
DROP TRIGGER instead_of_insert_trig ON main_view;
DROP TRIGGER instead_of_delete_trig ON main_view;
\d+ main_view
View "public.main_view"
Column | Type | Modifiers | Storage | Description
--------+---------+-----------+---------+-------------
a | integer | | plain |
b | integer | | plain |
View definition:
SELECT main_table.a,
main_table.b
FROM main_table;
Triggers:
after_del_stmt_trig AFTER DELETE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_del_stmt')
after_ins_stmt_trig AFTER INSERT ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_ins_stmt')
after_upd_stmt_trig AFTER UPDATE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('after_view_upd_stmt')
before_del_stmt_trig BEFORE DELETE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_del_stmt')
before_ins_stmt_trig BEFORE INSERT ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_ins_stmt')
before_upd_stmt_trig BEFORE UPDATE ON main_view FOR EACH STATEMENT EXECUTE PROCEDURE view_trigger('before_view_upd_stmt')
instead_of_update_trig INSTEAD OF UPDATE ON main_view FOR EACH ROW EXECUTE PROCEDURE view_trigger('instead_of_upd')
DROP VIEW main_view;
--
-- Test triggers on a join view
--
CREATE TABLE country_table (
country_id serial primary key,
country_name text unique not null,
continent text not null
);
INSERT INTO country_table (country_name, continent)
VALUES ('Japan', 'Asia'),
('UK', 'Europe'),
('USA', 'North America')
RETURNING *;
country_id | country_name | continent
------------+--------------+---------------
1 | Japan | Asia
2 | UK | Europe
3 | USA | North America
(3 rows)
CREATE TABLE city_table (
city_id serial primary key,
city_name text not null,
population bigint,
country_id int references country_table
);
CREATE VIEW city_view AS
SELECT city_id, city_name, population, country_name, continent
FROM city_table ci
LEFT JOIN country_table co ON co.country_id = ci.country_id;
CREATE FUNCTION city_insert() RETURNS trigger LANGUAGE plpgsql AS $$
declare
ctry_id int;
begin
if NEW.country_name IS NOT NULL then
SELECT country_id, continent INTO ctry_id, NEW.continent
FROM country_table WHERE country_name = NEW.country_name;
if NOT FOUND then
raise exception 'No such country: "%"', NEW.country_name;
end if;
else
NEW.continent := NULL;
end if;
if NEW.city_id IS NOT NULL then
INSERT INTO city_table
VALUES(NEW.city_id, NEW.city_name, NEW.population, ctry_id);
else
INSERT INTO city_table(city_name, population, country_id)
VALUES(NEW.city_name, NEW.population, ctry_id)
RETURNING city_id INTO NEW.city_id;
end if;
RETURN NEW;
end;
$$;
CREATE TRIGGER city_insert_trig INSTEAD OF INSERT ON city_view
FOR EACH ROW EXECUTE PROCEDURE city_insert();
CREATE FUNCTION city_delete() RETURNS trigger LANGUAGE plpgsql AS $$
begin
DELETE FROM city_table WHERE city_id = OLD.city_id;
if NOT FOUND then RETURN NULL; end if;
RETURN OLD;
end;
$$;
CREATE TRIGGER city_delete_trig INSTEAD OF DELETE ON city_view
FOR EACH ROW EXECUTE PROCEDURE city_delete();
CREATE FUNCTION city_update() RETURNS trigger LANGUAGE plpgsql AS $$
declare
ctry_id int;
begin
if NEW.country_name IS DISTINCT FROM OLD.country_name then
SELECT country_id, continent INTO ctry_id, NEW.continent
FROM country_table WHERE country_name = NEW.country_name;
if NOT FOUND then
raise exception 'No such country: "%"', NEW.country_name;
end if;
UPDATE city_table SET city_name = NEW.city_name,
population = NEW.population,
country_id = ctry_id
WHERE city_id = OLD.city_id;
else
UPDATE city_table SET city_name = NEW.city_name,
population = NEW.population
WHERE city_id = OLD.city_id;
NEW.continent := OLD.continent;
end if;
if NOT FOUND then RETURN NULL; end if;
RETURN NEW;
end;
$$;
CREATE TRIGGER city_update_trig INSTEAD OF UPDATE ON city_view
FOR EACH ROW EXECUTE PROCEDURE city_update();
\set QUIET false
-- INSERT .. RETURNING
INSERT INTO city_view(city_name) VALUES('Tokyo') RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
1 | Tokyo | | |
(1 row)
INSERT 0 1
INSERT INTO city_view(city_name, population) VALUES('London', 7556900) RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
2 | London | 7556900 | |
(1 row)
INSERT 0 1
INSERT INTO city_view(city_name, country_name) VALUES('Washington DC', 'USA') RETURNING *;
city_id | city_name | population | country_name | continent
---------+---------------+------------+--------------+---------------
3 | Washington DC | | USA | North America
(1 row)
INSERT 0 1
INSERT INTO city_view(city_id, city_name) VALUES(123456, 'New York') RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
123456 | New York | | |
(1 row)
INSERT 0 1
INSERT INTO city_view VALUES(234567, 'Birmingham', 1016800, 'UK', 'EU') RETURNING *;
city_id | city_name | population | country_name | continent
---------+------------+------------+--------------+-----------
234567 | Birmingham | 1016800 | UK | Europe
(1 row)
INSERT 0 1
-- UPDATE .. RETURNING
UPDATE city_view SET country_name = 'Japon' WHERE city_name = 'Tokyo'; -- error
ERROR: No such country: "Japon"
UPDATE city_view SET country_name = 'Japan' WHERE city_name = 'Takyo'; -- no match
UPDATE 0
UPDATE city_view SET country_name = 'Japan' WHERE city_name = 'Tokyo' RETURNING *; -- OK
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
1 | Tokyo | | Japan | Asia
(1 row)
UPDATE 1
UPDATE city_view SET population = 13010279 WHERE city_name = 'Tokyo' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
1 | Tokyo | 13010279 | Japan | Asia
(1 row)
UPDATE 1
UPDATE city_view SET country_name = 'UK' WHERE city_name = 'New York' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
123456 | New York | | UK | Europe
(1 row)
UPDATE 1
UPDATE city_view SET country_name = 'USA', population = 8391881 WHERE city_name = 'New York' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+---------------
123456 | New York | 8391881 | USA | North America
(1 row)
UPDATE 1
UPDATE city_view SET continent = 'EU' WHERE continent = 'Europe' RETURNING *;
city_id | city_name | population | country_name | continent
---------+------------+------------+--------------+-----------
234567 | Birmingham | 1016800 | UK | Europe
(1 row)
UPDATE 1
UPDATE city_view v1 SET country_name = v2.country_name FROM city_view v2
WHERE v2.city_name = 'Birmingham' AND v1.city_name = 'London' RETURNING *;
city_id | city_name | population | country_name | continent | city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------+---------+------------+------------+--------------+-----------
2 | London | 7556900 | UK | Europe | 234567 | Birmingham | 1016800 | UK | Europe
(1 row)
UPDATE 1
-- DELETE .. RETURNING
DELETE FROM city_view WHERE city_name = 'Birmingham' RETURNING *;
city_id | city_name | population | country_name | continent
---------+------------+------------+--------------+-----------
234567 | Birmingham | 1016800 | UK | Europe
(1 row)
DELETE 1
\set QUIET true
-- read-only view with WHERE clause
CREATE VIEW european_city_view AS
SELECT * FROM city_view WHERE continent = 'Europe';
SELECT count(*) FROM european_city_view;
count
-------
1
(1 row)
CREATE FUNCTION no_op_trig_fn() RETURNS trigger LANGUAGE plpgsql
AS 'begin RETURN NULL; end';
CREATE TRIGGER no_op_trig INSTEAD OF INSERT OR UPDATE OR DELETE
ON european_city_view FOR EACH ROW EXECUTE PROCEDURE no_op_trig_fn();
\set QUIET false
INSERT INTO european_city_view VALUES (0, 'x', 10000, 'y', 'z');
INSERT 0 0
UPDATE european_city_view SET population = 10000;
UPDATE 0
DELETE FROM european_city_view;
DELETE 0
\set QUIET true
-- rules bypassing no-op triggers
CREATE RULE european_city_insert_rule AS ON INSERT TO european_city_view
DO INSTEAD INSERT INTO city_view
VALUES (NEW.city_id, NEW.city_name, NEW.population, NEW.country_name, NEW.continent)
RETURNING *;
CREATE RULE european_city_update_rule AS ON UPDATE TO european_city_view
DO INSTEAD UPDATE city_view SET
city_name = NEW.city_name,
population = NEW.population,
country_name = NEW.country_name
WHERE city_id = OLD.city_id
RETURNING NEW.*;
CREATE RULE european_city_delete_rule AS ON DELETE TO european_city_view
DO INSTEAD DELETE FROM city_view WHERE city_id = OLD.city_id RETURNING *;
\set QUIET false
-- INSERT not limited by view's WHERE clause, but UPDATE AND DELETE are
INSERT INTO european_city_view(city_name, country_name)
VALUES ('Cambridge', 'USA') RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+---------------
4 | Cambridge | | USA | North America
(1 row)
INSERT 0 1
UPDATE european_city_view SET country_name = 'UK'
WHERE city_name = 'Cambridge';
UPDATE 0
DELETE FROM european_city_view WHERE city_name = 'Cambridge';
DELETE 0
-- UPDATE and DELETE via rule and trigger
UPDATE city_view SET country_name = 'UK'
WHERE city_name = 'Cambridge' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
4 | Cambridge | | UK | Europe
(1 row)
UPDATE 1
UPDATE european_city_view SET population = 122800
WHERE city_name = 'Cambridge' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
4 | Cambridge | 122800 | UK | Europe
(1 row)
UPDATE 1
DELETE FROM european_city_view WHERE city_name = 'Cambridge' RETURNING *;
city_id | city_name | population | country_name | continent
---------+-----------+------------+--------------+-----------
4 | Cambridge | 122800 | UK | Europe
(1 row)
DELETE 1
-- join UPDATE test
UPDATE city_view v SET population = 599657
FROM city_table ci, country_table co
WHERE ci.city_name = 'Washington DC' and co.country_name = 'USA'
AND v.city_id = ci.city_id AND v.country_name = co.country_name
RETURNING co.country_id, v.country_name,
v.city_id, v.city_name, v.population;
country_id | country_name | city_id | city_name | population
------------+--------------+---------+---------------+------------
3 | USA | 3 | Washington DC | 599657
(1 row)
UPDATE 1
\set QUIET true
SELECT * FROM city_view;
city_id | city_name | population | country_name | continent
---------+---------------+------------+--------------+---------------
1 | Tokyo | 13010279 | Japan | Asia
123456 | New York | 8391881 | USA | North America
2 | London | 7556900 | UK | Europe
3 | Washington DC | 599657 | USA | North America
(4 rows)
DROP TABLE city_table CASCADE;
NOTICE: drop cascades to 2 other objects
DETAIL: drop cascades to view city_view
drop cascades to view european_city_view
DROP TABLE country_table;
-- Test pg_trigger_depth()
create table depth_a (id int not null primary key);
create table depth_b (id int not null primary key);
create table depth_c (id int not null primary key);
create function depth_a_tf() returns trigger
language plpgsql as $$
begin
raise notice '%: depth = %', tg_name, pg_trigger_depth();
insert into depth_b values (new.id);
raise notice '%: depth = %', tg_name, pg_trigger_depth();
return new;
end;
$$;
create trigger depth_a_tr before insert on depth_a
for each row execute procedure depth_a_tf();
create function depth_b_tf() returns trigger
language plpgsql as $$
begin
raise notice '%: depth = %', tg_name, pg_trigger_depth();
begin
execute 'insert into depth_c values (' || new.id::text || ')';
exception
when sqlstate 'U9999' then
raise notice 'SQLSTATE = U9999: depth = %', pg_trigger_depth();
end;
raise notice '%: depth = %', tg_name, pg_trigger_depth();
if new.id = 1 then
execute 'insert into depth_c values (' || new.id::text || ')';
end if;
return new;
end;
$$;
create trigger depth_b_tr before insert on depth_b
for each row execute procedure depth_b_tf();
create function depth_c_tf() returns trigger
language plpgsql as $$
begin
raise notice '%: depth = %', tg_name, pg_trigger_depth();
if new.id = 1 then
raise exception sqlstate 'U9999';
end if;
raise notice '%: depth = %', tg_name, pg_trigger_depth();
return new;
end;
$$;
create trigger depth_c_tr before insert on depth_c
for each row execute procedure depth_c_tf();
select pg_trigger_depth();
pg_trigger_depth
------------------
0
(1 row)
insert into depth_a values (1);
NOTICE: depth_a_tr: depth = 1
NOTICE: depth_b_tr: depth = 2
CONTEXT: SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_c_tr: depth = 3
CONTEXT: SQL statement "insert into depth_c values (1)"
PL/pgSQL function depth_b_tf() line 5 at EXECUTE statement
SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: SQLSTATE = U9999: depth = 2
CONTEXT: SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_b_tr: depth = 2
CONTEXT: SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_c_tr: depth = 3
CONTEXT: SQL statement "insert into depth_c values (1)"
PL/pgSQL function depth_b_tf() line 12 at EXECUTE statement
SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
ERROR: U9999
CONTEXT: SQL statement "insert into depth_c values (1)"
PL/pgSQL function depth_b_tf() line 12 at EXECUTE statement
SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
select pg_trigger_depth();
pg_trigger_depth
------------------
0
(1 row)
insert into depth_a values (2);
NOTICE: depth_a_tr: depth = 1
NOTICE: depth_b_tr: depth = 2
CONTEXT: SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_c_tr: depth = 3
CONTEXT: SQL statement "insert into depth_c values (2)"
PL/pgSQL function depth_b_tf() line 5 at EXECUTE statement
SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_c_tr: depth = 3
CONTEXT: SQL statement "insert into depth_c values (2)"
PL/pgSQL function depth_b_tf() line 5 at EXECUTE statement
SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_b_tr: depth = 2
CONTEXT: SQL statement "insert into depth_b values (new.id)"
PL/pgSQL function depth_a_tf() line 4 at SQL statement
NOTICE: depth_a_tr: depth = 1
select pg_trigger_depth();
pg_trigger_depth
------------------
0
(1 row)
drop table depth_a, depth_b, depth_c;
drop function depth_a_tf();
drop function depth_b_tf();
drop function depth_c_tf();
--
-- Test updates to rows during firing of BEFORE ROW triggers.
-- As of 9.2, such cases should be rejected (see bug #6123).
--
create temp table parent (
aid int not null primary key,
val1 text,
val2 text,
val3 text,
val4 text,
bcnt int not null default 0);
create temp table child (
bid int not null primary key,
aid int not null,
val1 text);
create function parent_upd_func()
returns trigger language plpgsql as
$$
begin
if old.val1 <> new.val1 then
new.val2 = new.val1;
delete from child where child.aid = new.aid and child.val1 = new.val1;
end if;
return new;
end;
$$;
create trigger parent_upd_trig before update on parent
for each row execute procedure parent_upd_func();
create function parent_del_func()
returns trigger language plpgsql as
$$
begin
delete from child where aid = old.aid;
return old;
end;
$$;
create trigger parent_del_trig before delete on parent
for each row execute procedure parent_del_func();
create function child_ins_func()
returns trigger language plpgsql as
$$
begin
update parent set bcnt = bcnt + 1 where aid = new.aid;
return new;
end;
$$;
create trigger child_ins_trig after insert on child
for each row execute procedure child_ins_func();
create function child_del_func()
returns trigger language plpgsql as
$$
begin
update parent set bcnt = bcnt - 1 where aid = old.aid;
return old;
end;
$$;
create trigger child_del_trig after delete on child
for each row execute procedure child_del_func();
insert into parent values (1, 'a', 'a', 'a', 'a', 0);
insert into child values (10, 1, 'b');
select * from parent; select * from child;
aid | val1 | val2 | val3 | val4 | bcnt
-----+------+------+------+------+------
1 | a | a | a | a | 1
(1 row)
bid | aid | val1
-----+-----+------
10 | 1 | b
(1 row)
update parent set val1 = 'b' where aid = 1; -- should fail
ERROR: tuple to be updated was already modified by an operation triggered by the current command
HINT: Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.
select * from parent; select * from child;
aid | val1 | val2 | val3 | val4 | bcnt
-----+------+------+------+------+------
1 | a | a | a | a | 1
(1 row)
bid | aid | val1
-----+-----+------
10 | 1 | b
(1 row)
delete from parent where aid = 1; -- should fail
ERROR: tuple to be updated was already modified by an operation triggered by the current command
HINT: Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.
select * from parent; select * from child;
aid | val1 | val2 | val3 | val4 | bcnt
-----+------+------+------+------+------
1 | a | a | a | a | 1
(1 row)
bid | aid | val1
-----+-----+------
10 | 1 | b
(1 row)
-- replace the trigger function with one that restarts the deletion after
-- having modified a child
create or replace function parent_del_func()
returns trigger language plpgsql as
$$
begin
delete from child where aid = old.aid;
if found then
delete from parent where aid = old.aid;
return null; -- cancel outer deletion
end if;
return old;
end;
$$;
delete from parent where aid = 1;
select * from parent; select * from child;
aid | val1 | val2 | val3 | val4 | bcnt
-----+------+------+------+------+------
(0 rows)
bid | aid | val1
-----+-----+------
(0 rows)
drop table parent, child;
drop function parent_upd_func();
drop function parent_del_func();
drop function child_ins_func();
drop function child_del_func();
-- similar case, but with a self-referencing FK so that parent and child
-- rows can be affected by a single operation
create temp table self_ref_trigger (
id int primary key,
parent int references self_ref_trigger,
data text,
nchildren int not null default 0
);
create function self_ref_trigger_ins_func()
returns trigger language plpgsql as
$$
begin
if new.parent is not null then
update self_ref_trigger set nchildren = nchildren + 1
where id = new.parent;
end if;
return new;
end;
$$;
create trigger self_ref_trigger_ins_trig before insert on self_ref_trigger
for each row execute procedure self_ref_trigger_ins_func();
create function self_ref_trigger_del_func()
returns trigger language plpgsql as
$$
begin
if old.parent is not null then
update self_ref_trigger set nchildren = nchildren - 1
where id = old.parent;
end if;
return old;
end;
$$;
create trigger self_ref_trigger_del_trig before delete on self_ref_trigger
for each row execute procedure self_ref_trigger_del_func();
insert into self_ref_trigger values (1, null, 'root');
insert into self_ref_trigger values (2, 1, 'root child A');
insert into self_ref_trigger values (3, 1, 'root child B');
insert into self_ref_trigger values (4, 2, 'grandchild 1');
insert into self_ref_trigger values (5, 3, 'grandchild 2');
update self_ref_trigger set data = 'root!' where id = 1;
select * from self_ref_trigger;
id | parent | data | nchildren
----+--------+--------------+-----------
2 | 1 | root child A | 1
4 | 2 | grandchild 1 | 0
3 | 1 | root child B | 1
5 | 3 | grandchild 2 | 0
1 | | root! | 2
(5 rows)
delete from self_ref_trigger;
ERROR: tuple to be updated was already modified by an operation triggered by the current command
HINT: Consider using an AFTER trigger instead of a BEFORE trigger to propagate changes to other rows.
select * from self_ref_trigger;
id | parent | data | nchildren
----+--------+--------------+-----------
2 | 1 | root child A | 1
4 | 2 | grandchild 1 | 0
3 | 1 | root child B | 1
5 | 3 | grandchild 2 | 0
1 | | root! | 2
(5 rows)
drop table self_ref_trigger;
drop function self_ref_trigger_ins_func();
drop function self_ref_trigger_del_func();
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