--
-- 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
-- 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);
NOTICE:  CREATE TABLE will create implicit sequence "trigtest_i_seq" for serial column "trigtest.i"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "trigtest_pkey" for table "trigtest"
-- 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$$;
UPDATE trigger_test SET f3 = 'bar';
NOTICE:  row 1 changed
NOTICE:  row 2 changed
UPDATE trigger_test SET f3 = NULL;
NOTICE:  row 1 changed
NOTICE:  row 2 changed
UPDATE trigger_test SET f3 = NULL;
NOTICE:  row 1 not changed
NOTICE:  row 2 not changed
DROP TABLE trigger_test;
DROP FUNCTION mytrigger();
-- Test snapshot management in serializable transactions involving triggers
-- per bug report in 6bc73d4c0910042358k3d1adff3qa36f8df75198ecea@mail.gmail.com
CREATE FUNCTION serializable_update_trig() RETURNS trigger LANGUAGE plpgsql AS
$$
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;
-- Updates should fail without rules or triggers
INSERT INTO main_view VALUES (1,2);
ERROR:  cannot insert into view "main_view"
HINT:  You need an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
UPDATE main_view SET b = 20 WHERE a = 50;
ERROR:  cannot update view "main_view"
HINT:  You need an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
DELETE FROM main_view WHERE a = 50;
ERROR:  cannot delete from view "main_view"
HINT:  You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
-- Should fail even when there are no matching rows
DELETE FROM main_view WHERE a = 51;
ERROR:  cannot delete from view "main_view"
HINT:  You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
-- 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
);
NOTICE:  CREATE TABLE will create implicit sequence "country_table_country_id_seq" for serial column "country_table.country_id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "country_table_pkey" for table "country_table"
NOTICE:  CREATE TABLE / UNIQUE will create implicit index "country_table_country_name_key" for table "country_table"
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
);
NOTICE:  CREATE TABLE will create implicit sequence "city_table_city_id_seq" for serial column "city_table.city_id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "city_table_pkey" for table "city_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;
