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|
-- these triggers are dedicated to HPHC of RI who
-- decided that my kid's name was william not willem, and
-- vigorously resisted all efforts at correction. they have
-- since gone bankrupt...
CREATE FUNCTION users_insert() returns trigger
AS
'if TD["new"]["fname"] == None or TD["new"]["lname"] == None:
return "SKIP"
if TD["new"]["username"] == None:
TD["new"]["username"] = TD["new"]["fname"][:1] + "_" + TD["new"]["lname"]
rv = "MODIFY"
else:
rv = None
if TD["new"]["fname"] == "william":
TD["new"]["fname"] = TD["args"][0]
rv = "MODIFY"
return rv'
LANGUAGE plpythonu;
CREATE FUNCTION users_update() returns trigger
AS
'if TD["event"] == "UPDATE":
if TD["old"]["fname"] != TD["new"]["fname"] and TD["old"]["fname"] == TD["args"][0]:
return "SKIP"
return None'
LANGUAGE plpythonu;
CREATE FUNCTION users_delete() RETURNS trigger
AS
'if TD["old"]["fname"] == TD["args"][0]:
return "SKIP"
return None'
LANGUAGE plpythonu;
CREATE TRIGGER users_insert_trig BEFORE INSERT ON users FOR EACH ROW
EXECUTE PROCEDURE users_insert ('willem');
CREATE TRIGGER users_update_trig BEFORE UPDATE ON users FOR EACH ROW
EXECUTE PROCEDURE users_update ('willem');
CREATE TRIGGER users_delete_trig BEFORE DELETE ON users FOR EACH ROW
EXECUTE PROCEDURE users_delete ('willem');
-- quick peek at the table
--
SELECT * FROM users;
fname | lname | username | userid
--------+-------+----------+--------
jane | doe | j_doe | 1
john | doe | johnd | 2
willem | doe | w_doe | 3
rick | smith | slash | 4
(4 rows)
-- should fail
--
UPDATE users SET fname = 'william' WHERE fname = 'willem';
-- should modify william to willem and create username
--
INSERT INTO users (fname, lname) VALUES ('william', 'smith');
INSERT INTO users (fname, lname, username) VALUES ('charles', 'darwin', 'beagle');
SELECT * FROM users;
fname | lname | username | userid
---------+--------+----------+--------
jane | doe | j_doe | 1
john | doe | johnd | 2
willem | doe | w_doe | 3
rick | smith | slash | 4
willem | smith | w_smith | 5
charles | darwin | beagle | 6
(6 rows)
-- dump trigger data
CREATE TABLE trigger_test
(i int, v text );
CREATE FUNCTION trigger_data() returns trigger language plpythonu as $$
if 'relid' in TD:
TD['relid'] = "bogus:12345"
skeys = list(TD.keys())
skeys.sort()
for key in skeys:
val = TD[key]
plpy.notice("TD[" + key + "] => " + str(val))
return None
$$;
CREATE TRIGGER show_trigger_data_trig_before
BEFORE INSERT OR UPDATE OR DELETE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo');
CREATE TRIGGER show_trigger_data_trig_after
AFTER INSERT OR UPDATE OR DELETE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE trigger_data(23,'skidoo');
CREATE TRIGGER show_trigger_data_trig_stmt
BEFORE INSERT OR UPDATE OR DELETE OR TRUNCATE ON trigger_test
FOR EACH STATEMENT EXECUTE PROCEDURE trigger_data(23,'skidoo');
insert into trigger_test values(1,'insert');
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => INSERT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => STATEMENT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_stmt',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => INSERT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_before',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[new] => {'i': 1, 'v': 'insert'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => INSERT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_after',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[new] => {'i': 1, 'v': 'insert'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => AFTER',)
CONTEXT: PL/Python function "trigger_data"
update trigger_test set v = 'update' where i = 1;
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => UPDATE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => STATEMENT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_stmt',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => UPDATE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_before',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[new] => {'i': 1, 'v': 'update'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[old] => {'i': 1, 'v': 'insert'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => UPDATE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_after',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[new] => {'i': 1, 'v': 'update'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[old] => {'i': 1, 'v': 'insert'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => AFTER',)
CONTEXT: PL/Python function "trigger_data"
delete from trigger_test;
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => DELETE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => STATEMENT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_stmt',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => DELETE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_before',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[old] => {'i': 1, 'v': 'update'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => DELETE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => ROW',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_after',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ("TD[old] => {'i': 1, 'v': 'update'}",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => AFTER',)
CONTEXT: PL/Python function "trigger_data"
truncate table trigger_test;
NOTICE: ("TD[args] => ['23', 'skidoo']",)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[event] => TRUNCATE',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[level] => STATEMENT',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[name] => show_trigger_data_trig_stmt',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[new] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[old] => None',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[relid] => bogus:12345',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_name] => trigger_test',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[table_schema] => public',)
CONTEXT: PL/Python function "trigger_data"
NOTICE: ('TD[when] => BEFORE',)
CONTEXT: PL/Python function "trigger_data"
DROP FUNCTION trigger_data() CASCADE;
NOTICE: drop cascades to 3 other objects
DETAIL: drop cascades to trigger show_trigger_data_trig_before on table trigger_test
drop cascades to trigger show_trigger_data_trig_after on table trigger_test
drop cascades to trigger show_trigger_data_trig_stmt on table trigger_test
--
-- trigger error handling
--
INSERT INTO trigger_test VALUES (0, 'zero');
-- returning non-string from trigger function
CREATE FUNCTION stupid1() RETURNS trigger
AS $$
return 37
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger1
BEFORE INSERT ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid1();
INSERT INTO trigger_test VALUES (1, 'one');
ERROR: unexpected return value from trigger procedure
DETAIL: Expected None or a string.
CONTEXT: PL/Python function "stupid1"
DROP TRIGGER stupid_trigger1 ON trigger_test;
-- returning MODIFY from DELETE trigger
CREATE FUNCTION stupid2() RETURNS trigger
AS $$
return "MODIFY"
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger2
BEFORE DELETE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid2();
DELETE FROM trigger_test WHERE i = 0;
WARNING: PL/Python trigger function returned "MODIFY" in a DELETE trigger -- ignored
CONTEXT: PL/Python function "stupid2"
DROP TRIGGER stupid_trigger2 ON trigger_test;
INSERT INTO trigger_test VALUES (0, 'zero');
-- returning unrecognized string from trigger function
CREATE FUNCTION stupid3() RETURNS trigger
AS $$
return "foo"
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger3
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid3();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: unexpected return value from trigger procedure
DETAIL: Expected None, "OK", "SKIP", or "MODIFY".
CONTEXT: PL/Python function "stupid3"
DROP TRIGGER stupid_trigger3 ON trigger_test;
-- Unicode variant
CREATE FUNCTION stupid3u() RETURNS trigger
AS $$
return u"foo"
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger3
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid3u();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: unexpected return value from trigger procedure
DETAIL: Expected None, "OK", "SKIP", or "MODIFY".
CONTEXT: PL/Python function "stupid3u"
DROP TRIGGER stupid_trigger3 ON trigger_test;
-- deleting the TD dictionary
CREATE FUNCTION stupid4() RETURNS trigger
AS $$
del TD["new"]
return "MODIFY";
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger4
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid4();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: TD["new"] deleted, cannot modify row
CONTEXT: while modifying trigger row
PL/Python function "stupid4"
DROP TRIGGER stupid_trigger4 ON trigger_test;
-- TD not a dictionary
CREATE FUNCTION stupid5() RETURNS trigger
AS $$
TD["new"] = ['foo', 'bar']
return "MODIFY";
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger5
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid5();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: TD["new"] is not a dictionary
CONTEXT: while modifying trigger row
PL/Python function "stupid5"
DROP TRIGGER stupid_trigger5 ON trigger_test;
-- TD not having string keys
CREATE FUNCTION stupid6() RETURNS trigger
AS $$
TD["new"] = {1: 'foo', 2: 'bar'}
return "MODIFY";
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger6
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid6();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: TD["new"] dictionary key at ordinal position 0 is not a string
CONTEXT: while modifying trigger row
PL/Python function "stupid6"
DROP TRIGGER stupid_trigger6 ON trigger_test;
-- TD keys not corresponding to row columns
CREATE FUNCTION stupid7() RETURNS trigger
AS $$
TD["new"] = {'a': 'foo', 'b': 'bar'}
return "MODIFY";
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger7
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid7();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: key "a" found in TD["new"] does not exist as a column in the triggering row
CONTEXT: while modifying trigger row
PL/Python function "stupid7"
DROP TRIGGER stupid_trigger7 ON trigger_test;
-- Unicode variant
CREATE FUNCTION stupid7u() RETURNS trigger
AS $$
TD["new"] = {u'a': 'foo', u'b': 'bar'}
return "MODIFY"
$$ LANGUAGE plpythonu;
CREATE TRIGGER stupid_trigger7
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE stupid7u();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
ERROR: key "a" found in TD["new"] does not exist as a column in the triggering row
CONTEXT: while modifying trigger row
PL/Python function "stupid7u"
DROP TRIGGER stupid_trigger7 ON trigger_test;
-- calling a trigger function directly
SELECT stupid7();
ERROR: trigger functions can only be called as triggers
--
-- Null values
--
SELECT * FROM trigger_test;
i | v
---+------
0 | zero
(1 row)
CREATE FUNCTION test_null() RETURNS trigger
AS $$
TD["new"]['v'] = None
return "MODIFY"
$$ LANGUAGE plpythonu;
CREATE TRIGGER test_null_trigger
BEFORE UPDATE ON trigger_test
FOR EACH ROW EXECUTE PROCEDURE test_null();
UPDATE trigger_test SET v = 'null' WHERE i = 0;
DROP TRIGGER test_null_trigger ON trigger_test;
SELECT * FROM trigger_test;
i | v
---+---
0 |
(1 row)
|