1DROP TABLE mdt;
2
3CREATE TABLE mdt (
4	id		int4,
5	idesc		text,
6	moddate timestamp DEFAULT CURRENT_TIMESTAMP NOT NULL
7);
8
9CREATE TRIGGER mdt_moddatetime
10	BEFORE UPDATE ON mdt
11	FOR EACH ROW
12	EXECUTE PROCEDURE moddatetime (moddate);
13
14INSERT INTO mdt VALUES (1, 'first');
15INSERT INTO mdt VALUES (2, 'second');
16INSERT INTO mdt VALUES (3, 'third');
17
18SELECT * FROM mdt;
19
20UPDATE mdt SET id = 4
21	WHERE id = 1;
22UPDATE mdt SET id = 5
23	WHERE id = 2;
24UPDATE mdt SET id = 6
25	WHERE id = 3;
26
27SELECT * FROM mdt;
28