gCnqLhuS

1## mysql
2```sql
3CREATE TABLE IF NOT EXISTS test (
4	id bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
5	updated_at datetime(0) DEFAULT CURRENT_TIMESTAMP(0) ON UPDATE CURRENT_TIMESTAMP(0) NOT NULL
6)
7```
8
9## postgres
10```sql
11CREATE TABLE IF NOT EXISTS test (
12	id SERIAL NOT NULL PRIMARY KEY,
13	updated_at TIMESTAMP without time zone NULL
14)
15-- create a simple trigger
16CREATE OR REPLACE FUNCTION update_modified_column() RETURNS TRIGGER AS $$
17BEGIN NEW.modified = now(); RETURN NEW; END;
18$$ language 'plpgsql';
19CREATE TRIGGER update_customer_modtime BEFORE UPDATE ON test FOR EACH ROW EXECUTE PROCEDURE update_modified_column();
20```