So here’s my niffty trigger code for the day, which automatically updates the “last_updated” (timestamp) field in a table, when a record is inserted or updated:

CREATE TRIGGER `database_name`.`last_updated_insert_trigger`
BEFORE INSERT ON `database_name`.`table_name` FOR EACH ROW SET new.last_updated := UNIX_TIMESTAMP();

CREATE TRIGGER `database_name`.`last_updated_update_trigger`
BEFORE UPDATE ON `database_name`.`table_name` FOR EACH ROW SET new.last_updated := UNIX_TIMESTAMP();

There’s probably a better way to do this (and I think you can combine both triggers, using “OR BEFORE UPDATE”?) but this is the first I’ve worked with triggers in MySQL and I’m too lazy to fiddle. Hope it helps. As I’m sure you can guess, `database_name` is your database name, `last_updated_update_trigger` is the name of your trigger, `table_name` is your table name, and `last_updated` is your field name that will contain the timestamp.