Self-updating timestamp?

[Ted Roche]

I've read the documentation on Timestamp properties as of MySQL 4.1,

http://dev.mysql.com/doc/mysql/en/TIMESTAMP_4.1.html

and alter table,

http://dev.mysql.com/doc/mysql/en/ALTER_TABLE.html

but the exact syntax to create or modify a timestamp field so that it automatically is updated on insert and update eludes me. I've tried:

ALTER TABLE user MODIFY tChanged TIMESTAMP(10) NOT NULL DEFAULT NOW();

but that only sets the field to be filled in on INSERT, not to be updated on UPDATE. The top URL above refers to an ON UPDATE syntax that would do this, but the exact statement has eluded me. Any suggestions?

Ted Roche, MCSE, MCSD
Ted Roche & Associates, LLC
http://www.tedroche.com