mysql - Invalid default value for 'dateAdded'

I got a stupid problem with SQL that I can't fix.

ALTER TABLE  `news` 
 ADD  `dateAdded` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP AUTO_INCREMENT ,
 ADD PRIMARY KEY (  `dateAdded` )

Error:

(#1067)Invalid default value for 'dateAdded'

Can somebody help me?

Answer

CURRENT_TIMESTAMP is only acceptable on TIMESTAMP fields. DATETIME fields must be left either with a null default value, or no default value at all - default values must be a constant value, not the result of an expression.

relevant docs: http://dev.mysql.com/doc/refman/5.0/en/data-type-defaults.html

You can work around this by setting a post-insert trigger on the table to fill in a "now" value on any new records.