Lots of people are asking how to solve it with YII,We think its difficult with YII. But its easy to solve . There is no database triggers needed . we can simply sove it by extending a class(say "RActiveRecord") from CActiveRecord .Then extend all our model classes from that class.
If you are lucky enough and have the privilege to develop on a Linux based environment, this little tip might boost-up your TDD process (at least the Unit Testing part). Please note, that this should work just fine with Apple computers also, but not tested!