Yii And Log4Php Integration

I am new to yii and log4pgp, and in my project i want to integrate log4php. Using log4php, i want two log files, syslog and access log. In syslog, i want user logid, username,login time and logout time. In accesslog i need the changes made in tables in database and it should be something like logid, new_value,old_value(if present),field changed(attribute). How to integrate log4php and yii? and work this out?