yii更新并插入场景规则

我已经尝试使用yii场景在更新和创建新记录之间分离我的规则。当我把场景放在下面时，记录不会验证表单，场景也不起作用。我想知道哪里出了问题

return array(
            array('first_name, second_name, username, password, email, skype, attachment, just, cv', 'required','on'=>'insert'),
           array('first_name, second_name, username, password, email', 'required','on'=>'update'),
            array('first_name, second_name, username, password, email, skype, status, attachment, just, cv', 'length', 'max'=>255),
            // The following rule is used by search().
            // @todo Please remove those attributes that should not be searched.
            array('attachment, cv', 'file', 'types'=>'doc, docx, pdf, odt'),
            array('re_password','compare','compareAttribute'=>'password'),
        );

当我不使用场景时

  return array(
                array('first_name, second_name, username, password, email, skype, attachment, just, cv', 'required'),
                array('first_name, second_name, username, password, email, skype, status, attachment, just, cv', 'length', 'max'=>255),
                // The following rule is used by search().
                // @todo Please remove those attributes that should not be searched.
                array('attachment, cv', 'file', 'types'=>'doc, docx, pdf, odt'),
                array('re_password','compare','compareAttribute'=>'password'),
            );

这很有效，但有些专栏我不需要更新，比如简历和附件。

请亮灯，因为我错过了什么。