Yii 怎么给 left join 加 and 条件？ [ 1.1 版本 ]

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public function actionIndex ()
{
    parent::_acl(); 
    $model = new user();
    $criteria = new CDbCriteria();
    $criteria->order = 'user.id DESC';
    $criteria->alias = 'user';
    $criteria->join='LEFT JOIN user_authentication ON user.id=user_authentication.userid and user_authentication.status=2';
    $count = $model->count($criteria);
    $pages = new CPagination($count);
    $pages->pageSize = 10;
    $criteria->limit = $pages->pageSize;
    $criteria->offset = $pages->currentPage * $pages->pageSize;
    $result = $model->findAll($criteria);
    $this->render('user_index', array ('datalist' => $result , 'pagebar' => $pages ));
}

这样用，对应的sql语句是：

SELECT `t`.`id` AS `t0_c0`, `t`.`phone` AS `t0_c1`, `t`.`password` AS `t0_c2`, `t`.`paypass` AS `t0_c3`, `t`.`salt` AS `t0_c4`, `t`.`realname` AS `t0_c5`, `t`.`cerno` AS `t0_c6`, `t`.`regtime` AS `t0_c7`, `t`.`regip` AS `t0_c8`, `t`.`lastloginip` AS `t0_c9`, `t`.`lastlogintime` AS `t0_c10`, `t`.`status` AS `t0_c11`, `t`.`authentication` AS `t0_c12`, `authentication`.`id` AS `t1_c0`, `authentication`.`userid` AS `t1_c1`, `authentication`.`realname` AS `t1_c2`, `authentication`.`cerno` AS `t1_c3`, `authentication`.`cerpic1` AS `t1_c4`, `authentication`.`cerpic2` AS `t1_c5`, `authentication`.`cerpic3` AS `t1_c6`, `authentication`.`cardno` AS `t1_c7`, `authentication`.`cardpic1` AS `t1_c8`, `authentication`.`cardpic2` AS `t1_c9`, `authentication`.`applytime` AS `t1_c10`, `authentication`.`operator1` AS `t1_c11`, `authentication`.`operatetime1` AS `t1_c12`, `authentication`.`operator2` AS `t1_c13`, `authentication`.`operatetime2` AS `t1_c14`, `authentication`.`status` AS `t1_c15` FROM `user` `t` LEFT OUTER JOIN `user_authentication` `authentication` ON (`authentication`.`userid`=`t`.`id`) WHERE (authentication.status=2) ORDER BY t.id DESC LIMIT 10)