数据库联表查询

    /*SELECT a.*,GROUP_CONCAT(c.pri_name) pri_name FROM php34_role a LEFT JOIN
php34_role_privilege b ON a.id=b.role_id LEFT JOIN php34_privilege c ON b.pri_id
=c.id GROUP BY a.id;*/
        $data['data'] = $this->field('a.*,GROUP_CONCAT(c.pri_name) pri_name')->alias('a')->join('LEFT JOIN php34_role_privilege b ON a.id=b.role_id LEFT JOIN php34_privilege c ON b.pri_id=c.id')->where($where)->group('a.id')->limit($page->firstRow.','.$page->listRows)->select();