$this->alias('a')
->join('pd_admin_group w','w.id = a.group_id')
->join('pd_user c','c.id = a.user_id')
->select() 最佳答案
$this->alias('a')
->join('pd_admin_group w','w.id = a.group_id')
->join('pd_user c','c.id = a.user_id')
->select()