pdo回滚事件

<?php
public function index()
{
        $this->db->trans_begin();
        $this->db->query("update pdotest set name='songzhongji' where id='11'");
        $row = $this->db->affected_rows();
        echo $row;
        //影响行数为0 ==》回滚
        if($row == 0 )
        {
            $this->db->trans_rollback();
        } else {
            //不为0 ，修改成功，进行添加
            //判断状态，添加成功，进行提交
            $this->db->query("insert into pdotest(name,pwd) VALUES ('123','456')");
            if ($this->db->trans_status() === FALSE)
            {
                $this->db->trans_rollback();
            }
            else
            {
                $this->db->trans_commit();
            }
        }
}