首选innodb存储引擎才支持事务。

$table=M('table');
$table->startTrans();//开启事务
$table->commit();//成功则提交
$table->rollback();//不成功，则回滚

详见代码：

        $returnorder=M('return_order_goods_info');
        $returnorder->startTrans();//开启事务
        $data['type']=I('tmp_type');
        $data['description']=I('description');
        $data['return_type']=I('tem_return_type');
        $data['pick_up_province']=I('rev_province');
        $data['pick_up_city']=I('rev_city');
        $data['pick_up_county']=I('rev_county');
        $data['pick_up_address']=I('rev_address');
        $data['create_time']=time();
      
        $orderinfo['sku_name']=I['sku_name'];
        $orderinfo['sku_default_image']=I['sku_default_image'];
        
        
        $resultinfo=M('return_order_commodity_info')->add($orderinfo);
        $ceshi=M("return_order_commodity_info")->getLastSql();
        if($result && $resultinfo){
            $returnorder->commit();//成功则提交
            $this->ajaxReturn(array("data"=>$data,"info"=>'已提交成功，请耐心等待工作人员审核',"status"=>1));
        }else{
            $returnorder->rollback();//不成功，则回滚
            $this->ajaxReturn(array("data"=>$data,"info"=>'未提交成功，请联系客服',"status"=>0));
        }

第二种：

$trans_result = true;
                $trans = M();
                $trans->startTrans();   // 开启事务

                try {   // 异常处理
                    // 更新实施
                    $busbidList = M("busbid")->where($map)->select();
                    foreach($busbidList as $k => $v) {
                        $map['id'] = $busbidList[$k]['id'];
                        $result = M('busbid')->where($map)->data($data)->save();
                        if ($result === false) {
                            throw new Exception(“错误原因”);
                        }
                    }
                } catch (Exception $ex) {
                    $trans_result = false;
                    // 记录日志
                    Log::record("== xxx更新失败 ==", 'DEBUG'); 
                    Log::record($ex->getMessage(), 'DEBUG');
                }

                if ($trans_result === false) {
                    $trans->rollback();
                    // 更新失败
                    $array['status'] = 0;
                } else {
                    $trans->commit();
                    // 更新成功
                    $array['status'] = 1;
                }