php操作xml

 $note=<<<XML
<?xml version="1.0" encoding="UTF-8"?>
<DTC_Message>
    <MessageHead>
        <MessageType>PDD_ORDER_INFO</MessageType>
        <MessageId>1206aec0-099c-4196-8ebc-2e75a1bd7110</MessageId>
        <SenderId>BLPD</SenderId>
        <Password>5df5299731c9e125c17de5103770fc2b</Password>
    </MessageHead>
    <MessageBody>
        <DTCFlow>
            <ORDER_HEAD>
                <SOURCE>PDD</SOURCE>
                <ORIGINAL_ORDER_NO>XP2321091723501312498839002971</ORIGINAL_ORDER_NO>
                <PLATF_ORDER_NO>210917-534438266363791</PLATF_ORDER_NO>
                <BAR_CODE>80192021I817604016</BAR_CODE>
                <ESHOP_ENT_CODE>YSLH</ESHOP_ENT_CODE>
                <ESHOP_PLAF_CODE>3105961682</ESHOP_PLAF_CODE>
                <ESHOP_PLAF_NAME>上海寻梦信息技术有限公司</ESHOP_PLAF_NAME>
                <EXPRESS_COMPANY>STO</EXPRESS_COMPANY>
                <EXPRESS_NO>777057507689435</EXPRESS_NO>
                <BUYER_NAME>史**</BUYER_NAME>
                <BUYER_TEL>158****5877</BUYER_TEL>
                <BUYER_ID_NO>232332*********961</BUYER_ID_NO>
                <BUYER_REG_NO>158****5877</BUYER_REG_NO>
                <ver>3</ver>
                <signature>i9bDDgXLfGtoK7XUlx7++XGy6fhnIRiglMs3ZGwl29iYlxIkP5C6loPJD5SI37TxDQC1d52fBw2YJF+NgpuaAWu9ygK2M7rnFVfHx6rjQ4HK0gz7QMezAEQwijoxUbzUPrkZ4pWTrHrD0PXZooMGLOKyMrVbnHJCCB/wIvBCaV8=</signature>
                <templateUrl>https://file-link.pinduoduo.com/sto_one</templateUrl>
                <encryptedData>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</encryptedData>
                <RECEIVER_NAME>郭轩辰</RECEIVER_NAME>
                <RECEIVER_TEL>15842785877</RECEIVER_TEL>
                <RECEIVER_PROVINCE>辽宁省</RECEIVER_PROVINCE>
                <RECEIVER_CITY>盘锦市</RECEIVER_CITY>
                <RECEIVER_DISTRICT>盘山县</RECEIVER_DISTRICT>
                <RECEIVER_ADDRESS>吴家镇****</RECEIVER_ADDRESS>
                <REMARK></REMARK>
                <PAY_AMOUNT>462.00</PAY_AMOUNT>
                <PRICE_TYPE>1</PRICE_TYPE>
                <DISCOUNT>15.00</DISCOUNT>
                <TRANSPORT_FEE>0.00</TRANSPORT_FEE>
                <PAY_CODE>310598007D</PAY_CODE>
                <PAY_NO>19210917232010001111443517000196</PAY_NO>
                <TYPE>3</TYPE>
                <ORDER_DETAIL>
                    <SKU>9332045000198</SKU>
                    <GOODS_OWNER>YSLH</GOODS_OWNER>
                    <PRICE>159.00</PRICE>
                    <QTY>3</QTY>
                </ORDER_DETAIL>
            </ORDER_HEAD>
        </DTCFlow>
    </MessageBody>
</DTC_Message>
XML;

$xml=simplexml_load_string($note);
 
$xml->MessageBody->DTCFlow->ORDER_HEAD->ORDER_DETAIL->EXPIRY_DATE_START = '2021-11';
 
var_dump($xml->asXML());