在 PL/SQL 的 xmltype 变量（不在表中）中测试值是否存在（节点存在？）

Question

我有一个来自 PL/SQL 中的 SOAP 调用的结果变量，我得到的输出类型变量是 xmltype（没有编写包或过程，不要更改它）。我得到的变量类型是xmltype，我想检查是否有结果。我无法理解 PL/SQL 中有关 XML 的文档。

帐号将永远存在，我正在检查的是位置是否已返回。或者不止一个被退回（这很糟糕，但我应该检查一下）。

结果看起来像

<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:wsa="http://www.w3.org/2005/08/addressing">
   <env:Header>
      <wsa:Action>http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/applicationModule//CustomerAccountService/findCustomerAccountResponse</wsa:Action>
      <wsa:MessageID>urn:uuid:7dd64ecf-676f-4667-a761-dc7603e99929</wsa:MessageID>
   </env:Header>
   <env:Body>
      <ns0:findCustomerAccountResponse xmlns:ns0="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/applicationModule/types/">
         <ns0:result xsi:type="ns2:CustomerAccountResult" xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/" xmlns:ns1="http://xmlns.oracle.com/adf/svc/types/" xmlns:ns4="http://xmlns.oracle.com/apps/cdm/foundation/parties/partyService/" xmlns:tns="http://xmlns.oracle.com/adf/svc/errors/" xmlns:ns9="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccount/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
            <ns1:Message>
               <tns:code>25089</tns:code>
               <tns:message>JBO-25089: Too many matching records found. Specify additional criteria to limit the number of records.</tns:message>
               <tns:severity>SEVERITY_WARNING</tns:severity>
            </ns1:Message>
            <ns2:Value>
               <ns2:AccountNumber>XXXXX</ns2:AccountNumber>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/">
                  <ns2:CustomerAccountSiteUse xmlns:ns6="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSiteUse/">
                     <ns2:Location>XXXXXXXX</ns2:Location>
                  </ns2:CustomerAccountSiteUse>
               </ns2:CustomerAccountSite>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
            </ns2:Value>
         </ns0:result>
      </ns0:findCustomerAccountResponse>
   </env:Body>
</env:Envelope>

我觉得有点像

IF DBMS_LOB.INSTR(xml_response.getClobVal(), 'Location>XXXXXX<') > 0 THEN
     val_returned := TRUE;
END IF;

可行，但我认为这可能是一种不好的做法？我一直在尝试阅读文档，但它们都引用了从表格等中进行选择，而我没有表格。我可以在不引用表格的情况下在这些东西上使用 xml 表达式吗？我必须从双重或其他中选择吗？

Answer 1

是的，Oracle 中的 XPath 并不漂亮，尤其是在涉及名称空间的情况下。我不擅长，但也许这会让你朝着正确的方向开始：

DECLARE
  accountnumber VARCHAR2(100);
  location      VARCHAR2(100);
  x XMLType := XMLType('
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:wsa="http://www.w3.org/2005/08/addressing">
   <env:Header>
      <wsa:Action>http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/applicationModule//CustomerAccountService/findCustomerAccountResponse</wsa:Action>
      <wsa:MessageID>urn:uuid:7dd64ecf-676f-4667-a761-dc7603e99929</wsa:MessageID>
   </env:Header>
   <env:Body>
      <ns0:findCustomerAccountResponse xmlns:ns0="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/applicationModule/types/">
         <ns0:result xsi:type="ns2:CustomerAccountResult" xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/" xmlns:ns1="http://xmlns.oracle.com/adf/svc/types/" xmlns:ns4="http://xmlns.oracle.com/apps/cdm/foundation/parties/partyService/" xmlns:tns="http://xmlns.oracle.com/adf/svc/errors/" xmlns:ns9="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccount/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
            <ns1:Message>
               <tns:code>25089</tns:code>
               <tns:message>JBO-25089: Too many matching records found. Specify additional criteria to limit the number of records.</tns:message>
               <tns:severity>SEVERITY_WARNING</tns:severity>
            </ns1:Message>
            <ns2:Value>
               <ns2:AccountNumber>XXXXX</ns2:AccountNumber>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/">
                  <ns2:CustomerAccountSiteUse xmlns:ns6="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSiteUse/">
                     <ns2:Location>XXXXXXXX</ns2:Location>
                     <ns2:Location>YYYYYYYY</ns2:Location>
                  </ns2:CustomerAccountSiteUse>
               </ns2:CustomerAccountSite>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
               <ns2:CustomerAccountSite xmlns:ns7="http://xmlns.oracle.com/apps/cdm/foundation/parties/flex/custAccountSite/"/>
            </ns2:Value>
         </ns0:result>
      </ns0:findCustomerAccountResponse>
   </env:Body>
</env:Envelope>  
  ');
BEGIN
  SELECT EXTRACT(x, '//ns2:AccountNumber/text()', 'xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/"').getStringVal()
    INTO accountnumber FROM DUAL;
  dbms_output.put_line('accountnumber:'||accountnumber);
  
  SELECT EXTRACT(x, '//ns2:Location/text()', 'xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/"').getStringVal()
    INTO location FROM DUAL;
  dbms_output.put_line('locations:'||location);
  
  SELECT EXTRACT(x, '//ns2:Location[2]/text()', 'xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/"').getStringVal()
    INTO location FROM DUAL;
  dbms_output.put_line('location2:'||location);
  
  SELECT EXTRACT(x, '//ns2:Location[3]/text()', 'xmlns:ns2="http://xmlns.oracle.com/apps/cdm/foundation/parties/customerAccountService/"').getStringVal()
    INTO location FROM DUAL;
  dbms_output.put_line('location3:'||location);
END;
/

这将输出

accountnumber:XXXXX
locations:XXXXXXXXYYYYYYYY
location2:YYYYYYYY
location3: