您更新的XML具有名称空间，该名称空间最终揭示了问题所在.您需要指定名称空间作为XML提取的一部分，使用XMLTable方法更简单；在这种情况下，您可以将其视为默认名称空间:

Your updated XML has a namespace, which finally reveals the issue. You need to specify the namespace as part of the XML extraction, which is simpler with the XMLTable approach; in this case you can just treat it as the default namespace:

select itc.element_name, x.user_classification3
from i_transaction itc
cross join xmltable(
  xmlnamespaces(default 'http://xmlns.oracle.com/apps/otm'),
    '/TenderOffer/Shipment/RATE_OFFERING/RATE_OFFERING_ROW'
  passing xmltype(itc.xml_blob)
  columns user_classification3 varchar2(10) path 'USER_CLASSIFICATION3'
) x
where itc.i_transaction_no = 31553115
and rownum = 1;

ELEMENT_NA USER_CLASS
---------- ----------
dummy      ZXF       

或使用XMLQuery:

or with XMLQuery:

select itc.element_name, xmlquery(
  'declare default element namespace "http://xmlns.oracle.com/apps/otm"; (: :)
    /TenderOffer/Shipment/RATE_OFFERING/RATE_OFFERING_ROW/USER_CLASSIFICATION3/text()'
  passing xmltype(itc.xml_blob)
  returning content
) x
from i_transaction itc
where itc.i_transaction_no = 31553115
and rownum = 1;

ELEMENT_NA X                                                                               
---------- --------------------------------------------------------------------------------
dummy      ZXF                                                                             

如果您想继续使用不推荐使用的extractvalue()函数，则也可以提供名称空间作为其参数，再次

If you wanted to keep using the deprecated extractvalue() function you can supply the namespace as an argument to that too, again as shown in the documentation:

select itc.element_name,
  extractvalue(xmltype(xml_blob),
    '/TenderOffer/Shipment/RATE_OFFERING/RATE_OFFERING_ROW/USER_CLASSIFICATION3/text()',
    'xmlns="http://xmlns.oracle.com/apps/otm"')
from i_transaction itc where itc.i_transaction_no = 31553115 and rownum = 1;