使用Oracle SQL读取XML命名空间

Question

我的XML如下所示

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>  
<wfm:Statement xmlns:wfm="http://example.org/sample/xsd/sampleStatement/2013/05" xmlns:wfmMerchant="http://www.eds.com/sample/xsd/wfmMerchant/2012/03"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  
  <wfm:StatementParameters>  
    <wfmMerchant:HierarchyCd>012-12-002-107-050</wfmMerchant:HierarchyCd>   
  </wfm:StatementParameters>  
  <StatementAmount>27.140</StatementAmount>  
</wfm:Statement>

我试图使用如下的Oracle查询获取StatementAmount标记的值

select MS.MERCHANT,MS.CHAIN_HIERARCHY_CD,MS.CYCLE_DATE, X.StatementAmount
FROM CHAIN_STATMNT_HIST_XML MS  
CROSS JOIN XMLTABLE(XMLNAMESPACES('http://example.org/sample/xsd/sampleStatement/2013/05' AS "wfm", 'http://www.eds.com/sample/xsd/wfmMerchant/2012/03' as wfmmerchant
     default 'http://www.w3.org/2001/XMLSchema-instance')
     ,'/wfm:Statement/StatementAmount' passing xmltype(MS.XML_REPORT) 
     columns StatementAmount varchar(18) path '.')X

但是，我总是得到NULL。我能够从具有命名空间的XML成功检索Hierarchy值。但StatementAmount标签没有任何命名空间，我无法检索它。

有人可以帮助解决这个问题吗？

Answer 1

您的默认命名空间声明似乎导致了问题;没有它（并忽略wfmMerchant）：

-- CTE for sample data
with CHAIN_STATMNT_HIST_XML (merchant, chain_hierarchy_cd, cycle_date, XML_REPORT) as (
  select 1, 2, sysdate, '<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<wfm:Statement xmlns:wfm="http://example.org/sample/xsd/sampleStatement/2013/05" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<wfm:StatementParameters>
<!-- excluding this as namespace not provided -->
<!-- <wfmMerchant:HierarchyCd>012-12-002-107-050</wfmMerchant:HierarchyCd> -->
</wfm:StatementParameters>
<StatementAmount>27.140</StatementAmount>
</wfm:Statement>' from dual
)
-- actual query
select MS.MERCHANT,MS.CHAIN_HIERARCHY_CD,MS.CYCLE_DATE, X.StatementAmount
FROM CHAIN_STATMNT_HIST_XML MS  
CROSS JOIN XMLTABLE(
  XMLNAMESPACES('http://example.org/sample/xsd/sampleStatement/2013/05' AS "wfm"),
  '/wfm:Statement/StatementAmount' passing xmltype(MS.XML_REPORT)
  columns StatementAmount varchar(18) path '.'
) X
/

  MERCHANT CHAIN_HIERARCHY_CD CYCLE_DATE STATEMENTAMOUNT   
---------- ------------------ ---------- ------------------
         1                  2 2018-09-04 27.140            

我不确定为什么你会使用varchar2(18)作为数据类型而不是number;如果每个陈述只有一个陈述金额，你可以这样做：

select MS.MERCHANT,MS.CHAIN_HIERARCHY_CD,MS.CYCLE_DATE, X.StatementAmount
FROM CHAIN_STATMNT_HIST_XML MS  
CROSS JOIN XMLTABLE(
  XMLNAMESPACES('http://example.org/sample/xsd/sampleStatement/2013/05' AS "wfm"),
  '/wfm:Statement' passing xmltype(MS.XML_REPORT)
  columns StatementAmount number path 'StatementAmount'
) X