Question

如果我有两种不同类型的路径来处理信息，我如何使用oracle extractvalue函数选择xml数据？

对于年份和品牌，我可以使用以下方式恢复信息：

extractvalue(xmltype(x.xml, 0), '//Vehicle/Year') as VEC_YEAR,

但是对于地址我有错误消息：ORA31011无法解析xml和ORA19202和LPX00601：无效令牌：//品牌/信息/数据/地址

SELECT 
      extractvalue(xmltype(x.xml, 0), '//Vehicle/Year') as VEC_YEAR,
      extractvalue(xmltype(x.xml, 0), '//Vehicle/Brand') as VEC_BRAND,
    CASE 
      WHEN extractvalue(xmltype(x.xml, 0), '//Brand/Info/Data/Address') IS NOT NULL THEN extractvalue(xmltype(x.xml, 0), '//Brand/Info/Data/Address')
      WHEN extractvalue(xmltype(x.xml, 0), '//Brand/MainInfo/Info/Data/Address') IS NOT NULL THEN  extractvalue(xmltype(x.xml, 0), '//Brand/MainInfo/Info/Data/Address') 
    END as Adress,
    FROM xml_table x

这些是我必须查询的XML：

<?xml version="1.0" encoding="utf-8"?>
<VehicleValidation xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
    <Validation Id="Validation">
        <Vehicle>
            <Year>2017</Year>
            <Brand>One car brand</Brand>
        </Vehicle>

        <Brand>
            <Info>
                <Data>
                    <Address>
                    One car brand Address
                    </Address>
                <Data>
            </Info>
        </Brand>
    </Validation>
</VehicleValidation>

<?xml version="1.0" encoding="utf-8"?>
<VehicleValidation xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
    <Validation Id="Validation">
        <Vehicle>
            <Year>2017</Year>
            <Brand>One car brand</Brand>
        </Vehicle>

        <Brand>

            <MainInfo>

                <Info>
                    <Data>
                        <Address>
                            One car brand Address
                        </Address>
                    <Data>
                </Info>

            </MainInfo>
        </Brand>
    </Validation>
</VehicleValidation>

Answer 1

如何在品牌下方获取任何信息/数据/地址？即使用XPath //品牌//信息/数据/地址而不是//品牌/信息/数据/地址和//品牌/主要信息/信息/数据/地址 https://www.w3.org/TR/xpath/#path-abbrev

如果您需要准确，请尝试在when条件中使用existsnode而不是extractvalue https://docs.oracle.com/cd/B12037_01/appdev.101/b10790/xdb04cre.htm#i1032763

顺便说一句，在发布的xml中，Data标签没有正确关闭。

Answer 2

这是一个有效的例子..注意事项。请尽量不要使用extractValue（）。它已被弃用。您应该使用XML标准定义的SQL / XML运算符。要从XML文档中提取关系行，XMLTABLE应该是首选运算符..

SQL> with MY_TABLE as
  2  (
  3    select XMLTYPE(
  4  '<?xml version="1.0" encoding="utf-8"?>
  5  <VehicleValidation xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
  6      <Validation Id="Validation">
  7          <Vehicle>
  8              <Year>2017</Year>
  9              <Brand>One car brand</Brand>
 10          </Vehicle>
 11          <Brand>
 12              <Info>
 13                  <Data>
 14                      <Address>
 15                      One car brand Address
 16                      </Address>
 17                  </Data>
 18              </Info>
 19          </Brand>
 20      </Validation>
 21  </VehicleValidation>') as XMLDOC
 22      from DUAL
 23     union all
 24    select XMLTYPE(
 25  '<?xml version="1.0" encoding="utf-8"?>
 26  <VehicleValidation xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
 27      <Validation Id="Validation">
 28          <Vehicle>
 29              <Year>2017</Year>
 30              <Brand>One car brand</Brand>
 31          </Vehicle>
 32          <Brand>
 33              <MainInfo>
 34                  <Info>
 35                      <Data>
 36                          <Address>
 37                              One car brand Address
 38                          </Address>
 39                      </Data>
 40                  </Info>
 41              </MainInfo>
 42          </Brand>
 43      </Validation>
 44  </VehicleValidation>') as XMLDOC
 45    from dual
 46  )
 47  select Brand, Address
 48    from MY_TABLE,
 49         XMLTABLE(
 50           '/VehicleValidation/Validation'
 51           passing XMLDOC
 52           COLUMNS
 53             BRAND   VARCHAR2(32)   PATH 'Vehicle/Brand',
 54             ADDRESS VARCHAR2(64) PATH 'Brand//Info/Data/Address'
 55         )
 56  /

BRAND                            ADDRESS
-------------------------------- ----------------------------------------------------------------
One car brand
                                                     One car brand Address


One car brand
                                                             One car brand Address

Oracle extractvalue将xml数据选择到不同的Path中

2 个答案: