如何从具有XML数据的表中获取特定数据

Question

这是我用来从存储在表x列中的XML中获取数据的查询。

SELECT EXTRACTVALUE (IT.ADO_DATA, '/valueXML/IndividualADO/ado-name') "REFERENCE" 
    FROM ITEM_ADO IT 

，这里是XML数据

<valueXML xmlns="com.ado" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
    <IndividualADO> 
    <ado-name>LIMS</ado-name> 
    <field> 
     <ado-field-name>ADO_LIMS_LIMS_Custodian_First_Name</ado-field-name> 
     <ado-field-value xsi:nil="true"/> 
    </field> 
    </IndividualADO> 
</valueXML> 

我试图获取节点的数据 “ADO-名”

Answer 1

假设ADO_DATA是XMLType的类型，你的当前查询因为您的valueXML节点具有您需要包含在XPath中的名称空间，或者使用通配符，所以不会返回任何值：

SELECT EXTRACTVALUE (IT.ADO_DATA, '/*:valueXML/*:IndividualADO/*:ado-name') "REFERENCE" 
    FROM ITEM_ADO IT; 

REFERENCE                  
-------------------------------------------------------------------------------- 
LIMS                    

但extractvalue()被去除;你可以做同样的an XQuery：

select xmlquery(
    '/*:valueXML/*:IndividualADO/*:ado-name/text()' 
    passing ado_data 
    returning content) as reference 
from item_ado; 

REFERENCE                  
-------------------------------------------------------------------------------- 
LIMS 

还是用默认的命名空间而不是通配符（和显示CTE用于测试）：

with item_ado (ado_data) as (
    select xmltype('<valueXML xmlns="com.ado" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
    <IndividualADO> 
    <ado-name>LIMS</ado-name> 
    <field> 
     <ado-field-name>ADO_LIMS_LIMS_Custodian_First_Name</ado-field-name> 
     <ado-field-value xsi:nil="true"/> 
    </field> 
    </IndividualADO> 
</valueXML>') from dual 
) 
select xmlquery(
    'declare default element namespace "com.ado"; (: :) 
    /valueXML/IndividualADO/ado-name/text()' 
    passing ado_data 
    returning content) as reference 
from item_ado; 

REFERENCE                  
-------------------------------------------------------------------------------- 
LIMS