在类型化的xml列上选择节点的原子值

时间:2012-08-30 04:47:46

标签: sql sql-server-2008 xpath

如果你不能在它上面使用text(),你怎么能得到一个元素xml列中元素的原子价值?

此查询;

-- Add schema
CREATE XML SCHEMA COLLECTION MySchema AS N'<xs:schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xmlns:xs="http://www.w3.org/2001/XMLSchema"
            attributeFormDefault="unqualified"
            elementFormDefault="qualified"
            xmlns="http://mynamespace"
            targetNamespace="http://mynamespace">

  <xs:element name="element1" type="element1Type">
  </xs:element>

  <xs:complexType name="element1Type">
    <xs:sequence minOccurs="0" maxOccurs="unbounded">
      <xs:element name="element2" type="element2Type" />
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="element2Type">
    <xs:sequence>
      <xs:element name="element3" type="element3Type" minOccurs="0" maxOccurs="unbounded" />
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="element3Type">
    <xs:sequence minOccurs="0">
      <xs:element minOccurs="0" name="element4" />
    </xs:sequence>
  </xs:complexType>

</xs:schema>'
GO

-- Create table
CREATE TABLE [dbo].[MyTable](
    [XmlColumn] [xml](CONTENT [dbo].[MySchema]) NOT NULL
)
GO

-- Add test data
INSERT INTO MyTable SELECT N'<element1 xmlns="http://mynamespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <element2>
    <element3>
      <element4>my text here</element4>
    </element3>
  </element2>
</element1>'
GO

-- run query
WITH XMLNAMESPACES(
    'http://mynamespace' as s,
    DEFAULT 'http://mynamespace'
)
SELECT 
    T.rows.value('(element3/element4)[1]/text()', 'varchar(100)') as [AtomicValue]
FROM
    MyTable
CROSS APPLY
    XmlColumn.nodes('/element1/element2') T(rows)

结果;

XQuery [MyTable.XmlColumn.value()]: 'text()' is not supported on simple typed or
'http://www.w3.org/2001/XMLSchema#anyType' elements, found
'element({http://mynamespace}:element4,xs:anyType) ?'.

我已经阅读了this,但是我希望能够阅读的每个原子值上的模式进行大量编辑感觉就像是矫枉过正......

1 个答案:

答案 0 :(得分:3)

您可以使用query然后使用value

WITH XMLNAMESPACES(
    'http://mynamespace' as s,
    DEFAULT 'http://mynamespace'
)
SELECT 
    T.rows.query('element3/element4').value('.', 'varchar(100)')
FROM
    MyTable
CROSS APPLY
    XmlColumn.nodes('/element1/element2') T(rows)

或者您可以在架构中指定element4的类型。

<xs:element minOccurs="0" name="element4" type="xs:string"/>

并使用此查询

WITH XMLNAMESPACES(
    'http://mynamespace' as s,
    DEFAULT 'http://mynamespace'
)
SELECT 
    T.rows.value('(element3/element4)[1]', 'varchar(100)') as [AtomicValue]
FROM
    MyTable
CROSS APPLY
    XmlColumn.nodes('/element1/element2') T(rows)