XML 字段 - 查询答案

【问题标题】：XML Field - QueryXML 字段 - 查询
【发布时间】：2012-05-09 18:59:06
【问题描述】：

我无法构建正确的语法以在我的 sql sever 2008 上执行与 XML 字段相关的任何查询。

我有一个简单的表，其中包含 Idproduct、ProductName 和 XmlProduct 等字段。 ..XmlProduct 字段如下所示：

<DynamicProfile xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WinTest">
  <AllData xmlns:d2p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MyFirstValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
  </AllData>
</DynamicProfile>

例如，我需要编写一个查询，将包含节点值的所有行提取到“MySecondKey”。怎样才能做到这一点？

【问题讨论】：

标签： xml sql-server-2008 xml-serialization

【解决方案1】：

这里是带有 xquery 操作符的 ans-->

declare @xmldata xml
    set @xmldata = 
    '<DynamicProfile xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WinTest">
  <AllData xmlns:d2p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MyFirstValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  </AllData>
</DynamicProfile>'

;WITH XMLNAMESPACES 
(
    DEFAULT 'http://schemas.datacontract.org/2004/07/WinTest',
    'http://schemas.microsoft.com/2003/10/Serialization/Arrays' as d2p1
)
SELECT  x.c.value('(d2p1:Key)[1]', 'varchar(100)') as key3, x.c.value('(d2p1:Value)[1]', 'varchar(100)') as value
FROM @xmldata.nodes('/DynamicProfile/AllData/d2p1:KeyValueOfstringstring') x(c) where x.c.value('(d2p1:Key)[1]', 'varchar(100)') = 'MySecondKey'

【讨论】：

好吧，但在我的例子中，@xmldata 变量是一个表字段。所以，考虑你想执行一个查询来提取与 xml where clausole 匹配的所有行，我该怎么做？
查看这篇文章--> databasejournal.com/features/mssql/article.php/3674311/…
无事可做。对我来说，“翻译” xml 字段并不重要，相反，我只会检索受我的 where 条件影响的所有行。其中条件是指 xml 字段，但最后我想要实现的都是“本机”行，例如： Select * from MyTable WHERE XmlField.Value(key) = 'some value'
好的，解决了..以下正是我想要的： WITH XMLNAMESPACES ( 'schemas.microsoft.com/2003/10/Serialization/Arrays' as d2p1 ) select * from MyTable where MyXmlField.exist('//d2p1:Key[.= "MyFirstKey"]') = 1

【解决方案2】：

你可以使用下面的TSQL代码-->

declare @xmldata xml
    set @xmldata = 
    '<DynamicProfile xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WinTest">
  <AllData xmlns:d2p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MyFirstValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>
    <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MySecondKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  <d2p1:KeyValueOfstringstring>
      <d2p1:Key>MyFirstKey</d2p1:Key>
      <d2p1:Value>MySecondValue</d2p1:Value>
    </d2p1:KeyValueOfstringstring>  </AllData>
</DynamicProfile>'

 DECLARE @hDoc int, @rootxmlns varchar(100)
 SET @rootxmlns = '<AllData xmlns:d2p1="http://schemas.microsoft.com/2003/10/Serialization/Arrays" />'

 EXEC sp_xml_preparedocument @hDoc OUTPUT, @xmldata, @rootxmlns  

 SELECT *
 FROM OPENXML(@hDoc, '//d2p1:KeyValueOfstringstring',2)
 WITH ([d2p1:Key] varchar(100) , [d2p1:Value] varchar(100)) where [d2p1:Key] = 'MySecondKey'

 --clean up 
 EXEC sp_xml_removedocument @hDoc

【讨论】：

为什么需要声明@xmldata 变量？这已经存在于我的表 xml 字段中。另外，有没有使用 XQuery 的解决方案？诸如查询、值、存在方法之类的东西..？
这里推荐使用xquery的类似解决方案 --> stackoverflow.com/questions/1440848/openxml-with-xmlnsdt
请您给我发一个与我的问题相关的明确示例吗？