如何在SQL Server中的xml列中查詢xml值

Question

我喜歡在名為“AlgorithmLog”的表的[XMLValue]列中跟隨代碼：

<?xml version="1.0" encoding="utf-8"?>
<AdapterInfo xmlns:i="http://www.w3.org/2001/XMLSchema-instance"     
            xmlns:d1p1="http://schemas.datacontract.org/2004/07/Adapters.Adapter.CloudTrader"    
            xmlns="http://schemas.datacontract.org/2004/07/Adapters.Adapter"  
            i:type="d1p1:AlgorithmStatusReport">
    <SequenceNumber>0</SequenceNumber>
    <TrackingGuid i:nil="true" />
    <d1p1:Broker>Default</d1p1:Broker>
    ...
       <d1p1:XMLValue>&lt;?xml version="1.0"?&gt;&lt;int xmlns="http://schemas.microsoft.com/2003/10/Serialization/"&gt;1900&lt;/int&gt;</d1p1:XMLValue>
</AdapterInfo>

我想在節點<d1p1:XMLValue>獲取值“1900”

所以這是我的查詢：

WITH XMLNAMESPACES('http://schemas.datacontract.org/2004/07/Adapters.Adapter' AS x, 
                   'http://schemas.datacontract.org/2004/07/Adapters.Adapter.CloudTrader' As p,
                   'http://schemas.microsoft.com/2003/10/Serialization/'as w)
   SELECT  
       XMLValue.query('(/x:AdapterInfo/p:XMLValue/w:int)[1]')AS [XMLVaule]
   FROM AlgorithmLog 

但它什么也沒有回報。

誰能告訴我哪里做錯了或我怎么做？

謝謝。

Answer 1

由於您已在另一個XML節點內“編碼”了XML，並且無法使用.value() XQuery方法自動轉換為XML數據類型，因此所有內容都有所涉及 - 但這似乎對我有用：

;WITH XMLNAMESPACES('http://schemas.datacontract.org/2004/07/Adapters.Adapter' AS x, 
                    'http://schemas.datacontract.org/2004/07/Adapters.Adapter.CloudTrader' As p,
                    'http://schemas.microsoft.com/2003/10/Serialization/'as w)
   SELECT  
       CAST(XmlContent.value('(/x:AdapterInfo/p:XMLValue)[1]', 'varchar(2000)') AS XML).value('(w:int)[1]', 'int') AS [XMLValue]
   FROM AlgorithmLog
   WHERE .......  -- use whatever condition makes sense for you here