具有多个属性的XML查询

<LoSTResponseBodyType xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <LoSTResponseAdapter xmlns="urn:adapt:xml:ns:DataTypes:2.0">
       <findServiceResponse xmlns="urn:lost:params:xml:ns:lost1">
           <mapping sourceId="9999" expires="2015-08-24T14:27:58Z" lastUpdated="2015-06-17T21:36:43Z" source="mysourcename">
              <displayName xml:lang="en">mydisplayname</displayName>
              <service>myservice</service>
              <uri>myuri</uri>
              <serviceNumber>mynumber</serviceNumber>
           </mapping>
      </findServiceResponse>
    </LoSTResponseAdapter>
</LoSTResponseBodyType>

如何检索< uri>的值,即myuri？

我试过以下代码

WITH xmlnamespaces ('urn:adapt:xml:ns:DataTypes:2.0' as datatype,
                    'urn:lost:params:xml:ns:lost1' as findtype)
SELECT EventBody.value('(/LoSTResponseBodyType/datatype:LoSTResponseAdapter/findtype:findServiceResponse/mapping/uri)[1]', 'varchar(max)') 
FROM mytable

我得到一个NULL值.

如果我删除所有’mapping / uri’,我确实将所有值连接在一起,即displayname,service,uri,serviceNumber,它看起来像这样：
mydisplaynamemyservicemyurimynumber

这些元素也与findServiceResponse位于同一名称空间中.