元素不均匀时查询 XML答案

【问题标题】：querying XML when there are uneven elements元素不均匀时查询 XML
【发布时间】：2012-01-04 05:19:20
【问题描述】：

此代码的问题在于每个组中并不总是有一个 CEEBCode。它找到的第一个 ceebcode 实际上在第二组中，并且与第一组中的其他元素匹配。

当 ceeb 代码不存在时，是否可以将组保持在一起？

select 
UIN,
docXML.value('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/CEEBCode/text())[1]' 
    ,'varchar(6)'
    ) as ceeb1,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/IsGrad/text())[1]'
    ,'varchar(5)'
    ) as IsGradAns1,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/Country/text())[1]' 
    ,'varchar(25)'
    ) as Country1,
docXML.value('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/CEEBCode/text())[2]' 
    ,'varchar(6)'
    ) as ceeb2,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/IsGrad/text())[2]'
    ,'varchar(5)'
    ) as IsGradAns2,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool/Country/text())[2]' 
    ,'varchar(25)'
    ) as Country2
from tblDocument
where docxml is not null

示例 XML：

<SelfReportedTranscript>
  <HighSchools>
    <SelfReportedHighSchool>
      <Name>Ramay Jr High School</Name>
      <City>Fayetteville</City>
      <Country>United States of America</Country>
      <StateProvince>Arkansas</StateProvince>
      <IsGrad>false</IsGrad>
      <HighSchoolType>Domestic</HighSchoolType>
    </SelfReportedHighSchool>
    <SelfReportedHighSchool>
      <Name>Fayetteville Sr High Sch</Name>
      <CEEBCode>040770</CEEBCode>
      <City>Fayetteville</City>
      <Country>US</Country>
      <StateProvince>AR</StateProvince>
      <IsGrad>true</IsGrad>
      <HighSchoolType>Domestic</HighSchoolType>
    </SelfReportedHighSchool>
  </HighSchools>
</SelfReportedTranscript>

这适用于 SQL Server 2005 SP3

【问题讨论】：

能否提供 XML 示例？
我试过了。我不知道你是否能看到我添加的所有内容。
这适用于 [1] 的情况，但 [2] 返回空值。

标签： sql-server sql-server-2005 tsql

【解决方案1】：

试试这个。将[1] 和[2] 添加到SelfReportedHighSchool 标签，因为这是您从中获取“行”的地方。还需要把最后的[2]改成[1]。

select 
UIN,
docXML.value('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[1]/CEEBCode/text())[1]' 
    ,'varchar(6)'
    ) as ceeb1,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[1]/IsGrad/text())[1]'
    ,'varchar(5)'
    ) as IsGradAns1,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[1]/Country/text())[1]' 
    ,'varchar(25)'
    ) as Country1,
docXML.value('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[2]/CEEBCode/text())[1]' 
    ,'varchar(6)'
    ) as ceeb2,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[2]/IsGrad/text())[1]'
    ,'varchar(5)'
    ) as IsGradAns2,
docxml.value
    ('
    (/SelfReportedTranscript/HighSchools/SelfReportedHighSchool[2]/Country/text())[1]' 
    ,'varchar(25)'
    ) as Country2
from tblDocument
where docxml is not null

【讨论】：