如何从 SQL Server 2008 中的 xml 字段中选择特定值答案

【问题标题】：How to select specific values from xml field in SQL Server 2008如何从 SQL Server 2008 中的 xml 字段中选择特定值
【发布时间】：2011-12-08 22:15:34
【问题描述】：

我在表中有 xml 列，我想解析 xml 并将值插入新表中

如何将xml值插入到表中？

CREATE TABLE [dbo].[PubmedMeshDescriptors](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [PMID] [int] NULL,
    [Descriptor] [nvarchar](400) NULL,
    [DescriptorIsMajor] [char](1) NULL,
    [Qualifier] [nvarchar](400) NULL,
    [QualifierIsMajor] [char](1) NULL
)

另一个表中的xml列是这样的

<MedlineCitation Owner="NLM" Status="MEDLINE">
  <PMID Version="1">1</PMID>
  <MeshHeadingList>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Aldehyde Oxidoreductases</DescriptorName>
      <QualifierName MajorTopicYN="N">metabolism</QualifierName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Animals</DescriptorName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Carbon Dioxide</DescriptorName>
      <QualifierName MajorTopicYN="N">blood</QualifierName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Formates</DescriptorName>
      <QualifierName MajorTopicYN="N">blood</QualifierName>
      <QualifierName MajorTopicYN="Y">poisoning</QualifierName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Haplorhini</DescriptorName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Hydrogen-Ion Concentration</DescriptorName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Methanol</DescriptorName>
      <QualifierName MajorTopicYN="N">blood</QualifierName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Methods</DescriptorName>
    </MeshHeading>
    <MeshHeading>
      <DescriptorName MajorTopicYN="N">Pseudomonas</DescriptorName>
      <QualifierName MajorTopicYN="N">enzymology</QualifierName>
    </MeshHeading>
  </MeshHeadingList>
</MedlineCitation>

如何使用 sql 查询来做到这一点？

【问题讨论】：

标签： sql-server xml sql-server-2008

【解决方案1】：

将 xml 放入 xml 变量中，然后尝试如下操作：

INSERT PubmedMeshDescriptors (PMID, Descriptor, DescriptorIsMajor, Qualifier, QualifierIsMajor)
SELECT 
    PMIDNode.value('.', 'int') as PMID,
    DescriptorNode.value('.', 'nvarchar(400)') as Descriptor,
    DescriptorNode.value('(./@MajorTopicYN)[1]', 'char(1)') as DescriptorIsMajor,
    QualifierNode.value('.', 'nvarchar(400)') as Qualifier,
    QualifierNode.value('(./@MajorTopicYN)[1]', 'char(1)') as QualifierIsMajor
FROM @xml.nodes('/MedlineCitation') AS citation(citationNode)
CROSS APPLY 
    citationNode.nodes('./PMID')
    AS PMID(PMIDNode)
CROSS APPLY 
    citationNode.nodes('./MeshHeadingList/MeshHeading')
    AS MeshHeading(MeshHeadingNode)
OUTER APPLY 
    MeshHeadingNode.nodes('./DescriptorName')
    AS Descriptor(DescriptorNode)
OUTER APPLY 
    MeshHeadingNode.nodes('./QualifierName')
    AS Qualifier(QualifierNode)

【讨论】：