以XML作为单一扁平行返回SQL查询

Question

SQL Server 2008R2或2012

是否可以将XML节点查询作为单行而不是多行返回，其中每个返回项都是新列而不是一行？

例如，XML字段包含以下XML结构：

<MetaFieldData>
  <MetaField>
    <Name>Volume</Name>
    <Value>Large</Value>
  </MetaField>
  <MetaField>
    <Name>Code</Name>
    <Value>3DP</Value>
  </MetaField>
  <MetaField>
    <Name>Photo</Name>
    <Value>foo.png</Value>
  </MetaField>
  <MetaField>
    <Name>CommonName</Name>
    <Value>Foo Bar</Value>
  </MetaField>
</MetaFieldData>

使用以下SQL：

select 
    m.value('Name[1]', 'varchar(100)') as Name,
    m.value('Value[1]', 'varchar(max)') as Value
from MyTable 
cross apply MetaFieldData.nodes('/MetaFieldData/MetaField') as Meta(m)
where Id = 1

结果集将返回：

Name        Value
--------------------
Volume      Large
Code        3DP
Photo       foo.png
CommonName  Foo Bar

您如何将结果集返回为：

Volume     Code     Photo     CommonName
----------------------------------------------
Large      3DP      foo.png   Foo Bar

Answer 1

尝试这个

SELECT Volume,Code,Photo,CommonName
FROM 
(
    SELECT 
        m.value('Name[1]', 'varchar(100)') as Name,
        m.value('Value[1]', 'varchar(max)') as Value
    FROM MyTable 
    CROSS APPLY MetaFieldData.nodes('/MetaFieldData/MetaField') as Meta(m)
    WHERE Id = 1
) P
PIVOT
(
    MAX(Value) FOR Name IN (Volume,Code,Photo,CommonName)
) pvt