包含相同兄弟的 XML 的 MSSQL 解析答案

【问题标题】：MSSQL Parsing of XML that Contains same Sibling包含相同兄弟的 XML 的 MSSQL 解析
【发布时间】：2017-10-27 20:44:16
【问题描述】：

我正在尝试查询具有 XML 的 MSSQL 数据库并将其解析出来。

这是数据：

<Root>
<Relatives>
<Relative>
  <Relation>Father</Relation>
  <BcAge>50</BcAge>
  <BilatAge>0</BilatAge>
  <OcAge>0</OcAge>
</Relative>
<Relative>
  <Relation>Mother</Relation>
  <BcAge>58</BcAge>
  <BilatAge>0</BilatAge>
  <OcAge>0</OcAge>
</Relative>

这是想要的结果

Relation BcAge BilatAge OcAge Relation BcAge BilatAge OcAge 
Father   50     0       0      Mother  58    0         0

【问题讨论】：

标签： sql-server xml tsql xpath xquery

【解决方案1】：

我怀疑您是否真的希望并排获得结果...这不是有效的结果集，您的列名重复。

如果你真的需要这种方式，你可以这样做：

DECLARE @xml XML=
N'<Root>
<Relatives>
<Relative>
  <Relation>Father</Relation>
  <BcAge>50</BcAge>
  <BilatAge>0</BilatAge>
  <OcAge>0</OcAge>
</Relative>
<Relative>
  <Relation>Mother</Relation>
  <BcAge>58</BcAge>
  <BilatAge>0</BilatAge>
  <OcAge>0</OcAge>
</Relative>
</Relatives>
</Root>';

查询将使用 CTE 来获取具有 XQuery-predicate 的父亲和母亲

WITH Parents AS
(
    SELECT @xml.query(N'/Root/Relatives/Relative[(Relation/text())[1]="Father"]') AS Father
          ,@xml.query(N'/Root/Relatives/Relative[(Relation/text())[1]="Mother"]') AS Mother
)
SELECT 'Father' AS F_Relation
      ,Father.value(N'(/Relative/BcAge)[1]',N'int') AS F_BcAge
      ,Father.value(N'(/Relative/BilatAge)[1]',N'int') AS F_BilatAge
      ,Father.value(N'(/Relative/OcAge)[1]',N'int') AS F_OcAge
      ,'Mother' AS M_Relation   
      ,Mother.value(N'(/Relative/BcAge)[1]',N'int') AS M_BcAge
      ,Mother.value(N'(/Relative/BilatAge)[1]',N'int') AS M_BilatAge
      ,Mother.value(N'(/Relative/OcAge)[1]',N'int') AS M_OcAge
FROM Parents;

但您可能正在寻找的就是这个（<Relative> 的任意数量）：

SELECT rel.value(N'(Relation/text())[1]',N'nvarchar(max)') AS Relation
      ,rel.value(N'(BcAge/text())[1]',N'int') AS BcAge
      ,rel.value(N'(BilatAge/text())[1]',N'int') AS BilatAge
      ,rel.value(N'(OcAge/text())[1]',N'int') AS OcAge
FROM @xml.nodes(N'/Root/Relatives/Relative') AS A(rel)

【讨论】：