PowerShell 中的 Xpath：在两列中显示结果

Question

我将以这个示例数据为例：

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications 
      with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies, 
      an evil sorceress, and her own childhood to become queen 
      of the world.</description>
   </book>
</catalog>

数据链接：https://docs.microsoft.com/en-us/previous-versions/windows/desktop/ms762271(v=vs.85)

假设我想查询作者和价格

[xml]$XmlFileObj = Get-Content 'C:\Users\David\Documents\XmlSample.dtsx'

$XmlFileObj | Select-Xml -XPath "/catalog/book/author | /catalog/book/price "  | Select-Object -ExpandProperty Node

结果是：

#text               
-----               
Gambardella, Matthew
44.95               
Ralls, Kim          
5.95   

如果我希望结果看起来像：

#col1; col2               
-----               
Gambardella, Matthew; 44.95               
Ralls, Kim ; 5.95   

或者类似的表格形式...

Answer 1

不要分别提取<author>和<price>节点，而是使用Select-Xml枚举共同祖先——<book>节点——然后直接从每个节点中选择作者和价格节点：

$XmlFileObj |Select-Xml '/catalog/book' |Select -ExpandProperty Node |Select author,price

---

如果您想根据后代节点值进行过滤，您可以使用 XPath 谓词 (//node/selector[predicate goes here])：

# This will return the author and price, but only of "Midnight Rain" 
$XmlFileObj |Select-Xml '/catalog/book[genre = "Fantasy"]' |Select -ExpandProperty Node |Select author,price

如果您找不到合适的 XPath 函数或运算符，您还可以利用 PowerShell 的内置 XML 适配器，就像我们从 Select-Object （或任何其他 cmdlet 的）透视图，它们的属性就像在任何其他对象上一样：

# This will return the author and price, but only of "Midnight Rain" 
$XmlFileObj |Select-Xml '/catalog/book' |Select -ExpandProperty Node |Where genre -eq Fantasy |Select author,price