Powershell根据子节点值选择父xml节点并添加子元素

Question

查看下面的xml

    <catalog>
        <books>
           <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>
           <book id="bk103">
              <author>Corets, Eva</author>
              <title>Maeve Ascendant</title>
              <genre>Fantasy</genre>
              <price>5.95</price>
              <publish_date>2000-11-17</publish_date>
              <description>After the collapse of a nanotechnology 
              society in England, the young survivors lay the 
              foundation for a new society.</description>
           </book>
       </books>
    </catalog>

我想在powershell中选择作者是Corets，Eva的书节点/元素，然后添加书的子元素，另一个元素（价格的兄弟，直接在价格之后），例如长度。以及长度的新值“456”

因此，我运行代码后 book 元素的（部分）xml 代码如下所示：

<catalog>
    <books>
       <book id="bk103">
          <author>Corets, Eva</author>
          <title>Maeve Ascendant</title>
          <genre>Fantasy</genre>
          <price>5.95</price>
          <length>456</length>        
          <publish_date>2000-11-17</publish_date>
          <description>After the collapse of a nanotechnology 
          society in England, the young survivors lay the 
          foundation for a new society.</description>
       </book>
       <book>
        ....
       </book>
    </books>
<etc>

有人可以帮忙吗？现在卡了两天。谢谢

Answer 1

您可以使用XMLNode.InsertAfter 方法。

例子：

[xml]$books = Get-Content .\books.xml
$corets = $books.catalog.books.book | Where-Object { $_.author -eq 'Corets, Eva' }
$coretsPrice = $corets.SelectSingleNode('price')
$coretsLength = $books.CreateElement('length')
$coretsLength.InnerText = 495
$corets.InsertAfter($coretsLength, $coretsPrice)

Answer 2

您可以使用以下 XPath 表达式仅选择子节点 <author> 的文本值为 Corets, Eva 的 <book /> 节点：

//book[author[. = 'Corets, Eva']]

所以你可以这样做：

# Create a new XML document
$newDocument = [xml]'<catalog><books></books></catalog>'
$newBooks = $newDocument.SelectSingleNode('/catalog/books')

# Loop through all relevant <book> nodes in the existing document
foreach($book in $existingDocument.SelectNodes('//book[author[. = 'Corets, Eva']]')){
    # import book node to new document
    $newBook = $newDocument.ImportNode($book, $true)

    # add new required child node
    $newLength = $newDocument.CreateElement('length')
    $newLength.InnerText = '456'

    # insert new node after `price`
    [void]$newBook.InsertAfter($newLength, $newBook.SelectSingleNode('./price'))
    # insert new book node under /catalog/books
    [void]$newBooks.AppendChild($newBook)
}