按多个条件对 XML 节点进行排序

Question

我正在尝试按日期作为主要标准对以下 XML 进行排序，然后将价格作为第二个标准。

我认为先按价格排序，然后按日期排序就足够了。我预计bk108 的书会排在第一位，因为它是最新的且价格最高的，但第一本书却是bkXXX，尽管它的价格低于bk108 的。

$xml = [xml]@'
<?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>
   <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>
   <book id="bk104">
      <author>Corets, Eva</author>
      <title>Oberon's Legacy</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-03-10</publish_date>
      <description>In post-apocalypse England, the mysterious 
      agent known only as Oberon helps to create a new life 
      for the inhabitants of London. Sequel to Maeve 
      Ascendant.</description>
   </book>
   <book id="bk105">
      <author>Corets, Eva</author>
      <title>The Sundered Grail</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-09-10</publish_date>
      <description>The two daughters of Maeve, half-sisters, 
      battle one another for control of England. Sequel to 
      Oberon's Legacy.</description>
   </book>
   <book id="bk106">
      <author>Randall, Cynthia</author>
      <title>Lover Birds</title>
      <genre>Romance</genre>
      <price>1000</price>
      <publish_date>2000-09-02</publish_date>
      <description>When Carla meets Paul at an ornithology 
      conference, tempers fly as feathers get ruffled.</description>
   </book>
   <book id="bk107">
      <author>Thurman, Paula</author>
      <title>Splish Splash</title>
      <genre>Romance</genre>
      <price>1000</price>
      <publish_date>2000-10-02</publish_date>
      <description>A deep sea diver finds true love twenty 
      thousand leagues beneath the sea.</description>
   </book>
   <book id="bk108">
      <author>Knorr, Stefan</author>
      <title>Creepy Crawlies</title>
      <genre>Horror</genre>
      <price>999</price>
      <publish_date>2001-12-06</publish_date>
      <description>An anthology of horror stories about roaches,
      centipedes, scorpions  and other insects.</description>
   </book>
    <book id="bkXXX">
      <author>new auth</author>
      <title>some title</title>
      <genre>Horror</genre>
      <price>998</price>
      <publish_date>2001-12-06</publish_date>
      <description>would go here</description>
   </book>
     <book id="bk113">
      <author>Knorr, Stefan</author>
      <title>Creepy Crawlies</title>
      <genre>Horror</genre>
      <price>999</price>
      <publish_date>2000-12-06</publish_date>
      <description>An anthology of horror stories about roaches,
      centipedes, scorpions  and other insects.</description>
   </book>
   <book id="bk109">
      <author>Kress, Peter</author>
      <title>Paradox Lost</title>
      <genre>Science Fiction</genre>
      <price>6.95</price>
      <publish_date>2000-11-02</publish_date>
      <description>After an inadvertant trip through a Heisenberg
      Uncertainty Device, James Salway discovers the problems 
      of being quantum.</description>
   </book>
</catalog>
'@

[System.Xml.XmlNode]$orig = $xml.catalog
$orig.book | sort { [double] $_.price}  |
  foreach { [void]$xml.catalog.PrependChild($_) }
$xml.catalog.book

[System.Xml.XmlNode]$orig = $xml.catalog
$orig.book | sort { [DateTime] $_.publish_date}  |
  foreach { [void]$xml.catalog.PrependChild($_) }
$xml.catalog.book

$xml.Save('c:\work\foo.xml')

这是我的起点powershell xml sort nodes and replacechild

Answer 1

将[System.Xml.XmlNode]$orig = $xml.catalog 之后的代码替换为：

[xml]$sortedXml = @"
    <catalog>
        $(($orig.book | sort-object -Property {[double] $_.price},{[datetime]$_.publish_date} -descending).OuterXml)
    </catalog>
"@