如何使用csv列标题powershell获取xml字段值

当我使用 for 循环然后在代码中添加值 $b 时({ $_.'field_name' -eq $b}然后它给出空白值而不是结果。

$CSVpath = "G:\1.csv"
$columncount=((Get-Content $CSVpath)[0] -split ",").count
write-host $columncount
$xml= "G:\1.xml"
[xml] $xmlDoc = Get-Content $xml
for($i=0; $i -le $columncount;$i++){
$a = ((Get-Content $CSVpath)[0] -split(','))[$i]
$b= "'$a'"
Function xml{
param($value)
$xml= "G:\1.xml"
[xml] $xmlDoc = Get-Content $xml
$a1= $xmlDoc.enum_types.enum_type.Where({ $_.'field_name' -eq  $b}, 'First').items.item.where({ $_.id -eq 1}).value
$d = $a1.'#cdata-section'
write-host  $d
}
xml $b
}

请帮助我解决问题。 请找到xml：

    <enum_types>
    
        <enum_type field_name="Test1">
            <items>
                <item>
                    <id>1</id>
                    <value>A</value>
                </item>
            </items>
            </enum_type>
<enum_type field_name="Test2">
            <items>
                <item>
                    <id>1</id>
                    <value>A</value>
                </item>
            </items>
            </enum_type>
        </enum_types>

Please find csv file :

这是代码的简化版本：

$CSVpath = "G:\1.csv"
$xmlPath = "G:\1.xml"

# This is a more robust (and faster) way to load XML files.
($xmlDoc = [xml]::new()).Load((Convert-Path $xmlPath))

# Get all column names
$columnNames = (Get-Content -First 1 $CSVpath) -split ',' -replace '"'
Write-Host "Column count: $($columnNames.Count); names: $columnNames"

foreach ($columnName in $columnNames) {
  @($xmlDoc.enum_types.enum_type.Where({ $_.field_name -eq $columnName }, 'First').
   items).ForEach({ $_.item }).Where({ $_.id -eq 1 }).value
}

它为我输出以下内容：

Column count: 2; names: Test1 Test2
A
A

Note:

• 由于 XML 文档中没有 CDATA 部分，因此不需要.'#cdata-section'

• 使用理由.ForEach()枚举名为的子元素<item>，具体来说 - 虽然对于示例 XML 文档来说并不是绝对必要的，因为只有one这样的子元素 - 解释于这个答案 https://stackoverflow.com/a/68884190/45375.

  • Use of @(...), the array-subexpression operator https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_Operators#array-subexpression-operator--, in order to apply .ForEach() https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_Arrays#foreach (and .Where()) safely is only required in Windows PowerShell, due to an unfortunate bug^[1], which has since been fixed in PowerShell (Core) 7+.

  • 链接的答案还显示了一个更快的基于 XPath 的解决方案，通过Select-Xml https://learn.microsoft.com/powershell/module/microsoft.powershell.utility/select-xml，您可以类似地应用到[xml]实例已在内存中（$xmlDoc在这种情况下），通过其.SelectSingleNode() https://learn.microsoft.com/en-US/dotnet/api/System.Xml.XmlDocument.SelectSingleNode实例方法。

以上仅适用于列名CSV 文件的，带有硬编码的 id价值 - 就像你自己的尝试一样。

To 根据以下内容从 XML 中提取数据data在 CSV 中并根据填充的列:

$CSVpath = "G:\1.csv"
$xmlPath = "G:\1.xml"

# This is a more robust (and faster) way to load XML files.
($xmlDoc = [xml]::new()).Load((Convert-Path $xmlPath))

# Import the CSV.
$csvRows = Import-Csv $CSVpath
# Get the column names.
$columnNames = $csvRows[0].psobject.Properties.Name

foreach ($csvRow in $csvRows) {
  foreach ($columnName in $columnNames) {
    $id = $csvRow.$columnName
    if (-not $id) { continue }
    @($xmlDoc.enum_types.enum_type.Where({ $_.field_name -eq $columnName }, 'First').
      items).ForEach({ $_.item }).Where({ $_.id -eq $id }).value
  }
}

注意：对于这样的嵌套循环，绝对值得考虑切换到 XPath 解决方案.SelectSingleNode()以提高性能。

^{[1] .ForEach() and .Where() should work on any object, even scalar (non-collection) ones, but in Windows PowerShell that doesn't work with certain types, such as XML elements.}