How to get replace by id (Id value get from XML) and put into CSV, powershell

Question

I'm using below code from this answer to get value from id and I need to replace value of id in csv from xml by and save csv files :

 $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
      }
    }

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 below CSV Files for replace value ID value from above xml:

Answer 1

You need to modify the foreach loop to update the (in-memory) CSV rows (objects), and then save them back to a CSV file:

# ... 

foreach ($csvRow in $csvRows) {
  foreach ($columnName in $columnNames) {
    $id = $csvRow.$columnName
    if (-not $id) { continue }
    $newId = @($xmlDoc.enum_types.enum_type.Where( { $_.field_name -eq $columnName }, 'First').
               items).ForEach( { $_.item }).Where( { $_.id -eq $id }).value
    # Update the relevant CSV field.
    # Note: If the ID wasn't found, `$newId` contains $null
    #       and the field will be blanked out.
    $csvRow.$columnName = $newId
  }
}

# Export the updated CSV rows (objects)
# Note: This writes back to the input CSV file.
#       Be sure to make a backup of the original first.
# Adjust -Encoding as needed.
$csvRows | Export-Csv -NoTypeInformation -Encoding utf8 $CSVpath