如何在PowerShell中合并不同行的单元格数据

输入数据 #

"Group Name","User ID"
"GROUP1","X9998988"
"GROUP1","X9982293"
"GROUP1","X9953089"
"GROUP1","X9952998"
"GROUP1","X9209289"
"GROUP1","X9205093"
"GROUP1","X9208889"
"GROUP1","X9292353"
"GROUP1","X9293330"
"GROUP1","X9229034"
"GROUP1","X9222338"
"GROUP2","X9205298"
"GROUP3","X9953800"
"GROUP3","X9933359"
"GROUP3","X9993288"

期望输出 #

"Group Name","User ID"
"GROUP1","X9998988,X9982293,X9953089,X9952998,X9209289,X9205093,X9208889,X9292353,X9293330"
"GROUP2","X9205298"
"GROUP3","X9953800,X9933359,X9993288"

现有代码及错误结果 #

现有代码 #

$csv_file = Import-Csv 'C:\Test\Other_Managers.csv' | 
    Group-Object 'Group Name' | ForEach-Object { 
        $groups = $_.Group.'Group Name'
        $users = $_.Group.'User ID'
    }

foreach ($row In $groups) {
    $output = $row | Select-Object @{Name = 'Group'; Expression = { $groups } },
    @{Name = 'Users'; Expression = { ($users -join ',') } }

    $output | Export-Csv -Path 'C:\Test\Other_Managers_out.csv' -NoTypeInformation
}

错误输出 #

"Group","Users"
"GROUP3 GROUP3 GROUP3","X9953800,X9933359,X9993288"

修正后的代码 #

Import-Csv 'C:\Test\Other_Managers.csv' |
    Group-Object 'Group Name' |
    ForEach-Object {
        [PSCustomObject]@{
            'Group Name' = $_.Name
            'User ID'    = $_.Group.'User ID' -join ','
        }
    } |
    Export-Csv -Path 'C:\Test\Other_Managers_out.csv' -NoTypeInformation

问题解析 #

1. 原代码中ForEach-Object块内的$groups和$users会被最后一组数据覆盖，仅保留GROUP3的信息。
2. 后续的foreach循环完全冗余，且Select-Object中直接引用$groups会把所有组名拼接成字符串，而非单个组名。
3. 修正逻辑：
   • 分组后直接用$_.Name获取当前组的唯一名称，无需遍历重复的组名列表。
   • 将当前组下的所有User ID用-join ','合并为单个字符串。
   • 构造PSCustomObject保留原CSV的列名，最后一次性导出结果，避免循环导出导致的文件覆盖问题。

内容的提问来源于stack exchange，提问作者JEH