Group and select objects from CSV in PowerShell

Question

I have a list of users their device(s) and their managers. The manager and user can be duplicates but the deviceID is unique. How do I get a list so I can send every manager an email to let them know how many and which unit their employees are using? I am only interested in people with 2 or more devices.

Wanted output would be something like this (if anyone wants to give me a better output suggestion I am all ears).

Manager  deviceID
M1        U1=D1 D2, U3=D4 D5

What my code looks like now:

$csv = @"
manager,user,deviceID
M1,U1,D1
M1,U1,D2
M2,U2,D3
M1,U3,D4
M1,U3,D5
"@ -split "`r`n" | ConvertFrom-Csv

$csv | Group-Object -Property Manager |
     Select-Object @{N='Manager';E={($_.Group[0]).Manager}}, 
@{N="User";E={($_.group).user}}, 
@{N="deviceID";E={ foreach($row in $_.Group){ $row.user + ' = ' + $row.deviceID}}} 

Answer 1

Since you say you are only interested in listing the users that use more than one device, perhaps this could help you:

$csv = @"
manager,user,deviceID
M1,U1,D1
M1,U1,D2
M2,U2,D3
M1,U3,D4
M1,U3,D5
"@ -split "`r`n" | ConvertFrom-Csv

# first group on Manager
$result = $csv | Group-Object -Property Manager | ForEach-Object {
    $manager = $_.Name
    # next, group the groups on User and select only where a user is mentioned twice or more times
    $_.Group | Group-Object User | Where-Object { $_.Count -gt 1 } | ForEach-Object {
        [PsCustomObject]@{
            Manager = $manager
            User = $_.Name
            Devices = $_.Group.DeviceID -join ' '
        }
    }
}

# output on screen
$result

# output to CSV
$result | Export-Csv -Path 'managerReport.csv' -NoTypeInformation

Output:

Manager User Devices
------- ---- -------
M1      U1   D1 D2  
M1      U3   D4 D5

# to separate the results so each manager gets his/her personal report:
$result | Group-Object Manager | ForEach-Object {
    # send an email to the manager. For demo just output to console
    Write-Host "Send mail to manager $($_.Name):" -ForegroundColor Yellow
    $_.Group | Format-Table -AutoSize | Out-String
}