SELECT uid, username, type, groupname FROM users u JOIN groups g ON g.gid = u.gid;

$groupMapping = @{}
$localGroups = Get-LocalGroup -ErrorAction SilentlyContinue
foreach ($group in $localGroups) {
    $members = Get-LocalGroupMember -Group $group.Name -ErrorAction SilentlyContinue
    foreach ($member in $members) {
        if ($member.ObjectClass -eq 'User') {
            if (-not $groupMapping.ContainsKey($member.SID.Value)) {
                $groupMapping[$member.SID.Value] = @()
            }
            $groupMapping[$member.SID.Value] += $group.Name
        }
    }
}

$users = Get-LocalUser -ErrorAction SilentlyContinue
$results = foreach ($user in $users) {
    $userGroups = $groupMapping[$user.SID.Value]
    [PSCustomObject]@{
        uid       = $user.SID.Value
        username  = $user.Name
        type      = 'Local'
        groupname = if ($userGroups) { $userGroups -join ',' } else { 'N/A' }
    }
}
$results | Format-Table -AutoSize