How can you select unique objects based on two properties of an object in powershell?

Question

I have an array of Objects that have 6 properties. That look like this:

$csvData
CURRENT DATE AND TIME : 07/10/2015 08:17:17 CST
USER NAME             : userName
COMPUTER NAME         : computerName
IP ADDRESS            : 192.168.1.1
LOGON SERVER          : logonServer
LOGON/OFF             : logon

I want to create an array of objects where username and computer name are not duplicated. How can I get only the unique username/computername combo in powershell? Ultimately I would like to remove all duplicates and add a property 'Count' that keeps track of how many duplicates there are.

I have tried:

$csvDataUnique = $csvData | Select-Object 'User Name','Computer Name' -Unique
$csvDataUnique = $csvData | sort -Property 'User Name' | Get-Unique

Answer 1

Very similar to Mathias' answer, but will have all of the columns in the output:

$csvDataUnique = $csvData | 
  Group-Object 'User Name','Computer Name' | 
  %{ $_.Group | Select 'User Name','Computer Name' -First 1} | 
  Sort 'User Name','Computer Name' 

Answer 2

You can create a custom property with your Select-Object. So you were pretty close already. Try this:

Select-Object @{Label = "Index"; Expression = {"$($_.'User Name') $($_.'Computer Name')"} } -Unique

It basically combines the two fields into a single string and sorts unique on that. I called the field "Index" but it could be called anything.