How to fix A null key is not allowed in a hash literal in PowerShell - powershell

Question

I been following this Microsoft doc https://learn.microsoft.com/en-us/powershell/module/exchange/search-unifiedauditlog?view=exchange-ps and I'm trying to write a PowerShell Script that download Audit Log. So far everything is going well but I'm just wondering how can I read User Id from my csv file instead of having a user Id directly in my script?.
This is how my CSV file look right now.
C:\AuditLogSearch\Reference\User.csv
Name Email Id
................................
1. Ronaldo ronaldo#gmail.com KLIEKN
2. Messi messi#gmail.com LEK89K
3. LeBron lebron#gmail.com IKNLM9
I was hard coding like this in the script and it's working fine but
$Global:user = "KLIEKN", "LEK89K", "IKNLM9",
Search-UnifiedAuditLog -SessionId $sessionID -SessionCommand ReturnLargeSet -UserIds $user
I don't think that'll be good idea so I try to do read it from my CSV file like this
$Global:userPath = "C:\AuditLogSearch\Reference\User.csv"
function Log-Search {
Import-Csv $userPath | ForEach-Object -Property #{
$userId = $($_.Id)
}
Search-UnifiedAuditLog -SessionId $sessionID -SessionCommand ReturnLargeSet -UserIds $userId
}
but I'm getting this error
A null key is not allowed in a hash literal.
I'll be really appreciated any help or suggestion.

Answer 1

{} defines a [ScriptBlock] — which is what you'd pass to the ForEach-Object cmdlet to be invoked for each element — whereas #{} defines a [Hashtable]. $userId is $null because you have not assigned a value, so where you have...
#{
$userId = $($_.Id)
}
...you are trying to define a [Hashtable] with an element with a key of $null, hence the error.
There is also no such -Property parameter of ForEach-Object, so when you remove "-Property #", you end up with a valid script...
Import-Csv $userPath | ForEach-Object {
$userId = $($_.Id)
}
This is reading your CSV file but not yet passing the data to your Search-UnifiedAuditLog call. There are several ways to retrieve the Id field of each CSV record, but the shortest transformation from the previous snippet would be...
Import-Csv $userPath | ForEach-Object {
$_.Id
}
...which can be rewritten using the -MemberName parameter...
Import-Csv $userPath | ForEach-Object -MemberName Id
...and then all that's left is to store the pipeline results in $userId...
$userId = Import-Csv $userPath | ForEach-Object -MemberName Id
By the way, the CSV data you posted cannot be readily parsed by Import-Csv. If possible, save your data without the second line and using comma or tab as the delimiter (the latter being read with Import-Csv ... -Delimiter "`t"); otherwise, the script will have to do some manipulation before it can read the data.

Answer 2

Try this perhaps?
$userId=#()
Import-Csv $userPath | ForEach-Object {
$userId += $_.Id
}
or
$userId = Import-Csv $userPath | Select-Object -ExpandProperty Id