如何获取AD中的employeeID attritubute计数，其中employeeID = X

Question

I'm working on writing a Powershell script that automatically adds new employees on a scheduled task from an automatically generated list that is created nightly. One of the requirements, naturally, is to not create duplicate employees. So, my thought process is to count the number of occurances of an employee ID, and if it is >= "1", then to not create the account and proceed to the next one. When trying to find the count i'm using the following code. However, I'm consistently getting 0 as the return. Can someone correct my query for me. Thanks in advance.

$ID = 12345
$COUNT = (Get-ADUser -filter * |where '$_.EmployeeID -eq $ID').count
Write-Output $COUNT

Answer 1

There are two things going wrong here. First, when you use -Filter * , it gets all accounts (up to 1000, unless you use the ResultPageSize parameter), loads them all into memory and passes the big list to the where . That will take a whole lot longer and more memory than needed, and, if you have more than 1000 accounts in your domain, you won't get accurate results.

Second, Get-ADUser only returns a specific set of properties, unless you tell it otherwise. Since you didn't tell it that you want employeeID , it didn't return it. So $_.EmployeeID will always be empty.

Both issues can be solved at the same time by passing your EmployeeID filter directly to Get-ADUser :

$ID = 12345
$COUNT = (Get-ADUser -filter 'EmployeeID -eq $ID').count
Write-Output $COUNT