Return list values from column type 'User' and replace that user if they exist using PS in SP2016?

Question

First off my code is this.

foreach ($list in $web.lists)
{​​
    foreach ($field in $list.fields)
    {
        if ($field.type -eq 'User')
        {
            write-host $list.Title
            write-host $field
            write-host ""
        }​​
    }​​
}​​

I can get all the lists for the web, check each lists fields and if the field is a 'User' field (People Picker Value); I can get the list title and the 'User' type field name.

This works fine to find the lists I want to query.

Now I want to query those list fields for a particular user and replace that user with another user.

I can't seem to figure out how to pull back the actual data that is in the column.

Answer 1

Follow the example bellow, this reuse your script above:

function queryAndUpdateUser($siteUrl, $oldUser, $newUser){
  $web = Get-SPWeb -Identity $siteUrl
  $userToChange = $web.EnsureUser($oldUser)
  $newestUser = $web.EnsureUser($newUser)
   foreach ($list in $web.lists)
   {​​
     foreach ($field in $list.fields)
     {
        if ($field.type -eq 'User')
        {
           foreach ($item in $list.Items){
              if($item[$field.InternalName] == $userToChange){
                $item[$field.InternalName] = $newestUser
                $item.Update()
              }
           }
        }​​
     }​​
   }​​
 }
 queryAndUpdateUser -siteUrl "http://spsiteurl" -oldUser "DOMAIN\oldUser" -newUser "DOMAIN\newUser"

I hope I helped and good luck in your challenge!