How to check if a Site Column is being used before deleting

Question

Hi All,
Before deleting a SharePoint Online site column I would like to check to see if it is being used by any list or library. I know how to do this when the site is on
premise using a PowerShell script.
$web
= Get-SPWeb
http://”sitecollectionurl”
$column
= $web.Fields[“Column Display Name”]
$column.ListsFieldUsedIn()
but I am having problems doing it on a SharePoint Online site. I know how to connect to the site, but I can not find any information on getting the field details,
like above.
if ((Get-ModuleMicrosoft.Online.SharePoint.PowerShell).Count
-eq0) {
Import-Module
Microsoft.Online.SharePoint.PowerShell -DisableNameChecking
$username
= "[email protected]"
$url
= "https://mySite.sharepoint.com/sites/Dev"
Write-Host
"Connecting to SharePoint Online, URL = $url"
try
Connect-SPOService
-Url $url /
-credential $username
Write-Host "Successfully connected.."
-ForegroundColor Green
$web =
Get-SPOSite -Identity
https://mySite.sharepoint.com/sites/Team1
$column
= $web.Fields[“Column Display Name”]
$column.ListsFieldUsedIn()
=
$web.Fields[“Page Content”]
catch
Write-Error "Failed to connect to
$url - check the credentials and URL!"
$_
Write-Host
"Disconnecting from SharePoint Online, URL =
$url"
Disconnect-SPOService
Write-Host
"Successfully disconnected.."
-ForegroundColor Green
Does any know what I am doing wrong, or does anyone have a script examples.
Many thanks
Colin

Answer 1

Hi Colin,
Unfortunately the Get-SPOSite doesn't return a fully fledged SPWeb object like you're used to in On-Prem PowerShell.
The only way to get at particular objects like this is to use CSOM in PowerShell, however even then it doesn't return quite the same object that you see on prem. (In short, the method you want doesn't exist.. but I'll show you how to get there at least.)
You'll need the Microsoft.SharePoint.Client.dll installed (You can download the SharePoint 2013 Client SDK, just do a search for it.)
Once that's installed, then the following script will retrieve a single column which you can then run
$column | gm to see the available properties.
$siteCollectionURL = "https://<tenantname>.sharepoint.com/sites/etc"
$Credentials = Get-Credential -UserName "[email protected]" -Message "Enter the password for $AdminUser"
##Then we'll establish a ClientContext for CSOM.
$scContext = New-Object Microsoft.SharePoint.Client.ClientContext($siteCollectionURL)
$SPOcredentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Credentials.UserName, $Credentials.Password)
$scContext.Credentials = $SPOcredentials
$web = $scContext.Web
$siteCols = $web.Fields
$column = $sitecols.GetByInternalNameOrTitle("ColumnInternalName")
$scContext.load($web)
$scContext.load($siteCols)
$scContext.Load($column)
$scContext.ExecuteQuery()
Once you run that, $column contains as much info as you can get about the column.
Paul.
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