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Download Microsoft Sharepoint List Attachments using Powershell script

I stumble across a problem when trying to download attachment from the Sharepoint List. The list have more than 50,000 rows, the problem with the big list is Windows explorer is not able to display the list in Explorer view, so there is a need to use the Powershell script to download all the attachment programmatically.

Step 1. Make sure you have the Sharepoint Client dll required as specified in the following code


[void][Reflection.Assembly]::LoadFrom("$env:CommonProgramFiles\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.dll")
[void][Reflection.Assembly]::LoadFrom("$env:CommonProgramFiles\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.Runtime.dll")

Step 2. Define the sharepoint site and the list library

The sharepoint site and the library is defined using the following $webUrl variable and $library respectively, also don’t forget to specify the local folder where the files will be downloaded.

$webUrl = "http://website.com/sites/sharepointsite" 
$library = "SharepointLibrary"
Local Folder to dump files
$tempLocation = "C:\temp\"

Step 3. Define how many rows the CamlQuery should return on each iteration

The beauty of the PowerShell Script is that you can specify how many rows to return each time, so the script will not have a problem recursively going through a big list that are over 50,000 and being able to download all the attachment. The following code shows that we are limiting the query to return 3000 rows.

$camlQuery = New-Object Microsoft.SharePoint.Client.CamlQuery $camlQuery.ViewXml ="<View> <RowLimit>3000</RowLimit></View>"

Step 4. Define the folder structure to hold all the attachment to be downloaded

The following code is using the combination of Title and ID as the folder name to store the attachment. It also check whether the folder already exists prior to creating a new one.


    $folderName=$listItem["Title"]+"_"+$listItem["ID"]
    $destinationfolder = $tempLocation + "\"+ $folderName 

     #check if folder is exist or not, if not exist then create new
  if (!(Test-Path -path $destinationfolder))        
   {            
     $dest = New-Item $destinationfolder -type directory      
     Write-Host "Created Folder with Name:" $folderName    
   }

The following is the full code to download the list attachments and put them in the local folder. The credential used is the user credential where the script is executed, that means the login user will need to have access to the SharePoint Site and able to download the attachement.


[void][Reflection.Assembly]::LoadFrom("$env:CommonProgramFiles\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.dll")
[void][Reflection.Assembly]::LoadFrom("$env:CommonProgramFiles\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.Runtime.dll")
Clear-Host
#$cred = Get-Credential "user@microsoft.com"
#$credentials = New-Object Microsoft.Sharepoint.Client.SharePointOnlineCredentials($cred.Username, $cred.Password)
$webUrl = "http://website.com/sites/sharepointsite"

$clientContext = New-Object Microsoft.Sharepoint.Client.ClientContext($webUrl)
Write-Host "Connecting To Site: " $webUrl   

 $username = "$env:USERDOMAIN\$env:USERNAME"

$library = "SharepointLibrary" 
#Local Folder to dump files
$tempLocation = "C:\temp\"    

$global:web = $clientContext.Web;
$global:site = $clientContext.Site;

$clientContext.Load($web)
$clientContext.Load($site)

$listRelItems = $clientContext.Web.Lists.GetByTitle($library)

$clientContext.Load($listRelItems)
$clientContext.ExecuteQuery();
Write-Host "list item count " $listRelItems.ItemCount

$camlQuery = New-Object Microsoft.SharePoint.Client.CamlQuery
$camlQuery.ViewXml =" 3000"
 $listCollection = New-Object System.Collections.Generic.List[string] 
 $count = 0
Do {
$allItems=$listRelItems.GetItems($camlQuery)
$clientContext.Load($allItems)
$clientContext.ExecuteQuery()
$camlQuery.ListItemCollectionPosition = $allItems.ListItemCollectionPosition
foreach ($listItem in $allItems)
 {
    $folderName=$listItem["Title"]+"_"+$listItem["ID"]
    $destinationfolder = $tempLocation + "\"+ $folderName 

     #check if folder is exist or not, if not exist then create new
  if (!(Test-Path -path $destinationfolder))        
   {            
     $dest = New-Item $destinationfolder -type directory      
     Write-Host "Created Folder with Name:" $folderName    
   }
    $clientContext.load($listItem)
    $clientContext.ExecuteQuery();

    $attach = $listItem.AttachmentFiles
    $clientContext.load($attach)
    $clientContext.ExecuteQuery();
    if($attach -ne $null){
        Write-Host "No of attachment:" $attach.Count
        foreach ($attachitem in $attach){
            Write-Host "Downloading Attachements started: "   $attachitem.FileName
            $attachpath = $webUrl + "/Lists/"+ $library + "/Attachments/" + $listItem["ID"] + "/" + $attachitem.FileName
            Write-Host "path: " $attachpath 
         
            $path = $destinationfolder + "\" + $attachitem.FileName
            Write-Host "Saving to the location:"  $path

            $siteUri = [Uri]$attachpath
            $client = new-object System.Net.WebClient
            $client.UseDefaultCredentials=$true
            
            try{
                  $client.DownloadFile($attachpath, $path)
                  $client.Dispose()
            } catch{
                write-error "Failed to download $url, $_ "
            }

        }
    }else {
     Write-Host   "For above current item don't have any attachments" 
    }
  }
Write-Host " List item" $count
$count++
} while ($camlQuery.ListItemCollectionPosition -ne $null)
     Write-Host   "Script execution done !" 

Please let me know if the above script is of useful to you and don’t forget to share or subscribe for more frequent update to the similar topic. You can also drop me a line or questions if you have any.

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