SharePoint List Content Type Migration with Data Preservation

This sample shows how to update a SharePoint list to use a different content type using PowerShell PnP.

⚠️ Disclaimer: This will only work if the columns in the Content Type match those already present in the list.

Summary

This PowerShell script demonstrates how to update a SharePoint list to use a specific content type. The script connects to a SharePoint site, retrieves the target list, and updates its content types configuration.

How It Works 🤔

The script follows this process:

1. Create a Content Type: First, create your content type in SharePoint
2. Export as Template: Use Get-PnPSiteTemplate to export the content type as a PnP template XML file
3. Run the Script: The script will:
   • Load all list items with their values into memory 🧠
   • Remove the old columns that need to be replaced 🗑️
   • Apply the PnP template containing the new content type
   • Restore all values into the new columns ✅

Complete Column Migration

When you need to replace existing columns with new ones from a content type:

# Required variables for advanced mode
$siteUrl = "https://xxx.sharepoint.com/sites/xxx"
$listName = "YourListName"
$contentTypeName = "YourContentTypeName"
$columnsToMap = @("Column1", "Column2", "Column3")  # Replace with actual column names
$userFields = @("AssignedTo", "CreatedBy")  # Replace with actual user field names if needed
$templatePath = "..\ContentTypeTemplate.xml"

# Connect to SharePoint Online
Connect-PnPOnline -Url $siteUrl -Interactive

# Enable content type management on the list
Set-PnPList -Identity $listName -EnableContentTypes $true
Write-Host "Content types enabled on the list."

# Backup data from old columns
$items = Get-PnPListItem -List $listName -PageSize 5000
$backupData = @{}

foreach ($item in $items) {
    $itemData = @{}
    # Backup old column data
    foreach ($column in $columnsToMap) {
        $itemData[$column] = $item[$column]
    }
    $backupData[$item.Id] = $itemData
}

# Remove old columns
foreach ($column in $columnsToMap) {
    Remove-PnPField -List $listName -Identity $column -Force
    Write-Host "Removed old column:" $column
}

# Apply PnP Provisioning Template
Invoke-PnPSiteTemplate -Path $templatePath
Write-Host "PnP template applied to the site."

# Get the content type
$contentType = Get-PnPContentType -Identity $contentTypeName

# Add the content type to the list
Add-PnPContentTypeToList -List $listName -ContentType $contentType
Write-Host "Content type added to the list."

# Update items to the new content type and restore data to new columns
foreach ($item in $items) {
    $itemId = $item.Id
    $itemData = $backupData[$itemId]
    
    # Handle user fields
    foreach ($userField in $userFields) {
        if ($itemData[$userField]) {
            $UserDto = $itemData[$userField];
            write-host "User: " $UserDto.Email

            $itemData[$userField] = $UserDto.Email
        }
    }

    # Update item content type
    Set-PnPListItem -List $listName -Identity $itemId -Values @{"ContentTypeId" = $contentType.Id }
    
    # Restore data to new columns
    Set-PnPListItem -List $listName -Identity $itemId -Values $itemData
    Write-Host "Updated item ID:" $itemId
}

Write-Host "All items updated to the new content type and old columns removed."

# Disconnect from SharePoint Online
Disconnect-PnPOnline

What the Script Does 🛠️

1. Enable Content Types: Enables content type management on the list
2. Backup Data: Loads all rows with their values into memory 🧠
3. Remove Old Columns: Removes the columns specified in $columnsToMap 🗑️
4. Apply Template: Invokes the PnP template containing the new content type
5. Add Content Type: Adds the new content type to the list
6. Restore Data: Reloads all values into the new columns ✅
7. Handle User Fields: Properly processes user/people picker fields

Limitations ⚠️

As mentioned, this script doesn't solve everything:

• Any views created with the old columns will no longer work, even if the new columns have the same name
• Custom forms may need to be updated
• Workflows referencing old columns may break
• There's definitely room for improvement in the script

Contributors

Author(s)
Jeppe Spanggaard

Disclaimer

THESE SAMPLES ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.