How to update SharePoint Content Type?

Question

I need to update an existing SharePoint content type by adding a new field to the content type. I need to make sure this field gets added to all lists that use this content type.

Answer 1

If your content type was created using a Feature, as far as I know, you can't upgrade the Feature to add the new column to the content type.

That leaves you with two options:

1. Do it in the UI
2. Do it programmatically using the SharePoint object model

Here's an example of doing option #2: http://blogs.msdn.com/nidhishd/archive/2008/05/06/how-to-modify-content-type-once-it-is-deployed.aspx